In an appalling exposure, a new study has revealed that global warming has increased risk of heat rising to record levels.
The scientists say the summer of 2012 was a season of epic proportions, especially July, the hottest month in the history of US weather record keeping. And it’s likely that we’ll continue to see such calamitous weather.
A team of experts examined 12 wild weather episodes occurred in 2012, ranging from droughts in the United States and Africa to heavy rainfall in Europe, Australia, China, Japan and New Zealand.
Climate change caused by human use of fossil fuels played a significant role in causing about a half dozen extreme weather events last year, the researchers stressed.
One of the strongest examples of human influence was seen in an unusual heat wave in the eastern US from March to May last year. Mankind’s contribution to that event was estimated at 35 per cent, raising the risk of such a hot spell by a factor of 12, the report said.
Arctic sea ice hit a record low point of 3.41 million square kilometres in September last year, about half of the 1979-2000 average for that time of year.
Some of the events showed some sign of being worse than expected due to elements like warmer oceans and hotter temperatures brought on by the rise in greenhouse gas emissions and aerosols in the atmosphere.
The researchers focused primarily on understanding the physical processes that created the hazardous weather. They looked at how rare those conditions were over the history of available weather record s, going back over the last century. Using climate models, they quantified how the risk of such damaging weather has changed in the current climate of high greenhouse gas concentrations, as opposed to an era of significantly lower concentrations and no global warming.
Their findings don’t pinpoint global warming as the cause of particular extreme weather events, but they do reveal the increasing risk of such events as the world warms.
The study “Explaining Extreme Events of last year from a Climate Perspective” was published in the Bulletin of the American Meteorological Society.