John M. Balbus, senior advisor for public health at the National Institute of Environmental Health Sciences and co-chair of the Institute of Medicine Global Environmental Health and Sustainable Development Innovation Collaborative, opened the second webinar by highlighting the overarching goal of the webinar series, which is to illuminate the critical linkages between sustainable development and environmental health. As a short-term target, the webinar series is intended to inform the current United Nations (UN) development agenda process, which is setting the stage for new Sustainable Development Goals (SDGs) and post-2015 development goals. The webinars are designed to provide scientific information about how health and sustainability are linked and also offer some new ideas on how to integrate environmental health into the targets and metrics of relevant SDGs. During the first webinar (see Chapter 2), the discussion focused on how the Millennium Development Goals (MDGs) created silos that were helpful in simplifying messaging but made intersectoral coordination difficult at the country level. Balbus emphasized that this webinar will look at ways to achieve multidisciplinary collaboration in international processes related to the post-2015 development agenda and SDGs, focusing on aspects that can create real synergies and benefits that can leverage financial investments and organizational support across different sectors.
Kristie L. Ebi, Ph.D., M.P.H.
In thinking about how to move the MDGs into alignment with sustainable development, Kristie L. Ebi explained that in addition to identifying specific tasks, there is a need to think broadly about how to promote health within sustainable development. Achieving the SDGs will require more than an engineering approach to the world, where a problem is recognized and a technological solution identified. Top-down approaches to improving public health have worked effectively for a wide range of issues, which is why the MDGs and other inspirational goals mainly take this kind of approach. However, these approaches are unlikely to be sufficient to address the challenges presented by global environmental change and the need to achieve sustainable development goals; working with other sectors to address current and future challenges will be critical. Further, it is important to recognize that one size may not fit all with respect to global goals and targets to further sustainable development.
“Wicked Problems” and Managing Climate Change
Ebi noted that “wicked problems,” a term used in social planning, applies to this discussion. A wicked problem is one that is difficult or impossible to solve because of incomplete, contradictory, and changing requirements that are often difficult to recognize (Wikipedia, 2013). In addition, because of complex interdependencies, efforts to solve one aspect of a wicked problem may reveal or create other problems (Australia Public Service Commission, 2007). Ebi noted that those who work in climate change may immediately recognize how this term applies: there are high levels of uncertainty about how specific changes will occur in the atmosphere and what those changes will ultimately mean at a particular location at a particular time. Because of the complexities, efforts to solve one part of a wicked problem can cause problems somewhere else. This can be seen with climate change efforts undertaken in one sector, such as agriculture or water, which can then affect human health. She explained that actions to address health or other risks of climate change cannot be taken independently from what is being done in other sectors because they could affect other problems. It
is the responsibility of public health professionals to ensure that problems are reduced or resolved.
MDGs and Climate Change
Focusing on the MDGs, Ebi described how climate change is likely to interact with MDG 1 and why achieving Target 1C—which seeks to halve, between 1990 and 2015, the proportion of people who suffer from hunger—may be a challenge (all MDGs are listed in Box 1-2 in Chapter 1). Figure 3-1 is a map of the world scaled in terms of underweight children, rather than geographic size. China, Ethiopia, Indonesia, and Nigeria have the largest populations of underweight children, and almost 50 percent of the children less than 5 years of age living in Bangladesh, India, and Nepal are underweight (UNDP, 2004). Figure 3-2 shows the progress achieved to reach MDG 1 up to 2007. The red areas depict where there is no progress or a deterioration of progress since 1990.
Ebi noted that many challenges have made it difficult to alleviate extreme hunger and poverty throughout the world. One contributor may be climate change. Research looking at how climate change may affect current crop production, particularly the cereal crops, shows that observed increased temperature changes from 1980 to 2008 are associated with decreased crop yields in many of the places having difficulty achieving Target 1C (Lobell and Field, 2007). Some regions have seen increased production; warmer temperatures have been beneficial to wheat yields in Australia, Canada, and the United States and to maize yields in India. Rice yields have decreased in a number of areas throughout the world, showing (in part) the negative impacts of increased ambient temperatures. Research projecting yields of cereal crops in a changing climate indicates that increasing local temperatures in the mid- to high-latitudes will have benefits in coming decades, but any increase in temperature in low-latitude areas will result in reduced yields (Easterling et al., 2007). This reduction in cereal grains will likely impact the places that currently have the biggest problems with undernourished children and exacerbate existing struggles to feed those children.
Projections of how often the highest recorded temperatures from 1985 to 2005 will occur in future time periods indicate that within the next few decades in Africa, there could be a 40 percent increase in the recurrence of these very high temperatures (Diffenbaugh and Giorgi, 2012). The current 1-in-20-year extreme temperature will occur about once every 5–10 years within a couple of decades in many places throughout the world. Linking this back to the temperature sensitivity of crops, in many parts of the tropics, cereal crops are already growing at the edge of their temperature tolerance. Efforts are under way to develop drought- and
FIGURE 3-1 World Mapper view of the world scaled in terms of underweight children.
SOURCE: Worldmapper, 2006. © Copyright 2006 Sasi Group (University of Sheffield) and Mark Newman (University of Michigan).
FIGURE 3-2 Progress toward MDG 1: Hunger target.
NOTE: The calculation of progress compares countrylevel information on the prevalence of undernourishment (2005–2007) with the rates that existed in 1990–1992 (the base period for the hunger target). The projection for reaching MDG 1 in 2015 assumes the trends between both periods continue. Developed countries are not considered.
SOURCE: FAO, 2010. Reprinted with permission from the Food and Agriculture Organization of the United Nations.
salt-resistant crops for these changing environmental conditions. The research to develop new cultivars can take many decades, she said, often with an equally long period of time needed to deploy new varieties to farmers.
Ebi stated that it is apparent that climate change is presenting a significant challenge to achieving the 1C Target. The MDG targets were developed thinking about how to solve the problem of undernourished children but not thinking broadly across all the systems, particularly those affected by climate change. The challenges of global environmental change are calling on public health professionals to take a much broader perspective on how systems are changing, what these changes are likely to mean for human health, how these kinds of changes can best be managed, and what options are available for improving the lives of children around the world.
Interactions Among Nutrition, Disease, and Climate Change
Ebi noted that the number of undernourished children is affected not only by how many cereal grains are available. It also is important to understand other causes of food insecurity. For example, undernutrition and malaria interact in that undernourished children are more likely to succumb to malaria, and children with malaria are more likely to be undernourished. Temperature and precipitation are among the important determinants of geographic shifts in the incidence of malaria because they affect mosquito and parasite life cycles and behaviors (Parham and Michael, 2010). Thus, she said, there is a strong system of interdependencies across undernutrition, malaria, and climate.
