It is widely recognized that a major transformation of food systems is urgently needed if we are to achieve food and nutrition security globally, while also meeting global climate, biodiversity and health targets. What foods people eat, how and where it is produced, as well as how much is wasted and lost, have a significant impact on human and planetary health, including 11 million premature deaths, over 30% of global greenhouse gas (GHG) emissions, 70% of freshwater use and 80% of land conversion driving biodiversity loss. Paradoxically, while agriculture is currently the largest single source of environmental degradation and biodiversity loss, it is also likely to be the biggest victim of this degradation – the conversion of natural ecosystems into croplands and pastures, coupled with the impacts of agricultural pollution, severely threaten vital ecosystem services that underpin agriculture itself (Rockström et al. 2020).

Agroecology, as an ecological science, focuses on the contribution of biodiversity to enhancing the generation of ecosystem services to and from agriculture with the aim of regenerating these services. Diversification, agroecological, or regenerative agricultural practices are overlapping and include a diversity of management options from fields to landscapes (Source: Report Authors).

FAO and the HLP Report #14 (FAO-HLPE 2019) on "Agroecological and other innovative approaches" suggests a concise set of 13 agroecological principles related to: recycling; reducing the use of inputs; soil health; animal health and welfare; biodiversity; synergy (managing interactions); economic diversification; co-creation of knowledge (embracing local knowledge and global science); social values and diets; fairness; connectivity; land and natural resource governance; and participation.

2021 signals a pivotal year for the agricultural community. Major events such as the United Nations Food Systems Summit (UNFSS), the UNFCCC COP26, the UNCBD COP15, and the launch of the UN Decade of Ecosystem Restoration offer a real chance to make a step change towards the necessary transformation of our food systems – so they can become more sustainable and equitable and deliver affordable, healthy and nutritious food for all. Ensuring that there is a clear pathway for addressing biodiversity in all this, as well as highlighting its inextricable links to agriculture, is essential, given growing evidence that food system interventions have the potential to become the single largest solution space for both human and planetary health (Rockström et al. 2020).

### 1.1 Biodiversity Is Inextricably Linked to Food and Agriculture

Covering approximately 40% of the global land surface, agricultural ecosystems (including rangelands) comprise the world's largest terrestrial ecosystem, albeit a highly modified and heterogenous one. Biodiversity in agricultural ecosystems, as in natural ecosystems, is highly threatened, and this has very real consequences for the resilience and sustainability of both the production of food and environmental goods and services generated on agricultural lands and in water. The reduction of biodiversity in agriculture diminishes the ecosystem functions that contribute to local, regional and, when scaled, global processes. To ensure environmental and climate security by 2030, a transition is necessary toward treating agricultural lands as ecosystems, or as 'agroecosystems,' and greater investment in research, practices, technologies and incentives that reward the efforts of farmers just as much for the environmental services they produce as for the foods they produce.

Which and how much of the diversity of available foods we eat, and in what quantities, plays a key role in human health. Yet today, nearly half of the world's population struggles to access or afford either enough food or food that is healthy. Global progress against SDG2 – Zero Hunger – has stalled over the last few years, with current estimates showing that nearly 9 percent (690 million) of the world's population go hungry – up by 10 million people in 1 year and by nearly 60 million in 5 years (FAO I, UNICEF, WFP, and WHO 2020). Global food supply also falls alarmingly short of providing a low health-risk diet: nearly 2 billion struggle with hunger and malnutrition; another 2 billion struggle with diseases related to overconsumption (Global Panel on Agriculture and Food Systems for Nutrition 2020).

Producing healthy diets sustainably is dependent on biodiversity. Decades of research demonstrate that 'sharing space' for biodiversity on agricultural lands is logical and cost-effective for many reasons. The most notable example is our increasing dependence on pollinators to produce the foods that underpin healthy diets. Other examples of agriculture's dependence on biodiversity include: its roles in pest and disease regulation, in building resilience to shocks through crop and intra-species diversity, and in protecting the water cycle and maintaining soil health. However, investments in the kinds of agricultural practices that will build on and enhance these kinds of biodiversity benefits are severely lacking, including in modernizing and time-saving technologies that can increase biodiversity's contribution to production.

Tackling the global-scale challenges of stabilizing global climate, regulating regional water cycles and halting the extinction crisis is dependent on sparing sufficient intact nature from conversion across all biomes. Avoiding any further loss of intact nature is vital, particularly by halting ongoing conversion of land to agriculture, as called for by the Convention on Biological Diversity (CBD) Target 1, "ensuring that all land and sea areas globally are under integrated biodiversityinclusive spatial planning addressing land- and sea-use change, retaining existing intact and wilderness areas." Achieving these goals requires active contributions from agriculture, starting with the recognition that environmental and climate security are equally non-transgressible goals, along with food and nutritional security. Increasing the productivity of agricultural lands, shifting to nature-positive practices, reducing food waste and loss, and fostering more sustainable diets are four ways in which food systems contribute to CBD conservation targets.

# 1.2 Reconfigure Biodiversity in Agriculture to Meet Food, Nutrition, Climate and Water Security Targets

Over the last decade, multiple global reviews, commissions and academic papers have argued for more sustainable and healthy food, farming and agriculture. Promoting biodiversity in diets, in farms and fields, and in intact nature makes essential contributions to these goals. International policy frameworks that support this change include the Paris Agreement (UNFCCC), the United Nations Convention to Combat Desertification (UNCCD), the CBD and the SDGs.

In response, bold biodiversity targets to halt the loss of area and intactness of nature and securing nature's contributions to people are being set by the CBD in 2021. Achieving these targets is a prerequisite for food, nutrition, climate and water security, in addition to halting the ongoing extinction crisis. According to the Global Biodiversity Outlook 5, we have failed to meet the 2020 Aichi Biodiversity targets (Díaz et al. 2020; Diversity 2020). This failure points to the need for an urgent rethink and transformation of the relationships among food, agriculture and biodiversity (Rockström et al. 2020; Leclère et al. 2020) if we are to succeed in reaching the 2030 targets.

#### 1.3 Shifting from Crop Productivity to Systemic Productivity

While food production has increased over recent decades, this trend masks an underlying decline in ecosystem services that underpin production (Brauman et al. 2020), including pest and disease regulation, pollination and soil fertility. This rise in productivity similarly masks an alarming decline in dietary health across countries with different income statuses. The focus on crop productivity has fueled a false dichotomy between conservation and production that may have critical consequences for environmental and climate stability. This approach will ultimately also have negative effects on future food production and distribution. Transforming the objective outcomes of agriculture to encompass environmental and human health objectives is a first, and necessary, step in realigning food across multiple global goals. This requires refocusing food from yields per unit input to the food system's overall productivity and efficiency, or the number of people that can be fed healthy diets sustainably per unit input (Benton and Bailey 2019; Remans et al. 2014; DeFries et al. 2015).

### 1.4 Critical Actions for Reconciling Agriculture and Biodiversity

There is considerable evidence available about what needs to change in the food and agriculture system to enable nutritional, climate, environmental and livelihood security, and that innovative solutions can emerge when these goals are considered as equally non-transgressible. There is similarly substantial biophysical evidence that food and agriculture can provide healthy diets while contributing to environmental restoration and regeneration. But there is still insufficient evidence indicating and understanding how to make the necessary social, political, economic and agronomic transformations urgently. Much of the challenge lies in the siloed nature of policy and innovation, as well as entrenched political economies of food. Recognizing the role that agriculture plays within the Earth system, as an ecosystem; considering the dietary health impacts of food; and recognizing and utilizing the dependencies of agriculture on biodiversity for agroecosystem services suggests the need for agricultural systems that are radically different from those we have today.

In this review, we have attempted to provide the best available evidence of agriculture's relationships with biodiversity. This spans many dimensions of agriculture and biodiversity, including:

We have not covered livelihood security here, although we find no evidence that better integration of biodiversity in agriculture reduces the opportunities to create more meaningful and remunerative livelihoods in agriculture. There is recent and growing evidence, however, that small and medium fields and farms are better able to integrate biodiversity without compromising yield (Ricciardi et al. 2021).

We present five critical challenges to agriculture in relation to biodiversity that, borrowing from the Science Based Targets Network (SBTN), suggests that this interaction can be conceived as an AR3 T 'mitigation classification,' with targets aligned to the forthcoming CBD Kunming objectives (Fig. 1):

Fig. 1 Bold biodiversity targets are required to halt the loss of biodiversity and to secure biodiversity's contributions to Earth system and ecosystem processes (Maron et al. 2018). Several studies (Willett et al. 2019; Maron et al. 2018; Newbold et al. 2016; Dinerstein et al. 2017; DeClerck et al. In Review), using distinct methodologies, find that approximately half the Earth's land surface remains intact, making 'half intact' the equivalent of a no-net-loss target (CBD Goal A, Target 1). We define intactness here as a measure of biodiversity status measured as the relative abundance of originally present species or level of human pressures. Combined actions to avoid loss, restore intact nature, reduce impacts of human activities on nature, regenerate ecosystem service production through nature-positive production, and transform agricultural policies and actions are needed to maintain a safe environmental space for humanity (Rockström et al. 2020, 2021). (Figure adapted from Maron et al. 2018)

• Transform the food system by creating the policy instruments, demand and incentives for food production systems that leverage biodiversity's capacity to contribute to climate, environmental, food and nutritional securities (Willett et al. 2019; Rockström et al. 2009; Steffen et al. 2015).

### 2 Healthy Diets Require Dietary Diversity

#### Take-Home Messages

• Modern plant breeding threatens traditional crop varieties and crop wild relatives, but is completely dependent on the genetic diversity that they represent.

### 2.1 The Diversity of Foods Produced and Available Is Insufficient for Healthy Diets

While there is no single solution to the hunger and dietary health challenges afflicting nearly half the global population, low dietary diversity is a common thread. Only around 130 internationally significant food plants – including 20 cereal crops, 7 roots and tubers, 28 fruits, 19 vegetables, 11 pulses, 8 nuts, 16 oils, 15 herbs and spices, 2 sugars and 3 stimulants – make up the bulk of peoples' diets around the world. In addition, just 15–20 major domesticated land animals are used in food and agriculture (Bélanger and Pilling 2019).

Food diversity is as much about choice as it is about health. There is robust evidence showing that, while we produce enough food to meet the caloric needs of today's global population, current production systems fail to provide a healthy diet for all because of underproduction of food diversity. Global analyses of regional trends signal a nearly universal underconsumption of fruits, nuts, vegetables, whole grains and seeds; with regional patterns of over- and underconsumption of red and processed meat; and equally variable consumption of legumes (Afshin et al. 2019). High-sodium, low-diversity diets are the leading cause of mortality attributed to diet, accounting for an estimated 11 million premature deaths per year (Willett et al. 2019).

Global production and the availability of foods are fundamentally mismatched with recommended healthy consumption patterns (Willett et al. 2019; Kc et al. 2018). Ensuring healthy diets for all by 2050 requires an important shift in what foods are produced and consumed, including no significant increase in cereal production coupled with significant increases in vegetables, legumes, fruit, fish, nuts and seeds and a large reduction in red meat production and consumption globally (Afshin et al. 2019) – although, in some regions, meat consumption could be increased to counter nutritional deficiencies such as iron-deficient anemia (Golden et al. 2011) (Table 1). Increasing the diversity of animal-sourced proteins, notably, of healthier and often less energy intensive fish, shellfish, and poultry proteins, is consistently underexplored in discussions on shifts towards healthy and sustainable diets (see the UNFSS Blue Foods and Livestock Reports).

#### 2.2 Healthy Diets Include a Wide Range of Choices

At least five major food groups, and thus, at minimum, 4–5 species, are required in a healthy diet, with whole grains, fruits, vegetables, oils and protein (plant or animal) being essential (Table 1). The absence of one food group drives critical challenges of

Table 1 Summary of food groups, recommended healthy daily consumption

Willett et al. (2019) required change in production volume compared to current production to secure low risk diets globally, and approximate diversity of cultivable species.

malnutrition, which are stubbornly persistent in several hotspots requiring emergency assistance or fortification as an intermediate remedy. In both high- and low-income countries, however, increasing dietary diversity, within energetic requirements, would have significant impacts on improved health. Thousands more species, breeds and varieties could support human nutrition. Beyond the 130 odd species that dominate global production and consumption, about 120 other food crops that are less well monitored in production, trade and dietary data have regional significance. Practically nonexistent in food system data are well over 1000 wild plants known to be used, at least occasionally, as human food (Khoury et al. 2019), and the nutritional value of over 3200 aquatic animal species used as food has been documented, not including growing interest in edible aquatic plants (algae) commonly consumed in Asian diets (Rajapakse and Kim 2011). Seaweeds have largely been unexplored as a more important food source, but present an area of innovation for nutritious food production without land, freshwater, or fertilizer requirements (Bernhardt and O'Connor 2021).

