Tropical cyclones of higher intensity demand a new category

Subject: Geography

Section: Climatology

Tropical cyclones:

Tropical cyclones, forming over warm tropical oceans with sea surface temperatures above 26.5°C, are powerful storms characterized by strong winds, heavy rain, and storm surges, posing significant risks to coastal areas.
Annually, out of 85 tropical storms, more than half become cyclones, predominantly in the Western Pacific, the most active basin, while the North Indian basin, though only contributing to 4% of global cyclones, is highly vulnerable to their impacts.

Saffir-Simpson scale to measure the intensity of tropical cyclones:

The Saffir-Simpson scale, with categories 1 through 5 based on wind speeds, is used to communicate the intensity and risk of these cyclones to the public, highlighting the severe damage potential of category 5 storms with winds exceeding 252 km/h.

Impact of Global warming on the tropical cyclones:

The increase in greenhouse gas emissions and consequent global warming, with a 1.10°C rise since pre-industrial times, has affected ocean temperatures, thereby enhancing the intensity and potential destructiveness of tropical cyclones.
Observations indicate an increase in the frequency of intense storms, with each degree of warming leading to a 12% increase in wind speed and a 40% rise in destructive potential.
Additionally, cyclones are moving poleward and forming at higher latitudes, intensifying more rapidly, lasting longer, and producing more rainfall upon landfall, as evidenced by the record-setting 37-day duration of tropical cyclone Freddy in 2023.

Need for Category 6:

Recent research highlights that the intensity of storms is surpassing Category 5, suggesting the need for a new Category 6 for cyclones with wind speeds above 309 km/h, due to global warming.
Analysis of 197 Category 5 cyclones from 1980-2021 shows an increase in such intense storms, especially in the latter years, with some exceeding the proposed Category 6 threshold.
Future climate simulations indicate a rise in these extreme events. Introducing a Category 6 could enhance awareness and preparedness for these increasingly potent storms.
Given these trends, even regions currently less vulnerable, like the North Indian Ocean, may face Category 6 cyclones, prompting a reevaluation of disaster management and early warning systems.

Source: TH