A new study suggests the 2017 hurricane season was caused by warming ocean temperatures due to climate change. The monstrous, turbo-charged hurricane season was responsible for the deaths of 3,000 people and caused $250 billion in damage.
The new study was published in the journal Science, and as part of it, Hiroyuki Murakami, an associate research scholar at Princeton University, and his team analyzed all the information from the 2017 hurricane season in the Atlantic. They wanted to determine what made it so intense and deadly. Looking back to when records began in 1851, the last hurricane season was classified as the seventh most active season, in which there were 17 named storms. Of those 17, 10 became hurricanes, of which six became major deadly hurricanes.
To discover this, the team used high-res computer models to analyze the storms which occurred between July 1 and Nov. 30, 2017. They analyzed the factors that affected the storms and compared their intensity. La Nina, a phenomenon which cools temperatures in the Pacific and has been linked to Atlantic hurricane activity, was also included.
Their findings indicated that La Nina didn’t have a major influence on the storms in the 2017 hurricane season. Instead, warmer surface temperatures in the Atlantic Ocean were found to be a key factor. Even though these anomalies can be associated with the season’s inconsistencies, it “is also possible that greenhouse-induced global warming might have caused the emergence of the pronounced major hurricane activity,” the study said.
Scientists also used climate models to simulate the varying intensity of the hurricanes over time. Their findings suggest higher global temperatures and decreased aerosol use led to the higher number of devastating hurricanes.
“We found out that the last year’s active major hurricanes were made due to combined effect of natural variability and anthropogenic forcing [decrease in aerosols and increase in greenhouse gases],” Murakami told Newsweek. “Although estimation for contributions from each component is difficult, impact of anthropogenic forcing cannot be neglected.”
More research is needed to determine the exact impact of human activities on hurricanes and how much they were to blame for the violent 2017 hurricane season. It’s still impossible to determine whether Hurricane Florence, which hit the U.S. East Coast this year, also resulted from the influence of warming ocean temperatures.
“[What] we can say from our study is that increase in anthropogenic forcing indeed increases frequency of intense hurricanes,” Murakami said. “Therefore, it is possible that anthropogenic forcing contributes to the emergence of Hurricane Florence. Because reliable long-term observed tropical cyclone data is limited before satellite era, it is difficult to argue if the positive trend of intense hurricanes over recent years is due to anthropogenic forcing. The projected rate of increase in intense hurricanes by the climate model is also slow and the increase of intense hurricanes will be more significant toward the end of this century along with some variations caused by natural variability.”
Some hurricane experts who weren’t part of Murakami’s research don’t entirely agree with the study. For example, according to the Associated Press, University of Miami hurricane researcher Brian McNoldy believes the warmer waters are to blame for the 2017 hurricane season, but he isn’t yet ready to blame global warming.
“Hurricane seasons don’t just keep getting more active as the climate warms though. There is enormous variability,” McNoldy told the AP via email.