Context will determine whether any single food group is over- or underconsumed. Whole-of-plate approaches that ensure that everyone everywhere has access to a diversity of foods, notably, across food groups, are key to SDGs 2 and 3. While a healthy diet with balanced consumption across food groups is a universal goal, the diversity of foods within food groups offers people the possibility to match foods across the year to environmental contexts, individual tastes and cultural preferences.

### 2.3 The Demand and Supply of Healthy Diets Contributes to Climate and Environmental Outcomes

Diverse production can bring us closer to planetary health goals. A shift towards healthy diets could reduce per capita emissions from food production between 30% and 50%, while also accounting for a 20% reduction in freshwater consumption and a 20% decrease in the land needed to meet consumption demand (Willett et al. 2019; Clark et al. 2019; Tilman and Clark 2014). Globally, this would mean no net increase in agricultural lands, in line with CBD goals of no net loss of nature by 2050, primarily driven by reduced overconsumption of red meat (Tilman and Clark 2014; Clark et al. 2020).

### 3 Agriculture Must Share Space with Biodiversity to Meet Global Environmental Goals

#### Take-Home Messages

### 3.1 Agriculture Depends on Biodiversity

All agricultural systems depend on biodiversity for crop genetic diversity, pest control, animal-mediated pollination and healthy soils that promote nutrient capture and water delivery for crop growth. Diversified agroecological practices offer numerous opportunities at the field, farm and landscape scales, but are not a panacea. Thoughtful application and integration of novel technologies and practices that complement diversification are required, as well as mitigation of trade-offs such as pest species spilling over from natural or semi-natural habitats (Zhang et al. 2007).

### 3.2 Diversification Strategies Are Often Regenerative, Synergistic and Multipurpose

Agricultural practices that support biodiversity's contribution to soil nutrients, water, pollination and pest reduction, more often than not, are synergistic (Garibaldi et al. 2020; Tamburini et al. 2020; Garbach et al. 2016; Kennedy et al. 2013; Scheper et al. 2015; Landis et al. 2000; Rusch et al. 2017). Taken with genetic diversity, these ecosystem functions represent critical inputs into production systems globally. The aim of agroecology and diversification practices is to secure and make use of ecosystem services both to and from agriculture (DeClerck et al. 2016). Within the AR3T framework, the aim of diversification is to regenerate the ecosystem functions and services both from and to agriculture, while reducing its negative impacts, notably, habitat loss and pollution of soil and water (DeClerck et al. 2016).

#### 3.2.1 Diversification Within Fields and Pastures

Replacing low diversity annual systems with higher diversity annual or perennial systems has numerous beneficial impacts on ecosystem functions, for example, by reducing soil nutrient loss to aquatic environments, and extending the portion of the year that crops are actively being grown, thus reducing nutrient leaching. Integrating nitrogen-fixing legumes, either as a harvestable or cover crop, is one of the most common forms of diversification (Duchene et al. 2017; Bedoussac et al. 2015; Ghosh et al. 2007). Crop types have variable water needs and can influence demands on available water resources. Management techniques for promoting carbon sequestration and improving drought resilience include organic residue management, mulching and reduced or no-tillage (Amelung et al. 2020). Excessive use of biocides, nutrient inputs and tillage, in turn, favor soil ecosystems with very high carbon loss and little long-term storage potential (Palm et al. 2014). High-diversity cropping systems can also increase natural enemies of pests upwards of 44%, increase pest mortality by 54% and reduce crop damage by 23% (Letourneau et al. 2011; Cook et al. 2007). In-field diversification provides habitat, alternative hosts, pollen and nectar, as well as overwintering or nesting sites essential to diverse communities of pollinators, predators and parasitoids (Landis et al. 2000; Lichtenberg et al. 2017).

#### 3.2.2 Diversification Between Fields and Pastures

Natural elements such as grassed waterways, riparian buffers, prairie strips, hedgerows, live fences and wetlands incorporated around field and pasture margins are highly effective at capturing excess nutrients. To reduce erosion and regulate water, between-field habitat infrastructure can be complemented with engineered features such as terraces, water and sediment control basins, bioreactors and saturated buffers to control nutrient loss. These features also support pollination (Scheper et al. 2015; Nicholson et al. 2020; Kremen et al. 2019; M'Gonigle et al. 2015; Ponisio et al. 2016) and pest regulation (Letourneau et al. 2011; Shelton and Badenes-Perez 2006; Cook et al. 2007; Tschumi et al. 2015) by providing habitat for pollinating and pestregulating organisms, can serve as barriers to pest movement (Avelino et al. 2012), or can draw pests out of crop fields (Cook et al. 2007; Pickett et al. 2014). A recent synthesis indicated that the planting of annual flower strips on field borders increases pest control by 16% (Albrecht et al. 2020). Between-field habitats can have added value when they comprise multi-use species that provide fodder, fuel or food, and can be designed to reduce wind or evaporative stress in crops while creating corridors for wild biodiversity.

#### 3.2.3 Landscape Diversification

Even where the most extensive monocultures are practiced, landscape diversification, combined with habitat structures between fields, can have significant positive impacts on many services provided by agricultural biodiversity, notably, hydrological, pest regulation (Avelino et al. 2012; Chaplin-Kramer et al. 2011; Veres et al. 2013; Holland et al. 2017) and pollination services (Kennedy et al. 2013; Dainese et al. 2019; Garibaldi et al. 2011). In contrast, landscape simplification often leads to increased risk of pest infestation (Rusch et al. 2016). Diverse mosaics in agricultural land that include multiple farms and integrate natural areas are required to capture and potentially convert, store or sequester nutrients lost to the environment. Policies, or markets that either support increases in field or farm sizes, and/or concentrate the production of a single crop in a landscape, may increase efficiency, but drive loss of between-field cropping diversity and increase risks.

#### 3.2.4 Agricultural Landscapes Need at Least 10–20% of Diversified Habitats to Retain Ecological Integrity

Proposed targets for nature retention within agricultural landscapes (Willett et al. 2019; Garibaldi et al. 2020) are beginning to be reflected in agricultural policy (Díaz et al. 2020). A conservation target for agricultural ecosystems to retain at least 10–20% of habitat per km2 has been proposed to maintain ecological integrity in production landscapes (Willett et al. 2019; Maron et al. 2018; DeClerck et al., DeClerck et al. In Review; Garibaldi et al. 2020). The rationale for this target is that the services provided by biodiversity to agriculture are locally produced. Nitrogen fixation by legumes impacts soil fertility at the plant scale (0–10 cm), and pollination and pest control are provided by habitats at a wider scale (0–300 m), occasionally further for honeybees (3000 m) (Willett et al. 2019; DeClerck et al., DeClerck et al. In Review; Garibaldi et al. 2020; Fremier et al. 2013; Tscharntke et al. 2005; Tscharntke et al. 2007). Similarly, interception of sediment and nutrients lost from agriculture by buffers is most effective within tens of meters (Fremier et al. 2013). While specific impacts are highly contextual and difficult to predict, the evidence is clear: in the absence of proximate habitat (<500 m), ecosystem services to agriculture are not provided. Alarmingly, 18–33% of global agricultural lands are below this 10–20% km2 threshold respectively (Fig. 2; DeClerck et al. In Review).

Both the retention of habitat within agriculture and the diversity of cropping systems per unit area have been proposed as indicators to the CBD and to UNFSS12. The attraction of these targets is that they allow for alignment and the setting of both global and national goals while leaving ample scope for farming communities to identify the most locally appropriate practices contributing to their achievement. Additional research will be needed to define what qualifies as "semi-natural" habitat in different regions. Pastures are considered to be semi-natural habitats in European analyses. Agroforests, plantations and orchards may be more appropriate in agricultural systems located in forest biomes. In contrast, winter flooding of rice fields in California have provided critical overwintering habitat for migratory waterfowl and other biodiversity without compromising yield. Investments in local research on the relationships between semi-natural habitats and ecological integrity are needed.

Fig. 2 Global distribution of biodiversity intactness (light green) and ecological integrity. Regions in red are below proposed thresholds for biodiversity in agriculture. (Data from DeClerck et al. In Review. Nearly half the terrestrial landmass is currently classified as "intact." However, many agricultural lands have lost integrity (red), where remaining habitat quantity is insufficient to ensure biodiversity's contributions to food production)

# 4 Agriculture Must Spare Space for Biodiversity to Meet Global Environmental Goals

#### Take-Home Messages

Reducing and reversing the impact of agricultural systems on biodiversity requires a system-wide transformation of agriculture and food production (Tilman et al. 2017; Williams et al. 2020). A sustainable future must therefore be grounded in improving environmental quality and placing strong limits on biodiversity loss. At least 79% of Earth's remaining natural and semi-natural (terrestrial) ecosystems need to be retained simply to meet existing international goals for biodiversity conservation, carbon storage, soil conservation and freshwater regulation (Simmonds et al. 2021). This equates to keeping half of the planet intact – about the proportion that remains intact today. We can afford to lose very little more: so much land has been converted to agriculture that we are globally either at or nearing land conversion limits (Ceballos et al. 2020). Actions to ensure that intact habitats and their biodiversity can contribute to Earth system processes while also halting the ongoing biodiversity extinction crisis require both avoiding further loss of and restoring intact nature.

#### 4.1 Halting the Loss of Intact Ecosystems

Preventing the loss or conversion of intact areas, and, where necessary, enhancing their condition, requires setting limits on loss. How much intact land is needed to preserve functioning populations of all species is difficult to quantify precisely. Local contexts are important in determining extinction risk and are important spaces for setting conservation priorities. There is no 'one size fits all' solution (Maron et al. 2018; Allan et al. 2019). However, there is broad consensus that retaining intact habitat, and connectivity between habitats, is necessary to halt loss.

Biological intactness is not incompatible with human use. Relatively intact and ecologically functioning systems can and do support a multitude of human uses, including productive and extractive uses: many such ecosystems rely upon human intervention, and represent the product of millennia of sustainable traditional management. Extensive grazing in grassland and savannah biomes and the sustainable harvest of natural forests are demonstrable activities that retain intactness while supporting livelihoods. Indigenous areas critically overlap with intact nature, with strong evidence that recognizing Indigenous Peoples' rights to land, benefit sharing, and institutions is essential to meeting local and global conservation goals (Garnett et al. 2018). Identifying the range of nature-based benefits that each priority avoidance area supports can provide a guide to the human uses that are compatible with its ongoing provision of those benefits, so long as retaining biodiversity intactness is an explicit priority in these areas.

Interventions should therefore aim not to exclude human activities entirely from the areas we need to retain, particularly where local people depend on the natural resource base for their livelihoods. Proposed agricultural expansion can be managed to minimize impacts on biodiversity through the involvement of local people in decision-making. Land use policies, decision-making tools and private sector levers can contribute to nature retention (Garnett et al. 2018).

There is a growing call for the retention of at least half of the global land surface as intact (BII > 90) in order to halt extinction loss at 80% of known biodiversity (Willett et al. 2019; Rockström et al. 2020; Maron et al. 2018; Newbold et al. 2016; Dinerstein et al. 2017). Other estimates, using species-based approaches, find that 44% might be sufficient to protect the most important sites for terrestrial biodiversity (64 million km2 ) (Allan et al. 2019). While the specificity of this boundary is vigorously debated, most ecologists agree that, as the intact area of ecosystems dips below 50%, there is growing risk of population decline and extinction risk. Retaining at least half of the terrestrial realm, in each of the 782 ecoregions, would thus be necessary to halt extinction loss, and has been signaled as a biodiversity boundary for food systems (Willett et al. 2019). Retaining intact regions in ice-free areas (>67 M km2 ) and achieving half intactness for all ecoregions would require restoration on 23.9 M km2 . Observing that currently half of the terrestrial realm is considered intact, the CBD has adopted the boundary measure in its ongoing negotiations for a 'no net loss of nature' target. Ensemble models have demonstrated that no net loss is possible to achieve, but requires aligned actions across biodiversity conservation, food production and food consumption (Leclère et al. 2020).

