Modeling Framework Projects Significant Increase in Ozone-Related Deaths

A new modeling framework suggests that climate change alone could cause a 4.5% increase in the number of summer ozone-related deaths across the New York metropolitan region by the year 2050, according to a study published today in the November issue of the peer-reviewed journal Environmental Health Perspectives (EHP). When population growth and projected growth in greenhouse gas emissions are factored in, the model predicts a 59.9% increase in summer ozone-related deaths by 2050.

The larger projected impact is largely caused by expected growth in the populations most at risk. Numerous earlier studies have linked ozone with hospital admissions and emergency visits for respiratory conditions. Other recent studies have drawn a link between elevated ozone levels and mortality among residents in large cities.

This modeling framework provides a potentially useful new tool for assessing the health risks of climate change in specific regions. The framework was developed to better assess potential health effects of air pollution resulting from climate change. It comprises a global climate model from the National Aeronautics and Space Administration, a model from the National Center for Atmospheric Research, and the Community Multiscale Air Quality Atmospheric Chemistry Model.

With the new tool, the researchers simulated hourly regional meteorologic conditions and ozone levels for five consecutive summers in the 2020s, the 2050s, and the 2080s across the 31-county New York Metropolitan Area. The area incorporates the nation’s largest city, parts of northern New York, Long Island, southern Connecticut, and northeastern/central New Jersey, including an estimated 1,600 cities, towns, and villages.

“Under a variety of assumptions, climate change alone could increase regional summer ozone-related mortality by a median 4.5% in the 2050s compared with the 1990s,” the study authors write. “These assumptions do not include the effect of projected population growth. When a more fully elaborated picture of the likely regional future was evaluated, much greater changes in summer mortality are projected: Regional summer ozone-related mortality would increase by a median 59.9% in the 2050s compared with the 1990s.”

“This study takes existing climate model outputs and overlays them to project the likely future-year ozone concentrations for a specific region. By doing this, the authors were able to project a potentially significant public health impact,” said Dr. Jim Burkhart, science editor for EHP.

The lead author of the study was Kim Knowlton of the Mailman School of Public Health at Columbia University in New York. Other authors were Joyce E. Rosenthal, Christian Hogrefe, Barry Lynn, Stuart Gaffin, Richard Goldberg, Cynthia Rosenzweig, Kevin Civerolo, Jia-Yeong Ku, and Patrick L. Kinney.

EHP is published by the National Institute of Environmental Health Sciences, part of the U.S. Department of Health and Human Services. EHP became an Open Access journal in January 2004.