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Understanding the health effects of climate change

Extreme weather and natural disasters are an increasing threat


Daniel Knecht, MD, MBA Vice President & Chief Clinical Innovation Officer, CVS Caremark


Environmental Determinants of Health

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Researchers first started recording shifts in the Earth’s temperature in the late 1800s, starting with an average temperature of 56.7°F (13.7°C).1  Since then, the average temperature has continued to climb. In fact, an average yearly temperature of 58.8°F (14.9°C) in 2020 made it the warmest year to date.2

Scientists with the National Aeronautics and Space Administration note that an increase in greenhouse gas emissions directly contributes to this global warming, and that we will continue to see these temperature increases for years to come.3

The effects of climate change, from extreme heat and drought to increased rainfall, pose a threat to communities and infrastructures around the globe. These phenomena have a significant impact on human health as well.


How the environment impacts human health

Just as we recognize the impact of social determinants such as poverty and housing on health, the impact of environmental determinants is equally significant. These determinants include air quality, clean water, and sanitation, as well as weather effects such as heatwaves and wildfires.

The negative toll of the climate crisis is becoming more dire. Around 24 percent of all estimated global deaths are linked to the environment, and researchers estimate that climate change is expected to cause approximately 250,000 additional deaths per year between 2030 and 2050.4


24% of all estimated global deaths are linked to the environment5

Climate change inaction could cost the U.S. economy $14.5T by 20706

More than 1 billion work hours were lost to extreme heat in just 8 years7


Environmental phenomena drive varying health effects:

  • Extreme heat can lead to heat-related illnesses and cardiovascular failure
  • Air pollution may exacerbate asthma and respiratory disease
  • Severe weather (e.g., wildfires, hurricanes) can contribute to physical injuries, fatalities, and mental health impacts8

Certain populations are especially vulnerable, such as the very old and very young. As extreme weather events become more common, it’s important to support at-risk individuals and communities before, during, and after an environmental disturbance.


A priority for plan sponsors

We must view environmental threats with the same urgency as highly communicable diseases that can cause epidemics and pandemics. Weather data can help track and predict upcoming environmental concerns and inform strategies in mitigating health risks through extreme weather events, natural disasters, and wildfires.

Our new white paper defines environmental determinants of health and the ways they can affect member health and access to medication. It also explains why viewing environmental conditions as key inputs to operational processes and clinical programs can preserve or improve health outcomes and ensure business continuity.



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