For the first time, a state-of-the-art computer model of the atmosphere that incorporates physical and chemical environmental processes is showing the direct links between increased levels of carbon dioxide in the atmosphere and increases in human mortality. The study, conducted by Mark Jacobsen, a professor of civil and environmental engineering at Stanford, comes just after the Environmental Protection Agency’s recent ruling against states setting specific emission standards for this greenhouse gas. This was based in part on the lack of data showing the link between carbon dioxide emissions and their health effects.

The study details how for each increase of one degree Celsius caused by carbon dioxide, the resulting air pollution would lead annually to about 1,000 additional deaths and many more cases of respiratory illness and asthma in the United States. More than 20,000 air-pollution-related deaths per year per degree Celsius may be due to this greenhouse gas worldwide.  

Jacobson’s research has particular implications for California. The study finds that the effects of carbon dioxide’s warming are most significant where the pollution is already severe. Since California is home to six of the 10 US cities with the worst air quality, the state is likely to bear a disproportionate number of deaths if no new restrictions are placed on carbon dioxide emissions.