The Atlantic hurricane season ended Tuesday with 21 storms in 2021, the third-highest number of storms on record.

A study from the Massachusetts Institute of Technology released on Thursday warns that these storms are not just becoming more frequent, but also more destructive. According to the National Oceanic and Atmospheric Administration (NOAA), this latest storm season caused over $70 billion in damages and the agency used up all of the alphabetic designations.

In the study, led by MIT atmospheric scientist Kerry Emanuel, researchers measured past storm activity by using digital climate modeling to reconstruct a continuous record of hurricane activity over the past 150 years to discover any trends. These methods broke away from traditional ways to study storms, which relied more heavily on observational reports but were prone to inaccuracies.

According to the results published in Nature Communications, the MIT team determined that North Atlantic hurricanes have become more frequent over the last century, matching what historical records have shown. Beyond being more frequent, they are decidedly more destructive.

Global climate change is a commonly cited cause for the increase in severity of extreme weather events like hurricanes. In the aftermath of Hurricane Ida towards the end of August, President Joe Biden pointed the finger at climate change for making these incidents more dangerous. Earlier studies also backed the idea that the warming of the oceans is in fact intensifying the power of hurricanes, which grow stronger from this phenomenon.

This could be uniquely problematic for North America.

According to MIT researchers, the North Atlantic has seen an overall increase in storm activity but this has not been observed in the rest of the world. In fact, they found that the frequency of tropical storms globally has barely changed in the last century.

“The evidence does long-term increases in North Atlantic hurricane activity, but no significant changes in global hurricane activity,” said Dr. Emmanuel, the study's leader.

Kerry said that the new information will change how climate's effects on hurricanes will be understood, namely that it is "really the regionality of the climate, and that something happened to the North Atlantic that’s different from the rest of the globe."

"It may have been caused by global warming, which is not necessarily globally uniform,” he said.