Additionally, Ebi explained, there is an interdependency between children who are malnourished, the incidence of diarrheal disease, and climate. Children with diarrheal disease have a reduced capacity to absorb nutrients, which means they become malnourished much more easily. A range of environmental factors is associated with diarrheal disease, including acute weather events such as flooding and heavy rainfall (Cann et al., 2012). As temperatures around the world have increased, heavy rain events have also increased because warmer air holds more water. This increases the number of flooding events, which are associated with more frequent outbreaks of waterborne diseases (including diarrheal disease), especially in low-income countries. As shown in Figure 3-3, climate change will greatly increase the risk of diarrheal disease based on temperature projections alone, with new regions becoming susceptible and currently susceptible regions seeing increased diarrheal disease rates (Kolstad and Johansson, 2011). This will challenge much of the excellent work of control programs completed to date that have focused on investments in sanitation and access to safe drinking water (WHO and UNICEF, 2009).
FIGURE 3-3 Projected changes in the risk of diarrheal disease with climate change.
NOTE: The values are shown with distinct colors according to the corresponding α-values (the empirically derived increases in the relative risk for each 1°C temperature increase). Blue corresponds to α = 0.03, turquoise to α = 0.06, yellow to α = 0.08, and orange to α = 0.11. In each plot, relative risk projections are shown for 2010–2039 (left), 2040–2069 (middle), and 2070–2099 (right).
SOURCE: Kolstad and Johansson, 2011. Reprinted with permission from Environmental Health Perspectives.
Ebi stated that the health risks of climate change arise from the interactions of three factors: (1) how climate change will alter weather patterns and what this means, for example, for ecosystems that support mosquito populations; (2) who or what is exposed to these changing weather patterns; and (3) the underlying vulnerability of the exposed populations. It often does not take an extreme event to cause an extreme impact, which was the case in Zimbabwe in 2008, where the largest cholera outbreak in Africa followed a heavy rain event (IPCC, 2012). The reason there was such a large outbreak was the very high susceptibility and poor public health among the population in Zimbabwe.
Principles for SDGs
Ebi emphasized that sustainable development can be considered a series of aspirational goals and a plan for how to achieve those goals. Usually, the plans are fairly straightforward and appear relatively easy, but the reality is often quite different. Surprises certainly will occur, particularly with climate change. Thresholds are likely to be crossed, although there is limited understanding of where and when they will be encountered, such as from interactions across food, water, and energy.
There may be setbacks from factors that are not taken into consideration. This calls for a flexible approach, not just to set goals for sustainable development, but also to create flexibility so the necessary information, tools, and policy instruments are available to address challenges as they arise.
Sir Andrew Haines, M.D.
Professor of Public Health and Primary Care,
London School of Hygiene and Tropical Medicine
Andrew Haines began by stating that his talk would focus on the importance of bringing together health and sustainable development using the example of strategies that both reduce greenhouse gas emissions and improve health. He noted that there is a new window of opportunity with the review of the MDGs and through the proposed SDGs to integrate health and broader development issues into new globally agreed-upon goals.
Health Cobenefits from Greenhouse Gas Reduction Strategies
Looking at the potential projections for carbon dioxide emissions over time, different scenarios are projected based on the Intergovernmental Panel on Climate Change (IPCC) report from 2007 (see Figure 3-4). The scenarios are shown in the colored lines on the graph, and the black dotted line shows what is actually being observed. It will likely be extremely difficult, Haines said, to keep within the 2°C that many climatologists perceive as the limit above which dangerous climate change occurs (for instance, increases in extreme events and wide-scale melting of ice caps). He emphasized that it is important to try to reduce greenhouse gas emission quite dramatically, and in order to achieve this, industrialized countries (like the United Kingdom and United States) need to cut their emissions by approximately 80 percent by 2050. This kind of challenge can be quite difficult politically, especially considering the cost, but there will be many benefits to decreasing carbon dioxide emissions in the future.
Haines explained that there are many cobenefits that arise from greenhouse gas reduction strategies, in addition to any benefits that occur from reducing climate change itself. The studies he and his colleagues have done look predominately at four sectors—housing, transport, food
FIGURE 3-4 Fossil fuel carbon dioxide emissions compared to the Intergovernmental Panel on Climate Change (IPCC) marker scenarios used for climate projections.
NOTES: RCP = Representative Concentration Pathway. The four RCP trajectories displayed in the figure come from the IPCC and represent a possible range of radiactive forcing values in the year 2100.
SOURCE: Peters et al., 2013. Reprinted with permission from Glen P. Peters and Corinne Le Quéré.
and agriculture, and electricity generation—in both low- and high-income settings. In each of those, there are strategies that can result in substantial reductions in greenhouse gas emissions and can also improve human health, in some cases in a relatively short time period. The studies consider different strategies in the four sectors and look at both greenhouse gas emissions and human health implications of the strategy in question compared with a business-as-usual strategy without specific policies to reduce greenhouse gas emissions. In the case of the United Kingdom, the Climate Change Act set a target for at least an 80 percent reduction of 1990 levels of greenhouse gas emissions by 2050. The emission reductions studied were intended to put the country on a trajectory to meet these emission reductions.
Household Energy Sector
The first sector Haines outlined was household energy. In a country like the United Kingdom, there are many inefficient houses that allow a lot of heat to escape through the walls and windows. A research team conducted a study that modeled the effects of improved household energy efficiency and ventilation control to achieve the desired greenhouse gas emission reductions (Wilkinson et al., 2009). He noted that in designing energy-efficient housing, it is important to consider ventilation control improvements in addition to insulation control to avoid increased indoor air pollution that may result from sealing the houses to reduce heat loss. The results of the study showed that approximately 90 deaths per million in the UK population could be avoided annually from energy-efficient upgrading, not including the benefits from addressing cold exposure. This would also result in saving roughly 41 million tons of carbon dioxide compared with 2010 baseline values (Wilkinson et al., 2009).
Haines noted that in low-income countries—where the MDGs are particularly relevant as they are currently configured—household air pollution is a major risk factor for acute respiratory infections in children and chronic obstructive pulmonary disease in women (Wilkinson et al., 2009). A study investigated the health and climate benefits of installing approximately 150 million improved-efficiency cookstoves in India over a 10-year period (Wilkinson et al., 2009). Although the numbers may seem ambitious, said Haines, China implemented a similar program in the 1980s in which 100 million improved cookstoves were installed over the same period. These cookstoves are relatively cheap to install and maintain, costing less than $50 per household every 5 years or so. In comparison to traditional open-fire or very inefficient cookstoves, a modern cookstove can greatly reduce household air pollution and greenhouse gas pollutants (such as black carbon and ozone precursors, including methane and carbon monoxide) by up to 1 billion tons of carbon dioxide equivalent over 10 years. An improved cookstove program of this magnitude could avert 2 million premature deaths, mainly in
women and children, over a decade (Wilkinson et al., 2009). Haines emphasized that this initiative directly impacts some of the MDGs, particularly those related to child mortality, and is particularly relevant for the countries where much of the poorest part of the population uses either open fires or inefficient cookstoves.
