address food insecurity, inaccessibility of fresh foods, and unjust practices on multiple levels of the food system; and this discussion has been led by different actors, including food-insecure individuals, farm workers, educators and academics, policymakers, social movements, organizations, and marginalized people globally. the issue of food security is accompanied by the related movements of food justice and food sovereignty. these movements incorporate urban agriculture in how they address food-resources of a community. food sovereignty, in addition to promoting food access, also seeks to address the power dynamics and political economy of food; it accounts for the embedded power structures of the food system, ownership of production, and decision-making on multiple levels (i.e. growing, processing, and distribution): under this framework, representative decision-making and responsiveness to the community are core features. agroecological agroecology is a scientific framework, movement, and applied practice of agricultural management systems that seeks to achieve food sovereignty within food systems and prioritizes sustainability, farmer and consumer well-being, traditional knowledge revival, and democratized learning systems. transdisciplinarity and diversity of knowledge is a central theme to agroecology, so many urban agroecology initiatives address topics of social justice, gender empowerment, ecological sustainability, indigenous sovereignty, and participation in addition to promoting food access. under an agroecological framework, urban agriculture has the potential to play a role as a "public space, as an economic development strategy, and as a community-organizing tool" while alleviating food insecurity. impact a sprouting glass jar with mung beans in itin general, urban and peri urban agriculture (upa) contributes to food availability, particularly of fresh produce, provides employment and income and can contribute to the food security and nutrition of urban dwellers. economic urban and peri-urban agriculture (upa) expands the economic base of the city through production, processing, packaging, and marketing of consumable products. this results in an increase in entrepreneurial activities and the creation of jobs, as well as reducing food costs and improving quality. upa provides employment, income, and access to food for urban populations, which helps to relieve chronic and emergency food insecurity. chronic food insecurity refers to less affordable food and growing urban poverty, while emergency food insecurity relates to breakdowns in the chain of food distribution. upa plays an important role in making food more affordable and in providing emergency supplies of food. research into market values for produce grown in urban gardens has been attributed to a community garden plot a median yield value of between approximately $200 and $500 (us, adjusted for inflation). social the needs of urban landscaping can be combined with those of suburban livestock farmers. (kstovo, russia) urban agriculture can have a large impact on the social and emotional well-being of individuals. ua can have an overall positive impact on community health, which directly impacts individuals social and emotional well-being. urban gardens are often places that facilitate positive social interaction, which also contributes to overall social and emotional well-being. many gardens facilitate the improvement of social networks within the communities that they are located. for many neighborhoods, gardens provide a "symbolic focus", which leads to increased neighborhood pride. urban agriculture increases community participation through diagnostic workshops or different commissions in the area of vegetable gardens. activities which involve hundreds of people. when individuals come together around ua, physical activity levels are often increased. this can also raise serotonin levels akin to working out at a gym. there is the added element of walking/biking to the gardens, further increasing physical activity and the benefits of being outdoors. upa can be seen as a means of improving the livelihood of people living in and around cities. taking part in such practices is seen mostly as an informal activity, but in many cities where inadequate, unreliable, and irregular access to food is a recurring problem, urban agriculture has been a positive response to tackling food concerns. due to the food security that comes with ua, feelings of independence and empowerment often arise. the ability to produce and grow food for oneself has also been reported to improve levels of self-esteem or of self-efficacy. households and small communities take advantage of vacant land and contribute not only to their household food needs but also the needs of their resident city. the cfsc states that: community and residential gardening, as well as small-scale farming, save household food dollars. they promote nutrition and free cash for non-garden foods and other items. as an example, you can raise your own chickens on an urban farm and have fresh eggs for only $0.44 per dozen. this allows families to generate larger incomes selling to local grocers or to local outdoor markets while supplying their household with the proper nutrition of fresh and nutritional products. a vegetable garden in the square in front of the train station in ezhou, china some community urban farms can be quite efficient and help women find work, who in some cases are marginalized from finding employment in the formal economy. studies have shown that participation from women have a higher production rate, therefore producing the adequate amount for household consumption while supplying more for market sale. as most ua activities are conducted on vacant municipal land, there have been raising concerns about the allocation of land and property rights. the idrc and the fao have published the guidelines for municipal policymaking on urban agriculture, and are working with municipal governments to create successful policy measures that can be incorporated in urban planning. over a third of us households, roughly 42 million, participate in food gardening. there has also been an increase of 63% participation in farming by millennials from 2008-2013. us households participating in community gardening has also tripled from 1 to 3 million in that time frame. urban agriculture provides unique opportunities to bridge diverse communities together. in addition, it provides opportunities for health care providers to interact with their patients. thus, making each community garden a hub that is reflective of the community. energy efficiency edible oyster mushrooms growing on used coffee grounds the current industrial agriculture system is