Many parts of the world are currently in intactness deficit, considering a 50% intactness target. Estimates of how much restoration is needed range between 19 and 24 million km2 , with the lower value targeting high conservation value areas (Allan et al. 2019; Strassburg et al. 2020), and the higher value targeting half-intact ecoregions, across all ecoregions (DeClerck et al. In Review). In 552 ecoregions globally (69%), less than 10% of the area remains intact and may be too far gone for meaningful restoration of intactness, or may conflict with food and nutrition security. In these locations, integrating biodiversity into production will be a more viable option.

#### 4.2 Mitigating Climate Change

While reducing fossil fuel burning and halting land conversion are critical strategies to reduce GHG emissions, biodiversity, through photosynthesis, is the only known process to transfer GHG from the atmosphere to the biosphere. The retention and restoration of natural ecosystems, notably, carbon-dense forest and wetland ecosystems, are key in this regard. It has been proposed that 75% of forest biomes be conserved globally because of their specific contribution to climate mitigation (Steffen et al. 2015). Temperate and tropical forest biomes are currently below this threshold, although temperate forest areas are increasing due to agricultural abandonment, whereas tropical forest areas are decreasing due to agricultural expansion. Boreal forest biomes remain above this threshold for the moment (Dinerstein et al. 2017; Ramankutty et al. 2018). The potential of reforestation to contribute to climate mitigation (i.e., 2.7–17.9 Pg CO2e y-1 ) depends on several assumptions (Griscom et al. 2017).

#### 4.3 Regulating Hydrological Cycles

Large tracts of intact nature are key to maintaining regional hydrological patterns (Chapman et al. 2020; McAlpine et al. 2009), including flood pulse flow regulation (Bradshaw et al. 2007) and distribution of rainfall patterns that are critical to agriculture. However, the relationship between water fluxes (storage, evapotranspiration, precipitation and run-off) of extensive intact areas is complex. Intact nature may or may not produce greater volumes of water than converted lands, as losses to storage and evapotranspiration can be greater than in simplified systems such as agricultural ecosystems. However, most evidence does indicate that heavily vegetated ecosystems (e.g., forests, grasslands) provide better flow regulation – while natural ecosystems reduce run-off, they may have greater losses to evapotranspiration. Studies suggest that about 40% of irrigation water currently drawing from surface water bodies is at the expense of environmental flows (Jägermeyr 2020) and roughly 20% of irrigation water depletes groundwater bodies(Döll et al. 2012; Wada et al. 2012; Wada et al. 2016), indicating that 50–60% of current global irrigation practice is unsustainable (Rosa et al. 2019; Rosa et al. 2018).

#### 4.4 Restoring Ecosystems

A growing number of research articles now point toward options for restoration, and evaluate contributions to climate, biodiversity, and food security, but there remains an important research gap on local and regional implementation of such strategies, including the trade-offs over multiple spatial and temporal scales, as well as between different social groups (Leclère et al. 2020; Strassburg et al. 2020; Mehrabi et al. 2018). Restoration, in contrast to regeneration, must include improvements in biodiversity intactness (Newbold et al. 2016; Scholes and Biggs 2005) measured by changes in species richness and population abundance. Defined as such, restoration can be interpreted as driving a net reduction in land available for food production, with the exception of wild harvest systems, and potentially extensive grazing systems. Restoring 15% of converted lands in priority areas could avoid 60% of expected extinctions while sequestering 299 Gt CO2e – 30% of the total CO2 increase in the atmosphere since the Industrial Revolution (Strassburg et al. 2020).

# 5 Conclusions and Recommendations: Food and Agriculture Must Be the Solution to Food, Environmental and Climate Security

While the evidence on when and how biodiversity contributes to global goals is highly context specific, we find that agriculture has the potential to reconcile global goals that have often been considered contradictory: food and nutritional security versus environmental and climate security. There is strong evidence that realizing this potential requires placing biodiversity at the heart of agriculture policy, investment and innovation, with much greater consideration of the role of agriculture as a provider of benefits to biodiversity, rather than just a driver of biodiversity loss. As the lifeline of the entire system, people must be anchored in solutions to upend the system of policies and incentives that are currently stacked against their livelihoods and health.

Understanding that there is a menu of solutions, with related opportunities and trade-offs, will help in progress toward a future that optimizes sustainable agriculture and prioritizes feeding everyone. Biodiversity strategies are among those solutions and can help us move beyond staple crops and commodities when considering policy, investment and research. Three elements, as already detailed in this review, can offer a way to bridge conversations among policymakers engaged in the environment, food, agriculture, finance and social protection sectors, and must be considered in a holistic solution for food and biodiversity: (1) How can we optimize the opportunities and minimize the trade-offs for ensuring diverse diets for all? (2) How can we maintain shared space where agriculture optimizes ecosystem services, and other contributors to regenerative and resilient production systems? And (3) how can we strike the right balance of land sparing, by halting the expansion of agriculture into the intact ecosystems necessary to halt the loss of biodiversity while mitigating climate change and producing enough healthy food?

#### 5.1 Policy Implications: The Transformation Challenge

Biodiversity needs to be part of a sustainable agriculture that will feed a projected population of 10 billion with healthy, culturally appropriate and delicious foods by 2050. The first step is for policymakers to adopt a new conceptual framing that recognizes that all parts of food systems need to work together as a whole if they are to deliver diets that are high quality and sustainable. This leads to thinking about 'food system productivity,' rather than agricultural productivity (Benton and Bailey 2019), and requires all sectors of government to break out of their own conceptual silos and institutional structures. For a true transformation of the food system, there is a need to create the policy instruments, demand and incentives for food production systems that leverage biodiversity's capacity to contribute to climate, environmental, food and nutritional security (Willett et al. 2019; Rockström et al. 2009; Steffen et al. 2015).

#### 5.2 Correcting Distortions Requires Reinvestment

Our food system has been distorted by a framework of subsidies (including for research focused on staples), market incentives (including investment in commoditybased transport infrastructure and marketing/retail incentives for hyper-processed food), and a lack of regulations to curb the externalization of costs onto environmental and healthcare systems. The heavily subsidized agricultural sectors of many countries in the Global North result in trade distortion, or in inequitable trade relationships among many developed and developing countries, adversely affecting the economic prospects of farmers in the Global South (OECD, 2016). These have a strong influence on both the foods that are delivered and their price and accessibility, and in encouraging the supply, demand and consumption of foods that may be less conducive to healthy diets and sustainability in food systems.

In considering the relationship between agriculture and biodiversity, several key areas for investment emerge [High Agreement, Robust Evidence]:

During the next decade, priority approaches to diversify production systems should target:

Food security cannot trump other critical goals, notably, nutritional, climate, environmental and livelihood security. Treating these as inevitable trade-offs fails to highlight key areas of synergy. Making the transition to food production systems that achieve synergy with biodiversity will require significant transitions in the policy landscape. Therefore, agriculture must be more strongly:

# 5.3 Developing more Dynamic Investment and Financial Opportunities

There is potential to unlock and unblock investment and facilitate better financial flows to encourage farmers to protect and enhance the environment by rewarding them for the provision of ecosystem services, while mitigating the risks to the adoption of sustainable practices. Current agricultural investments and practices often overlook the important potential for increasing the ecosystem services that agroecosystems can provide (Wood et al. 2018). The CGIAR Commission on the Sustainable Intensification of Agriculture finds "an uplift in finance could come from reorienting current innovation spending to promote environmental, climate change, inclusivity and nutrition outcomes. A recent study commissioned by CoSAI identified that although around USD 50–70 bn per year is spent on agricultural innovation for the Global South, less than 7% explicitly aims to improve environmental and climate outcomes. And only around half of this also addresses social or nutrition outcomes" (CoSAI. 2021).

Farmers and farming communities can produce public goods (e.g., climate mitigation, soil water-holding capacity, water quality improvement), but promoting these public good functions has been consistently underexplored and underresourced, even though they are also necessary for creating sustainable and resilient production systems. Recognizing that farmers and farmlands can produce these benefits in addition to quality food presents an opportunity for revitalizing rural communities by repurposing public funds for public goods.

### 5.4 Changing Availability Through Subsidy and Research Reform

Currently, more than US\$620 billion is spent globally each year on agricultural subsidies (e.g., commodity support, services) (OECD 2020). Over the past decade, OECD governments have allocated roughly 26% of their subsidy support to cereal grains, and 14% to fruits and vegetables (Freund and Springmann Under review). This value is inverse to the diversity of potential crops within these food categories, inverse to the recommended consumption levels of food groups, and inverse to the projected yield production deficits. While the share of sectoral support to fruit and vegetables was much higher in non-OECD countries, at 37%, the other 63% of subsidy support went to cereals, livestock, oilseeds, sugar, production of fiber (wool) and more (Freund and Springmann Under review).

Even a relatively modest repurposing of subsidies (e.g., 25%) toward promoting production of nutrient-rich perishable foods, and reduced food loss and nutrient waste, would amount to US\$150 billion in capital to support the generation of a greater diversity of nutrient-rich foods, while simultaneously lowering the environmental footprint, potentially allowing more nature-positive farming methods.

Only 6% of public sector support to the agricultural sector is dedicated to research (Searchinger et al. 2020). This is a small percentage, but amounts to a big number globally. However, it is typically targeted at productivity improvements in major commodities. A key research need is for a much greater focus on innovation in diverse farming systems, rather than individual crops, for instance, through circular agriculture to prevent waste and leakage while supporting reuse, regenerative, agroecological systems, complex rotations, mixed farming, and so on.

#### 5.5 Reimagining International Trade

With almost 20% of the global dietary energy supply derived from imported foodstuffs, trade policy must better integrate its impact by creating greater space for diversification of commodities, supporting the conservation of intact ecosystems, and including trade in environmental goods and services. Trade expansion over recent decades has enabled "higher-income countries to 'off-shore' the adverse impacts of their consumption on ecosystems and biodiversity through trade in commodities, goods and services with lower-income countries" (Dasgupta 2021) International market stability and prices are highly dependent on a few key players (Dasgupta 2021), yet investing well in international trade could bring a range of benefits. It is crucial to find ways to support sustainability via trade (e.g., 'due diligence' requirements for supply chains such as the Global Reporting Initiative (GRI), enhancing traceability through mechanisms such as Trase, or through border tariffs). A key component of the evolution of the food system's focus on large-scale commodity production is the ability to store, transport and process grains with less loss than with fresh produce.

Acknowledgements This paper was funded with support from the CGIAR Collaborative Research Program on Water Land and Ecosystems.

#### References

Griscom BW et al (2017) Natural climate solutions. Proc Natl Acad Sci 114:11645–11650

Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License ( ), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made. http://creativecommons.org/licenses/by/4.0/

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

# Water for Food Systems and Nutrition

Claudia Ringler, Mure Agbonlahor, Kaleab Baye, Jennie Barron, Mohsin Hafeez, Jan Lundqvist, J. V. Meenakshi, Lyla Mehta, Dawit Mekonnen, Franz Rojas-Ortuste, Aliya Tankibayeva, and Stefan Uhlenbrook

# 1 Introduction

Water is essential for all life and is integral to the function and productivity of the Earth's ecosystems, which depend on a complex cycle of continuous movement of water between the Earth and the atmosphere. Water is also fundamental for food systems, and a food systems transformation will be essential to meeting SDG 6 on water and sanitation. As described by the High-Level Panel of Experts on Food

C. Ringler (\*)

M. Agbonlahor African Union Commission, Ouagadougou, Burkina Faso

K. Baye Addis Ababa University, Addis Ababa, Ethiopia

J. Barron Swedish University of Agricultural Sciences, Uppsala, Sweden

M. Hafeez International Water Management Institute, Lahore, Pakistan

J. Lundqvist Stockholm International Water Institute, Stockholm, Sweden

J. V. Meenakshi University of Delhi, New Delhi, India

Norwegian University of Life Sciences, Ås, Norway

D. Mekonnen International Food Policy Research Institute, Addis Ababa, Ethiopia

International Food Policy Research Institute (IFPRI), Washington, DC, USA e-mail<EMAIL_ADDRESS>
L. Mehta Institute of Development Studies, Falmer, UK

Fig. 1 The linkages between water and food systems (Source: HLPE 2015)

Security and Nutrition (HLPE) (HLPE 2015) and illustrated in Fig. 1, the key dimensions of water that are of importance for humanity are its availability, access, stability, and quality. These have multiple, close linkages and feedback loops with food systems, which can be defined as the activities involved in the production, processing, distribution, preparation, and consumption of food within wider socioeconomic, political, and environmental contexts (HLPE 2017). For example, waste streams from food processing often re-enter water bodies, affecting other components of food systems, such as drinking water supplies (water is itself essential for all bodily functions and processes, and is an important source of nutrients) (UNSCN 2020), as well as water-based and water-related ecosystems.

