Global warming will cause more deaths in summer because of higher temperatures but these will not be offset by fewer deaths in milder winters finds an analysis published online ahead of print in Occupational and Environment Medicine.
The Harvard researchers analysed city-specific weather data related to the deaths of more than 6.5 million people in 50 US cities between 1989 and 2000.
They found that during two-day cold snaps there was a 1.59% increase in deaths because of the extreme temperatures. However, during similar periods of extremely hot weather death rates went up by 5.74%. Deaths did not rise as steeply when temperature fluctuations were less extreme.
Deaths from all causes are known to rise when temperatures go up, and heart attacks and cardiac arrests are more likely when it is very cold. It was anticipated that global warming would increase deaths during hot temperatures but that this would be compensated for by fewer deaths in the winter.
But the authors conclude: ‘Our findings suggest that decreases in cold weather as a result of global warming are unlikely to result in decreases in cold-related mortality in the US. Heat-related mortality, in contrast, may increase, particularly if global warming is associated with increased variance of summer temperature.’
While all 50 US cities showed similar rises in deaths when temperatures plummeted, more deaths were seen during extreme temperature rises in cities with milder summers, less air conditioning and higher population density.
The authors suggest that this is because the use of central heating is widespread, whereas fewer people have air-conditioning in their homes.
They say: ‘Central heating, which constitutes an important adaptive mechanism against cold, is almost universal in the US and this may explain why the US population seemed fully acclimatised to cold.
‘Making air conditioning universally available may reduce heat-related mortality but would, on the other hand, have a perverse effect by enhancing global warming through carbon dioxide emissions from electricity consumption.’
Source: BMJ Specialty Journals
Related stories:
Higher temperatures helped new strain of West Nile virus spread
Higher temperatures helped a new strain of West Nile virus invade and spread across North America, according to a study published in the June 27 issue of the journal
PLoS Pathogens.
Climate change does double-whammy to animals in seasonal environments
Plant-eating animals in highly seasonal environments, such as the Arctic, are struggling to locate nutritious food as a result of climate change, according to research that will be published in the 21 May 2008 online edition of the journal
Proceedings of the Royal Society B.
Researcher strives for watershed moment
According to the World Health Organization, water scarcity affects four out of every 10 people around the world and population growth, urbanization and increased domestic and industrial water use are making the problem worse. By examining the relationship between global warming and pollution, a researcher at The University of Western Ontario hopes to help protect future water resources.
Microbes could be the key to coral death
Coral reefs could be dying out because of changes to the microbes that live in them just as much as from the direct rise in temperature caused by global warming.
Coral reefs and climate change: Microbes could be the key to coral death
Coral reefs could be dying out because of changes to the microbes that live in them just as much as from the direct rise in temperature caused by global warming, according to scientists speaking today at the Society for General Microbiology’s 162nd meeting being held this week at the Edinburgh International Conference Centre.
First-ever study to link increased mortality specifically to carbon dioxide emissions
A Stanford scientist has spelled out for the first time the direct links between increased levels of carbon dioxide in the atmosphere and increases in human mortality, using a state-of-the-art computer model of the atmosphere that incorporates scores of physical and chemical environmental processes. The new findings, to be published in
Geophysical Research Letters, come to light just after the Environmental Protection Agency’s recent ruling against states setting specific emission standards for this greenhouse gas based in part on the lack of data showing the link between carbon dioxide emissions and their health effects.
Economist examines costs of extreme cold weather
Fatalities in the continental United States tend to climb for several weeks after severe cold spells, ultimately numbering 360 per chilly day and 14,380 per year, according to a new study co-authored by a University of California, Berkeley, economist.
Ozone key to link between heat and increased cardiovascular death risk
Ozone may prove the key to the link between high temperature and the increased risk of death from heart disease or stroke, suggests research published ahead of print in
Occupational and Environmental Medicine.