A new analysis of 90 years worth of observational data has shown that summer climates across the globe are changing, in most cases warming, yielding valuable location-by-location insights rather than vague global averages which hold the potential to be more relevant in understanding changes to flora and fauna in any particular region.
“It is the first time that we show on a local scale that there are significant changes in summer temperatures,” said lead author Irina Mahlstein, who works in the Chemical Sciences Division of the National Oceanic and Atmospheric Administration’s Earth System Research Laboratory and is part of the Cooperative Institute for Research in Environmental Sciences headquartered at the University of Colorado Boulder.
“This result shows us that we are experiencing a new summer climate regime in some regions [and] if the summers are actually significantly different from the way that they used to be, it could affect ecosystems.”
Their analysis looked at 90 years worth of data and found that some changes in temperature variability occurred a early as the 1960s in the tropics, regions where temperatures varied little throughout the years, so the scientists could more easily detect any changes that did occur, Mahlstein said.
The scientists found significant summer temperature changes in 40 percent of tropical areas in their study and another 20 percent of higher-latitude areas. In the majority of cases there was a noticeable warming detected, however, as expected in such a large system, there were some cooling trends as well.
What is intriguing is that this study matches up with other approaches used to find the same answers, such as modelling and analysis trends. However, this technique used only observed data, and still reached the same result.
“Looking at the graphs of our results, you can visibly see how things are changing,” Mahlstein said.