Climate change can now be measured on a global scale using multiple weather variables, according to new research from Kent State University.

Headshot of Cameron C. Lee

In 2018, Cameron C. Lee, Ph.D., assistant professor in the Department of Geography at Kent State, began researching how weather types have changed over a 40-year period.

Lee’s published research “Trends and Variability in Airmass Frequencies: Indicators of a Changing Climate” can be found in the American Meteorological Society’s Journal of Climate. 

Air masses, or multivariate weather situations like hot and humid, or cold and dry, take into account many climate variables to provide a simplified classification of the daily weather. Past resources for measuring climate change most often used single variables such as temperature or precipitation. 

“I attempted to examine how these air masses have changed in terms of their frequency over the course of a 40-year period from 1979 until 2018,” Lee said. “By creating an index that tracks air masses as opposed to individual variables, and because this index takes the entire globe into consideration you can see that, if the index is above zero, then there are still more abnormally warm areas on Earth than there are abnormally cold areas.” A second index that Lee developed in this research - called the Global Extremes Index - tracks the long-term trends in extreme weather, and also shows a significant increase. 

Lee hopes other scientists will use this research to continue learning about climate change. He is in the process of transitioning the research to an official indicator on the U.S. Global Change Research Program website.

“Part of the reason we are so confident about climate change, that it is occurring and that it’s going to continue to occur in the future, is because of all of these different independent sources that are all pointing to the same thing,” Lee said. “This is another piece of evidence that is pointing to long term changes in the climate system.”

Lee estimates 97 to 99% of climate scientists are positive that climate change is happening, and that the main source of climate change is the use of fossil fuel.

While international cooperation is needed to completely reverse the effects of climate change, Lee said everyone can do their part by increasing their energy efficiency. Changing light bulbs, heating and cooling systems, appliances and waste amounts can save money and help the planet.

“There is always something we can do to prevent more disastrous impacts,” Lee said. “The most important thing you can do is vote for people that have climate change at the top of their agenda.”

Visit the Department of Geography website at for more information.


POSTED: Thursday, October 8, 2020 12:00 AM
Updated: Friday, December 9, 2022 01:02 PM