Devastating rains that triggered floods in Cameroon, Chad, Niger, Nigeria and Sudan in recent months - killing hundreds of people and displacing millions - were worsened by human-caused climate change, a team of international scientists announced Wednesday.
Global warming made the seasonal downpours this year about 5-20 percent more intense across the Niger and Lake Chad basins, said World Weather Attribution (WWA), a group of scientists studying the link between climate change and extreme weather.
In a study published Wednesday, it also said such intense rainfall could occur annually if warming continues.
"Spells of heavy summer rainfall have become the new normal in Sudan, Nigeria, Niger, Cameroon and Chad," said Izidine Pinto, one of the study's authors and a researcher at the Royal Netherlands Meteorological Institute.
"These results are incredibly concerning," he said, warning that "with every fraction of a degree of warming, the risk of extreme floods will keep increasing."
He called for the UN's Cop29 climate summit to "accelerate the transition away from fossil fuels" when it meets in Azerbaijan next month.
This year's floods killed around 1,500 people and displaced over 1 million more in West and Central Africa, according to the UN aid agency OCHA. The rainfall also overwhelmed dams in Nigeria and Sudan.
Deadly floods in Sudan displace thousands, hinder aid delivery
The severed floods in June, July, August and September hit an extremely vulnerable region, and have "significantly deepened a complex humanitarian crisis in Sudan, straining the capabilities of aid organisations and government bodies to respond," the WWA said.
If global warming increases to 2 degrees Celsius above pre-industrial levels, which could happen as early as the 2050s, downpours like this are expected to occur nearly every year in the affected regions, WWA said, calling for more investment in early warning systems and dam upgrades.
"Africa has contributed a tiny amount of carbon emissions globally, but is being hit the hardest by extreme weather," said Joyce Kimutai, researcher at the Centre for Environmental Policy at Imperial College in London.
She said the onus was on Cop29 to ensure rich nations contribute "meaningful finance" to help.
(with newswires)