Urban Transport Sector
The second sector Haines outlined was urban transport. He noted that this sector is responsible for a large and growing amount of greenhouse gas emissions in many countries and impacts air pollution, road traffic injuries, and, very importantly, sedentary lifestyles. Obesity and diabetes rates are going up in many parts of the world, conditions that are partly related to sedentary lifestyles. Haines noted that one of the most important ways of increasing people’s physical activity is changing their habitual activities of daily living, particularly walking (or cycling) to school, work, shops, and so on. This type of activity is increasingly difficult in many urban environments. Haines mentioned a study that modeled the effect of different travel scenarios—investigating the differences in increased active travel (cycling and walking for short distances), low-carbon driving (more efficient cars), and business-as-usual policies (without specific policies to reduce greenhouse gas emissions)—in the cities of London and Delhi (Woodcock et al., 2009). This study looked at how introducing these new strategies could reduce greenhouse gas emissions and also impact human health. Active travel had the largest effect on health because sedentarism is such an important risk factor for seven major conditions (ischaemic heart disease, cerebrovascular disease, dementia, breast cancer, diabetes, depression, and bowel cancer). According to the scenario developed in the study, heart disease, stroke, dementia, and breast cancer could be reduced by up to 19 percent, 18 percent, 8 percent, and 13 percent, respectively, in London (Woodcock et al., 2009). Haines noted that there may be increased deaths and injuries due to road traffic crashes as more people cycle and walk (a 19 to 39 percent increase), even if road vehicle use is reduced; however, this drawback is vastly outweighed by all the benefits that would occur (Woodcock et al., 2009).
Haines discussed another study that assessed the possibility of averting health services expenditures as a result of these same transport strategies (Jarrett et al., 2012). National Health Service expenditures that could be averted by the increased active travel scenario in the United Kingdom were broken down by year and by health outcome. Over a 20-year period, the savings could total UK £17 billion (in 2010 prices) with additional savings accumulating after this period. Reducing the prevalence of diabetes had the largest impact because diabetes is so costly to the whole system (Jarrett et al., 2012). Haines noted that people often live with diabetes for many years and that over that time they accrue extensive costs to the health system (perhaps higher than the
study projections, which do not include the effects of reducing obesity to avoid double counting). By preventing some cases of diabetes, in addition to the potentially large savings for the health system, there will be potential improvements in labor productivity and other social benefits.
Food and Agriculture Sector
The third sector Haines outlined was food and agriculture. He noted that on a global level the food supply system is somewhat dysfunctional—roughly 1 billion people are suffering from hunger and at the same time obesity is growing around the world. Approximately 40 percent of all the grain harvested in the world is fed to animals (Smil, 2000), and livestock are major contributors to greenhouse gas emissions (particularly through methane from ruminants). Haines summarized results from a modeling study that investigated the health impact of reducing animal-source saturated fat by 30 percent and replacing it with polyunsaturated fat of plant origin. In a country similar to the United Kingdom and a city similar to São Paulo, Brazil,1 the burden of ischemic heart disease could be reduced by approximately 15 percent (this is equivalent to 2,850 and 2,180 disability-adjusted life years [DALYs] per million population in 1 year in the United Kingdom and São Paulo, respectively) (Friel et al., 2009). Haines noted that although it is important to improve the efficiency of energy use in the agriculture and food sector, this alone will not be sufficient to achieve the kind of targets needed to adequately reduce greenhouse gas emissions in order to stabilize the climate. In high-consumption countries like the United States and the United Kingdom, it is difficult to avoid the conclusion that reducing animal product consumption is needed and will provide additional health benefits from increasing fruit and vegetable consumption, as outlined in the study from Friel and colleagues.
Electricity Generation Sector
The fourth sector Haines outlined was electricity generation. He summarized a study that examined the health burden associated with equivalent carbon dioxide emissions from different sources of electricity generation (Markandya and Wilkinson, 2007). The results indicated that lignite, coal, and, to a somewhat lesser extent, oil produce a large amount of greenhouse gas emissions and also produce large health impacts from air pollution and accidents (see Figure 3-5). Nuclear energy produced the
1 The authors of the study chose the United Kingdom and São Paulo, Brazil, because both populations consume similar amounts of saturated fat; however, the United Kingdom is a high-income country and emits large quantities of greenhouse gases, whereas Brazil is an emerging economy with increasing greenhouse gas emissions. São Paulo is the largest city in Brazil, with a population of approximately 10.4 million in 2010 (Friel et al., 2009).
lowest health impacts according to this analysis, but is controversial for reasons such as waste and potential accidents. Haines stated that renewable energy sources (for example, solar or wind) are not shown in the figure, but they would clearly be at the bottom-left corner, below gas and close to nuclear, because many renewable technologies do not produce fine-particulate air pollution, which is the major risk factor from the combustion of coal and lignite. Haines highlighted that there is a range of new technologies coming to the market (including renewable technologies for clean energy) that offer great promise for reducing not only carbon dioxide emissions, but also fine-particulate air pollution and thus the health burden from outdoor air pollution. For example, one new technology involves placing solar-concentrating power panels on a vertical tower containing molten sodium, which then drives turbines to generate electricity. Haines suggested that the whole electricity supply of North America and Europe could be supplied by solar-concentrating power established in the North American desert, if appropriate investments were made.
FIGURE 3-5 Electricity generation and air pollution impacts from equivalent carbon dioxide (CO2) emissions.
NOTE: (a) deaths from air pollution and accidents and (b) cases of serious illness from air pollution.
SOURCE: Markandya and Wilkinson, 2007. Reprinted from The Lancet, © Copyright 2007, with permission from Elsevier.
Haines concluded by saying that there is a range of policies in at least these four sectors, and possibly in others, that can both help address public health priorities and promote sustainable development, particularly by mitigating climate change. Considering the impacts of these policies on both environmental goals and health goals simultaneously will make them much more attractive to policy makers than focusing on either in isolation. Haines stated that his presentation had outlined the potential for some metrics and goals, which would be the topic of the next presentation. For example, both sustainable development and public health targets could focus on household air pollution, active travel, and low-carbon generation of electricity. Haines emphasized that the health gains associated with these mitigation policies are in addition to the benefits from reducing climate change, and these health gains can likely help avert health service costs and also offset the cost of implementing low-carbon policies.
Christopher J. L. Murray, M.D., D.Phil.
