GLOBAL warming made the heavy rains that caused KZN’s devastating floods last month twice as likely as they would have been if greenhouse gas emissions had never heated the planet, scientists said on Friday.
Flash floods in and around Durban killed 435 people, left tens of thousands homeless and caused R10 billion worth of damage to roads, power lines, water pipes and one of Africa's busiest ports.
The World Weather Attribution group analysed weather data and digital simulations to compare today's climate to that of before the Industrial Revolution in the late 1700s, when the world was about 1.2°C cooler.
"The results showed that an extreme rainfall episode such as this one can now be expected to happen about once every 20 years," a report on the study said.
"Without human-caused global warming, such an event would only happen once every 40 years, so it has become about twice as common as a result of greenhouse gas emissions."
It added that when extreme downpours do happen, they could be expected to be 4-8 percent heavier than if no human-induced global warming had occurred.
Africa's south-eastern coast was on the front line of seaborne weather systems that climate change is making nastier, scientists say. South Africa's tropical northern neighbour Mozambique has suffered multiple cyclones and floods in the past decade, including one in April that killed more than 50 people.