The first detailed predictions of future temperatures across North America have been produced, using a combination of climate models and some complicated statistics.
Through a series of maps, people can see how their own region’s temperature will likely change by 2070 – overall, and for individual seasons of the year.
The analysis, developed by statisticians at Ohio State University, examines groups of regional climate models, finds the commonalities between them, and determines how much weight each individual projection should be given.
“One of the criticisms from climate-change skeptics is that different climate models give different results, so they argue that they don’t know what to believe,” says professor of statistics Noel Cressie.
“We wanted to develop a way to determine the likelihood of different outcomes, and combine them into a consensus climate projection. We show that there are shared conclusions upon which scientists can agree with some certainty, and we are able to statistically quantify that certainty.”
The result is a series of possible temperature changes that, says the team, includes the true temperature change with 95 percent probability.
The researchers examined temperature changes for the four seasons, for the Hudson Bay, the Great Lakes, the Midwest, and Rocky Mountain regions.
And Hudson Bay looks set for the biggest temperature swings. Winter temperatures are estimated to rise by an average of about 10.7 degrees Fahrenheit – possibly because ice reflects less energy away from Earth’s surface as it melts. Hudson Bay summers, on the other hand, are estimated to experience only an increase of about 2.1 degrees Fahrenheit.
The Midwest and Great Lakes regions show a rise in temperature of about 5 degrees Fahrenheit, regardless of the season. The Rocky Mountains region shows a summer increase of about 6.3 degrees Fahrenheit, and 4.1 degrees in winter.
The team now plans to turn its attention to other climate variables, such as precipitation.