Lighting the Way: Toward a Sustainable Energy Future

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  • 1. The Sustainable Energy Challenge

    Humankind has faced daunting problems in every age, but today’s generation confronts a unique set of challenges. The environmental systems on which all life depends are being threatened locally, regionally, and at a planetary level by human actions. And even as great numbers of people enjoy unprecedented levels of material prosperity, a greater number remains mired in chronic poverty, without access to the most basic of modern services and amenities and with minimal opportunities for social (e.g., educational) and economic advancement. At the same time, instability and conflict in many parts of the world have created profound new security risks.

    Energy is critical to human development and connects in fundamental ways to all of these challenges. As a result, the transition to sustainable energy resources and systems provides an opportunity to address multiple environmental, economic, and development needs. From an environmental perspective, it is becoming increasingly clear that humanity’s current energy habits must change to reduce significant public health risks, avoid placing intolerable stresses on critical natural systems, and, in particular, to manage the substantial risks posed by global climate change. By spurring the development of alternatives to today’s conventional fuels, a sustainable energy transition could also help to address the energy security concerns that are again at the forefront of many nations’ domestic and foreign policy agendas, thereby reducing the likelihood that competition for finite and unevenly distributed oil and gas resources will fuel growing geopolitical tensions in the decades ahead. Finally, increased access to clean, affordable, high-quality fuels and electricity could generate multiple benefits for the world’s poor, easing the day-to-day struggle to secure basic means of survival; enhancing educational opportunities; reducing substantial pollution-related health risks; freeing up scarce capital and human resources; facilitating the delivery of essential services, including basic medical care; and mitigating local environmental degradation.

    Energy, in short, is central to the challenge of sustainability in all its dimensions: social, economic, and environmental. To this generation falls the task of charting a new course. Now and in the decades ahead no policy objective is more urgent than that of finding ways to produce and use energy that limit environmental degradation, preserve the integrity of underlying natural systems, and support rather than undermine progress toward a more stable, peaceful, equitable, and humane world. Many of the insights, knowledge, and tools needed to accomplish this transition already exist but more will almost certainly be needed. At bottom the decisive question comes down to this: Can we humans collectively grasp the magnitude of the problem and muster the leadership, endurance, and will to get the job done?


    • 1.1 The scope of the challenge

      Linkages between energy use and environmental quality have always been apparent, from the deforestation caused by fuelwood use even in early societies to the high levels of local air and water pollution that have commonly accompanied the early phases of industrialization. In recent decades, advances in scientific understanding and in monitoring and measurement capabilities have brought increased awareness of the more subtle environmental and human-health effects associated with energy production, conversion, and use. Fossil-fuel combustion is now known to be responsible for substantial emissions of air pollutants—including sulfur, nitrogen oxides, hydrocarbons, and soot—that play a major role in the formation of fine particulate matter, ground-level ozone, and acid rain; energy use is also a major contributor to the release of long-lived heavy metals, such as lead and mercury, and other hazardous materials into the environment. Energy-related air pollution (including poor indoor air quality from the use of solid fuels for cooking and heating) not only creates substantial public health risks, especially where emission controls are limited or nonexistent, it harms ecosystems, degrades materials and structures, and impairs agricultural productivity. In addition, the extraction, transport, and processing of primary energy sources such as coal, oil, and uranium are associated with a variety of damages or risks to land, water, and ecosystems while the wastes generated by some fuel cycles—notably nuclear electricity production—present additional disposal issues.