More than 70% of all freshwater withdrawals are currently used for agriculture, and about 85% of withdrawn resources are consumed in irrigated agricultural production. With these resources, irrigated crop areas generate 40% of global food production on less than one-third of the globally harvested area (Ringler 2017). Another key water-food system linkage is water supply for WASH (water, sanitation

F. Rojas-Ortuste

Development Bank of Latin America, Montevideo, Uruguay

A. Tankibayeva

S. Uhlenbrook International Water Management Institute (IWMI), Battaramulla, Sri Lanka

Al-Farabi Kazakh National University, Almaty, Kazakhstan

and hygiene), which is important for human health, can support nutrition outcomes, particularly if combined with other interventions (Cumming et al. 2019), and is a basic human right, as is the right to food. Water is also essential for agricultural processing and food preparation.

Climate change and other environmental and societal changes (e.g., land use changes, biodiversity loss, urbanisation, and changing lifestyles and diets) are impacting the dynamics of natural water cycles and water resource availability, with further, subsequent impacts on food systems. More than half of all natural wetland areas have been lost due to human activity since 1900 and forest degradation affects streamflow regulation (Sun et al. 2017). At the same time, the growing frequency and severity of floods and droughts in many regions of the world (IPCC 2021) increase competition over water resources. This calls for changes in water management, including increased water productivity, integrated storage solutions, accelerated land restoration and smarter water distribution to support food systems, as well as a reduction in impacts on domestic, industrial, energy-related, and environmental water uses.

### 2 SDG 2 and SDG 6 Can Only Be Achieved If the Water and Food System Communities Work Together

### 2.1 Water Scarcity and Pollution Are Growing, Affecting Poorer Populations, Particularly Food Producers

Freshwater-related ecosystems include wetlands, rivers, aquifers, and lakes that sustain biodiversity and life (UN Environment 2018). Although they cover less than 1% of the Earth's surface, these habitats host approximately one-third of vertebrate species and 10% of all species (Stayer and Dudgeon 2010), including mammals, birds (IUCN 2019), and fish (Fricke et al. 2020). Water-related ecosystems are also vital for the function of all terrestrial ecosystems, providing regulating, provisioning, and cultural services (Martin-Ortega et al. 2015). Furthermore, hydropower is an essential energy source, accounting for 85% of global renewable electricity generation in 2015, but has since declined to around 60% (IEA 2016, 2020), and is also key for commerce and industry (Willet et al. 2019). Notably, de-carbonising the energy system can also adversely impact the water system, particularly in the case of increasing hydropower and biofuel production.

Progress on achieving the water and sanitation targets of SDG 6 has been unsatisfactory and uneven. More than 2 billion people live in places with high water stress (FAO SOFA 2020; UN 2018): by 2050, every second person, half of the world's grain production, and close to half of the globe's Gross Domestic Product might well be at risk from water insecurity (Ringler et al. 2016). In 2020, approximately 2.0 billion people lacked access to safely managed drinking water, and 3.6 billion people lacked access to safely managed sanitation services. One in ten people lacked basic services, including the 122 million people who depend on untreated surface water, mostly in sub-Saharan Africa (UNICEF, WHO 2021). Poor women and girls, who are responsible for more than 70% of all water collection, spend about 200 million hours a day on this task, undermining their health and livelihood opportunities (UNICEF n.d.; Geere and Cortobius 2017).

In terms of agricultural water use, farmers across the world, but particularly in sub-Saharan Africa, continue to rely heavily on rainfall for food production. More than 62 million hectares of crop and pastureland experience high to very high water stress and drought, affecting about 300 million farm households (FAO 2020). With climate change, temperatures and crop evaporation levels are increasing, and there is growing uncertainty about the timing, duration and quantity of rainfall, increasing the risks related to producing food and undermining the livelihood security of the majority of rural people (AUC 2020). Fertiliser use on crop land and livestock excreta are key sources of agricultural water pollution, affecting aquatic life and threatening human health. Projections suggest that nitrogen and phosphorous deposition in water bodies will grow rapidly, particularly in low- and middle-income countries (Xie and Ringler 2017).

With respect to the other SDG 6 targets, such as water use efficiency, waterdependent ecosystems, and integrated water management, progress has been slow and is often not well understood, due to the lack of effective monitoring mechanisms and insufficient data. New, integrated approaches and reinforced efforts to measure and manage water are urgently needed (Sadoff et al. 2020).

While water availability differs dramatically around the globe, differences in access are most often due to politics, public policy, lack of capacity and investment, and flawed water management strategies, as well as exclusions due to geography (i.e., remote rural areas), gender, ethnicity, caste, race, and class. In many cases, water does 'flow uphill' to power and money (Mehta et al. 2019). Furthermore, increasing urbanisation and changing diets are affecting the demand and supply of water resources for food systems and aggravating water stress in many parts of the world, particularly in water-scarce areas of low/middle-income countries where coping capacity is often insufficient.

### 2.2 Malnutrition Levels Are on the Rise and Are Closely Linked to Water Scarcity

An estimated 690 million people, or 8.9% of the global population, were undernourished in 2019, prior to the COVID-19 pandemic (Headey et al. 2020). The number has since grown to between 720 and 811 million people (2020 values). Moreover, 149 million children below the age of five were stunted, 45 million were wasted, and another 39 million were overweight (FAO, IFAD, UNICEF, WFP and WHO 2021). Climate change, associated conflict, and a lack of sufficient water for food production, including irrigation for fruit and vegetable production, are key contributors to unaffordable diets and overall levels of undernutrition. At the same time, overweight continues to dramatically increase around the globe, including in children. Latin America, in particular, suffers from the associated public health burden. Overall, rural areas are currently experiencing the most rapid rate of increase in overweight (NCD Risk Factor Collaboration et al. 2019). Given these trends, neither the 2025 World Health Assembly nutrition targets nor the 2030 SDG nutrition targets will be met. As with inequities in access to water, inequities in access to food and nutrition are highest in rural areas (Perez-Escamilla et al. 2018).

#### 2.3 SDG 2 and SDG 6 Targets Are Co-Dependent

Ending hunger and malnutrition requires access to safe drinking water (SDG 6.1), as well as equitable sanitation and hygiene (SDG 6.2). The underlying productivity (SDG 2.3) and sustainability (SDG 2.4) of agricultural systems are also dependent on adequate availability (SDG 6.4 and 6.6) of good quality (SDG 6.3) water. Moreover, water and related ecosystems (e.g., wetlands, river or lakes in SDG 6.6), which are embedded in sustainable landscapes, are important contributors to sustainable agriculture through regulating and providing water for food production (SDG 2.4) (Ringler et al. 2018).

A key contributor to poor nutritional outcomes in subsistence farming households in low-income countries is the seasonality of production, leading to a seasonality in diets, which can affect pregnancy outcomes and child growth (Baye and Hirvonen 2020; Madan et al. 2018). Well-managed irrigation systems can buffer seasonal gaps in diets, contributing to improved food security and nutritional outcomes, for example, through homestead gardening (Baye et al. n.d.; Hirvonen and Headey 2018).

It is equally important to stress the need for changes in food systems in meeting SDG 6 targets: reducing food loss and waste in food value chains (SDG 12.3), lowering pollution from slaughterhouses, food processing, and food preparation, and considering environmental sustainability in food-based dietary guidelines. All of these actions will be essential to meet the SDG 6 targets (UNSCN 2020).

### 3 Solutions for Improving Food System Outcomes and Water Security

Based on the above assessment, as well as recent water-food system reviews (Ringler et al. 2018; UNSCN 2020; Mehta et al. 2019; Young et al. 2021), the following actions are proposed for uptake by governments, the private sector, and civil society.

### 3.1 Strengthen Efforts to Retain Water-Based Ecosystems and Their Functions

The ecological processes underlying the movement, storage, and transformation of water are under severe threat from deforestation, erosion, and pollution, with impacts on local, regional, and global water cycles (WWAP 2018). In addition to a direct halt of deforestation and the destruction of water-based ecosystems, nature-based solutions that use or mimic natural processes to enhance water availability (e.g., groundwater recharge), improve water quality (e.g., riparian buffer strips, wetlands), and reduce risks associated with water-related disasters and climate change (e.g., floodplain restoration, wetlands) should be strengthened (WWAP 2018). Limiting overconsumption of water, particularly in water-stressed regions, will be necessary to stay within sustainable water use limits (Yu et al. 2021).

### 3.2 Improve Agricultural Water Management for Better Diets for All

Around 3 billion people on this planet cannot afford a healthy diet, particularly dairy, fruits, vegetables, and protein-rich foods (FAO, IFAD, UNICEF, WFP, WHO 2021). Both rainfed and irrigated systems play essential roles in lowering the prices of nutrient-dense foods, growing incomes to be able to afford these foods, and strengthening the diversity of foods available in local markets (Hirvonen et al. 2017).

#### 3.2.1 Strengthen the Climate Resilience of Rainfed Food Systems

Rainfed systems produce the bulk of food, fodder, and fibre, and most animal feed is produced under rainfed conditions (Heinke et al. 2020). These systems are under severe and growing stress from climate change, including extreme weather (FAO 2020). This can be addressed, to some extent, through structural measures (e.g., terracing, soil bunds, drainage), investment in breeding, improved agronomic practices, effective incentives (e.g., payments for watershed conservation), and strong institutions for water, soil and land management (e.g., watershed committees) (Jägermeyr et al. 2016; World Bank 2010).

#### 3.2.2 Strengthen the Nutrient Density of Irrigated Agriculture

As irrigation accounts for the largest share of freshwater withdrawals by humans (more than 90% in some agrarian economies), the potential for water conservation is also largest in this sector. Irrigation development needs keep environmental limits – which are increasingly affected by climate change – in mind. This includes addressing groundwater depletion. The potential for increasing water and nutrition productivity in irrigation remains large. It includes crop breeding for transpiration efficiency, salinity tolerance, climate resilience and increased micronutrients, integrated storage solutions – such as joint use of grey and green infrastructure – advanced irrigation technology, and soil moisture monitoring (Rosegrant et al. 2009). There are clear trade-offs between the nutrient density of foods and irrigation water use. Fruit and vegetable yields depend on frequent water applications in many parts of the world (although the water content of the end product also tends to be high) and need precision applications of agrochemicals to maximise water inputs and avoid water pollution (Meenakshi and Webb 2019). Many livestock products are highly waterintensive due to animal feeds, although the majority of the feed comes from rainfed agriculture. Awareness-raising and social learning interventions can help internalise the water externality of water-intensive diets. Improved coordination of water with other agricultural inputs can also enhance yield per drop of water. This requires access to technology packages, as well as to better agricultural information (Lundqvist et al. 2021), which is increasingly supported by ICTs (Asenso-Okyere and Mekonnen 2012). Moreover, subsidies for water-intensive crops, such as rice, milk and sugar, should be revisited and eventually removed. For water-scarce countries, importing virtual water via food and other commodities will remain essential (Allan 1997).

#### 3.2.3 Address Water Pollution to Improve Food Production, Food Safety, and Water-Based Ecosystems

Globally, 80% of municipal sewage and industrial wastewater with heavy metals, solvents, toxic sludge, pharmaceuticals, and other waste are directly discharged into water bodies, affecting the safety of food, particularly vegetable production, and also, directly, human health (WWAP 2018). Agriculture also directly pollutes aquatic ecosystems and risks food production with pesticides, organic matter, fertilisers, sediments, pathogens, and saline drainage (UNEP 2016). Key measures to address agricultural and overall water pollution include the breeding of crops with higher crop nutrient use efficiency, better agronomic practices, the expansion of nature-based solutions for pollution management, low-cost pollution monitoring systems, improved incentive structures for pollution abatement, and continued investment and innovation in wastewater treatment, including approaches such as implementing the 3Rs (reduce, reuse, and recycle) of the circular economy across the entire food system (Mateo-Sagasta et al. 2018).