Director, Institute for Health Metrics and Evaluation
University of Washington
Christopher J. L. Murray noted that he would present current evidence from the Global Burden of Disease Study 20102 to support some of the linkages between health and the environment highlighted by previous speakers. Then he would provide a brief outline of desirable attributes for proposed metrics for the post-2015 development agenda.
Global Burden of Disease Study 2010
The Global Burden of Disease Study 2010 is the latest version of a 20-year effort to systematize the evidence on the state of health around the world by disease, injury, and risk factor. In the current study, 291 diseases and injuries and 67 risk factors are evaluated at the country level over time. Murray noted that looking at change in health over time will likely be essential when thinking about some of the issues that will be
2 The Global Burden of Disease Study 2010 was published as seven separate articles in The Lancet in December 2012. Further information on the study and links to the articles can be found at http://www.thelancet.com/themed/global-burden-of-disease (accessed August 20, 2013).
important as the post-2015 development agenda is established (further detail on this process is provided in Chapter 2).
In looking at the health changes from 1990 through 2010, Murray said, three large drivers have been identified and studied in detail. The first is a demographic transition, namely, larger population size and an older population, which can have profound effects on the leading health problems. The second is a cause-of-death transition, where there is a marked shift away from the burden associated with communicable diseases (such as diarrhea and pneumonia) to the burden from noncommunicable diseases (NCDs) (such as cardiovascular disease and diabetes). The third is a disability transition, where there is a progressive shift to disabling conditions that do not necessarily cause death, but cause a substantial fraction of the burden of disease (such as mental health, substance abuse, and musculoskeletal disorders).
The impact of these transitions can be seen in changes in population measures over this 20-year period. Murray explained that measures of DALYs—a measure of healthy years of life lost that captures both premature mortality and illness—have shifted away from burden in children (although many children are still affected) toward burden in young and middle-aged adults. He noted that this shift is moving at a steady pace, so decade by decade the burden will likely progressively shift from children to adults. In addition, the disability transition has impacted the distribution of the burden of disease between years of life lost and years lost to disability. When looking at 21 regions around the world, years lost to disability in 1990 accounted for roughly 10 percent of the burden of disease in the least developed regions and almost 40 percent in the most developed regions (Murray et al., 2012). In 2010, years lost to disability substantially increased in comparison to years of life lost in all regions, and generally increased with the demographic and epidemiological transition—with the most profound shifts occurring in transitional regions (e.g., East Asia, tropical Latin America, the Middle East, and North Africa). The years lost to disability in regions with an advanced demographic and epidemiologic transition accounted for approximately 50 percent of the burden of disease (including Western Europe and high-income areas of the Asian Pacific and North America) (Murray et al., 2012).
Murray explained that shifts in the burden of disease have changed the ranking of the leading health problems from 1990 to 2010 (Murray et al., 2012). In Figure 3-6, the red boxes indicate communicable, maternal, neonatal, and nutritional disorders, which have become less prevalent between 1990 and 2010. For example, over the two decades, diarrhea has decreased by about 50 percent in terms of the burden of disease, despite increases in population over this time frame. The blue boxes indicate NCDs, which have increased between 1990 and 2100.
FIGURE 3-6 Ranks with 95 percent uncertainty intervals for the top 25 causes of global disability-adjusted life years in 1990 and 2010, and the percent change with 95 percent uncertainty intervals between 1990 and 2010.
SOURCE: Murray et al., 2012. Reprinted from The Lancet, © Copyright 2012, with permission from Elsevier.
The leading cause of global DALYs is now ischemic heart disease (up by about 29 percent), and, moving down the list, there is a progressive transition from communicable diseases to NCDs over the past two decades. However, HIV is up from much lower levels in 1990 and malaria has remained relatively constant from 1990 to 2010. The green boxes in the figure indicate injury. Murray highlighted that road injuries have seen about a 34 percent increase in the burden of disease over this period of time, and this may be important for transport agendas.
When looking at the global burden of disease attributable to different risk factors, high blood pressure is at the top of the list in terms of contributing to the percent of DALYs, followed by tobacco smoking and alcohol use (Lim et al., 2012). Murray noted that household air pollution from burning solid fuels is number 4 on the list, which is an important finding for thinking about connections to the environment. Ambient particulate matter pollution is number 9 on the list, accounting for 3 percent of the global burden of disease (Lim et al., 2012). Murray pointed out that both ambient air pollution and household air pollution are important risk factors because of the distribution and concentration found in dense high-population areas.
New Metrics for the Post-2015 Development Agenda
Murray outlined the five key attributes he believes are important in designing new metrics for the post-2015 development agenda. First, although there is an incredible array of indicators that can be utilized for development, health, the environment, and the intersection of these areas, it is important to have indicators for the post-2015 development agenda that are large and have true population impacts on environmental, health, or economic outcomes. Second, there is a tendency in the discussion of indicators to confuse the essential indicator with the measurement strategy, which sometimes leads people to propose distal proxies instead of measuring the thing they actually care about. Murray noted that it is necessary, particularly for a long-running agenda, to measure the true quantity of interest rather than some distant proxy. Third, some indicators are problematic if they are not clearly interpretable by a broad audience, and monotonicity is desirable. For example, sometimes people propose indicators where there is a somewhat U-shaped curve, where more could be bad or good; these indicators do not work very well because the outcomes are harder to communicate. Fourth, before the proposal of a new indicator, a practical measurement strategy should be developed as a route for good measurement; the strategy does not necessarily need to be operational immediately, because this can take several years to implement, but should be achievable in a reasonable time frame. Fifth, it is particularly important for the post-2015 development agenda to propose indicators that are relevant to a broad set of countries rather than a small group
(even if it is very important for that small group of countries) because of the political buy-in and consensus required to achieve improved outcomes globally.
Murray then proposed four indicators at the intersection between the environment and health that warrant attention for the post-2015 development agenda. He noted that this list is not terribly evidence-based but is based on the global burden of disease work and knowledge of what may be tractable indicators.
Murray noted that one of the things that is quite new in the Global Burden of Disease Study 2010 is the much larger magnitude of harm related to PM2.5, which is fine particulate matter smaller than 2.5 micrometers in size. In terms of the global burden of disease, ambient and household air pollution combined account for 6–7 percent of the total burden, which is quite a large percentage and much greater than, for example, the entire HIV epidemic (Lim et al., 2012). Murray emphasized that this is an area where the solutions are in the environmental arena and the outcomes can improve health. In addition, some of the strategies to reduce ambient and household PM2.5 may also reduce carbon emissions (as Haines mentioned in his presentation). It is feasible going forward, although somewhat complicated, he said, to achieve real measurements of human exposure to PM2.5, rather than proxy measures that are commonly used (such as cooking with biomass fuels). Murray stated that human exposure to PM2.5 would be a tremendously useful indicator on which various environmental policies would have an impact and one that would allow the harm to humans to be tracked rather easily.
