Very early in mid-February, a record-breaking heat wave hit southern West Africa. Climate change has made such extreme heat events ten times more likely, according to a new analysis by an international team of scientists. It also made the heat index about 4 degrees Celsius higher than it would have been without the additional greenhouse gases in the atmosphere from burning fossil fuels.
Officials have seen abnormal temperatures approaching, and national meteorological services in Ghana and Nigeria have issued warnings to the public. Because the African Cup of Nations soccer tournament was held in Ivory Coast in the sweltering heat, players had to take extra breaks to rehydrate during the game.
What's particularly striking about this heat wave is that the high temperatures began early in the year, giving people less time to adjust to the rising temperatures. “Many people may not have adapted to the heat,” said Wasiu Adeniyi Ibrahim, director of the Central Forecasting Department at the Nigeria Meteorological Service and author of the study.
During hot periods, humidity increases the risk. During the worst of the outbreak, temperatures rose above 40 degrees Celsius (104 degrees Fahrenheit). However, the high humidity made the air feel hotter. The heat index, which measures the effects of heat and humidity on the human body, rose to around 50 degrees Celsius (122 degrees Fahrenheit).
Researchers have limited data on how the heat has affected people across West Africa more broadly, and whether it has led to many hospitalizations and deaths. But there is reason to believe there may have been widespread damage, according to Maja Vahlberg, a risk consultant at the Red Cross Red Crescent Climate Center and one of the authors of the analysis.
Many people in the region do not have adequate access to water, energy and sanitation. This means that during heat waves, “people have very limited choices for personal coping strategies, such as using air conditioning, drinking alcohol or showering more,” Mr. Vahlberg said. About half of the region's urban population lives in informal housing, including houses built with heat-trapping sheet metal.
Elderly people, people with underlying health conditions, and outdoor workers are especially vulnerable to heat waves.
The group's analysis, known as World Weather Attribution, took longer than similar studies the group's scientists have conducted on other weather extremes. West Africa has less data available from weather stations than other regions of the world, making it more difficult to conduct research linking weather there and climate change. But last month's extreme heat was an early sign of what was to come for both the region and the rest of the Northern Hemisphere this summer, even before spring had begun.