West Africa's deadly heat wave driven by climate change, scientists say

In late March and early April, as Ramadan was coming to a close, a powerful heat wave descended on West Africa. A new report says it would not have occurred withouthuman-caused climate change.

The day and nighttime temperature soared above 40 C in many countries between March 31 and April 4.

The heat wave in Mali and Burkina Faso was so severe that it was equated to a once-in-200-year event, according to a report on the Sahel region by World Weather Attribution (WWA), a U.K.-based group.

The WWA's report, produced by a team of international scientists, concluded the temperatures would not have been reached if industry had not warmed the planet by burning fossil fuels and other activities.

"We find that a five-day heat wave of this intensity would not have been possible," Clair Barnes, a WWA statistician and a research associate at Imperial College London, said in an online briefing.

"This trend is projected to continue as the world continues to warm."

WATCH | Extreme heat causes extensive health problems:

Deadly West African heat wave driven by climate change, scientists say

3 months ago

Duration 2:04

As a heat wave with temperatures nearing 50 C stretches from Senegal to Chad, hundreds have died, and climate scientists say temperatures this high would not have been possible without human-induced climate change from greenhouse gas emissions.

Extreme heat worsened by climate change

West Africa is accustomed to stretches of hot weather in April, but according to the report:

• The extreme heat over a five-day period observed in Mali and Burkina Faso would have been 1.5 C cooler if not for human-caused climate change.
• The nighttime temperatures would have been 2 C cooler.
• El Nio, a natural cyclical phenomenonin the Pacific Ocean that warmsthe atmosphere above it, played only a minor role in the heat wave, leading to a 0.2 C increase.

Extreme temperatures were reported across the Sahel region, including in Senegal, Guinea, Mali, Burkina Faso, Niger, Nigeria and Chad.

The analysis was not subject to peer review.

The WWA, founded in 2015, studies extreme weather events, such as droughts, floods and heat waves,and how climate change plays a role in them, as part of the growing field of attribution science.

The reports are often subsequently published in scientific journals. Last year, the research group concluded the wildfires in Quebec were made twice as likely because of climate change.

WATCH | More on the heat wave in West Africa:

CBC's Natasha Fatah talks to climate scientist Kiswendsida Guigma about the heat wave in West Africa

3 months ago

Duration 5:38

CBC's Natasha Fatah talks to climate scientist Kiswendsida Guigma about the heat wave in West Africa

Heat wave's full impact not yet known

The heat wave coincided with power outages and Ramadan, the Muslim holy month that involves fasting from dawn until sunset.

The fasting, which includes abstaining from drinking water and other beverages, compounded the danger from the heat,said Kiswendsida Guigma, a climate scientist at the Red Cross Red Crescent Climate Centre who contributed to the report. The temperature remained high overnight, as well, further contributing to the issue.

"The impacts are really severe on people," he told CBC News.

The researchers noted that death tolls from heat waves are often underreported and not known until months after the event, but said the Gabriel Tour hospital in Bamako, Mali, reported a surge in admissions and deaths.

The hospital recorded 102 deaths over the four-day period, according to the report. It's far more than usual a year ago, it saw 130 deaths over the entire month of April.

The need to reduce worldwide emissions

Guigma said the findings drive home the need to reduce greenhouse gas emissions and for additional support from the global community. He said the parts of Africa most impacted by climate change are also contributing "close to nothing" to the actual emissions meaning they're experiencing the consequences of other people's actions.

In 2021, the average NorthAmerican emitted 11times more energy-related CO2than the average African, according to the International Energy Agency.

The Sahel region is one of the most vulnerable areas in Africa for extreme heat because of its relatively larger land mass, meaning it warms up faster. Furthermore, Burkina Faso and Mali are among countries that will be almost unlivable for humans by 2080, if temperatures continue to rise at their current pace, according to a study from the University of Exeter in the U.K.

Dr. Wassila Thiaw, a meteorologist with the National Oceanic and Atmospheric Administration's climate prediction centre, has been watching the weather in the region closely.

He said such extreme heat brings concern of health impacts, particularly for children, older people and those with pre-existing conditions.

As the climate continues to warm, Thiaw said a strategy to deal with extreme weather in the region will be crucial.

"It's important that we start talking to government about this issue and at least minimize exposure and impact to human beings," he said.