KZN coast could be hit by tropical cyclones in future due to global warming

A team of geologists examined the sediment record from the seabed off the coast of Durban and found that there was a period – under higher sea levels – when storms were much more extreme than they are now.

FILE: Tropical Cyclone Eloise made landfall in the Beira area on Saturday, 23 January 2021 before heading to South Africa.  Picture: SA Weather Service

JOHANNESBURG - Tropical storms and cyclones - much like storms such as Eloise, which hit South Africa early last year - may become a more regular occurrence on the KwaZulu-Natal coast in a few years, thanks to global warming.

This is according to new research by the University of KwaZulu-Natal (UKZN), the University of Bremen and the University of Stirling, which investigated seabed sediments, revealing that severe tropical cyclones made landfall on the eastern coast of South Africa in the past and that under projected climate change conditions, these damaging phenomena could arise in the future.

Head of the Marine Geology Research Unit at UKZN, Professor Andrew Green, led the research with Honorary Research Professor Andrew Cooper and Shannon Dixon from UKZN, Professor Matthias Zabel and Dr Annette Hahn from the University of Bremen’s Center for Marine Environmental Sciences in Germany, and Dr Carlos Loureiro from the University of Stirling in the UK.

The team of geologists examined the sediment record from the seabed off the coast of Durban and found that there was a period – under higher sea levels – when storms were much more extreme than they are now.

“We found distinctive sediments that were deposited by severe storms that struck the coast between approximately five and seven thousand years ago. These storms were much bigger than any storm that happened in the 4,000 years since. This has allowed the storm sediments, or tempestites, to be preserved just beneath the seabed," said Professor Green.

“This important work demonstrates that the past climate conditions that allowed very intense tropical cyclones to reach the South African coast are very similar to the ones projected now under climate change,” added Professor Loureiro.

According to the researchers, if such a storm were to happen now, beachfront infrastructure would be devastated and the rainfall associated with tropical cyclones would cause serious flooding.

This researchers added that this gives rise to the need to evaluate hazards along South Africa’s east coast that will be more vulnerable to tropical cyclones making landfall.