Tropical Cyclones Decrease because of Global Warming, Is it a Good Thing?

According to a recent study, the annual number of tropical cyclones emerging globally reduced by roughly 13% from the 19th century to the 20th.

Massive low-pressure systems known as tropical cyclones develop in tropical oceans when the prevailing environmental factors are favorable. The sea surface temperature and several factors, such as vertical wind shear-changes in wind speed and direction with altitude-are among these conditions.

Tropical cyclones can harm a great deal of property. Extreme rains, strong winds, and coastal dangers like erosion, destructive waves, storm surges, and estuary flooding are frequently brought on by them.

The most recent assessment from the Intergovernmental Panel on Climate Change described how human emissions have caused tropical ocean temperatures to rise above pre-industrial levels. Experts have been voicing out warnings since the middle of the 20th century. Storms should get stronger as a result of these increases in sea surface temperature.

In addition, as a result of 20th-century global warming, the atmospheric conditions that influence the genesis of tropical cyclones have weakened.

Savin Chand, a senior lecturer in the Applied Mathematics and Statistics department at the Federation University Australia, is the lead author of the research. Their research offers proof that a rise in human-caused global warming coincides with a decline in the frequency of tropical storms.

Limited Records

Chand noted that his team requires a trustworthy record of cyclones to determine if cyclone frequency has increased or decreased over time. However, it is difficult to identify this historical context.

Records were prone to discontinuity and sampling problems before the arrival of geostationary weather satellites in the 1960s, which remained stationary with regard to the rotating Earth.

Even though satellite technology allowed for better observations, it appears that solid global records didn't start to emerge until the 1990s due to changes in satellite technology and monitoring throughout the early decades.

Therefore, the team's post-satellite tropical cyclone record is not very long. And because of natural climatic variability, longer-term weather trends based on a short record may be hidden. As a result, many analyses of tropical cyclone trends have been conducted.

Decreasing Counts

Chand's team used the Twentieth Century Reanalysis dataset to rebuild cyclone counts as far back as 1850 to get beyond the limitations of the tropical cyclone record. This reanalysis research employs precise measurements to build a picture of the worldwide atmospheric weather conditions since the invention of satellites.

Their rebuilt record shows a drop in the annual number of tropical cyclones since 1850, on both a global and regional scale. They base this conclusion on a relationship with the observed weakening of two major atmospheric circulations in the tropics. Specifically, compared to the time between 1850 and 1900, the number of storms each year decreased by around 13% in the 20th century.

Since the 1950s, the reduction in the majority of tropical cyclone basins-including Australia-has increased. Areas, where they happen most frequently, are the tropical cyclone basins. Chand emphasized that this was the time when warming caused by humans also picked up speed.

The North Atlantic basin is the only region where the trend is not true, as there have been more tropical cyclones there recently. This could be related to the basin's recovery from a population reduction brought on by aerosol impacts in the late 20th century.

Despite this, there are still fewer tropical cyclones here each year than there were before the industrial revolution.

Low Count but High Intensity and Dispersion

Although their study didn't focus on cyclone activity in the twenty-first century, their results support those of other research that has anticipated a decline in tropical storm frequency as a result of global warming.

The fact that fewer cyclones are emerging now than they did in the second half of the 19th century may at first appear to be good news. It should be recognized, however, that frequency is simply one component of the risk posed by tropical cyclones.

Tropical cyclone intensity and geographic dispersion have increased over the past few decades. Tropical cyclones are advancing toward coastal regions with expanding people and development in several parts of the world.

These adjustments, along with rising tropical cyclone-related rainfall and a tendency for hurricanes to linger longer after making landfall, could indicate a future in which tropical cyclones do unheard-of damage there.

Chand also emphasized that their study did not evaluate these additional characteristics. The team is hoping that advancements in climate modeling and data will enable scientists and researchers to determine how other measures, such as landfalling activity and cyclone severity, have been impacted by human-induced climate change.