Global warming has increased the risk of drought in the Horn of Africa by about a hundred times, according to research by the international research group World Weather Attribution. The ongoing severe drought would not have happened without greenhouse gas emissions.
The researchers state that the drought in the area in East Africa is not only related to the amount of rain, but especially to how much water immediately evaporates. When the soil is warmer, a lot of water evaporates before it is absorbed. And evaporation goes faster when it’s warmer.
‘Shocking result’
The researchers are increasingly looking at a connection between global warming and natural disasters. “Sometimes it is impossible to demonstrate whether something is caused by climate change,” says Gerbrand Koren, assistant professor at Utrecht University and one of the researchers. But in this case it clearly was. Koren speaks of a “shocking result”.
More rain does not necessarily solve the drought. “Without precipitation, of course, nothing can be recorded. So that precipitation is important, but the effect of that temperature is much greater, it now appears,” says Sjoukje Philip of KNMI, also one of the researchers.
The temperature rise of 1.2 degrees Celsius, which the researchers calculated, therefore has a major impact on the fertility of the soil. For the Horn of Africa, warming is a bigger problem than for many other areas. Because in areas where much more rain falls, it is less worrying if part of it evaporates.
The drought in the Horn of Africa has been causing enormous problems for years. People and animals are dying and crops barely grow, resulting in conflicts and displaced inhabitants. “In the last two years, about one and a half million people have been displaced in the region, with an increase in the past six months,” said Astrid van Genderen Stort of the UN refugee agency UNHCR in January this year.
About 43,000 Somalis died last year due to the country’s worst drought in 40 years, according to a report by the World Health Organization (WHO) and UNICEF. Neighboring countries Ethiopia and Kenya are also suffering from the drought.
Rainy periods
There are two rainy periods in the Horn of Africa. Over the past few years, the researchers have not been able to detect any trend over the two periods together that could link a lack of precipitation to climate change. “Less rain can be part of the normal variation, it doesn’t have to be due to climate change,” says Koren.
Regardless of whether it rains more or less in a whole year; it also matters when that precipitation falls, says researcher Philip. If that happens in a relatively short period of time, the moisture will not always penetrate the soil. “With such a short, heavy rain period, the soil does not absorb the water well. The risk of flooding then increases because a lot of water flows away, instead of entering the soil.”
The fact that dry soil absorbs less water than more saturated soil is not new, but that warming does lead to so much more evaporation. An important scientific conclusion, but it does not solve the problem for the inhabitants.
“There are global initiatives to slow down climate change,” says Gerbrand Koren. But that does not mean that the warming has disappeared. So we need to see what can help. “What is possible is looking at local solutions, such as opting for other crops or better irrigation,” adds the researcher.
In any case, the problem is not necessarily solved with more rain, the researchers believe.
- Hardly any rain in the Horn of Africa again, ‘situation increasingly distressing’
- Climate scientists: every heat wave now has a link to climate change
- Tens of thousands of Somalis died during record drought last year
