Climate change is a hot topic in the scientific community, and now a new study suggests that it may be having a significant impact on weather in the U.S. Professor James Eisner conducted the he study, which was published in the journal Climate Dynamics this week.

Climate change tornado

Climate change affecting tornado trends

Previously, many researchers believed that climate change wasn’t really impacting tornado frequency or severity in the U.S. According to Eisner, they didn’t see a particular pattern regarding how many tornado days there were in a year. For example, in 1971, there were 187 days on which tornadoes occurred in the U.S., but last year, only 79 days had tornadoes. In 2011, there were almost 1,700 storms during tornado season. So far this year, there have been 189 storms.

However, Eisner said he found that as time goes on, the type of storms that form and also the number of storms that happen on a particular day have increased in severity. He said that now when there is a risk of severe weather, meteorologists and also the public should realize that rather than just a single storm, there now could be multiple storms on the same day. In addition, he said that the tornadoes that do form tend to be more severe than they were in the past.

According to Eisner, the reason for these changes in tornado patterns may be because of the changing moisture content and heat in the atmosphere, which is caused by climate change. He did add though that a greater number of people watching for tornadoes could be contributing to the increase in the number of tornadoes. However, the findings of his study are not unlike those in studies that have shown that the number of heavy downpours is on the rise as well.

Tornado outbreaks becoming more common

To conduct the study, Eisner and his team focused on days with at least four, eight, 16 and 32 tornadoes. They discovered that the number of days with at least four tornadoes was falling. However, the number of days with at least 16 and 32 tornadoes has risen within the last 60 years. They found a significant increase since 1980.

Over the entire time frame, the researchers discovered that the odds of a day in which there are 32 tornadoes or more occurring has more than doubled, although it’s still pretty rare for that to happen.

A bit of good news

Eisner did say that climate change doesn’t appear to be affecting the number of geographic areas that are most often impacted by tornadoes. He said the number of tornado-prone areas in the U.S., like the so-called “tornado alley” in the lower Midwest and Great Plains regions, doesn’t appear to be increasing.