accountable for high energy costs for the transportation of foodstuffs. according to a study by rich pirog, associate director of the leopold center for sustainable agriculture at iowa state university, the average conventional produce item travels 1,500 miles (2,400 km), using, if shipped by tractor-trailer, 1 us gallon (3.8 l; 0.83 imp gal) of fossil fuel per 100 pounds (45 kg). the energy used to transport food is decreased when urban agriculture can provide cities with locally grown food. pirog found that traditional, non-local, food distribution system used 4 to 17 times more fuel and emitted 5 to 17 times more co2 than the local and regional transport. similarly, in a study by marc xuereb and region of waterloo public health, it was estimated that switching to locally-grown food could save transport-related emissions equivalent to nearly 50,000 metric tons of co2, or the equivalent of taking 16,191 cars off the road. a windowfarm, incorporating discarded plastic bottles into pots for hydroponic agriculture in urban windows carbon footprint as mentioned above, the energy-efficient nature of urban agriculture can reduce each city's carbon footprint by reducing the amount of transport that occurs to deliver goods to the consumer. such areas can act as carbon sinks offsetting some of the carbon accumulation that is innate to urban areas, where pavement and buildings outnumber plants. plants absorb atmospheric carbon dioxide (co2) and release breathable oxygen (o2) through photosynthesis. the process of carbon sequestration can be further improved by combining other agriculture techniques to increase removal from the atmosphere and prevent the release of co2 during harvest time. however, this process relies heavily on the types of plants selected and the methodology of farming. specifically, choosing plants that do not lose their leaves and remain green all year can increase the farm's ability to sequester carbon. reduction in ozone and particulate matter the reduction in ozone and other particulate matter can benefit human health. reducing these particulates and ozone gases could reduce mortality rates in urban areas along with increase the health of those living in cities. a 2011 article found that a rooftop containing 2000 m2 of uncut grass has the potential to remove up to 4000 kg of particulate matter and that one square meter of green roof is sufficient to offset the annual particulate matter emissions of a car. soil decontamination vacant urban lots are often victims to illegal dumping of hazardous chemicals and other wastes. they are also liable to accumulate standing water and "grey water", which can be dangerous to public health, especially left stagnant for long periods. the implementation of urban agriculture in these vacant lots can be a cost-effective method for removing these chemicals. in the process known as phytoremediation, plants and the associated microorganisms are selected for their chemical ability to degrade, absorb, convert to an inert form, and remove toxins from the soil. several chemicals can be targeted for removal, including heavy metals (e.g. mercury and lead), inorganic compounds (e.g. arsenic and uranium), and organic compounds (e.g. petroleum and chlorinated compounds like pbcs). phytoremeditation is both an environmentally-friendly, cost-effective and energy-efficient measure to reduce pollution. phytoremediation only costs about $5–$40 per ton of soil being decontaminated. implementation of this process also reduces the amount of soil that must be disposed of in a hazardous waste landfill. urban agriculture as a method to mediate chemical pollution can be effective in preventing the spread of these chemicals into the surrounding environment. other methods of remediation often disturb the soil and force the chemicals contained within it into the air or water. plants can be used as a method to remove chemicals and also to hold the soil and prevent erosion of contaminated soil decreasing the spread of pollutants and the hazard presented by these lots. one way of identifying soil contamination is through using already well-established plants as bioindicators of soil health. using well-studied plants is important because there has already been substantial bodies of work to test them in various conditions, so responses can be verified with certainty. such plants are also valuable because they are genetically identical as crops as opposed to natural variants of the same species. typically urban soil has had the topsoil stripped away and has led to soil with low aeration, porosity, and drainage. typical measures of soil health are microbial biomass and activity, enzymes, soil organic matter (som), total nitrogen, available nutrients, porosity, aggregate stability, and compaction. a new measurement is active carbon (ac), which is the most usable portion of the total organic carbon (toc) in the soil. this contributes greatly to the functionality of the soil food web. using common crops, which are generally well-studied, as bioindicators can be used to effectively test the quality of an urban farming plot before beginning planting. noise pollution large amounts of noise pollution not only lead to lower property values and high frustration, they can be damaging to human hearing and health. the study "noise exposure and public health" found that exposure to continual noise is a public health problem. examples of the detriment of continual noise on humans to include: "hearing impairment, hypertension and ischemic heart disease, annoyance, sleep disturbance, and decreased school performance." since most roofs or vacant lots consist of hard flat surfaces that reflect sound waves instead of absorbing them, adding plants that can absorb these waves has the potential to lead to a vast reduction in noise pollution. nutrition and quality of food daily intake of a variety of fruits and vegetables is linked to a decreased risk of chronic diseases including diabetes, heart disease, and cancer. urban agriculture is associated with increased consumption of fruits and vegetables which decreases risk for disease and can be a cost-effective way to provide citizens with quality, fresh produce in urban settings. produce from urban gardens can be perceived to be more flavorful and desirable than store bought produce which may also lead to a wider acceptance and higher intake. a flint, michigan study found that those participating in community gardens consumed fruits and vegetables 1.4 times more per day and were 3.5 times more likely to consume fruits or vegetables at least 5 times daily (p. 1). garden-based education can also yield nutritional benefits in children. an idaho study reported a positive association between school gardens and increased