#### 3.3 Reduce Water and Food Losses Beyond the Farmgate

Irrigated agriculture is often focused on high-value crops with a higher share of marketed surplus, compared to rainfed agriculture (Nkonya et al. 2011). At the same time, many irrigated crops, such as fruits and vegetables, are time-sensitive, perishable products that require efficient market linkages to consumption centres. Strengthening market linkages includes investment in physical infrastructure that supports on-farm production (irrigation, energy, transportation, pre- and post-harvest storage), efficient trading and exchange (telecommunications, covered markets), value addition (agro-processing and packaging facilities), and improved transportation and bulk storage (Warner et al. 2008). Investments are also needed in ICTs that facilitate farmers' access to localised and tailored information about weather, water consumption, diseases, yield, and input and output prices (Elsabber 2020).

### 3.4 Coordinate Water with Nutrition and Health Interventions

#### 3.4.1 Strengthen Institutional Coordination and Develop Joint Programmes

Governance and management of water for various uses and functions, as shown in Fig. 1, follow different institutional arrangements. Similarly, professionals engaged in various roles within water-related institutions have different kinds of training and experiences. Few irrigation engineers have a professional background or skills related to WASH, and few WASH professionals have the technical skills needed to design water infrastructure for multiple uses, for example. The notion of integrated water resource management (SDG 6.5) has been promoted as a principle to overcome problems due to sectoral division. Coordination at the lowest appropriate levels is urgently needed between WASH and irrigation for improved food security, nutrition, and health outcomes, as well as to strengthen women's agency over water decisions. Multiple-use water systems can increase food security and WASH outcomes (van Koppen et al. 2014). An example is the MiAgua programme in Bolivia supported by CAF, the development bank of Latin America, which included rural water supply, climate change adaptation measures such as watershed protection, and micro-irrigation projects for small-scale agriculture. MiAgua benefited 2.25 million people with improved or new access to water and contributed to increasing rural water coverage from 59 percent in 2011 to 69% in 2020. At a larger scale, improved coordination across riparian countries is essential for improving water securities linked to competing uses. A key example is the Aral Sea Basin, where lack of coordination between upstream and downstream countries affect both energy and food security (Bekchanov et al. 2015).

#### 3.4.2 Implement Nutrition-Sensitive Agricultural Water Management

Nutrition and health experts need to join forces with water managers at the farm household level, at the community level, and at the government level to strengthen positive transmission pathways between both rainfed and irrigated agriculture and food and nutrition security. A recent guidance (Bryan et al. 2019) describes eight actions for increasing the nutrition sensitivity of water resource management and irrigation, as well as indicators for monitoring progress.

### 3.5 Increase the Environmental Sustainability of Food Systems

The water footprint of diets varies dramatically between rich and poor countries, but also by socioeconomic group within countries (Lundqvist et al. 2021). More work is urgently needed on the impact of current dietary trends on environmental resources, including water. Food-based dietary guidelines should consider the environmental footprint of proposed diets, whereby government regulations and consumer awareness should be strengthened to reduce the over-consumption of food, and further efforts are needed to reduce post-harvest waste and losses (UNSCN 2020).

### 3.6 Explicitly Address Social Inequities in Water-Nutrition Linkages

Vulnerable groups need to be proactively included in the development of water services, including incorporating their needs and constraints into initial infrastructure design. For rural smallholders who most lack water and food security, irrigation design should consider multiple uses of water, such as drinking, irrigation, and livestock watering, to meet women's and men's needs. While women make up a large part of the agricultural workforce, they often lack recognition and formal rights, and farmers are often considered to be 'male' in many parts of the world. Women's productive roles should be promoted, and they should be trained in irrigation and water management. Their involvement has important implications for water and food security (Meinzen-Dick et al. 2021; Balasubramanya 2019). It is also important to ensure that women and disadvantaged social groups (e.g., lower castes, stigmatised social groups) have equal access to credit, irrigable land, labour, and markets to be able to buy agricultural inputs and sell their produce (Mehta et al. 2019; UNSCN 2020).

### 3.7 Improve Data Quality and Monitoring for Water-Food System Linkages, Drawing on Innovations in ICT

Better data are needed if we are to truly understand the water footprint of diets and devise policies that co-maximise water and food security and nutrition goals. Challenges include poor water and poor food intake data and a lack of indicators connecting the two, but improvements are emerging (Bryan et al. 2019; HWISE network (https://hwise-rcn.org/); Lundqvist et al. 2021). More and better data will support better water management and food systems and increase transparency in decision-making. This requires sustained investments in the monitoring of a wide range of hydrological and food-related parameters worldwide. Modern Earth observation methods can support larger-scale assessment, but need to be complemented by dedicated field measurements.

Acknowledgement The support of the CGIAR Research Initiative 'NEXUS Gains – Realising benefits across on water, energy, food and ecosystems' and conceptual support from the WASAG Working Group on Water and Nutrition are gratefully acknowledged.

#### References

Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License ( ), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made. http://creativecommons.org/licenses/by/4.0/

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

# Climate Change and Food Systems

Alisher Mirzabaev, Lennart Olsson, Rachel Bezner Kerr, Prajal Pradhan, Marta Guadalupe Rivera Ferre, and Hermann Lotze-Campen

# 1 Introduction

Climate change affects the functioning of all of the components of food systems (IPCC 2019) that embrace the entire range of actors and their interlinked valueadding activities involved in the production, aggregation, processing, distribution, consumption, and recycling of food products that originate from agriculture (including livestock), forestry, fisheries, and food industries, and the broader economic, societal, and natural environments in which they are embedded (von Braun et al. 2021). At the same time, food systems are a major cause of climate change, contributing about a third (21–37%) of the total GHG emissions through agriculture

A. Mirzabaev (\*)

L. Olsson Centre for Sustainability Studies (LUCSUS), Lund University, Lund, Sweden R. B. Kerr Department of Global Development, Cornell University, Ithaca, NY, USA P. Pradhan Potsdam Institute for Climate Impact Research (PIK), Member of the Leibniz Association, Potsdam, Germany M. G. R. Ferre INGENIO (CSIC-Universitat Politècnica de València), Valencia, Spain H. Lotze-Campen Potsdam Institute for Climate Impact Research (PIK), Member of the Leibniz Association, Potsdam, Germany The Agricultural Model Intercomparison and Improvement Project (AgMIP), New York, NY, USA

Food System Economics Commission (FSEC), Potsdam, Germany

Center for Development Research (ZEF), University of Bonn, Bonn, Germany e-mail<EMAIL_ADDRESS>
Fig. 1 Linkages between climate change and food systems

and land use, storage, transport, packaging, processing, retail, and consumption (Mbow et al. 2019) (Fig. 1).

Climate change will affect food systems differentially across world regions. While some areas, such as northern temperate regions, may even experience some beneficial changes in the short term, tropical and sub-tropical regions worldwide are expected to face changes that are detrimental to food systems. Such changes will have effects on food and nutrition security through a complex web of mechanisms (Fig. 1). Critical climate variabilities that affect food and nutrition security include increasing temperatures, changing precipitation patterns and greater frequency or intensity of extreme weather events such as heatwaves, droughts and floods (Mbow et al. 2019). They impact the productivity of crops, livestock and fisheries by modulating water availability and quality, causing heat stress, and altering the pests and disease environment, including through the faster spread of mycotoxins and pathogens. Increased frequency and intensity of floods and droughts can lead to considerable disruptions in food supply chains through harvest failures and infrastructure damage. The exposure of people to heatwaves, droughts and floods can harm their health and lower their productivity, affecting their livelihoods and incomes, especially for those engaged in climate-sensitive sectors or working outdoors. This exposure can strongly affect more vulnerable groups in many lowerincome countries, e.g., smallholder farmers, low-income households, women and children. Other factors related to climate change that affect food systems are the rise in atmospheric concentrations of CO2, and, indirectly, land degradation, and a reduction in pollination services. Changes in CO2 levels in the atmosphere affect both crop yields and their nutrient content. Climate change will exacerbate land degradation through increased soil erosion, especially in sloping and coastal areas, increased soil salinity in irrigated lands, and climates that are more arid and more prone to desertification in some dryland areas (Olsson et al. 2019; Mirzabaev et al. 2019). The potential reduction or loss of pollination services also leads to lower crop yields. Conservative estimates, which consider these climate change impacts only partially, show that the number of people at risk of hunger may increase by 183 million by 2050 under high emission and low adaptation scenario [i.e., under Shared Socioeconomic Pathway (SSP) 3], compared to low emission and high adaptation scenarios (SSP1). An additional 150–600 million people are projected to experience various forms of micronutrient deficiency by 2050 in the higher emission scenario (Myers et al. 2017; Zhu et al. 2018; Medek et al. 2017).

The interactions between climate change and food systems have considerable repercussions across all of the dimensions of sustainable development. In fact, in six of the 17 sustainable development goals (SDGs), climate change-food system interactions increasingly play a major role. These relate to the social goals of zero hunger (SDG 2) and gender equality (SDG5), and the four environmental goals of water resources (SDG 6), climate action (SDG 13), life below water (SDG 14), and life on land (SDG 15). Solutions addressing the challenges posed by climate changefood system interactions can serve as a critical entry point for promoting the 2030 Agenda for sustainable development well beyond the timeline of the current SDGs (Pradhan et al. 2017). Since these interactions vary according to the country's income, region, and population groups (i.e., gender, age, and location of its population), solutions prioritising women, youths, and rural people, i.e., "leaving no one behind," can better leverage the achievements of the SDGs (Warchold et al. 2021).

### 2 How Climate Change Interacts with Food Systems and Food Security

#### 2.1 Food Availability

Considerable evidence has by now emerged indicating that climate change is already negatively affecting crop production in many areas across the world (Kim et al. 2019; FAO 2018). Reductions of 21% in total factor productivity of global agriculture since 1961 have been estimated (Ortiz-Bobea et al. 2021). It has been found that climate change over the last four-five decades has reduced the yields of cereals by about 2–5% on average globally, compared to the situation if there had been no climate change (Iizumi et al. 2018). This range of about 5% lower cereal yields due to climate change was also found in regional studies, for example, for wheat and barley in Europe (Moore and Lobell 2015), for wheat in India (Gupta et al. 2017), and for maize in Africa, Central and Eastern Asia (Ray et al. 2019), and Central and South America (Verón et al. 2015). Higher losses equalling about 5–20% were found for millet and sorghum yields in West Africa (Sultan et al. 2019), and maize yields in Eastern and Southern Europe were estimated to be lower by about 5–25% (Agnolucci and De Lipsis 2020). There is growing literature documenting the negative impacts of climate change on the yields of legumes, vegetables, and fruits in drylands, tropical and sub-tropical areas (Mbow et al. 2019; Scheelbeek et al. 2018). These losses in yields have occurred after the taking of coping and adaptive actions (Mbow et al. 2019).

In temperate climatic zones, such as northern China, parts of Russia, northern Europe, and parts of Canada, observed climatic changes are increasing the agricultural potentials, leading to higher crop production (Moore and Lobell 2015; Ray et al. 2019; Potopová et al. 2017; Meng et al. 2014; Wang and Hijmans 2019; Bisbis et al. 2018). However, in many areas, this increased production is coming at the expense of lower yield stability due to higher weather variability between seasons. Climate change accounts for about half of food production variability globally. Presently, adaptive strategies for increasing crop yields (crop breeding, improved agronomic management, adaptations based on indigenous and local knowledge, etc.) can withstand, at a global average, any impacts of climate change on said yields. However, the acceleration of climate change can overwhelm this trend in the future; and the impacts are already being experienced in many regions. Climate change increased drought-induced food production losses in southern Africa, leading to 26 million people in the region requiring humanitarian assistance in 2015–2016 (Funk et al. 2018). Climate change is also increasing ocean acidification and temperatures, reducing farmed fish and shellfish production, as well as wild fish catches, with some regions experiencing losses of 15%–35% (Mbow et al. 2019).

The impacts of climate change on food production are projected to worsen after the 2050s, particularly under higher emission scenarios (Mbow et al. 2019). In agriculture, the biggest crop yield declines due to climate change are expected to occur in those areas that are already hot and dry, especially in the tropics and sub-tropics, as well as in the global drylands where water scarcity is projected to become more acute (Mirzabaev et al. 2019). More recent modelling shows that previous projections of climate change impacts on future crop yields underestimated the extent of potential yield declines. For example, many crop modelling studies do not consider the effect of short-term extreme weather events. Although extreme weather events have always posed the threat of disruptions in food systems, climate change is increasing the likelihood of simultaneous crop failures in major cropproducing areas in the world (Anderson et al. 2019; Heino et al. 2020). Disruptions in storage and distribution infrastructures and on food provisioning due to extreme event systems will also impact food availability, as well as bringing about a reduction in food exchanges due to lower productivity (Rivera Ferre 2014).