      Although the most obvious environmental impacts from energy production and use have always been local, significant impacts—including the long-range transport of certain pollutants in the atmosphere—are now known to occur on regional, continental, and even transcontinental scales. And at a global level, climate change is emerging as the most consequential and most difficult energy-environment linkage of all. The production and use of energy contributes more than any other human activity to the change in radiative forcing that is currently occurring in the atmosphere; in fact, fossil-fuel combustion alone currently accounts for well over half of total greenhouse gas emissions worldwide (after accounting for different gases’ carbon dioxide equivalent warming potential). Since the dawn of the industrial era, carbon dioxide levels in the atmosphere have increased by about 40 percent; going forward, trends in energy production, conversion, and use—more than any other factor within human control—are likely to determine how quickly those levels continue to rise, and how far. The precise implications of the current trajectory remain unknown, but there is less and less doubt that the risks are large and more and more evidence that human-induced global warming is already underway. In its recent, Fourth Assessment report, for example, the Intergovernmental Panel on Climate Change (IPCC) concluded that evidence for the warming of the Earth’s climate system was now ‘unequivocal’ and identified a number of potential adverse impacts associated with continued warming, including increased risks to coasts, ecosystems, fresh-water resources, and human health (IPCC, 2007a: p. 5; and 2007b) . In this context, making the transition to lower-carbon energy options is widely acknowledged as a central imperative in the effort to reduce climate-change risks.

      Another issue that will continue to dominate regional, national, and international energy policy debates over the next several decades is energy security. Defined as access to adequate supplies of energy when needed, in the form needed, and at affordable prices, energy security remains a central priority for all nations concerned with promoting healthy economic growth and maintaining internal as well as external stability. In the near to medium term, energy security concerns are almost certain to focus on oil and, to a lesser extent, on natural gas. As demand for these resources grows and as reserves of relatively cheap and readily accessible supplies decline in many parts of the world, the potential for supply disruptions, trade conflicts, and price shocks is likely to increase. Already, there is concern that the current environment of tight supplies and high and volatile prices is exacerbating trade imbalances, slowing global economic growth, and directly or indirectly complicating efforts to promote international peace and security. The problem is particularly acute for many developing countries that devote a large fraction of their foreign exchange earnings to oil imports, thus reducing the resources available to support investments needed for economic growth and social development.

      Box 1.1 Energy and the Millennium Development Goals

      Energy services can play a variety of direct and indirect roles in helping to achieve the Millennium Development Goals:

      To halve extreme poverty. Access to energy services facilitates economic development – micro-enterprise, livelihood activities beyond daylight hours, locally owned businesses, which will create employment – and assists in bridging the ‘digital divide. ’

      To reduce hunger and improve access to safe drinking water. Energy services can improve access to pumped drinking water and provide fuel for cooking the 95 percent of staple foods that need cooking before they can be eaten.

      To reduce child and maternal mortality; and to reduce diseases. Energy is a key component of a functioning health system, contributing, for example, to lighting operating theatres, refrigerating vaccines and other medicines, sterilizing equipment, and providing transport to health clinics.

      To achieve universal primary education, and to promote gender equality and empowerment of women. Energy services reduce the time spent by women and children (especially girls) on basic survival activities (gathering firewood, fetching water, cooking, etc.); lighting permits home study, increases security, and enables the use of educational media and communications in schools, including information and communication technologies.

      To ensure environmental sustainability. Improved energy efficiency and use of cleaner alternatives can help to achieve sustainable use of natural resources, as well as reduce emissions, which protects the local and global environment.

      Providing the energy services needed to sustain economic growth and, conversely, avoiding a situation where lack of access to such services constrains growth and development, remains a central policy objective for all nations, and an especially important challenge for developing nations given the substantial resource and capital investments that will be required. Within that larger context, a third important set of issues (in addition to the environmental and energy-security issues noted above) concerns the specific linkages between access to energy services, poverty alleviation, and human development. These linkages have recently drawn increased international attention and were a major focus of the 2002 World Summit for Sustainable Development in Johannesburg, which recognized the importance of expanded access to reliable and affordable energy services as a prerequisite for achieving the United Nation’s Millennium Development Goals. These linkages are discussed in detail in other reports (notably in the 2000 and 2004 World Energy Assessments undertaken by the United Nations Development Programme, United Nations Department of Economic and Social Affairs, and World Energy Council) and summarized in Box 1.1 (DFID, 2002).

