What are the expected health impacts of climate change? - Years Of Living Dangerously

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Joseph Romm, Ph.D. Chief Science Advisor

What are the expected health impacts of climate change?

Not only does extreme weather create a direct risk of harm and death, but rising global temperatures facilitate the spread of tropical diseases and increase the risk of death due to heat waves.

Human health will be negatively affected by climate change in a number of ways. Not only does extreme weather create a direct risk of harm and death, but rising global temperatures facilitate the spread of tropical diseases and increase the risk of death due to heat waves. Floods and droughts will also impact health by threatening sources of clean water and food.

Climate change is expected to have a broad range of direct and indirect impacts on health this century. These impacts range from increased mortality due to longer and stronger heat waves to health problems created by warming-driven urban smog to risks posed by malnutrition and lack of access to water. Warming will have some beneficial impacts, most notably a modest drop in cold-related illness and death. “But globally over the 21st century, the magnitude and severity of negative impacts are projected to increasingly outweigh positive impacts,” as the Intergovernmental Panel on Climate Change (IPCC) concluded in its comprehensive 2014 literature review on “Impacts, adaptation, and vulnerability.”

Most worrisome, if humanity stays near its current path of greenhouse gas emissions, the IPCC warns with “high confidence” that “the combination of high temperature and humidity in some areas for parts of the year is projected to compromise normal human activities, including growing food or working outdoors.” In that case, simply being outdoors in summer months will be unhealthy, and those areas of the world would increasingly be seen as uninhabitable.

Although one might think that the human health impacts of global warming would be among the most well studied areas of climate change, it is only in the last decade that the medical community and other health professionals have focused on this issue in depth. As recently as 2009, a landmark Health Commission created by The Lancet medical journal and the University College London (UCL) Institute for Global Health could warn that the “full impact” of climate change to human health “is not being grasped by the healthcare community or policymakers.” Lead author, Anthony Costello, a pediatrician and director of UCL Institute for Global Health, said that he himself “had not realised the full ramifications of climate change on health until 18 months ago.”

The report, “Managing the Health Effects of Climate Change,” concluded, “Climate change is the biggest global health threat of the 21st century.” It warned, “Climate change will have devastating consequences for human health from”:

– Changing patterns of diseases, and increased deaths due to heat waves

– An increase in the frequency and magnitude of extreme climate events (hurricanes, cyclones, storm surges) causing flooding and direct injury

– Increasing vulnerability for those living in urban slums and where shelter and human settlements are poor

– Large-scale population migration and the likelihood of civil unrest

A 2011 editorial in The British Medical Journal, led by the surgeon rear admiral of the UK’s Ministry of Defence, reviewed and synthesized recent reports on “Climate change, ill health, and conflict.” The editorial warned that “Climate change poses an immediate and grave threat, driving ill health and increasing the risk of conflict, such that each feeds on the other.” The threat posed by climate change to regional security “will limit access to food, safe water, power, sanitation, and health services and drive mass migration and competition for remaining resources.” There will be a rise in starvation, diarrhea, and infectious diseases as well as in the death rate of children and adults. The authors note that “in 2004, seven of the 10 countries with the highest mortality rates in children under 5 were conflict or immediate post-conflict societies.”