John R. Balmes and George D. Thurston

The third National Climate Assessment report, due to be released this month, confirms both the role of human activities in causing climate change and the broad range of adverse health consequences that climate change brings. The report was produced by the federal government’s multi-agency U.S. Global Change Research Program (USGCRP), established by Presidential initiative in 1989.

The effects of climate change on human health are of particular concern to the physician and scientist members of the American Thoracic Society. Our patients have cardiopulmonary disease and, therefore, are particularly susceptible to the air pollution emitted along with the carbon dioxide that contributes to climate change, which, itself, is injurious to respiratory health.

According to the World Health Organization, the No. 1 environmental cause of death in the world is particulate matter air pollution. The WHO estimates that outdoor air pollution in both cities and rural areas caused 3.7 million premature deaths worldwide in 2012. At the same time, the adverse health effects that can be triggered by the effects of climate change include asthma and allergic rhinitis due to changing pollen levels, critical care illness caused by heat waves, and chronic obstructive pulmonary disease (COPD) and cardiovascular diseases caused by increased air pollution associated with climate change.

The new National Climate Assessment report, while noting that progress is being made towards mitigating climate change, indicates that the level of current policy efforts is insufficient.


The American Thoracic Society believes that an aggressive approach that harmonizes climate change and air quality improvement policies offers the best and most efficient hope for addressing the short- and long-term health and economic consequences of each.

Because the effects of climate change occur over long periods of time, policymakers have not given them the same attention given to air pollution, which has immediate, measurable effects on health. The two are intertwined, however. The burning of fossil fuels, for instance, produces particulate matter and black carbon -- air pollutants that have immediate adverse respiratory and cardiovascular health effects -- along with carbon dioxide emissions, which have longer-term effects on the atmosphere and climate change. A policy aimed at increasing the efficiency of automobiles, for example, would simultaneously improve air quality while also reducing the long-term contributions of automobile emissions to climate change.

A number of studies, including a 2013 study by J. Jason West of the University of North Carolina at Chapel Hill and colleagues in the journal Nature Climate Change, have shown that savings in health care costs from reduced air pollutants more than offsets the costs of implementing measures that reduce emissions that cause climate change over time. And, importantly, the greatest health benefits of the associated cleaner air accrue to those countries that do the most climate change mitigation. The long-term health benefits of slowing climate change and the resulting cost savings from cleaner air require a comprehensive and harmonized policy that addresses both air quality and climate change together.

"The long-term health benefits of avoiding mortality and morbidity due to temperature extremes, air pollution, pollen, floods, droughts, storms, desertification, and malnutrition justify climate change mitigation not only from an economic standpoint but also from a moral one," according to a March 2014 article by Mary B. Rice of Massachusetts General Hospital and colleagues in the ATS journal Respiratory and Critical Care Medicine.

We have the tools and the knowledge needed to improve the quality of the air we breathe, while simultaneously slowing climate change and reducing the substantial economic and human toll of both air pollution and climate change. What is needed now are sufficient resources and bold political action to make the achievement of both of these two concordant goals a reality.

Dr. John R. Balmes and George D. Thurston, D.Sc. are Chair and Vice Chair of the American Thoracic Society’s Environmental Health Policy Committee.