Five percent increase in max cyclonic wind speeds if the world warmed by 2 degrees Celsius by 2100

By Nabarun Bhaumik

Chemical Engineering, JU

A major Tropical storm by far is the world’s costliest natural disaster. Many study now found that the increasing sea temperature making these storms much more frequent as well as destructive. Major Tropical storms have become 15% more likely over the last 4 decades.

Scientists from the National Oceanic and Atmospheric Administration (NOAA) and Princeton University in the United States and the University of East Anglia in the United Kingdom analyzed 90 peer-reviewed articles to understand the impact of a changing climate on tropical cyclones — a combined name used for the three cyclonic storms. They concluded that there could be a five percent increase in maximum cyclonic wind speeds if the world warmed by two degrees Celsius by 2100.

In general, the warmer the water temperature more heat energy available, and the higher the chance of a tropical cyclone generate. A Study found that Oceans have absorbed 90% of excess heat from greenhouse gas emissions since 1970, leading to warmer surface temperatures, more moisture in the atmosphere, and thus increasingly severe cyclones.

As an effect, it is found that the proportion of severe cyclones of categories 3-5, based on the metric called the Saffir-Simpson hurricane wind scale, had increased by five percent per decade and the intensity of tropical cyclones making landfall along the coasts of eastern and southeastern Asia from 1977-2018 had increased by 12-15 percent.

The wind is not only the destructive factor of cyclone extremely heavy rainfall and storm surge responsible for nearly 50% of deaths since 1963 worldwide.

Rising seawater levels will intensify the destructive impact of the cyclonic storms due to increased storm surges that inundate coastal areas during the Storm. Many Small islands submerged in water due to several cyclones in the Sundarban area of West Bengal. The finest example is “New Moore Island” - A island located in off the coast of the Ganges-Brahmaputra delta region which was partially submerged in water after 1999 cyclone “Bhola” and complete submerged thereafter.

There are other impacts of warming on tropical cyclones such as rapid intensification which could make them unpredictable and difficult to monitor. In 2020, Cyclone “Amphan” displayed rapid intensification when it developed from a cyclone (wind speeds of 70-80 km per hr.) to a super cyclone (wind speeds more than 220 km per hr.) in about 40 hours.

Threats from tropical systems, and in particular from the most intense cyclones, are increasing.

This trend will continue in the near future. Although some of these anticipated impacts are already baked into our warmer climate, the most serious escalations can still be averted but for that, we need to be more aware of our Environment otherwise these effects will make these storms even deadlier in the future.