Clean and Safe Transport
The second indicator at the intersection between health and the environment that Murray proposed is clean and safe transport. The combined burden of disease related to road traffic injuries, ambient air pollution from vehicle use, and lead from vehicle use is quite substantial in all regions of the world. Some of investments required to improve or achieve clean and safe transport come from the transport sector and from institutions investing in road infrastructure or mass transit systems. Changes in this sector can be carried out in a way that will realize both transport needs and clean and safe transport outcomes. In addition, changes can achieve both greenhouse gas reduction goals and health goals. Murray explained that a likely indictor could be the fraction of miles traveled using clean and safe transport, which is complicated to calculate but not impossible. And the measurement could go one step further to capture the extent to which some transport alternatives
encourage physical activity as well. Including all of this in one indicator may be complex but is certainly worth exploring.
Burden Due to Poor Diet
The third indicator that Murray proposed relates to the new science around diet components and how “healthy diets” relate to the way foods are produced, distributed, and sold. In the past, he said, the message on diet was about salt, sugar, and saturated fat. Interestingly, the latest systematic reviews do not show that saturated fat is harmful when compared to other sources of calories, in that if you substitute carbohydrates for saturated fat, there actually is no health gain. All components of diet combined account for more than 10 percent of the burden of disease (Lim et al., 2012). Murray noted that current evidence shows that certain components can promote healthy diets, such as fruits, nuts and seeds, whole grains, fiber, and vegetables (in that particular order). One could imagine both agricultural policy and tax and subsidy policies that could encourage the consumption of those resources and also result in environmental benefits if agricultural systems were developed in the right way. Lost years of healthy life from poor diet, an indicator tracking just burden, is now available at the country level and could be used to track many environmental or agricultural concerns over time.
Healthy Life Expectancy
The fourth indicator that Murray proposed sounds entirely like a health measure, but would entail more connections between the environment, social development, and health. He explained that healthy life expectancy—which summarizes mortality and nonfatal outcomes in a single measure—is a good health indicator for the post-2015 development agenda because it is an excellent summary of overall health, it is measurable, it is currently measured, it is available now for all countries from 1990 to 2010, and it reflects not just public health and medical care, but also many key determinants such as educational attainment, environmental concerns, and economic development. Healthy life expectancy would provide a way to frame health more broadly as an intersectoral concern, and in so doing could encourage greater consideration and focus on the overlapping areas between sectors.
At the same time, there is some resistance in the health sector to such a measure because it is perceived to not focus enough on medical care and public health and because other sectors have so much impact on healthy life expectancy. The Global Burden of Disease Study 2010 measures healthy life expectancy by country from 1990 to 2010. Of course, Murray said, there is a huge range seen globally, which reflects varying levels of both disease and mortality, but the good news is that healthy life expectancy has increased in most regions of the world in the
past decade. Healthy life expectancy is a measurable outcome that could provide a broad indicative strategy for a number of sectors and their connections to health.
A brief discussion among the speakers and participants followed the presentations. Their remarks are summarized in this section.
Economic Argument for Health Cobenefits
Bernard Goldstein, professor emeritus in the Department of Environmental and Occupational Health at the University of Pittsburgh, began the discussion by commenting on the economic benefits from averting disease. He noted that many economists argue that basically there is no real economic benefit from preventing cardiovascular disease due to ambient or household air particulates because a person is going to experience disease and death from something else, which will lead to the same end-of-year life cost on average. Goldstein asked Haines to comment on this and explain how he would argue that the economic cobenefits from health are real. Haines noted that the argument depends on the disease being averted and the assumptions that are included. Haines stated that you need to consider not just impacts on the health system, but also impacts on things like labor productivity in order to look more broadly at the impacts of health cobenefits on the economy. For some cobenefit strategies, the economic benefits can more or less offset the costs, but for other strategies this is not true. For example, in the food and agricultural sector, if you were to move human consumption away from animal products and toward greater intake of plant-based products, it would have negative economic impacts at least in the short term. Haines noted that this raises the question of to what extent policy decisions should focus on gross domestic product (GDP) growth, highlighting that in his opinion GDP is a flawed indicator of the economic success of different human societies. Haines stated that there is a need to look more broadly at other metrics of human development, whether well-being or healthy life expectancy, as Murray suggested. Haines explained that it is somewhat dangerous to consider only GDP growth as an indicator of societal success, but noted that it may take time for the public to catch up with this debate and consider other ways of measuring the success of societies in order to develop an alternative that is politically acceptable.
Particulate Exposure Indicator
Balbus commented on the presentation from Murray and asked whether the PM2.5 indicator that was proposed could indeed become part of the post-2015 development agenda or the SDGs. Balbus noted that the MDGs tend to include indicators that relate to just one goal, and wondered if the next round of global goals will allow for a crosscutting indicator like PM2.5, which has its own intrinsic value as a health indicator but is also connected to everything from agriculture to transport to energy production. Murray explained that during the process leading to the creation of the MDGs, an indicator of household air pollution, namely, the fraction of households using solid fuels for cooking, was included in the preliminary environmental goals. However, he said, that indicator was never really adopted by a group and was dropped in a later revision of the indicators. Murray noted that a crosscutting indicator for the next round of global goals needs to appeal to enough groups to champion it throughout the process. Developing a crosscutting indicator may present a challenge, because it may not be the number-one indicator for any given sector, but because it does apply to many sectors, one would hope there is a way to use those connections to gain support this time around.
Water and Sanitation Indicator
Ana Treasure, environmental health advisor at the Pan American Health Organization representation in Jamaica, directed a question to Murray about his thoughts on possible indicators for water and sanitation given the updated information from the Global Burden of Disease Study 2010. Murray noted that water and sanitation remains an important agenda item, particularly for parts of West Africa and other places where waterborne diseases remain prevalent. However, because of the powerful trends in the data for diarrheal disease, it is likely that diarrhea will decrease another 30 or 40 percent over the next 10 years. From a health point of view, he said, one would likely not argue for indicators around water and sanitation for the post-2015 development agenda because the trend is so favorable with respect to diarrheal disease. It may be counter to many people’s natural instincts, but it seems that in looking forward, water and sanitation will not meet the first principle he outlined in choosing indicators for the post-2015 development agenda, which was to focus on the really large issues. Murray stated that one may argue for water and sanitation indicators for nonhealth reasons, such as household well-being, access to clean water, and use of household time, but framing in this way does not create significant links to health. Murray pointed out that it is important to continue to monitor water and sanitation programs appropriately, but that is a little different than choosing new indicators to replace the MDGs.
