Reaping the Health Benefits of Tackling Environmental Change

Without action, rapid global environmental change in the 21^st century risks undermining, and even reversing, the gains in public health and human development made in the 20^th century.¹ The world is looking at a rise in average global temperature of 2.6 to 4.8 °C by 2100.² In the hyper-connected world in which we live, the direct and indirect impacts of such a radical shift would be profound.

The UN World Health Organization (WHO) estimates an additional 250,000 lives could be lost annually because of climate change by the 2040s.³ However, this estimate is likely a very conservative one given that it accounts for only well-understood risks. More likely, a suite of direct and indirect effects such as extreme weather, water scarcity, economic damages, and conflict will result in many more premature deaths.

In June 2015, the Lancet Commission on Health and Climate Change noted that “tackling climate change could be the greatest health opportunity of the 21^st century,”⁴ with climate risk mitigation and adaptation strategies likely to yield significant public health co-benefits. Indeed health, climate, and sustainable development frequently overlap and should reinforce one another. Even so, among the Sustainable Development Goals that were recently adopted by the United Nations General Assembly, only one of the 17 goals addresses health directly.⁵

The Lancet Commission carefully assessed the likely impacts of climate change and presented a set of strategies designed to curb and reverse the rise in greenhouse gas emissions. The strategies included shifting away from fossil fuels, promoting public and active transport, and moderating the consumption of animal products.⁶ Work is also being done to identify and quantify, in economic terms, the health co-benefits of these changes.⁷ Moreover, in a paper in the Lancet in 2015, Dora et al. suggested specific policy relevant indicators for the health benefits related to a post-2015 sustainable global development agenda across four key themes: cities, energy, water, and food.⁸ Here, I briefly touch on the health-sustainability linkages of each.

 

Focus on Activity for Healthy Cities

Over-reliance on fossil fuels and private motor vehicles has made many, if not most, modern cities unhealthy places to live and work. In order to improve the health of its residents, urban development now needs to be geared towards low-emission vehicles, greater access to public transport, and the promotion of cycling and walking. By clearing the air, quieting neighborhoods and streets, fostering physical activity, and making roads safer, such strategies reduce the risk of a host of health problems such as obesity, diabetes, cardiovascular disease, and some cancers.^9,10

Access to green space is strongly associated with public health dividends beyond simply facilitating sport. The global diabetes and obesity epidemics underscore the need to set aside plenty of open green space, and evidence suggests people are happier and healthier if parks, trees, community gardens, and playgrounds are plentiful and accessible.¹¹ But, planners in our most polluted cities may face a conundrum: how to promote outdoor activities without exposing people to greater risk of inhaling pollution?¹² Old age, obesity, cardiovascular disease, diabetes, and other conditions that benefit from exercise may be made worse by pollutants and heat stress from urban heat-islands—two things likely to be aggravated by global warming.¹³ Fortunately, a study published by Andersen et al. in June 2015 suggests that mortality is reduced by exercise even in moderately polluted areas.¹⁴ Nevertheless, planners need to be mindful in channeling active transport away from pollution and heat risks.

 

Cleaning Up Our Energy

According to the WHO, air pollution from the combustion of wood and fossil fuels today kills around seven million people annually, including around four million from contaminated air indoors.¹⁵ The combustion of coal and petroleum products releases particulates into the air that, when inhaled, raise the risk of cardiopulmonary diseases, including lung cancer.¹⁶ The use of coal has been linked to reduced lung development, a higher rate of heart attacks, and impaired intellectual development.¹⁷

Coal mining is associated with cardiovascular, kidney, and lung diseases such as pneumoconiosis (“black lung”) and comes with higher risks of accident and injury than renewable or nuclear energy.^18,19 Even setting aside climate change, the switch to clean, low- and zero-emissions energy would deliver enormous social benefits to society, including better air quality.

