Human-induced climate change has worsened an “exceptional” three-year drought that has spanned areas of Syria, Iraq and Iran, a study has said.
Since 2020, a region encompassing the Euphrates and Tigris rivers, as well as Iran, has experienced unusually low rainfall and persistent heat, which have led to a severe drought in a region highly dependent on wheat farming.
By September 2022, the drought had displaced nearly two million people from rural areas in Syria.
Rana El Hajj, of the Red Cross Red Crescent Climate Centre, said the drought has had “dire consequences” on the livelihoods and health of people living in Iran, Syria and Iraq.
“Farmers have witnessed fertile lands dry up and millions of people have struggled to access clean water. Land degradation, desertification, water stress and conflict have all contributed to increasing vulnerability to drought," she said.
“In Syria and Iraq, the impacts of conflict and security concerns have greatly reduced people’s ability to respond to the drought.”
Scientists from Iran, the Netherlands, the UK and the US, led by the World Weather Attribution Group, set about finding out to what extent human-induced climate change played a role in the drought, in a world that has already warmed by 1.2°C.
They found high temperatures, driven by climate change, made the drought much more likely to happen – about 25 times more likely in Syria and Iraq, and 16 times more likely in Iran.
The heat accelerated the evaporation of water from soil and plants, making the drought much more severe. But it did not appear to have an impact on rainfall.
The scientists concluded that the drought, the second worst on record which was classed as “extreme” on the US Drought Monitor scale, was driven by soaring temperatures.
“We find that over the [Euphrates and Tigris] basin the likelihood of such a drought occurring has increased by a factor of 25 compared to a 1.2°C cooler world. Over Iran the likelihood of such a drought occurring has increased by a factor of 16 compared to a 1.2°C cooler world,” it said.
“To understand the meteorological drivers behind this change in agricultural drought we also analysed rainfall and temperature separately and found there to be little change in the likelihood and intensity of rainfall but a very large increase in temperature.
“We thus conclude that this strong increase in drought severity is primarily driven by the very strong increase in extreme temperatures due to the burning of fossil fuels.”
In the present climate, events of the drought’s severity are expected to occur at least every decade.
But the authors warn unless the world stops burning fuels, droughts like the one affecting the region will become even more common in the future.
“In a world 2°C warmer than pre-industrial an event like this would be an exceptional drought, the worst category possible,” they say.
Ben Clarke, researcher at the Grantham Institute, Imperial College London's climate change and environment hub, said: “Prolonged heat, driven by climate change, is playing a crucial role in droughts around the world.”
He added: “Attribution studies are showing us that even if climate change doesn’t have a significant influence on low levels of rainfall, higher temperatures are turning many droughts into extreme events.”
Data released by the Copernicus Climate Change Service (C3S) showed an average surface air temperature across the planet of 15.3°C for the month.
This is 0.4°C warmer than the previous global record for October set in 2019 and 1.7°C warmer than the pre-industrial average, between 1850 and 1900.
Recent research by Imperial College found the window to limit global warming to 1.5°C is closing.
The team issued the warning after analysing the global carbon budget, which calculates how much carbon dioxide can be emitted into the atmosphere while keeping temperature rises within certain limits.
The study, published in Nature Climate Change, shows that if carbon emissions remain at 2022 levels of about 40 gigatonnes a year, the carbon budget will be exhausted by about 2029, committing the world to warming of 1.5°C above pre-industrial levels.