Ebi provided a differing opinion, noting that while there are positive trends in diarrheal disease, there are counter trends coming with changes in temperature and precipitation that will likely affect how people use water in ways that tend to increase diarrheal disease. One of the questions becomes whether you want indicators that are only backward-looking, measuring how well something was done, or whether you also want indicators that are more forward-looking. She explained that these forward-looking indicators may provide projections of how water availability is going to change in a number of regions, which would allow for the establishment of preventive programs, and progress in these programs could then be measured with the backward-looking indicators. Ebi noted that it is important to think about how these interactions with environmental variables could affect health and to use these environmental variables to design health programs and monitor progress.
Healthy Life Expectancy Indicator
Balbus asked Murray to elaborate on the healthy life expectancy indicator and provide further information on the metrics available at the country and subnational levels. Murray noted that there are two fundamental strategies for measuring healthy life expectancy, in which a mortality measurement and life table is combined with a measure of the prevalence of ill health and disability. One strategy is to conduct a household survey, using one of the health-related quality of life or health status instruments that are available. A second strategy, which was utilized in the Global Burden of Disease Study 2010, is to construct the prevalence of disabling conditions and ill health from prevalence numbers by disease and sequela, using rich data from around the world, and to construct that prevalence country by country. Murray stated that the latter strategy is more analytically complicated, but said that in his view it is more robust, because the strategy is grounded in the same case definitions by disease and sequela and is intrinsically more comparable than household surveys. Murray noted that this strategy could be done at the subnational level, but it would require sophisticated data systems within the country.
Clean and Safe Transport Indicator
Referencing the clean and safe transport indicator that was presented, Balbus asked Murray to comment on the robustness and comparability of this indicator across countries, since it appears to be dependent on household surveys. Murray pointed out that household surveys are likely being conducted with relatively high frequency in every country around the world. For instance, the latest library at the World Bank shows that most countries average more than one nationally represented household
survey per year and often more than one per year if you look across sectors. However, the issue of good comparability and measurement management remains. Because the clean and safe transport indicator is a new idea, it would require mapping out a new measurement strategy that combines the cleanliness and safety with consumer choice or behavior data. Murray noted that this could be managed by enhancing data about personal behaviors and transport use with measures of how clean and safe those choices are at the local level.
Murray explained that an indicator on diet is a little more straightforward because the measure could be constructed from data on household consumption, which come from food balance sheets and reported diet consumption data that are collected in nutritional surveys. Overall, Murray said, mapping this indicator would require planning, thinking, and persuasive argument that it is worth carrying out and important to measure.
Australian Public Service Commission. 2007. Tackling wicked problems: A public policy perspective. http://www.apsc.gov.au/publications-and-media/archive/publications-archive/tackling-wicked-problems (accessed August 20, 2013).
Cann, K. F., D. R. Thomas, R. L. Salmon, A. P. Wyn-Jones, and D. Kay. 2013. Extreme water-related weather events and waterborne disease. Epidemiology and Infection 141(4):671–686.
Diffenbaugh, N. S., and F. Giorgi. 2012. Climate change hotspots in the CMIP5 global climate model ensemble. Climatic Change 114(3-4):813–822.
Easterling, W. E., P. K. Aggarwal, P. Batima, K. M. Brander, L. Erda, S. M. Howden, A. Kirilenko, J. Morton, J. F. Soussana, J. Schmidhuber, and F. N. Tubiello. 2007. Food, fibre and forest products. In Climate change 2007: Impacts, adaptation and vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Edited by M. L. Parry, O. F. Canziani, J. P. Palutikof, P. J. van der Linden, and C. E. Hanson. Cambridge, UK: Cambridge University Press.
FAO (Food and Agriculture Organization of the United Nations). 2010. Progress towards Millennium Development Goal 1: Hunger target. http://www.fao.org/fileadmin/templates/es/Hunger_Portal/MDG_Progress_Map.pdf (accessed September 3, 2013).
Friel, S., A. D. Dangour, T. Garnett, K. Lock, Z. Chalabi, I. Roberts, A. Butler, C. D. Butler, J. Waage, A. J. McMichael, and A. Haines. 2009. Public health benefits of strategies to reduce greenhouse-gas emissions: Food and agriculture. The Lancet 374(9706):2016–2025.
IPCC (Intergovernmental Panel on Climate Change). 2012. Managing the risks of extreme events and disasters to advance climate change adaptation. A special report of Working Groups I and II of the Intergovernmental Panel on Climate Change. New York: Cambridge University Press.
Jarrett, J., J. Woodcock, U. K. Griffiths, Z. Chalabi, P. Edwards, I. Roberts, and A. Haines. 2012. Effect of increasing active travel in urban England and Wales on costs to the National Health Service. The Lancet 379(9832):2198–2205.
Kolstad, E. W., and K. A Johansson. 2011. Uncertainties associated with quantifying climate change impacts on human health: A case study for diarrhea. Environmental Health Perspectives 119(3):299–305.
Le Quéré, C., M. R. Raupach, J. G. Canadell, G. Marland, L. Bopp, P. Ciais, T. J. Conway, S. C. Doney, R. A. Feely, P. Foster, P. Friedlingstein, K. Gurney, R. A. Houghton, J. I. House, C. Huntingford, P. E. Levy, M. R. Lomas, J. Majkut, N. Metzl, J. P. Ometto, G. P. Peters, I. C. Prentice, J. T. Randerson, S. W. Running, J. L. Sarmiento, U. Schuster, S. Sitch, T. Takahashi, N. Viovy, G. R. van der Werf, and F. I. Woodward. 2009. Trends in the sources and sinks of carbon dioxide. Nature Geoscience 2(12):831–836.