      In brief, substantial inequalities in access to energy services now exist, not only between countries but between populations within the same country and even between households within the same town or village. In many developing countries, a small elite uses energy in much the same way as in the industrialized world, while most of the rest of the population relies on traditional, often poor-quality and highly polluting forms of energy. It is estimated that today roughly 2.4 billion people use charcoal, firewood, agricultural residues, or dung as their primary cooking fuel, while some 1.6 billion people worldwide live without electricity. Without access to affordable, basic labor-saving devices or adequate lighting and compelled to spend hours each day gathering fuel and water, vast numbers of people, especially women and girls, are deprived of economic and educational opportunities; in addition, millions are exposed to substantial health risks from indoor air pollution caused by traditional cooking fuels. The challenge of expanding access to energy services revolves primarily around issues of social equity and distribution—the fundamental problem is not one of inadequate global resources or of a lack of available technologies. Addressing the basic energy needs of the world’s poor is clearly central to the larger goal of sustainable development and must be a top priority for developing countries in the years ahead if some dent is to be made in reducing current inequities.

    • 1.2 The scale of the challenge

      The scale of the sustainable energy challenge is illustrated by a quick review of current consumption patterns and of the historic linkages between energy use, population, and economic growth. Human development to the end of the 18th century was marked by only modest rates of growth in population, per capita income, and energy use. As the Industrial Revolution gathered pace, this began to change. Over the last century alone, world population grew 3.8 times, from 1.6 to 6.1 billion people; worldwide average per capita income increased nine-fold (to around US$8,000 per person in 2000) ; annual primary energy use rose by a similar amount (ten-fold) to 430 exajoules (EJ); and fossil-fuel use alone increased twenty-fold.

      Throughout this period, energy use in many countries followed a common pattern. As societies began to modernize and shift from traditional forms of energy (such as wood, crop residues, and dung) to commercial forms of energy (liquid or gaseous fuels and electricity), their energy consumption per capita and per unit of economic output (gross domestic product) often grew rapidly. At a later stage of development, however, further growth in energy consumption typically slowed as the market for energy-using devices reached a point of saturation and as wealthier economies shifted away from more energy-intensive manufacturing and toward a greater role for the less energy-intensive service sector. The rate of growth in energy consumption also diminished in some industrialized countries as a result of concerted energy efficiency and conservation programs that were launched in the wake of sharp oil price increases in the early 1970s. Figure 1.1 shows declining energy intensity trends for OECD and non-OECD countries over the last 18 years.

      In recent years, the energy intensity of the world’s industrialized economies has been declining at an average annual rate of 1.1 percent per year, while the energy intensity of the non-OECD economies has been declining, on average, even faster (presumably because these economies start from a base of higher intensity and lower efficiency). Because the rate of decline in energy intensity has generally not been sufficient to offset GDP growth, total energy consumption has continued to grow in industrialized countries and is growing even faster in many developing countries.














      Figure 1.1 Energy intensity versus time, 1985-2005
      TPES is total primary energy supply; GDP is gross domestic product; PPP is purchasing power parity; toe is ton oil equivalent.
      Source: IEA, 2005

      Looking ahead, current projections suggest that the world’s population will grow by another 50 percent over the first half of this century (to approximately 9 billion by 2050), world income will roughly quadruple, and energy consumption will either double or triple, depending on the pace of future reductions in energy intensity. But projections are notoriously unreliable: patterns of development, structural economic shifts, population growth, and lifestyle choices will all have a profound impact on future trends. As discussed later in this report, even small changes in average year-to-year growth or in the rate of intensity reductions can produce very different energy and emissions outcomes over the course of several decades. Simply boosting the historical rate of decline in energy intensity from 1 percent per year to 2 percent per year on a global average basis, for example, would reduce energy demand in 2030 by 26 percent below the business-as-usual base case. Numerous engineering analyses suggest that intensity reductions of this magnitude could be achieved by concerted investments in energy efficiency over the next half century, but even seemingly modest changes in annual average rates of improvement can be difficult to sustain in practice, especially over long periods of time, and may require significant policy commitments.

