September 6, 2013
Summer 2012’s Extreme Heat Expected To Repeat Due To Greenhouse Gas
redOrbit Staff & Wire Reports - Your Universe Online
Last July was the hottest month in the history of US weather record keeping, but it may not hold that title for long, researchers from Stanford University claim in a recently-published report.
According to Noah Diffenbaugh, an associate professor of environmental Earth system science at the California institution, and research assistant Martin Scherer, extreme weather is more than four times more likely to occur now than it was during the pre-industrial era.
In research that was part of a larger report edited by scientists at the National Oceanic and Atmospheric Administration (NOAA) and published Sept. 5 in the Bulletin of the American Meteorological Society, the duo reportedly found strong evidence that elevated atmospheric greenhouse gas levels have increased the likelihood of future instances of severe heat similar to that which occurred in the US during the summer of 2012.
“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 records, going back over the last century,” the university said.
Then, through the use of climate models, they were able to quantify how the risk of these types of damaging whether events has changed due to the high greenhouse gas concentrations caused today (versus an era of lower concentrations and no discernible global warming).
While their findings do not specifically point to this phenomenon as the cause of any particular extreme weather events, they do demonstrate the increasing risk of these types of events as the world continues to warm. In the future, scientists interested in understanding and managing climate risks need to understand the likelihood of such hazards instead of trying to determine whether global warming caused any one disaster, Diffenbaugh said.
Last year alone, the researchers reported that the US suffered 11 extreme weather events, each causing at least $1 billion in damages. “It's clear that our greenhouse gas emissions have increased the likelihood of some kinds of extremes,” Diffenbaugh said, “and it's clear that we're not optimally adapted to that new climate.”
“The report includes studies of a dozen 2012 extreme weather events by research teams around the world, about half of which found some evidence that human-caused climate change contributed to an extreme weather event,” the university added. “Close study of extreme weather events can help quantify the likelihood that society will face conditions similar to those that occurred in the summer of 2012, thereby informing efforts to reduce vulnerability and increase resilience.”
"Knowing how much our emissions have changed the likelihood of this kind of severe heat event can help us to minimize the impacts of the next heat wave, and to determine the value of avoiding further changes in climate," Diffenbaugh said.