Lim, S. S., T. Vos, A. D. Flaxman, G. Danaei, K. Shibuya, H. Adair-Rohani, M. A. AlMazroa, M. Amann, H. R. Anderson, K. G. Andrews, M. Aryee, C. Atkinson, L. J. Bacchus, A. N. Bahalim, K. Balakrishnan, J. Balmes, S. Barker-Collo, A. Baxter, M. L. Bell, J. D. Blore, F. Blyth, C. Bonner, G. Borges, R. Bourne, M. Boussinesq, M. Brauer, P. Brooks, N. G. Bruce, B. Brunekreef, C. Bryan-Hancock, C. Bucello, R. Buchbinder, F. Bull, R. T. Burnett, T. E. Byers, B. Calabria, J. Carapetis, E. Carnahan, Z. Chafe, F. Charlson, H. Chen, J. S. Chen, A. T. A. Cheng, J. C. Child, A. Cohen, K. E. Colson, B. C. Cowie, S. Darby, S. Darling, A. Davis, L. Degenhardt, F. Dentener, D. C. Des Jarlais, K. Devries, M. Dherani, E. L. Ding, E. R. Dorsey, T. Driscoll, K. Edmond, S. E. Ali, R. E. Engell, P. J. Erwin, S. Fahimi, G. Falder, F. Farzadfar, A. Ferrari, M. M. Finucane, S. Flaxman, F. G. R. Fowkes, G. Freedman, M. K. Freeman, E. Gakidou, S. Ghosh, E. Giovannucci, G. Gmel, K. Graham, R. Grainger, B. Grant, D. Gunnell, H. R. Gutierrez, W. Hall, H. W. Hoek, A. Hogan, H. D. Hosgood, D. Hoy, H. Hu, B. J. Hubbell, S. J. Hutchings, S. E. Ibeanusi, G. L. Jacklyn, R. Jasrasaria, J. B. Jonas, H. Kan, J. A. Kanis, N. Kassebaum, N. Kawakami, Y. H. Khang, S. Khatibzadeh, J. P. Khoo, C. Kok, F. Laden, R. Lalloo, Q. Lan, T. Lathlean, J. L. Leasher, J. Leigh, Y. Li, J. K. Lin, S. E. Lipshultz, S. London, R. Lozano, Y. Lu, J. Mak, R. Malekzadeh, L. Mallinger, W. Marcenes, L. March, R. Marks, R. Martin, P. McGale, J. McGrath, S. Mehta, Z. A. Memish, G. A. Mensah, T. R. Merriman, R. Micha, C. Michaud, V. Mishra, K. M. Hanafiah, A. A. Mokdad, L. Morawska, D. Mozaffarian, T. Murphy, M. Naghavi, B. Neal, P. K. Nelson, J. M. Nolla, R. Norman, C. Olives, S. B. Omer, J. Orchard, R. Osborne, B. Ostro, A. Page, K. D. Pandey, C. D. H. Parry, E. Passmore, J. Patra, N. Pearce, P. M. Pelizzari, M. Petzold, M. R. Phillips, D. Pope, C. A. Pope, J. Powles, M. Rao, H. Razavi, E. A. Rehfuess, J. T. Rehm, B. Ritz, F. P. Rivara, T. Roberts, C. Robinson, J. A. Rodriguez-Portales, I. Romieu, R. Room, L. C. Rosenfeld, A. Roy, L. Rushton, J. A. Salomon, U. Sampson, L. Sanchez-Riera, E. Sanman, A. Sapkota, S. Seedat,
P. Shi, K. Shield, R. Shivakoti, G. M. Singh, D. A. Sleet, E. Smith, K. R. Smith, N. J. C. Stapelberg, K. Steenland, H. Stöckl, L. J. Stovner, K. Straif, L. Straney, G. D. Thurston, J. H. Tran, R. Van Dingenen, A. van Donkelaar, J. L. Veerman, L. Vijayakumar, R. Weintraub, M. M. Weissman, R. A. White, H. Whiteford, S. T. Wiersma, J. D. Wilkinson, H. C. Williams, W. Williams, N. Wilson, A. D. Woolf, P. Yip, J. M. Zielinski, A. D. Lopez, C. J. L. Murray, and M. Ezzati. 2012. A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990–2010: A systematic analysis for the Global Burden of Disease Study 2010. The Lancet 380(9859):2224–2260.
Lobell, D. B., and C. B. Field. 2007. Global scale climate—crop yield relationships and the impacts of recent warming. Environmental Research Letters 2(1): doi:10.1088/1748-9326/2/1/014002.
Markandya, A., and P. Wilkinson. 2007. Electricity generation and health. The Lancet 370(9591):979–990.
Murray, C. J. L., T. Vos, R. Lozano, M. Naghavi, A. D. Flaxman, C. Michaud, M. Ezzati, K. Shibuya, J. A. Salomon, S. Abdalla, V. Aboyans, J. Abraham, I. Ackerman, R. Aggarwal, S. Y. Ahn, M. K. Ali, M. A. AlMazroa, M. Alvarado, H. R. Anderson, L. M. Anderson, K. G. Andrews, C. Atkinson, L. M. Baddour, A. N. Bahalim, S. Barker-Collo, L. H. Barrero, D. H. Bartels, M. G. Basáñez, A. Baxter, M. L. Bell, E. J. Benjamin, D. Bennett, E. Bernabé, K. Bhalla, B. Bhandari, B. Bikbov, A. B. Abdulhak, G. Birbeck, J. A. Black, H. Blencowe, J. D. Blore, F. Blyth, I. Bolliger, A. Bonaventure, S. Boufous, R. Bourne, M. Boussinesq, T. Braithwaite, C. Brayne, L. Bridgett, S. Brooker, P. Brooks, T. S. Brugha, C. Bryan-Hancock, C. Bucello, R. Buchbinder, G. Buckle, C. M. Budke, M. Burch, P. Burney, R. Burstein, B. Calabria, B. Campbell, C. E. Canter, H. Carabin, J. Carapetis, L. Carmona, C. Cella, F. Charlson, H. Chen, A. T.-A. Cheng, D. Chou, S. S. Chugh, L. E. Coffeng, S. D. Colan, S. Colquhoun, K. E. Colson, J. Condon, M. D. Connor, L. T. Cooper, M. Corriere, M. Cortinovis, K. C. de Vaccaro, W. Couser, B. C. Cowie, M. H. Criqui, M. Cross, K. C. Dabhadkar, M. Dahiya, N. Dahodwala, J. Damsere-Derry, G. Danaei, A. Davis, D. D. Leo, L. Degenhardt, R. Dellavalle, A. Delossantos, J. Denenberg, S. Derrett, D. C. Des Jarlais, S. D. Dharmaratne, M. Dherani, C. Diaz-Torne, H. Dolk, E. R. Dorsey, T. Driscoll, H. Duber, B. Ebel, K. Edmond, A. Elbaz, S. E. Ali, H. Erskine, P. J. Erwin, P. Espindola, S. E. Ewoigbokhan, F. Farzadfar, V. Feigin, D. T. Felson, A. Ferrari, C. P. Ferri, E. M. Fèvre, M. M. Finucane, S. Flaxman, L. Flood, K. Foreman, M. H. Forouzanfar, F. G. R. Fowkes, M. Fransen, M. K. Freeman, B. J. Gabbe, S. E. Gabriel, E. Gakidou, H. A. Ganatra, B. Garcia, F. Gaspari, R. F. Gillum, G. Gmel, D. Gonzalez-Medina, R. Gosselin, R. Grainger, B. Grant, J. Groeger, F. Guillemin, D. Gunnell, R. Gupta, J. Haagsma, H. Hagan, Y. A. Halasa, W. Hall, D. Haring, J. M. Haro, J. E. Harrison, R. Havmoeller, R. J. Hay, H. Higashi, C. Hill, B. Hoen, H. Hoffman, P. J. Hotez, D. Hoy, J. J. Huang, S. E. Ibeanusi, K. H. Jacobsen, S. L. James, D. Jarvis, R. Jasrasaria, S. Jayaraman, N. Johns, J. B. Jonas, G. Karthikeyan, N. Kassebaum, N. Kawakami, A. Keren, J.-P. Khoo, C. H. King, L. M. Knowlton, O. Kobusingye, A. Koranteng, R. Krishnamurthi, F. Laden, R. Lalloo, L. L. Laslett, T. Lathlean, J. L. Leasher, Y. Y. Lee, J. Leigh, D. Levinson, S. S. Lim, E. Limb, J. K. Lin, M. Lipnick, S. E.
