Climate Change

Up to 2.6 billion people in Asia, Africa could be exposed to heatwaves by 2090: IOM

River floods are expected to affect up to 156 million people, with 87% of them projected to live in Asia  

By Kiran Pandey
Published: Friday 08 December 2023
In 2022, close to 62,000 deaths in Europe were attributed to heatwaves. Photo for representation: iStock

Close to 568 million people could be exposed to heatwaves by 2030 under a high-warming (HW) scenario where global temperature rises by 3-4 degrees Celsius by 2100, according to the new Climate Mobility Impacts dashboard of the Global Data Institute at the International Organization for Migration (IOM). Under the scenario, up to 2.79 billion people could be exposed to heatwaves by 2090. 

The open-access interactive tool was launched by IOM on December 5, 2023. The dashboard indicated that of these 2.79 billion, almost 2.6 billion or roughly 93 per cent, are projected to live in  Asia and Africa. 

The low- and high-warming scenarios represent different future trajectories in greenhouse gas concentrations. Under the low-warming (LW) scenario, a global temperature rise below 2°C by 2100 is likely. 

The number of people exposed to heatwaves worldwide under HW scenario will nearly double compared to the number exposed under LW scenario, according to GDI estimates

This indicates that under the HW scenario, the population exposed to heatwaves will grow by two times (over the LW scenario). 

People in Asia and Africa will be most exposed to heatwaves 

All regions — Africa, Asia, Americas, Europe and Oceania — are expected to see a worrying increase in the number of people exposed to heatwave under the HW scenario compared to LW scenario 

Under both the scenarios, over 90 per cent of the population exposed to heatwaves will be in Africa and Asia. So if absolute numbers are considered, most of the people exposed to heatwaves are projected to live in Asia and Africa. 


Population exposed in low warming scenario in 2090 (in millions) 

Population exposed in high warming scenario in 2090 (in millions) 

Increase in population exposed during high warming scenario (over LW scenario) 




2 times increase  




1.7 times increase 




2.15 times increase




2.62 times increase




5.39 times increase




2.94 times increase

The HW scenario will increase the number of people exposed to heatwaves by five times — around 145 million will be exposed to heatwaves by 2090 in the LW scenario compared to 778 million in the HW. 

The recent trends indicate the threat of heatwaves in Europe. In 2023, several countries in the European region experienced record-breaking heatwaves. In 2022, close to 62,000 deaths in Europe were attributed to heatwaves

Oceania will have the second-highest rise in population exposed to the HW scenario relative to the LW. The number of individuals in Oceania who will be exposed to heatwaves by 2090 will rise by more than 2.9 times, relative to the LW scenario. 

In the Americas, a high-warming scenario might expose up to 187 million people to heatwaves by 2090. This is more than 2.62 times the number of people exposed in a scenario with minimal warming.

Heatwaves attributed to climate change have killed thousands of people every year. They will become deadlier with every further increment of climate change, warned the United Nations Office for the Coordination of Humanitarian Affairs, the International Federation of Red Cross and Red Crescent Societies and the Red Cross Red Crescent Climate Centre in October 2022.

No region in the world will be immune to the impacts of climate change, according to the interactive dashboard of the GDI. It shows the level of human exposure to climate hazards and includes heatwaves, droughts, wildfires, river floods, tropical cyclones and crop failure.

156 million to be exposed to river floods in 2090

According to the HW scenario, river floods will potentially affect up to 156 million people by 2090. Asia will account for more than 87 per cent of these. Up to 39 million people are expected to be at risk of river flooding in this scenario, with sub-Saharan Africa's population being most impacted.

The interactive tool can be used to get regional insights into where to prioritise forward-looking and proactive support measures for communities getting exposed to climate-related risks, including displacement.

“In the past decade, over 200 million people have been displaced by floods, storms, and wildfires,” said Koko Warner, IOM GDI director, in a statement. “Understanding how climate change will affect when and where these impacts will occur is crucial for delivering effective anticipatory action and solutions,” she said.

The interactive atlas is a significant initiative of the IOM, as the leaders are negotiating and discussing on how to limit and prepare for future climate change and its impacts, which includes extreme weather events.

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