Five heat waves that hit different parts of the globe in 2013 have been linked to man-made climate change primarily triggered by the burning of fossil fuels.
Other extreme climate events such as droughts, heavy rain and storms were not as clearly linked to human activity in the recent report published by the Bulletin of the American Meteorological Society. The annual report looked at 16 distinct weather events that occurred across four continents, the National Oceanic and Atmospheric Administration (NOAA) reported.
"This annual report contributes to a growing field of science which helps communities, businesses and nations alike understand the impacts of natural and human-caused climate change," said Thomas R. Karl, director of NOAA's National Climatic Data Center. "The science remains challenging, but the environmental intelligence the report yields to decision makers is invaluable and the demand is ever-growing."
The confidence in the findings was boosted due to the fact that a number of groups used various methods and all came to similar conclusions.
In one case five independent research teams looked at factors relating to extreme heat waves in Australia that occurred in 2013, and found human-caused climate change increased both the likelihood and severity of these events. In another series of studies three research teams looked at droughts in California and were not able to find a clear link between human activity and lack of rainfall. One team found a connection between human-related climate change and increased atmospheric pressure patterns, but could not clearly link this phenomenon to the drought.
"There is great scientific value in having multiple studies analyze the same extreme event to determine the underlying factors that may have influenced it," said Stephanie C. Herring, lead editor for the report at NOAA's National Climatic Data Center. "Results from this report not only add to our body of knowledge about what drives extreme events, but what the odds are of these events happening again-and to what severity."