      Confronted with the near certainty of continued growth in overall energy demand, even with concerted efforts to further improve efficiency, reduce energy intensity, and promote a more equitable distribution of resources, the scale of the sustainability challenge becomes more daunting still when one considers the current mix of resources used to meet human energy needs. Figure 1.2 shows total primary energy consumption for the OECD countries, developing countries, and transition economies (where the latter category chiefly includes Eastern European countries and the former Soviet Union), while Figures 1.3 and 1.4 show global primary energy consumption and global electricity production, broken down by fuel source.

      Non-renewable, carbon-emitting fossil fuels (coal, oil, and natural gas) account for approximately 80 percent of world primary energy consumption (Figure 1.3). Traditional biomass comprises the next largest share (10 percent) while nuclear, hydropower, and other renewable resources (including modern biomass, wind, and solar power), respectively, account for 6, 2, and 1 percent of the total. Figure 1.4 shows the mix of fuels used to generate electricity worldwide. Again, fossil fuels—primarily coal and











      Figure 1.2 Regional shares in world primary energy demand, including business-as-usual projections
      1 megaton oil equivalent(Mtoe) equals 41.9 petajoules.
      Source: IEA, 2006

      natural gas—dominate the resource mix, accounting for two-thirds of global electricity production. The nuclear and hydropower contributions are roughly equal at 16 percent of the total, while non-hydro renewables account for approximately 2 percent of global production.

      Most projections indicate that fossil fuels will continue to dominate the world’s energy mix for decades to come, with overall demand for these fuels and resulting carbon emissions rising accordingly.

      Table 1.1 shows a reference case projection for future energy demand developed by the International Energy Agency (IEA) based largely on business-as-usual assumptions. It must be emphasized that these projections










      Figure 1.3 World primary energy consumption by fuel, 2004
      Note: Total world primary energy consumption in 2004 was 11,204 megatons oil equivalent (or 448 exajoules).
      Source: IEA, 2006












      Figure 1.4 World electricity production by energy source, 2004
      Note: Total world electricity production in 2004 was 17,408 terawatt-hours (or 63 exajoules).
      Source: IEA, 2006.









      Note: 1 million ton oil equivalent equals 41.9 petajoules.
      Source: IEA 2006

      do not incorporate sustainability constraints (such as mitigation measures that might be necessary to manage climate risks)—as such, they are not intended to portray an inevitable future, much less a desirable one. Rather the usefulness of such projections lies in their ability to illuminate the consequences of allowing current trends to continue. For example, IEA’s reference case projections assume moderate growth in the use of renewable energy technologies. But since non-hydro renewables accounted for only 2 percent of world electricity production in 2004, fossil-fuel consumption and global carbon emissions continue to grow strongly by 2030. Indeed current forecasts suggest that a continuation of business-as-usual trends will produce a roughly 55 percent increase in carbon dioxide emissions over the next two decades.

      The implications of these projections, from a climate perspective alone, are sobering. If the trends projected by IEA for the next quarter century continue beyond 2030, the concentration of carbon dioxide in the atmosphere would be on track to reach 540–970 parts per million by 2100—anywhere from two to three times the pre-industrial concentration of 280 parts per million. By contrast, it is increasingly evident that the responsible mitigation of climate-change risks will require significant reductions in global greenhouse gas emissions by mid-century. As part of its Fourth Assessment Report, the IPCC has identified numerous adverse impacts on water supplies, ecosystems, agriculture, coasts, and public health that would be predicted (with ‘high’ or ‘very high’ confidence) to accompany continued warming. Moreover, the current IPCC assessment places the onset for several of these ‘key impacts’ at a global mean temperature change of 2–3 degrees Celsius (IPCC, 2007a: p 13). The IPCC further estimates that limiting global warming to a 2–3 degrees Celsius change will require stabilizing atmospheric concentrations of greenhouse gases somewhere in the range of 450–550 parts per million in carbon dioxide equivalent terms. Based on numerous IPCC-developed scenarios, achieving stabilization within this range could require absolute reductions in global emissions of as much as 30–85 percent compared to 2000 levels by mid-century (IPCC 2007b: p 23-5). Hence, a major goal of this report is to offer recommendations for shifting the world’s current energy trajectory through the accelerated deployment of more efficient technologies and sustainable, low-carbon energy sources.

