Consecutive years of low rainfall in Madagascar in the Indian Ocean have ruined crops and left hundreds of thousands of people insecure about their next meals. Aid agencies say the situation there is approaching a humanitarian disaster.
But human-induced climate change does not appear to be the driving cause, a team of climate scientists said Wednesday.
Rainfall in hard-hit southern Madagascar naturally fluctuates quite a bit, the researchers said, and they didn’t find that a warming climate made prolonged droughts significantly more likely.
Still, they stressed that the island still needs to try to bolster its ability to cope with dry spells. Scientists convened by the United Nations have determined that drought in Madagascar as a whole is likely to increase if global average temperatures rise by more than 2 degrees Celsius — a higher level of warming than the 1.2 degrees found in the new analysis. considered.
The average temperature on Earth has already risen by 1.1 degrees Celsius from pre-industrial levels. Scientists have said countries should try to prevent temperatures from rising more than 1.5 degrees Celsius or 2.7 degrees Fahrenheit, which is the threshold above which they say the chances of catastrophic fires, floods, droughts, heat waves and other disasters are significant. increases. Current policies put the planet on course for a warming of about 3 degrees Celsius by 2100.
“What it shows is that current climate variability is already causing severe humanitarian suffering,” said Maarten van Aalst, director of the Red Cross Red Crescent Climate Center and one of 20 scientists involved in the Madagascar research. “In places like this, anything that would exacerbate climate change would very quickly become a very big additional problem.”
A large island off the east coast of Africa, Madagascar is known for its sandy beaches, emerald waters and ring-tailed lemurs. But low rainfall since 2019 in the country’s southwestern end — known as Le Grand Sud, or the Deep South — has left that part of the island in a dire state.
According to the United Nations, more than 1.3 million people, or nearly half of Grand Sud’s population, experience high levels of food insecurity. Half a million children under the age of 5 are at risk of severe malnutrition.
The climate researchers estimated that such a long dry spell had a one in 135 chance of occurring in that part of Madagascar in any given year.
Environmental degradation has exacerbated the effects of the drought. Sandstorms fueled by deforestation have devastated cropland and pastures. An outbreak of locusts threatens further destruction.
According to the United Nations World Food Programme, residents of the Grand Sud are forced to eat grass, leaves and even clay to survive. Children have dropped out of school to help their families forage for food. Amnesty International has collected testimonies suggesting that some people have starved to death.
The drought analysis was conducted by an international scientific collaboration called the World Weather Attribution Initiative, which specializes in uncovering the links between climate change and individual weather events. The group conducts such analyzes at a speed that is unusual in the world of scientific publishing: it aims to present sound science to the public while the events are still fresh in their minds.
The team’s Madagascar study is not peer-reviewed, although it is based on peer-reviewed methods. Essentially, the approach to use computer simulations to compare the existing world, in which humans have been pumping greenhouse gases into the atmosphere, is to a hypothetical world without that activity.
It may seem counterintuitive that global warming is not contributing to a marked increase in the likelihood of drought. However, scientists have found that the relationship is not so simple. Climate change generally causes more intense rainfall, but also shifts rainfall patterns.
“Drought has so many dimensions,” says Dr. van Aalst. “It’s not as simple as just, how much average annual rainfall do you get? The question is also, do you get it nicely distributed, or do you just get it in huge quantities at once? Will you make it in the right seasons?”
“We have to be a little bit careful,” he added, “drawing too straight a line from purely our precipitation observations or projections to what ultimately affects people.”
World Weather Attribution has linked other extreme weather events to man-made climate change in recent years. The group found that this summer’s extraordinary heatwave in the Pacific Northwest almost certainly wouldn’t have happened without it.
For climate scientists, “drought is a combination of factors that is much more difficult to deal with” than, say, heatwaves, said Piotr Wolski of the Climate System Analysis Group at the University of Cape Town in South Africa.
“We have the predominant story today that drought is largely caused by anthropogenic climate change,” said Dr. Wolski, who also worked on the Madagascar study. “It’s not a bad story, because they are — it’s just not everywhere and not in all cases.”
In Madagascar, livelihoods are easily destabilized by wild swings in precipitation, said Daniel Osgood, a research scientist at the International Research Institute for Climate and Society at Columbia University who was not involved in the study.
dr. Osgood is working on a project to provide farmers in Madagascar with affordable drought insurance. The aim is to help them become more resilient to the economic shocks that the weather can cause. “It’s not about how much you eat on average,” he said. “It’s how much you eat each night that really makes a difference.”