Scientists say global warming doesn't decrease winter mortality rate

WASHINGTON, June 20 (UPI) -- A new study from Columbia University's Mailman School of Public Health disproves the assumption that increased global warming will decrease the amount of winter-related deaths around the world.

Researchers analyzed temperature and mortality data from 39 cities in the U.S. and France and concluded that a warmer climate has little if any correlation to weather-related mortality rates during winter months.

"Some have claimed that warmer winters due to climate change will lead to big reductions in winter deaths. Our work suggests that this is unlikely to be the case," lead author Professor Patrick Kinney, director of Columbia's Climate and Health Program, said in a press release.

Kinney and his colleagues obtained mortality rate data from 36 cities in the United States and 3 in France between the years 1971 and 2007. They found cities that experienced warm winters have similar rates to those with colder winters, and there was little correlation between temperature levels and the number of deaths.

"These cities vary widely in demography, urban design, and socio-cultural background, all of which might influence exposure to outdoor temperature and related mortality risks," said Kinney, who also serves on the New York City Panel on Climate Change and was a lead author of the Intergovernmental Panel on Climate Change's recent report.

Because there is still an excess of deaths that occur during the winter, the scientists observe that other non-temperature related factors may be the cause. Lack of exercise and mobility, low humidity in the air and increased time spent indoors -- which increases the risk of flu and respiratory infections -- may be more prevalent reasons.

The study is published in the journal IOP Science.