New twenty-first century projections by the Agricultural Model Intercomparison and Improvement Project (AgMIP) (Rosenzweig et al. 2021a), using ensembles of latest-generation crop and climate models, suggest markedly more pessimistic yield responses for maize, soybean, and rice, compared to the original ensemble. End-ofcentury maize productivity is shifted from +5 to -5% (SSP126) and from +1 to - 23% (SSP585), explained by warmer climate projections and a revised crop model ensemble (Jägermeyr et al. 2021). In contrast, wheat shows stronger high-latitude gains, related to higher CO2 responses. The 'emergence' of the climate impact signal—when mean changes leave the historical variability—consistently occurs earlier in the new projections, as early as 2030 in several of the main producing regions. While future yield estimates remain uncertain, these results suggest that major breadbasket regions may contend with a changing profile of climatic risks within the next few decades (Jägermeyr et al. 2021). While many fruit, vegetable and perennial crops are understudied, higher temperatures are projected to negatively impact their production, with one study estimating a 4% reduction in fruit and vegetable production as the result of climate change (Springmann et al. 2016).

The impacts of climate change on livestock systems and fisheries have been studied much less than those on the major crops. Nonetheless, considerable evidence indicates that increased frequency of heatwaves and droughts under climate change can lower livestock productivity and reproduction through heat stress, reduced availability of forage, increased water scarcity and the spread of livestock diseases (Mbow et al. 2019; Rojas-Downing et al. 2017). Increased levels of CO2 can favour the growth of pasture grasses, especially during rainier seasons and in more humid locations (Mirzabaev et al. 2019; Herrero et al. 2016). In contrast, in many arid and semi-arid locations, the projected effects are mostly negative (Rojas-Downing et al. 2017; FAO 2015; Boone et al. 2018). Climate change was found to reduce the maximum sustainable yield of several marine fish populations by about 4% (Free et al. 2019). Every 1 °C increase in global warming was projected to decrease mean global animal biomass in the oceans by 5% (Lotze et al. 2019), as well as redistributing fish populations away from sub-tropical and tropical seas towards poleward areas (Oremus et al. 2020). It is clear that the association between climate change and human nutrition goes beyond issues of caloric availability, and a growing challenge by 2050 will be providing nutritious and affordable diets (Springmann et al. 2016).

#### 2.2 Food Access

The impacts of climate change on agricultural production, supply chains and labour productivity in climate-sensitive sectors will influence both food prices and incomes, strongly affecting people's ability to purchase food through these price and income changes (Baarsch et al. 2020). Climate change is projected to increase global cereal prices by between 1% to 29%, depending on the Shared Socioeconomic Pathway considered (Mbow et al. 2019). The reductions in the yields of legumes, fruits and vegetables will also lead to higher prices for them. The impacts of these price increases on food access are not straightforward. Net food-selling agricultural producers can benefit from higher food prices (Hertel et al. 2010). Those same higher food prices will primarily hurt the urban poor and net food-buying agricultural producers (Mbow et al. 2019). Increased temperatures and more frequent heatwaves will reduce labour productivity for outdoor work and work in closed areas without air conditioning. Lower labour productivity will result in lower incomes and lower purchasing power.

#### 2.3 Food Stability

Climate change will increase the frequency of extreme water events, such as droughts, floods, hurricanes, and sea storms. Resulting inter-annual variability in food production, the destruction of transportation infrastructures, and greater food price instability can ultimately lead to more volatile global and regional food trade, undermining people's ability to access food in a stable way (Mbow et al. 2019). These disruptions could have a particularly negative impact on land-locked countries with less infrastructural access to the global food trade, as well as vulnerable social groups, especially in those locations without functioning or sufficient social protection schemes (FAO 2018).

#### 2.4 Food Utilisation and Safety

Climate change is projected to adversely impact childhood undernutrition, stunting, and undernutrition-related childhood mortality and increase the number of disabilityadjusted life years lost, with the largest risks being in Africa and Asia (Hasegawa et al. 2018a). Moreover, climate-related changes in food availability and diet quality are estimated to result in 529,000 excess climate-related deaths with about 2 °C warming by 2050 (Springmann et al. 2016). Most of these deaths are projected to occur in South and East Asia. Extreme climate events will even increase risks of undernutrition on a regional scale, via spikes in food prices and reduced income. Exposure to one pathway of food insecurity risk (e.g., lower yields) does not exclude exposure to other pathways (e.g., income reduction). Higher concentrations of atmospheric CO2 reduces the protein and mineral content of cereals, degrading the quality of food and, subsequently, food utilisation (Mbow et al. 2019). Rising temperatures are improving the conditions for the spread of pathogens and mycotoxins, posing risks to human health and increasing food waste and loss (Battilani 2016). Climate change is projected to increase the area of spread of mycotoxins from tropical and sub-tropical areas to temperate zones (Mbow et al. 2019). Reduction in water quality due to climate change will also negatively affect food utilisation.

#### 2.5 Impacts of Food Systems on Climate Systems

GHG emissions from food systems are a major contributor to climate change. Food systems are responsible for about one-quarter of global GHG emissions, or even up to one-third if indirect effects on deforestation are included (21%–37%) (Mbow et al. 2019). Specifically, new estimates by the Food Climate Partnership (Rosenzweig et al. 2021b) show that total GHG emissions from the food system were about 16 CO2 eq year-1 in 2018, or one-third of the total global anthropogenic GHG emissions. Three-quarters of these emissions, 13 Gt CO2 eq year-1 , were generated either during on-farm production or in pre- and post-production activities, such as manufacturing, transport, processing, and waste disposal. The remainder was generated through land use change of natural ecosystems to agricultural land. Results further indicate that pre- and post-production emissions were proportionally more important in high-income than in low-income countries, and that, during the period 1990–2018, land use change emissions decreased while pre- and postproduction emissions increased (Tubiello et al. 2021).

Even if fossil fuel-related emissions were stopped immediately, continuation of the current food system emissions could make the below 2 °C climate target unachievable (Clark et al. 2020). There are significant opportunities for reducing these emissions (Smith et al. 2019),, but at the same time, it is important to bear the food security implications in mind when implementing climate mitigation efforts (Frank et al. 2019; Hasegawa et al. 2018b). Without compensatory policies in place, stringent, abrupt and large-scale application of mitigation options, particularly those that are land-based, can have a negative impact on global hunger and food consumption, with the detrimental impacts being especially acute for vulnerable, low-income regions that already face food security challenges (Hasegawa et al. 2018a). However, many climate solutions can have mitigation and adaptation synergies together with other co-benefits, including for health, livelihood, and biodiversity (Smith et al. 2019; Rosenzweig et al. 2020).

### 3 Solutions for Climate Change Adaptation and Mitigation in Food Systems

Based on the above assessment, as well as the recent IPCC special report on Climate Change and Land (IPCC ), the following actions are proposed for uptake by governments, the private sector and civil society. These actions are of two types. Firstly, there are a wide range of both well-tested, ready-to-go solutions, and potential solutions for climate change adaptation and mitigation within food systems (Herrero et al. ) (Actions 1 to 7). Many of these already available solutions are well known and are being applied at local scales around the world, even if not at sufficient levels. Hence, the major effort to unleash their potential would involve overcoming various technical and structural barriers for their much wider application. The second type of action (8 and 9) focuses on key promising solutions that can help us meet the longer-term challenges of climate change within the context of food systems in the second half of this century, when most food production practices will face unprecedented challenges. 2020 2019

1. Amplify efforts for sustainable land management

Sustainable management of land (SLM), which includes water, supports and maintains ecosystem health, increases agricultural productivity, and contributes to climate change adaptation and mitigation (Olsson et al. ; Mirzabaev et al. ). SLM is defined as the use of land resources, including soils, water, animals and plants, to produce goods that meet changing human needs, while simultaneously ensuring the long-term productive potential of these resources and the maintenance of their environmental functions (UN 1992 Rio Earth Summit). 2019 2019

There are many practical examples of SLM. Application of water-efficient irrigation methods such as sprinkler and drip irrigation can help increase resilience to increasing aridity under climate change (Mirzabaev et al. 2019). Adoption of drought-resistant crop cultivars under diversified cropping systems is an essential adaptive strategy in many dryland areas (Mirzabaev et al. 2019). Where suitable, agroforestry is a powerful practice for reducing soil erosion and increasing carbon sequestration, while diversifying livelihoods (Smith et al. 2019). Rangeland management systems based on sustainable grazing and re-vegetation can increase rangeland resilience and long-term productivity while supporting a wide range of ecosystem services. Agroforestry practices, shelterbelts and silvio-pasture systems help reduce soil erosion and sequester carbon, while increasing biodiversity that supports pollination and other ecosystem services (Kuyah et al. 2019). SLM also includes agroecological practices, such as use of organic soil amendments, crop diversification, cover crops, intercropping, conservation agriculture practices, etc., that can have positive impacts on ecosystem services, food security and nutrition (Bezner Kerr et al. 2021; Beillouin et al. 2019; Muller et al. 2017; Tamburini et al. 2020; Kremen and Merenlender 2018). Indigenous knowledge and local knowledge hold a great array of practices for SLM (Rivera Ferre et al. 2021). Protection, restoration and climate-friendly management of peatlands are key elements for ambitious emission reduction strategies (Humpenöder et al. 2020).

Although SLM has been proven to provide positive social and economic returns, the adoption is currently insufficient. Important barriers for adoption are access to the resources for changing practices and the time required for the new practices to become productive. Introduction of payments for ecosystem services and subsidies for SLM can help. Enabling policy frameworks that include both incentives and disincentives are needed for promoting the adoption of SLM. Land tenure considerations are a major factor contributing to the adoption of SLM (Olsson et al. ), particularly for women. Various forms of collective action are crucial for implementing SLM in both privately and communally managed lands (Pretty ), although such efforts need to be strengthened and supported by policy (Isgren ). A greater emphasis on understanding gender-specific differences over land use and land management practices can promote SLM practices more effectively. Improved access to markets, including physical (e.g., transportation), economic (e.g., fair prices), and political (e.g., fair competition) support, raises agricultural profitability and motivates investment into climate change adaptation and SLM. Developing, enabling and promoting access to clean energy sources and technologies can contribute to reducing land degradation and mitigating climate change through decreasing the use of fuelwood and crop residues for energy, while significantly improving health for women and children (Sana et al. ). Finally, looking at co-benefits between addressing climate change (adaptation and mitigation) and 2019 2018 2003 2019

other urgent problems, like land degradation and biodiversity conservation, much can be gained by promoting SLM in agriculture.

2. Promote open and equitable food trade

The very heterogeneous effects of climate change on food production worldwide and the increase in extreme weather events that disrupt local food production activities highlight the importance of international food trade as a key adaptation option to this volatile environment (Van Meijl et al. 2018; Stevanović et al. 2016). At the same time, strengthening regional and local food systems, through policies and programmes that support sustainable local production, can help build a resilient food system. Such policies can include support for urban and peri-urban production, public procurement, and subsidies that encourage the application of sustainable production approaches.

Adapting to changing climate will require a combination of enhanced regional and local food trade, as well as international food trade, that can act as safety nets in the context of climate crises. To this aim, reducing transaction costs of food trade and maintaining transparent and well-enforced international food trade governance can strengthen food systems' resilience. This will particularly include avoiding imposing export bans. Food trade and food sovereignty are complementary elements of food security, and should not be regarded as mutually exclusive; rather, transparent and fair norms need to be agreed upon.

Fiscal instruments (e.g., carbon taxes) need to be given high priority in order to reduce fossil fuel use in agriculture. Agricultural subsidies need to be adjusted to encourage the application of sustainable production approaches and make sure that any negative effects that arise from them will be reduced through trade, and they need to take power differences into account, e.g., the impacts of subsidised food exports by high-income countries that make it harder for farmers in low-income countries to use sustainable methods or sell their products. Trade agreement mechanisms that allow low-income countries to have an equal say in trade governance are needed.