      The consequences of current trends are also troubling, however, from an energy security perspective given the longer-term outlook for conventional oil supplies and given the energy expenditures and environmental impacts it implies, for countries struggling to meet basic social and economic-development needs. Recent forecasts suggest that a continuation of business-as-usual trends will produce a nearly 40 percent increase in world oil consumption by 2030, at a time when many experts predict that production of readily accessible, relatively cheap conventional oil will be rapidly approaching (or may have already reached) its peak. Moreover, IEA reference case projections, though they anticipate a substantial increase in energy consumption by developing countries, assume only modest progress over the next several decades toward reducing the large energy inequities that now characterize different parts of the world. This is perhaps not surprising insofar as the IEA projections are based on extrapolating past trends into the future; as such they do not account for the possibility that developing countries might follow a different trajectory than industrialized countries.


    • 1.3 The need for holistic approaches

      Beyond the scope and scale of the issues involved, the challenge of moving to sustainable energy systems is complicated by several additional factors. First is the fact that different policy objectives can be in tension (or even at odds), especially if approached in isolation. For example, efforts to improve energy security—if they led to a massive expansion of coal use without concurrent carbon sequestration—could significantly exacerbate climate risks. Similarly, emulating historic patterns of industrialization in developing countries could, in a 21st century context, create substantial environmental and energy-security liabilities. Achieving sustainability almost certainly requires a holistic approach in which development needs, social inequities, environmental limits, and energy security are addressed—even if they cannot always be resolved at the same time. Priorities should be set, by region and by country.

      Extending basic energy services to the billions of people who now lack access to electricity and clean cooking fuels, for example, could be accomplished in ways that would have only minimal impact on current levels of petroleum consumption and carbon dioxide emissions. Indeed, closer examination of the relationship between energy consumption and human well-being suggests that a more equitable distribution of access to energy services is entirely compatible with accelerated progress toward addressing energy-security and climate-change risks. Figure 1.6 compares per capita consumption of electricity in different countries in terms of their Human Development Index (HDI) — a composite measure of wellbeing that takes into account life expectancy, education, and GDP. The figure indicates that while a certain minimum level of electricity services is required to support human development, further consumption above that threshold is not necessarily linked to a higher HDI. Put another way, the figure indicates that a relatively high HDI (0.8 and above) has been achieved in countries where per capita levels of electricity consumption differ by as much as six-fold.

      Box 1.2 A focus on cooking in the developing world

      Clean, efficient stoves represent a major opportunity to extend energy and public health benefits to the billions of people who rely on traditional fuels for their household cooking needs.

      Household energy ladder. Over 2.4 billion people in developing countries still rely on solid biomass fuels for their cooking needs. This number increases to 3 billion when the use of various types of coal for cooking is included. In fact, the use of solid biomass fuels for cooking accounts for as much as 30–90 percent of primary energy consumption in some developing countries. As incomes rise, people generally upgrade from dirtier fuels (animal dung, crop residues, wood, charcoal, and coal) to liquid fuels (kerosene) to gaseous fuels (liquid petroleum gas, natural gas, and biogas) and finally, sometimes, to electricity. Conversely, when prices of liquid and gaseous petroleum-based fuels rise, people tend to downgrade again to solid fuels—at least for certain tasks. As households move up the energy ladder, the fuels and stoves they use tend to become cleaner, more efficient, and easier to control—but also more costly. Because solid-fuel combustion for cooking is often inefficient and poorly controlled, the cost per meal prepared is generally not a simple function of the cost of the fuel or stove technology used.

