Climate change, adaptation, and mortality

About

The World Health Organization has referred to climate change as “the single biggest health threat facing humanity.” Climate change is already impacting human health in a myriad of ways, including by leading to death and illness from increasingly frequent extreme weather events, such as heatwaves, storms and floods, the disruption of food systems, increases in food-, water- and vector-borne diseases, and mental health issues. Furthermore, climate change is undermining many of the social determinants for good health, such as livelihoods, equality and access to health care and social support structures. Climate-sensitive health risks are disproportionately felt by the most vulnerable and disadvantaged, including women, children, ethnic minorities, poor communities, migrants or displaced persons, older populations, and those with underlying health conditions.

Climate adaptation can help to ward off some of the most severe of these impacts, but adaptation capacity around the world is highly variable depending on socioeconomic, geopolitical, and environmental factors, among many others. In order to understand and better prepare for the human health consequences of climate change, we examine the connections between rising global temperatures, climate adaptation, and mortality in different contexts.

Approach

We completed a series of empirical studies using historical temperature data in different contexts around the world. We examine the regional evolution of the temperature-mortality relationship in the US for 1900 to 2004, observe whether hot weather shocks have unequal effects on mortality in rural versus urban populations in India for 1957 to 2000, and assess the complex relationship between extreme temperatures and mortality in 16 Asian countries - where more than 50% of the world's population resides - using a country-year panel on mortality rates and various measures of high temperatures for 1960 to 2015.

Key findings

Key takeaways from this series of investigations include:

• Continuing differences in the mortality consequences of hot days suggests that health motivated adaptation to climate change may be slow and costly around the world.
• In the US, "business as usual" climate predictions indicate that by the end of the century, climate change will lead to a 3% increase in the age-adjusted mortality rate and an 11% increase in annual residential energy consumption.
• High temperatures significantly increase annual mortality rates in Asia, and this increase is larger in countries with cooler climates where high temperatures are infrequent.
• Rural Indians are more acutely impacted by hot weather shocks, and our estimates imply that global warming in a “business as usual” scenario will lead to meaningful reductions in life expectancy in rural India by the 2015-2029 period and quite large declines by the end of the century.

Cumulatively, these findings highlight the need for concrete and rapid actions to help individuals and communities adapt to climate change.

Partners

This portfolio of research was completed in partnership with Dr. Michael Greenstone (University of Chicago), Dr. Joseph S. Shapiro (Yale), Dr. Robin Burgess (London School of Economics), Dr. Dave Donaldson (MIT), Dr. Karen Clay (Carnegie Mellon), and Dr. Alan Barreca (UCLA).