3. Include food systems in climate financing at scale

Food systems represent a range of actors and their interlinked value-adding activities that are most impacted by climate change. Food systems are also a major source of GHG emissions. This makes food systems a high priority target for adaptation and mitigation investments. However, investments into climate change adaptation and mitigation in food systems to date have only accounted for a tiny fraction of the total amounts of climate finance. Investments into climate change mitigation in food systems need to be commensurate with the share of GHG emissions coming from those systems, i.e., about a third of all mitigation funding, which is presently dominated by the energy sector and infrastructure. To illustrate, there are considerable opportunities for climate change adaptation and mitigation through investments into land restoration (e.g., reforestation, sustainable land management, re-seeding degraded rangelands) that allow for sequestering carbon in soils, increasing crop and livestock productivity and providing a wide range of other ecosystem services. Estimates show that every dollar invested in land restoration yields anywhere from 3 to 6 dollars of return, depending on the location across the world (Nkonya et al. 2015). Investments in food value chains for reducing food waste and loss is another area with substantial mitigation and adaptation benefits. A wide range of public and private sources could be harnessed for these investments, such as increasing substantially the annual development aid dedicated to agricultural and rural development, food and nutrition security, increased investments by international and regional development banks in food systems, and more active involvement of the private sector (e.g., green bonds) and philanthropies.

4. Strengthen social protection and empowerment of the vulnerable

It is now practically impossible to fully adapt to climate change impacts. Even without climate change, extreme weather events periodically inflict significant disruptions on food systems at the local, regional and even global levels. Climate change will make these disruptions more frequent and more extensive. Therefore, it is essential to strengthen the social protection for vulnerable populations in terms of accessing food during the times of such disruptions. Social protection can involve many forms, such as access to subsidised food banks, cash transfers, insurance products, pension and employment guarantee schemes, weather index insurance, and universal income.

The impacts of climate change on food systems are not suffered equally by all social groups. Age, class, gender, race, ethnicity, and disability, among others, are social factors that make some people more vulnerable than others. Actions to address such inequality and differential impacts imply, on the one hand, strengthening social protection and, on the other hand, empowering marginalised social groups through collective action. Empowering women in societies increases their capacity to improve food security under climate change, making substantial contributions to their own well-being, that of their families and that of their communities. Women's empowerment is crucial to creating effective synergies among adaptation, mitigation, and food security, including targeted agriculture programmes to change socially-constructed gender biases (Kerr et al. 2016). Empowerment through collective action and groups-based approaches in the near-term has the potential to equalise relationships on the local, national and global scales (Ringler et al. 2014).

5. Encourage healthy and sustainable diets

Transitioning to more healthy and sustainable diets and minimising food waste could reduce global mortality from 6% to 19% and food-related GHG emissions by 29%– 70% by 2050 (Springmann et al. 2016; Willett et al. 2019). According to the WHO, healthy diets are essential to end all forms of malnutrition and protect people from non-communicable diseases, including diabetes, heart disease, stroke and cancer. Currently, food consumption deviates from healthy diets with either too much (e.g., red meat and calories) or too little (e.g., fruits and vegetables) food and nutrition supply (Pradhan and Kropp 2020). Healthy diets have an appropriate calorie intake, according to gender, age and physical activity level. They are mainly composed of a diversity of plant-based foods, including coarse grains, pulses, fruits and vegetables, nuts, and seeds, with low amounts of animal source foods (Willett et al. 2019). The current diets of many high-income countries comprise a large share of animal source foods that are emission-intensive, with red meat consumption higher than the recommended value. Simultaneously, consumption of fresh fruits and vegetables is below the recommended value in most countries (Bodirsky et al. 2020).. Changes towards healthier diets have a mitigation potential of 0.7–8.0 GtCO2-eq year-1 by 2050, but social, cultural, environmental, and traditional factors need to be considered to achieve this potential at broad scales (Mbow et al. 2019; Rosenzweig et al. 2020). One critical problem is that, currently, healthy diets are unaffordable to broad sections of societies, even in high-income countries. Sustainable and healthy diets based on diversified intake are often linked to diversified production systems, highlighting the linkages between production and consumption (Chepkoech et al. 2020).

To encourage dietary transitions towards healthy and sustainable diets, a full range of policy instruments, from hard to soft measures, is needed (Willett et al. 2019). For example, unhealthy consumption of emission-intensive animal source foods can be disincentivised by applying taxes and charges, whereas adequate consumption of healthy foods such as fruits and vegetables can be incentivised by providing subsidies and raising consumer awareness. Importantly, policies promoting healthy diets need to pay due consideration to the differential roles of animal source foods in different parts of the world and the important role livestock can play in sustainable agriculture. For example, a recent study from Nepal, Bangladesh and Uganda showed a reduction in stunting in young children due to adequate intake of animal source foods (Zaharia et al. 2021).

6. Reduce GHG emissions from the food systems

Before promoting particular changes to the food systems, it is important to have an overview of where the most important potentials for reducing GHG emissions are. Agriculture is responsible for about 60% (or even 80%, if the indirect land use change is included) of total GHG emissions from the global food system (Mbow et al. 2019). One important message from a systematic meta-analysis of 38,700 farms and 1,600 food processors is the wide range of emissions – about a 50-fold difference between the best and worst practices (Poore and Nemecek 2018). This means that political and economic measures can achieve major reductions in GHG emissions from existing food systems by more broadly applying current best practices and without waiting for new technologies or behaviour changes.

Reducing GHG emissions requires integrated interventions both at the production and consumption sides. On the production side, all of those practices that increase soil organic matter contribute to both adaptation and mitigation, while also decreasing soil degradation and erosion. Globally, cropland soils have lost an estimated 37 GtC (136 Gt CO2) since the Neolithic revolution (Sanderman et al. 2017); recapturing that lost carbon through SLM would not only contribute to climate change mitigation, it would also increase the ecological resilience of agroecosystems and provide opportunities for income and employment in rural societies. A wide range of practices exist, e.g., conservation agriculture practices, lower GHG emissions from fertilisers, agroecology-based approaches, agroforestry or the integration of agriculture and livestock systems that have an estimated potential to sequester 3–6.5 GtCO2-eq/year (Arneth et al. 2021). In rangelands as well, extensive and mixed farming systems, through improved management practices, have the capacity to reduce emissions. Presently, there are between 200 and 500 million pastoralists in the world who act as stewards for 25% of the world's land (Niamir-Fuller 2016).

Meat and dairy consumption is often considered a major culprit of high GHG emissions from food systems, but the discussion often lacks nuance. It is clear that the overall emissions from consumption of animal protein (mainly meat and dairy products) must be reduced to achieve mitigation targets compatible with the Paris Agreement. However, in some regions of the world, an increased consumption of animal protein would be desirable from a health perspective. It is also clear that livestock plays an important role in sustainable food systems – in particular, extensive livestock can help to reduce the need for mineral fertilisers, and they can produce food from areas unsuitable for growing crops (notably, drylands, cold regions and mountainous regions). Finally, expansion of post-harvest processing, refrigeration, subsidy shifts and behavioural changes are needed to reduce food loss and waste and lower the consumption of animal products in those places where intake is too high. Incentives for emission reductions should also be given to agricultural producers by applying GHG emission taxes in agriculture, or including agriculture in existing emission trading schemes.

7. Support urban and peri-urban agriculture

Promoting urban and peri-urban agriculture (PUA) can help increase the resilience of local and regional food systems, create jobs, and, under certain conditions, help reduce GHG emissions from food transportation (Pradhan et al. 2020) and decrease uncertainties that may be associated with disruptions in food systems. PUA includes crop production, livestock rearing, aquaculture, agroforestry, beekeeping, and horticulture within and around urban areas (Clinton et al. 2018). Around 1 billion urban inhabitants (i.e., 30% of the global urban population) can be nourished by producing food through PUA (Kriewald et al. 2019). Simultaneously, PUA can support the regionalisation of food systems, reducing emissions from food transportation (Pradhan et al. 2020). Moreover, PUA is multi-functional and is practised to follow various purposes: it helps to improve food security, generate income, provide employment (Poulsen et al. 2015; Warren et al. 2015), especially for women and youths, and reconnect urban habitants with nature cycles. Subsequently, PUA not only has great potential to reduce poverty and improve nutrition, but also provides a series of ecosystem services such as reduced urban heat island effects (Li et al. 2014) or the fixation of atmospheric nitrogen and carbon when using the appropriate vegetation (Beniston and Lal 2012), thus contributing to climate change mitigation and adaptation. PUA also comprises elements of a circular economy, in which household organic waste can be used as livestock and poultry feed, rather than treated as waste (Ibrahim and Elariane 2018), subsequently reducing environmental pollution and GHG emissions. PUA contributes to increasing the resilience of urban poor households to food price shocks. Previous research on PUA showed that it was the main and only economic activity of poor urban households in many low-income countries. And even when PUA is not the main economic activity of poor urban households, it made a significant contribution to smoothening seasonal food consumption shocks among the urban poor (Poulsen et al. 2015).

8. Invest in research

There have been tremendous advances in better understanding of the interactions between climate change and food systems in recent decades (IPCC 2019; Wheeler and Von Braun 2013). These investments in research and science need to be expanded into the future, not least to ensure viable agricultural systems in the long term when climate change will expose current staple food crops to unprecedented stress. Areas for investment include agroecological approaches to food production, which have so far received far lower investment (HLPE 2019), the breeding of drought-resistant crop cultivars and cultivars with improved nitrogen use to avoid emission of N2O (Coskun et al. 2017), improved understanding of climate change impacts on both staple and non-staple foods, including impacts on the nutrition values of crops (Soares et al. 2019), particularly vegetables and fruits, and the subsequent implications for healthy diets and the full costs of said diets. Along with these environmental dimensions, increased investment in research on the social and economic impacts of climate change are needed, for example, in such areas as understanding the impacts of climate change and mitigation and adaptation options on vulnerable groups, research on participatory and transdisciplinary approaches to facilitating dialogue between indigenous and scientific knowledge, research on collective action, social innovation and mechanisms to increase food security.

9. Support perennial crop development and cultivation

About 87% of the world's harvested area is cultivated with annual crops, mainly grains (cereals, oilseeds, and pulses) that are germinated [?] and re-sown every year/ season (Monfreda et al. 2008). A shift to perennial grain crops would drastically cut GHG emissions from agriculture, and even turn cropping into a carbon sink, while significantly reducing erosion and nutrient leakage. Continued climate change is rendering our existing cultivars increasingly vulnerable to stress, and will ultimately make them unfit for many regions of the world (Altieri et al. 2015). New perennial cultivars have the potential to create cropping systems that are genuinely adapted for the climatic conditions towards the second half of this century. Perennial crops have the potential to drastically reduce the costs of farming by cutting the need for external inputs (seeds, fertilisers, pesticides, machinery, energy, and labour), and hence generate social and economic advantages, particularly or farmers and rural societies (Crews et al. 2018).

Development of new perennial grain crops through de novo domestication and wide hybridisation have advanced tremendously in the last decade, thanks to scientific and technological advancements such as genomic selection technology (Crain et al. 2021). The key benefits of perennial crops are that their widespread root systems can help sequester carbon in the soils for extended periods of time, water and minerals are used more efficiently by perennial plants, and weeds are more effectively managed (Crews et al. 2018; DeHaan et al. 2020). They are also exceptionally drought-resistant and can bring soil erosion and nutrient-leaching to a practical minimum (Crews et al. 2016). There are already commercial cultivars of perennial rice (Zhang et al. 2021) and successful semi-commercial experiments with perennial Kernza, a wheat relative (Lanker et al. 2020). The yields of Kernza are still low compared to conventional wheat, but continued breeding can result in a competitive perennial alternative to wheat in 20–25 years (Bajgain et al. 2020). A range of other crops is in the pipeline for domestication and breeding as perennial crops, such as barley, oilseeds and pulses. Equally important is the development of perennial polycultures, such as the intercropping of perennial grains and legumes, making the system more or less self-sufficient in nitrogen. These results are proof of concept that high yielding perennial cultivars can be developed within the timeframe of a few decades, but research on all aspects of such a "perennial revolution" is urgently needed.

#### 4 Conclusion

This chapter has two central messages. The bad news is that climate change is projected to affect food systems around the world significantly, often in ways that exacerbate existing frailties/weaknesses and inequalities among regions of the world and groups in society. The good news is that many practices, technologies, and wells of knowledge and social capital already exist to address climate change constructively, in terms of both mitigation and adaptation, as well as synergies between them and co-benefits with other important goals such as the conservation of biodiversity and other ecosystem services. Therefore, food systems can and should play a much bigger role in climate policies. In the short term, pro-poor policy changes and support systems can unleash a range of positive changes well beyond food systems without delay. In the long term, there is an urgent need to invest in research to ensure food security and ecosystem integrity for coming generations.