      Health and environmental impacts. The use of traditional fuels for cooking, often under poorly ventilated conditions, is a significant public health issue in many developing counties (Figure 1.5). Globally, exposure to smoke from household fuel combustion is estimated to be responsible for 1.6 million deaths annually, a death toll almost as high as that from malaria. Small children are disproportionately affected: they account for roughly 1 million of these deaths each year, usually from acute lower respiratory infections. Women are the next most affected group: they account for most of the remaining deaths, primarily from chronic pulmonary obstructive diseases (WHO, 2002).In addition to generating high levels of air pollution, extensive reliance on some traditional solid fuels—notably wood—can lead to unsustainable harvesting practices that in turn contribute to deforestation and generate other adverse impacts on local ecosystems. Moreover, some recent research suggests that biomass fuels used in cooking, even when they are harvested renewably (as crop residues and animal dung invariably are), can generate even higher overall greenhouse gas emissions than petroleum-fuel alternatives when emissions of non-carbon dioxide pollutants from incomplete combustion are accounted for (Smith and others, 2005).

      Saving energy and saving lives. Several strategies have been tried in various places around the world to reduce the adverse impacts of cooking with solid fuels. Typically they combine simultaneous efforts to address three areas of opportunity: reducing exposure, reducing emissions, and using cleaner fuels. Options for reducing exposure include increasing ventilation, providing stoves with hoods or chimneys, and changing behavior. Options for reducing emissions include improving combustion efficiency, improving heat transfer efficiency, or preferably both. Fuel upgrades can involve switching to briquettes or charcoal (which creates problems of its own) and biogas. Several countries have subsidized shifts to kerosene and liquid petroleum gas in an effort to help poor households ‘leapfrog’ up the energy ladder. Smith (2002) has shown that if even a billion people switched from solid biomass cooking fuels to liquid petroleum gas, this would increase global emissions of carbon dioxide from fossil fuels by less than 1 percent. Emissions of greenhouse gases on an equivalent basis might actually decrease. Subsidizing cleaner fuels, however, suffers from several important drawbacks: it is expensive (India’s expenditures for liquid petroleum gas subsidies exceed all its expenditures for education); it is inefficient (government subsidies often end up benefiting households that do not need them); and it can actually increase household spending on energy as subsidized fuels get diverted to other uses (for example, kerosene and liquid petroleum gasare often diverted to transportation uses). Some countries, notably China, have implemented very successful programs to replace traditional cookstoves with cleaner models. Elsewhere, as in India, such programs have had mixed results.

      In fact, U.S. citizens now consume electricity at a rate of roughly 14,000 kilowawtt hour per person per year while Europeans enjoy similar standards of living using, on average, only 7,000 kilowatt-hours per person per year.10 Improvements in energy efficiency represent one obvious opportunity to leverage multiple policy goals, but there are others — most notably, of course, changing the energy supply mix. To take an extreme example: if the resources used to meet energy needs were characterized by zero or near-zero greenhouse gas emissions, it would be possible to address climate-change risks without any reductions in consumption per se. In









      Figure 1.5 The energy ladder: Relative pollutant emissions per meal
      Note: Health-damaging pollutants per unit energy delivered: ratio of emissions to liquid petroleum gas (LPG). Using a log scale in Figure 1.5, the values are shown as grams per megajoule (g/MJ-d) delivered to the cooking pot.
      Source: Smith and others, 2005.
















      Figure 1.6 Relationship between human development index (HDI) and per capita electricity consumption, 2003 – 2004

      Note: World average HDI equals 0.741. World average per capita annual electricity consumption, at 2,490 kWh per person.year, translates to approximately 9 gigajoules (GJ)/person.year [10,000 kilowatts (kWh) = 36 GJ]

      Source: UNDP, 2006.

      reality, of course, some combination of demand reductions and changes in the supply mix will almost certainly be necessary to meet the sustainability challenges of the coming century. Meanwhile, deploying renewable and other advanced, decentralized energy technologies can improve environmental quality, reduce greenhouse gas emissions, stimulate local economic development, reduce outlays for fuel imports, and make it more feasible to extend energy services to poor households, especially in remote rural areas.

