Climate change caused an early heat wave in West Africa that was ten times more likely
In mid-February, a remarkably early, record-breaking heat wave hit the southern part of West Africa. Climate change made this extreme heat ten times more likely, according to a new analysis by an international team of scientists. It also pushed the heat index about four degrees Celsius higher than it would have been without the extra greenhouse gases in the atmosphere from burning fossil fuels.
Officials saw the unusual temperatures coming and national weather agencies in Ghana and Nigeria warned the public. The Africa Cup of Nations football tournament took place in Ivory Coast during the heat wave and players had to take extra breaks during the matches to hydrate.
What was particularly striking about this heat wave was the onset of high temperatures so early in the year, when people had less time to adapt to rising temperatures. “Many, many people would not have acclimatized to the heat,” said Wasiu Adeniyi Ibrahim, head of the Nigerian Meteorological Agency’s central forecast office and author of the study.
During the heat wave, humidity increased the danger. During the worst of the event, temperatures rose above 40 degrees Celsius, or 104 degrees Fahrenheit. But the high humidity made the air feel even hotter. The heat index, which measures the combined effect of heat and humidity on the human body, rose to about 50 degrees Celsius or 122 degrees Fahrenheit.
Researchers have limited data on how this heat has affected people more broadly in West Africa, and whether it has led to many hospitalizations and deaths. But there is reason to believe there may be widespread damage, said Maja Vahlberg, a risk advisor at the Red Cross Red Crescent Climate Center and one of the authors of the analysis.
Many residents of the region do not have adequate access to water, energy and sanitation. That means that during heat waves, people have “very limited options for individual coping strategies, such as using air conditioning and drinking or showering more often,” Ms. Vahlberg said. About half of the region’s urban population lives in informal housing, including houses built with sheet steel, which retains heat.
The elderly, people with existing illnesses and outdoor workers are especially vulnerable to extreme heat.
The analysis, conducted by a group known as World Weather Attribution, took longer than similar studies the group’s scientists have conducted on other extreme weather events. West Africa has less data from weather stations than other parts of the world, making studies linking weather there to climate change more difficult to conduct. But last month’s extreme heat was an early sign, before spring had even started, of what would happen this summer in this region and across the Northern Hemisphere.