#### References

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# Delivering Climate Change Outcomes with Agroecology in Low- and Middle-Income Countries: Evidence and Actions Needed

Sieglinde Snapp, Yodit Kebede, Eva Wollenberg, Kyle M. Dittmer, Sarah Brickman, Cecelia Egler, and Sadie Shelton

# 1 Introduction

# 1.1 Does Agroecology Lead to Better Climate Change Outcomes?

Food systems need to meet food security, nutrition and environmental goals, especially in a world with growing demand and a changing climate. There is now broad consensus on the need to transform current food systems towards more sustainable models. Agroecology is increasingly seen as a framework for transforming food systems (HLPE 2019). A key question is: how far can agroecology meet the needs for climate change adaptation and mitigation in food systems, especially in low- and middle-income countries (LMICs) and at large scales?

Y. Kebede

French National Research Institute for Sustainable Development (IRD), Montpellier, France

E. Wollenberg · C. Egler · S. Shelton

K. M. Dittmer

S. Brickman University of Vermont, Burlington, VT, USA

S. Snapp (\*)

Department of Plant, Soil and Microbial Sciences, Center for Global Change and Earth Observations, Michigan State University, East Lansing, MI, USA e-mail<EMAIL_ADDRESS>
CGIAR Research Program of the CGIAR on Climate Change, Agriculture and Food Security (CCAFS), University of Vermont, Burlington, VT, USA

The Alliance of Bioversity International and International Center for Tropical Agriculture (CIAT), University of Vermont, Burlington, VT, USA

#### Box 1: Contemporary Approaches to Defining Agroecology

Gliessman (2018): "Agroecology is the integration of research, education, action and change that brings sustainability to all parts of the food system: ecological, economic, and social." It is transdisciplinary, participatory, actionoriented and "grounded in ecological thinking where a holistic, systems-level understanding of food system sustainability is required."

To address this question, we conducted a rapid, evidence-based review to assess the quality and strength of evidence regarding (i) the impact of agroecological approaches on climate change mitigation and adaptation in LMICs, and (ii) the programming approaches and conditions supporting large-scale transitions to agroecology.

Defining agroecology with precision is a challenge. The interpretation of agroecology in development has been divergent and contested, viewed variously as a set of practices, a social movement or the science of sustainable agriculture (Wezel et al. 2009, 2020). Moreover, differentiating agroecology from other forms of alternative agriculture for sustainability can be challenging due to vague or diverse definitions (Newton et al. 2020; Giller et al. 2021; Petersen and Snapp 2015). Box 1 provides examples of approaches to defining agroecology. Box 2 summarises major schemes for sustainable agriculture related to agroecology and climate change. All share the aim to reduce the negative impacts of agriculture, but approaches vary in their reliance on ecological processes, external inputs, whole system design, or emphasis on specific outcomes.

For this analysis, we considered approaches to be more agroecological to the extent that they made use of ecological processes, supported increasing autonomy from external inputs, or enabled whole system change, rather than focusing on changing single practices (Sinclair et al. 2019; Leippert et al. 2020). We focused on the biophysical science and practice aspects of agroecology to assess impacts on climate change adaptation and mitigation, and on drivers and enabling conditions of farmer behaviour for the analysis of scaling.

We identified agroecology practices and systems guided by the United Nations' Food and Agriculture Organisation (FAO) 10 Elements of Agroecology and Gliessman's (2016) transitions framework. To distinguish agricultural approaches aligned with agroecology, we considered field, farm and landscape-level approaches

#### Box 2: Schemes for Sustainable Agriculture Related to Agroecology and Climate Change (Adapted from Petersen and Snapp 2015)

that relied on enhanced ecological processes and services, compared to business-asusual agricultural development. Examples of the agroecology approaches reviewed included diversifying crop production through cover crops, green manure and hosts for beneficial insects; managing organic nutrient sources; biopesticides; croplivestock integration; agroforestry and organic farming.

The evidence for the review was based on the published scientific literature and semi-structured interviews with representatives from agricultural development programmes. For the literature review, we identified eighteen synthesis papers relevant to the impacts of agroecology on climate change adaptation and mitigation or to the scaling of agroecology, representing over 10,212 studies. Only four of the eighteen synthesis papers focused on LMICs, and only five others included at least 50% of the studies reviewed on LMICs, indicating the poor representation of LMICs for available syntheses in English. In addition, we conducted a systematic literature review of the primary evidence from LMICs for agroecological approaches and climate change outcomes related to nutrient management (15,674 articles) and pests and diseases (5,498 articles), resulting in a final selection of 138 papers representing about 20 agroecological practices. Of these papers, 71% represented data from Africa, 21% from Asia and 7% from Latin America, the latter suggesting the need for a similar review of the Spanish-language literature. One percent of the papers covered multiple regions. Seventy-eight percent of the papers addressed small farms, 9% addressed medium farms and 2% large farms. The full report is available online.

#### 2 What Does the Evidence Tell Us?

#### 2.1 Climate Change Adaptation

Substantial evidence1 exists in favour of climate change adaptation in LMICs that is associated with practices and systems aligned with agroecology, e.g., farm diversification,2 agroforestry and organic agriculture (Fig. 1). The agroecological approach with the strongest body of evidence for its impacts on climate change adaptation was farm diversification (strong evidence and high agreement). This included positive impacts of diversification on crop yield, pollination, pest control, nutrient cycling, water regulation and soil fertility. This is consistent with a recent global systematic review of similar practices within smallholder agriculture (Reich et al. 2021).

We found profound evidence concerning the impacts of agroforestry and organic agriculture on adaptation. Agroforestry had a positive impact on biodiversity, water regulation, soil carbon, nitrogen and soil fertility and the buffering of temperature extremes (Beillouin et al. 2019; Niether et al. 2020; Kuyah et al. 2019). Organic agriculture improved regulating (pest, water, nutrient) and supporting services (soils, biodiversity) (Smith et al. 2019).

Very little information was found about how agroecological approaches can improve resilience to extreme weather, which may be partly due to the challenges

1 The number of articles with primary evidence from LMICs for adaptation was 120 out of 138, based on indicators of productivity (100), diversity (58), water and nutrient regulation (41), soil health (52), and pollination services and pest regulation (59). The quality and relevance of the eight synthesis papers found were mostly medium to high.

Two synthesis papers were found for diversification (covering crop diversification, organic farming, intercropping, accessory crops, and agroforestry) with 98 and 99 high-quality metaanalysis articles, respectively.

2 "Agricultural diversification is the intentional addition of functional biodiversity to cropping [and livestock] systems at multiple spatial and/or temporal scales, and it aims at regenerating biotic interactions underpinning provisioning [regulating and supporting] ...ecosystem services. It embraces a variety of practices encompassing the management of crops, noncrop habitats, soil, and landscapes." Tamburini et al. 2020. Brackets added by brief authors.

of studying responses to erratic, rare events and the need for modelling and global analytical approaches that were outside the scope of the studies reviewed.

#### 2.2 Climate Change Mitigation

Evidence regarding impacts on mitigation is modest,3 except for enhanced carbon sequestration in soil and biomass (Fig. 1). The agroecological approach with the strongest body of evidence concerning its impacts on climate change mitigation was tropical agroforestry, which was associated with the sequestration of carbon in biomass and soil (medium evidence, high agreement) (Corbeels et al. 2019; Feliciano et al. 2018). Also, there is a moderate and growing body of evidence in favour of organic agriculture and associated gains in soil carbon, predominantly from temperate regions and high income countries (Gattinger et al. 2012; Smith et al. 2019).

For example, Gattinger et al. (2012) reported that soil carbon stocks were higher by 3.50 ± 1.08 Mg C ha-1 , and soil carbon sequestration rates were higher by 0.45 ± 0.21 Mg C for pairwise comparisons of organic compared to non-organic farming, based on datasets from 74 studies. Nitrous oxide mitigation evidence was modest for tropical agriculture overall, and data on methane mitigation was very limited. Evidence from the global North suggests that reliance on organic nutrient sources and organic farming would likely avoid increased nitrous oxide emissions

3 The number of articles with primary evidence from LMICs was limited: greenhouse gas emissions (6 articles), biomass carbon (4), and soil carbon (12), from a total of 138 articles. The quality and relevance of the six synthesis papers found were low to medium. Two synthesis papers were found for agroforestry, with 66 and 86 articles, respectively.

compared to the use of synthetic nitrogen fertiliser (medium evidence, medium agreement).

As the greenhouse gas (GHG) footprint of outcomes depends on where system boundaries are drawn, multi-scalar analysis is needed to capture flows of inputs and GHG impacts beyond the farm scale; for example, emissions associated with nutrient sources (e.g., industrial fertiliser production), land-use change or feed production (Connor 2018). The almost complete lack of data on tropical agriculture GHG emissions in agroecology exacerbates this research gap (Box 3).

#### Box 3: Evidence Used for the Assessment

To assess the evidence concerning the impact of agroecology on climate change outcomes, we compiled information from two sources and triangulated findings. We selected:

For the primary evidence papers, studies were only selected for analysis if they also indicated an aspect of scaling up agroecology. Scaling was defined broadly, and included adoption, farmer innovation, scaling mechanisms or enabling conditions, learning, market or policy incentives and participatory research methods. For these papers, we documented the presence of indicators as evidence in favour of adaptation and mitigation impacts. This did not include whether impacts were positive or negative relative to a control.

We also conducted semi-structured interviews with twelve organisations involved in agricultural development in LMICs, including several organisations implementing agroecology at large scales. These interviews aimed to explore the conditions and constraints for scaling up agroecology, as experience with agroecology is still novel, and thus this information was not widely available in the scientific literature.

Evidence was evaluated based on its quality and the level of agreement based on Intergovernmental Panel on Climate Change (IPCC) guidance for conducting syntheses (Mastrandrea et al. 2010). The evaluation was qualitative and relative. The strength of evidence was based on the degree of scientific robustness (statistical significance, sample size, use of systematic comparison, pairwise comparison, number of articles), relevance to agroecology, extent of geographic representativeness, relevance to LMICs, and overall quality or credibility of an article. The level of agreement was generally "high" if there were more than 100 articles with strong evidence, "medium" if there were 50–99 articles with strong evidence, or "low" if there were less than 50 articles with strong evidence, or, in the case of interviews, where the majority of the respondents agreed.

#### 2.3 Adaptive Capacity

Evidence suggests that agroecology provides more climate change adaptation and mitigation than conventional, higher-input agricultural development in LMICs by emphasising locally relevant solutions, participatory processes and the co-creation of knowledge as core values. Specifically, the co-creation and sharing of knowledge supported farmers' capacity to adapt practices more successfully to local conditions (strong evidence, medium agreement). In addition, multiple lines of evidence have shown that engaging with local knowledge through participatory and educational approaches effectively adapts technologies to local contexts, and thereby delivers improved climate change adaptation and mitigation.

Most interview respondents agreed that system approaches that prioritised local adaptation provided substantial benefits for climate change outcomes, often more than single practices. One respondent explained that "farmers are inherently systembased, and adjusting to their reality has made the work effective and created more opportunities."

#### 2.4 Yields

Evidence concerning trade-offs between yields and climate change adaptation and mitigation exists, but was not systematically reported. There were win-win outcomes for yields and climate change mitigation associated with crop diversity and organic nutrient management. There was some evidence for modest trade-offs between yields and climate outcomes for organic farming and agroforestry. Diversification was associated with increased or maintained yields (although variable) compared to conventional agriculture (high evidence, high agreement). Conversely, variable and sometimes modestly lower yields were reported for organic agriculture (Skinner et al. 2014). Agroforestry systems had variable impacts on yield depending on the main crop, agroecological zone and soil type. For example, cocoa agroforestry produced lower cocoa yields, but higher overall yields from other crops in the system and improved climate change mitigation and adaptation (Niether et al. 2020). A review of agroforestry in sub-Saharan Africa found that agroforestry significantly increased yields and soil carbon (Kuyah et al. 2019).

#### 2.5 Agroecological Transitions for Large-Scale Impacts

Evidence in the scientific literature relevant to scaling and enabling conditions of agroecology was poor, with only four relevant systematic reviews identified. The scientific robustness of the evidence was also mixed. Most reviews did not address agroecology at scale explicitly or compare the scaling conditions of agroecology and conventional agriculture. The literature review of primary evidence in favour of agroecology approaches to nutrient and pest management reported many of the same interventions and enabling conditions as those observed for scaling conventional agriculture interventions. These included the need for farmer capacity-building, use of markets, the necessity of involving government, the lack of cooperation between government offices of agriculture and offices of the environment, and poor implementation of policies (low evidence, medium agreement).