      Other factors complicate the sustainable energy challenge and further underscore the need for holistic policy approaches. A high degree of inertia characterizes not only the Earth atmosphere climate system but also much of the energy infrastructure that drives energy-usage patterns, as well as the social and political institutions that shape market and regulatory conditions. Because the residence times of carbon dioxide and other greenhouse gases in the atmosphere are on the order of decades to centuries, atmospheric concentrations of greenhouse gases cannot be reduced quickly, even with dramatic cuts in emissions. Similarly, the momentum behind current energy consumption and emissions trends is enormous: the average automobile lasts more than ten years; power plants and buildings can last 50 years or longer; and major roads and railways can remain in place for centuries. The growth that has recently occurred in worldwide wind and solar energy capacity is heartening, but there are very few examples of new energy forms penetrating the market by indefinitely sustaining growth rates of more than 20 percent per year. Fundamental changes in the world’s energy systems will take time, especially when one considers that new risks and obstacles almost always arise with the scaling up the deployment of new technologies, even if these risks and obstacles are hardly present when the technologies are first introduced. As a result, the process of transition is bound to be iterative and shaped by future developments and scientific advances that cannot yet be foreseen.

      Precisely because there are unlikely to be any ‘silver-bullet’ solutions to the world’s energy problems, it will be necessary to look beyond primary energy resources and production processes to the broader systems in which they are embedded. Improving the overall sustainability of these systems requires not only appropriate market signals—including prices that capture climate change impacts and other externalities associated with energy use—but may also demand higher levels of energy-related investment and new institutions. Most current estimates of energy sector investment go only so far as delivered energy, but investments in the devices and systems that use energy—including investments in buildings, cars or airplanes, boilers or air conditioners—will arguably matter as much, if not more.11 In all likelihood, much of the required investment can be taken up in normal capital replacement processes. With estimated world income in 2005 of US$60 trillion (based on purchasing power parity) and an average capital investment rate close to US$1 trillion per month, there should be substantial scope to accelerate the deployment of improved technologies.

    • 1.4 Summary points


      The multiple linkages between energy, the environment, economic and social development, and national security complicate the task of achieving sustainable outcomes on the one hand and create potentially promising synergies on the other.

