Climate change: An opportunity for public health
Dr Maria Neira, WHO Director, Department of Public Health, Environmental and Social Determinants of Health (PHE)
Ahead of the 2014 UN Climate Summit, the health sector added its voice, loud and clear, to growing concerns around climate change and called for swift action to mitigate the human cost of a warming world.
At a global conference convened by WHO, some 400 delegates from all regions—including senior government officials, leading scientists and development partners—agreed unanimously that climate change poses “unacceptable risks” to global public health. From water shortages to changing patterns of disease, they spoke of present-day climate trends that are endangering the health of people in their own countries.
Impact of climate change
The impact of climate change on human health is, indeed, alarming.
Around the world, variations in climate are affecting, in profoundly adverse ways, the air we breathe, the food we eat and the water we drink. We are losing our capacity to sustain human life in good health.
Consider air pollution, the single greatest environmental health risk we face. In 2012 alone, exposure to indoor and outdoor pollutants killed more than 7 million people—one in eight deaths worldwide.
Under-nutrition already accounts for 3 million deaths each year in the world’s poorest regions. Rising temperatures and more variable rainfall patterns are expected to reduce crop yields, further compromising food security.
Floods are increasing in frequency and intensity, creating breeding grounds for disease-carrying insects. Mosquito-borne diseases, like malaria, are particularly sensitive to changes in heat and humidity. What will happen if rising temperatures accelerate the lifecycle of the malaria parasite?
According to WHO estimates, climate change will cause an additional 250 000 deaths per year between 2030 and 2050. Most will likely perish from malaria, diarrhoea, heat exposure and under-nutrition.
Children and the elderly will be among the most vulnerable. Areas with weak health infrastructure will be least able to cope. Developing countries will be hardest hit. The health gaps we have been trying hard to close may grow even wider.
Yet against this troubling backdrop, I am optimistic.
We know that climate change mitigation can yield substantial and immediate health benefits. It is time now to translate knowledge into action.
Let me offer specific recommendations, echoing some of the views expressed at the WHO conference:
First, health sector leaders must stand hand-in-hand with climate negotiators to confront climate change. For too long, policy discussions on climate and health have been too divided. We must position health as a central pillar in the climate debate rather than an ancillary agenda.
Second, health systems must become more resilient to climate change, particularly in developing countries. Hospitals and health centres should be reinforced to withstand powerful storms, heat waves and other extreme weather events. And we must ensure that water and sanitation services continue to function under flood and drought conditions.
Third, surveillance systems for climate-sensitive infectious diseases like malaria, dengue and cholera should be fortified. Countries should make better use of early-warning information to predict the onset, intensity and duration of epidemics. Such predictions allow health officials to pre-position medicines and vaccines, which can reduce the death toll.
Fourth, we should maximize the twin benefits of climate change mitigation and improved health. Reducing emissions of short-lived climate pollutants, like black carbon and methane, would slow the rate of global warming while also saving nearly 2.5 million lives per year. Sustainable, low-carbon urban transport—such as cycling or walking as alternatives to driving cars—could lead to dramatic reductions in heart disease, stroke, breast cancer and other ailments. And there are more health benefits to be reaped from more climate-friendly housing that protects occupants from heat waves, biodiverse food production that supports healthy diets, and renewable energy systems that improve access to electricity among hundreds of millions of people in developing countries—not to mention primary health clinics where women today often give birth in the dark.
Finally, the health sector should lower its own climate footprint. Hospitals, as they operate today, are energy-intensive enterprises that contribute substantially to climate change. To reduce their environmental impact, they can adopt basic measures such as reducing toxic waste, using safer chemicals and purchasing eco-friendly products.
Green policies can yield substantial cost savings. In Jaipur, India, a 350-bed health facility cut its total energy bill in half between 2005 and 2008 through solar-powered water heaters and lightning. In Brazil, one efficiency project reduced the demand for electricity of a group of 101 hospitals by 1035 kilowatts at a cost savings of 25%.
Since 2007, I have described climate change as the defining issue for public health in this century. Today, I would add that it is one of the greatest opportunities we face to improve human health.
At the UN Climate Summit and beyond, I will seek support from health sector leaders and development partners to push this issue to centre stage.