Switching to cleaner power sources can substantially reduce these health risks. European and North American studies show that economies decoupled from fossil fuels would see tens of thousands fewer lives ended prematurely each year.^20,21 Reducing the emissions of short-lived pollutants, principally black carbon (soot and other particulates from fossil fuels and wood), methane, and ground-level ozone will significantly improve population health outcomes.²²

Moreover, reduced disease burdens free up healthcare providers, families, and employees, reducing financial and time strains on health systems, communities, and other institutions.^23,24 One review of the economic value of the health co-benefits accrued through improved air quality in the United States suggests an average benefit corresponding to nearly USD$50 for every metric ton less emitted carbon dioxide.²⁵

 

Winning Health Benefits from Energy-Efficient Buildings

Efficiency improvements in heating, cooling, and lighting buildings can relieve occupants of a host of physical ailments, as well as reduce the incidence of allergies. For example, retrofitting housing in the United Kingdom to high-energy efficiency standards would not only shrink the UK’s carbon footprint, but also reduce residents’ exposure to indoor pollutants. This is particularly important in minimizing health risks to vulnerable populations, such as the elderly and children. However, it is crucial that the retrofitting is properly implemented, lest insufficient ventilation could result in substantial negative effects on health.²⁶

The International Energy Agency reports that when the health dividends are taken into account, the rate of return on retrofitting investments is as high as four to one.²⁷ Furthermore, the benefits could translate into productivity and other economic gains with one European building modernization study suggesting it is possible to generate an annual saving of up to USD$260 billion within the European Union.²⁸ Ratcheting up the energy efficiency of offices, homes, hospitals, commercial centers, etc. would therefore seem to be a high priority for the development agenda.

 

Water and Health in a Warming World

A rapidly changing climate is likely to compound problems with access to safe drinking water, sanitation, and hygiene—all recognized as cornerstones of public health, equity, and poverty alleviation.²⁹  According to the World Bank, currently 1.6 billion people live in parts of the world where water is extremely scarce.³⁰ By 2025, this number is expected to grow to 2.8 billion.

Rising average temperatures and shifting weather patterns are set to increase water scarcity in some areas, affecting food security and nutrition. In coastal areas, contamination of water resources by saltwater intrusion is likely to become a greater risk to health and food production as sea levels rise.

 

Towards a Climate-Sensitive Food System

While highly productive, the modern global food and farming system is nevertheless a significant contributor to environmental degradation, including climate change.³¹ Livestock production, in particular, is a major source of methane and nitrous oxide emissions through the use of fertilizers.³² While changes in production systems and supply chains could potentially make a significant dent in the sector’s emissions profile, changes in consumption will be important, too.^33,34 In affluent countries and those with fast-rising incomes, moderating the consumption of animal products (in particular, red meat), while raising fruit and vegetable consumption will help to curb rising rates of obesity, ischemic heart disease, and stroke incidences, as well as reduce the incidence of colorectal cancers.³⁵

Conversely, urban farming is linked to a range of health and community benefits, including provision of fresh healthy food, exercise, socializing, green space, reduced private motor vehicle use, less air pollution, and more.³⁶ That said, urban farming is not without potential drawbacks. Participants will need to take steps to minimize the risks from food that has been contaminated by pollution,³⁷ as well as address the potential risk of water contamination from excess nutrients.

 

Capturing the Health Dividends of Climate Action

Historically, experts and policymakers have been successful in establishing international strategies to tackle major challenges to human health. The rise of climate change as the overarching global problem of the 21^st century brings home just how interdependent the health, sustainable development, and environmental agendas are. Recognizing the health (and hence the economic) co-benefits of a variety of climate-related actions may well assist in getting those actions realized, with policymakers and investors looking for win-win outcomes. Needless to say, it behooves experts and practitioners in health, sustainable development, and climate change to work more closely together to make sure multiple benefits are recognized and, wherever possible, delivered.

 

Acknowledgements

This contribution is based on deliberations in the session ‘Elucidating sustainability-health interactions’ at the IARU Sustainability Science Congress 2014.

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