The heavy rains behind recent devastating floods in Nigeria, Niger and Chad were made about 80 times more likely by the climate crisis, a study found.
The finding is the latest stark example of the dire impact global warming is already having on communities, even with only a 1°C increase in global temperature so far. It is pressuring the nations of the world at the UN Climate Summit Cop27 in Egypt to take meaningful action to protect and compensate affected countries.
The floods that hit between June and November were among the deadliest on record for the region. Hundreds of people died, 1.5 million were displaced and more than 500,000 hectares of farmland were damaged.
The study, conducted by an international team of climate scientists as part of the World Weather Attribution (WWA) group, used weather data and computer models to compare the likelihood of heavy rainfall in today’s heated world to a world without global warming. Such rain would have been extremely rare without man-made heating, they found, but is now expected to occur once every 10 years.
A critical issue for success at Cop27 is establishing funding for “loss and damage” – compensation for rebuilding after the inevitable climate catastrophes that affect increasingly vulnerable developing countries, which have contributed little to the climate crisis. These countries demand action from rich countries.
According to the WWA study, the floods were so disastrous that people in the region were already very vulnerable to extreme weather, due to poverty, violent conflict and political instability.
“The analysis found a very clear fingerprint of anthropogenic climate change,” said Prof. Maarten van Aalst, the director of the Red Cross Red Crescent Climate Center, who is with Cop27. “The floods have caused enormous suffering and damage, especially in the context of great human vulnerability.
“As scientists, we are not in a position to tell Cop27 negotiators whether it should be a loss and damage fund, or a facility, or a mosaic of solutions, as all are being discussed,” he said. “But what is very clear from the science is that this is a real and current problem and it is the poorest countries that are being hit very hard, so it is clear that solutions are needed.”
Prof Johan Rockström, the director of the Potsdam Institute for Climate Impact Research and also at Cop27, said analyzes such as the WWA’s clearly showed the link between global warming and climate catastrophes: “So the legitimacy of loss and damage is still never been this high as of today.”
The WWA team also assessed the 2021 drought in Africa’s central Sahel region, which damaged crops and contributed to a 2022 food crisis. However, the scientists were unable to estimate the impact of the climate crisis due to a lack of weather station data. noting the need for investments in weather stations.
“We are seeing the importance of knowing what the weather is like today all over the world so that we can understand how it is changing and where we should focus our adaptation efforts,” said Dr Friederike Otto from Imperial College London.
A recent Guardian analysis of hundreds of studies exposed the devastating intensification of extreme weather that is causing people around the world to lose their lives and livelihoods. At least a dozen major events, from killer heat waves to scorching seas, would have been virtually impossible without man-made global warming.
Serious events in 2022 include the catastrophic floods in Pakistan, where global warming increased rainfall intensity by about 50%, and the northern hemisphere’s record summer drought, which would have been expected only once every four centuries without the climate crisis. A deadly South Asian heat wave earlier this year was made 30 times more likely.
The WWA analysis focused on two regions: the Lake Chad basin, which experienced above-average rainfall during the wet season, and the lower Niger basin, which experienced shorter, more intense rainfall. The research team consisted of researchers from Nigeria, Cameroon, South Africa, Europe and the US.