      • The scope and scale of the sustainable energy challenge require innovative, systemic solutions as well as new investments in infrastructure and technology. Much of the infrastructure investment will need to happen anyway, but in most places the market and regulatory environment is not currently providing the feedback signals necessary to achieve a substantial shift in business-as-usual patterns. And by several measures, current worldwide investment in basic energy research and development is not adequate to the task at hand.12
      • Change will not come overnight. Essential elements of the energy infrastructure have expected life of the order of one to several decades. That means the energy landscape of 2025 may not look that different from the energy landscape of today. Nevertheless, it will be necessary within the next decade to initiate a transition such that by 2020 new policies are in place, consumer habits are changing, and new technologies are gaining substantial market share.
      • The problem of unequal access to modern energy services is fundamentally a problem of distribution, not of inadequate resources or environmental limits. It is possible to meet the needs of the 2 billion-plus people that today lack access to essential modern forms of energy (i.e., either electricity or clean cooking fuels) while only minimally changing the parameters of the task for everyone else. For example, it has been estimated that it would cost only US$50 billion to ensure that all households have access to liquid petroleum gas for cooking. Moreover, the resulting impact on global carbon dioxide emissions from fossil-fuel use would be on the order of 1or 2 percent (IEA, 2004; 2006). Reducing current inequities is a moral and social imperative and can be accomplished in ways that advance other policy objectives.
      • A substantial course correction cannot be accomplished in the timeframe needed to avoid significant environmental and energy-security risks if developing countries follow the historic energy trajectory of already industrialized countries. Rich countries, which have consumed more than their share of the world’s endowment of resources and of the absorptive capacity of the planet’s natural systems, have the ability and obligation to assist developing countries in ‘leapfrogging’ to cleaner and more efficient technologies.
      • To succeed, the quest for sustainable energy systems cannot be limited to finding petroleum alternatives for the transport sector and low-carbon means of generating electricity—it must also include a set of responsible and responsive demand-side solutions. Those solutions must address opportunities at the city level (with special focus on the use of energy and water), new energy-industrial models (incorporating modern understanding of industrial ecology), and advanced mobility systems. In addition, it will be necessary to focus on opportunities at the point of end-use (cars, appliances, buildings, etc.) to implement the widest range of energy-saving options available. Most of the institutions that frame energy policy today have a strong supply-side focus. The needs of the 21st century call for stronger demand-side institutions with greater country coverage than is, for example, provided by the IEA with its largely industrialized country membership.
      • Given the complexity of the task at hand and the existence of substantial unknowns, there is value in iterative approaches that allow for experimentation, trying out new technologies at a small scale and developing new options. Science and engineering have a vital role to play in this process and are indispensable tools for finding humane, safe, affordable, and environmentally responsible solutions. At the same time, today’s energy challenges present a unique opportunity for motivating and training a new generation of scientists and engineers.
      • The experience of the 20th century has demonstrated the power of markets for creating prosperous economies. Market forces alone however will not create solutions to shared-resource problems that fall under the ‘tragedy-of-the-commons’ paradigm (current examples include international fishing, water and air pollution, and global warming emissions). 13 Governments have a vital role to play in defining the incentives, price signals, regulations, and other conditions that will allow the market to deliver optimal results. Government support is also essential where markets would otherwise fail to make investments that are in society’s long-term best interest; examples include certain types of infrastructure, basic research and development, and high-risk, high-payoff technologies.


      DFID (Department for International Development). 2002. Energy for the Poor: Underpinning the Millennium Development GoalsLondon, United Kingdom.

      IEA (International Energy Agency). 2006. World Energy Outlook 2006. Paris.
      ——. 2005. Energy Balances of Non-OECD Countries 2002-2003. International Energy Agency, Paris.

      IPCC (Intergovernmental Panel on Climate Change). 2007a. Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth AssessmentReport of the Intergovernmental Panel on Climate Change. Cambridge University Press:Cambridge, United Kingdom and New York, NY, USA.

      ——. 2007b. Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [B. Metz, O. R. Davidson,P. R. Bosch, R. Dave, L. A. Meyer (eds)], Cambridge University Press: Cambridge, United Kingdom and New York, NY, USA.

      Smith, K.R. 2002. ‘In Praise of Petroleum.’ Science 19(5): 589-600.

      Smith, K.R., J. Rogers, and S. C. Cowlin. 2005. Household Fuels and Ill Health in DevelopingCountries: What Improvements Can Be Brought by LPG Gas? World LP Gas Association.Paris.

      UN (United Nations). 2005. Energy Services for the Millennium Development Goals. United Nations. New York, New York.

      UNDP (United Nations Development Program). 2006. Human Development Report 2006:Beyond Scarcity: Power, Poverty, and the Global Water Crisis. United Nations. New York, New York.

      UNDP, UNDESA, and WEC (United Nations Development Program, United Nations Department of Economic and Social Affairs, and World Energy Council). 2004. World EnergyAssessment. Overview, 2004 Update. United Nations. New York, New York.
      ——. 2000. World Energy Assessment: Energy and the Challenge of Sustainability. United Nations. New York, New York.

      USDOE (United States Department of Energy). 2006. International Energy Outlook 2006.Energy Information Administration. DOE/EIA-0484(2007). Washington, D.C.

      WHO (World Health Organization). 2002. World Health Report: Reducing Risks, Promoting Healthy Life. Geneva: World Health Organization.