Lipshultz, W. Liu, M. Loane, S. L. Ohno, R. Lyons, J. Mabweijano, M. F. MacIntyre, R. Malekzadeh, L. Mallinger, S. Manivannan, W. Marcenes, L. March, D. J. Margolis, G. B. Marks, R. Marks, A. Matsumori, R. Matzopoulos, B. M. Mayosi, J. H. McAnulty, M. M. McDermott, N. McGill, J. McGrath, M. E. Medina-Mora, M. Meltzer, Z. A. Memish, G. A. Mensah, T. R. Merriman, A. C. Meyer, V. Miglioli, M. Miller, T. R. Miller, P. B. Mitchell, C. Mock, A. O. Mocumbi, T. E. Moffitt, A. A. Mokdad, L. Monasta, M. Montico, M. Moradi-Lakeh, A. Moran, L. Morawska, R. Mori, M. E. Murdoch, M. K. Mwaniki, K. Naidoo, M. N. Nair, L. Naldi, K. M. V. Narayan, P. K. Nelson, R. G. Nelson, M. C. Nevitt, C. R. Newton, S. Nolte, P. Norman, R. Norman, M. O’Donnell, S. O’Hanlon, C. Olives, S. B. Omer, K. Ortblad, R. Osborne, D. Ozgediz, A. Page, B. Pahari, J. D. Pandian, A. P. Rivero, S. B. Patten, N. Pearce, R. P. Padilla, F. Perez-Ruiz, N. Perico, K. Pesudovs, D. Phillips, M. R. Phillips, K. Pierce, S. Pion, G. V. Polanczyk, S. Polinder, C. A. Pope, S. Popova, E. Porrini, F. Pourmalek, M. Prince, R. L. Pullan, K. D. Ramaiah, D. Ranganathan, H. Razavi, M. Regan, J. T. Rehm, D. B. Rein, G. Remuzzi, K. Richardson, F. P. Rivara, T. Roberts, C. Robinson, F. R. De Leòn, L. Ronfani, R. Room, L. C. Rosenfeld, L. Rushton, R. L. Sacco, S. Saha, U. Sampson, L. Sanchez-Riera, E. Sanman, D. C. Schwebel, J. G. Scott, M. Segui-Gomez, S. Shahraz, D. S. Shepard, H. Shin, R. Shivakoti, D. Singh, G. M. Singh, J. A. Singh, J. Singleton, D. A. Sleet, K. Sliwa, E. Smith, J. L. Smith, N. J. C. Stapelberg, A. Steer, T. Steiner, W. A. Stolk, L. J. Stovner, C. Sudfeld, S. Syed, G. Tamburlini, M. Tavakkoli, H. R. Taylor, J. A. Taylor, W. J. Taylor, B. Thomas, W. M. Thomson, G. D. Thurston, I. M. Tleyjeh, M. Tonelli, J. A. Towbin, T. Truelsen, M. K. Tsilimbaris, C. Ubeda, E. A. Undurraga, M. J. van der Werf, J. van Os, M. S. Vavilala, N. Venketasubramanian, M. Wang, W. Wang, K. Watt, D. J. Weatherall, M. A. Weinstock, R. Weintraub, M. G. Weisskopf, M. M. Weissman, R. A. White, H. Whiteford, N. Wiebe, S. T. Wiersma, J. D. Wilkinson, H. C. Williams, S. R. M. Williams, E. Witt, F. Wolfe, A. D. Woolf, S. Wulf, P.-H. Yeh, A. K. M. Zaidi, Z.-J. Zheng, D. Zonies, and A. D. Lopez. 2012. Disability-adjusted life years (DALYs) for 291 diseases and injuries in 21 regions, 1990–2010: A systematic analysis for the Global Burden of Disease Study 2010. The Lancet 380(9859):2197–2223.
Parham, P. E., and E. Michael. 2010. Modeling the effects of weather and climate change on malaria transmission. Environmental Health Perspectives 118(5):620–626.
Peters, G. P., R. M. Andrew, T. Boden, J. G. Canadell, P. Ciais, C. Le Quéré, G. Marland, M. R. Raupach, and C. Wilson. 2013 The challenge to keep global warming below 2°C. Nature Climate Change 3:4–6.
Raupach, M. R., G. Marland, P. Ciais, C. Le Quéré, J. G. Canadell, G. Klepper, and C. B. Field. 2007. Global and regional drivers of accelerating CO2 emissions. Proceedings of the National Academy of Sciences of the United States of America 104(24):10288–10293.
Smil, V. 2000. Feeding the world: A challenge for the twenty-first century. Cambridge, MA: The MIT Press.
UNDP (United Nations Development Programme). 2004. Human Development Report 2004: Cultural liberty in today’s world. New York: United Nations Development Programme.
WHO (World Health Organization) and UNICEF (United Nations Children’s Fund). 2009. Diarrhoea: Why children are still dying and what can be done. Geneva, Switzerland: World Health Organization.
Wikipedia. 2013. Wicked problem. http://en.wikipedia.org/wiki/Wicked_problem (accessed August 20, 2013).
Wilkinson, P., K. R. Smith, M. Davies, H. Adair, B. G. Armstrong, M. Barrett, N. Bruce, A. Haines, I. Hamilton, T. Oreszczyn, I. Ridley, C. Tonne, and Z. Chalabi. 2009. Public health benefits of strategies to reduce greenhouse-gas emissions: Household energy. The Lancet 374(9705):5–11.
Woodcock, J., P. Edwards, C. Tonne, B. G. Armstrong, O. Ashiru, D. Banister, S. Beevers, Z. Chalabi, Z. Chowdhury, A. Cohen, O. H. Franco, A. Haines, R. Hickman, G. Lindsay, I. Mittal, D. Mohan, G. Tiwari, A. Woodward, and I. Roberts. 2009. Public health benefits of strategies to reduce greenhousegas emissions: Urban land transport. The Lancet 374(9705):1930–1943.
Worldmapper. 2006. Underweight children. Map No. 182. http://www.worldmapper.org/display.php?selected=182# (accessed August 20, 2013).
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