Climate change: global warming of 2.7 degrees will expose 2 billion people to ‘dangerous heat’ by end of century, study shows
- Some 2 billion people or 20 per cent of the world’s population will be exposed to dangerous heat conditions if global warming reaches 2.7 degrees, study says
- India and Nigeria will be the two countries with the greatest population exposed at this level of global warming
Some 2 billion people, or more than a fifth of the global population, will be exposed to dangerously hot temperatures by the end of this century if the world reaches 2.7 degrees Celsius of global warming, according to research that outlines the human cost of climate change.
Reducing global warming from 2.7 to 1.5 degrees, as sought under the Paris Agreement, could reduce the population exposed to unprecedented heat – those living under an average annual temperature of 29 degrees or higher, by five-fold, protecting a sixth of the world’s population by 2100, according to the study by researchers at the Global Systems Institute at the University of Exeter and Nanjing University, which was published in the peer-reviewed journal Nature Sustainability on Monday.
Compared to previous studies, which often estimated the cost of global warming in financial terms, this study highlights “the phenomenal human cost of failing to tackle the climate emergency”, according to Tim Lenton, professor and director of the Global Systems Institute.
“For every 0.1 degree of warming above present levels, about 140 million more people will be exposed to dangerous heat,” said Lenton. “This reveals both the scale of the problem and the importance of decisive action to reduce carbon emissions.”
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The study starkly detailed how the narrow subset of earth’s inhabitable climate, the “human climate niche”, is rapidly shrinking, putting millions in the future at risk.
About 600 million people, or 9 per cent of the current world population, are already exposed to dangerous heat conditions, the researchers found. If global warming reaches 3.6 or even 4.4 degrees, half of the world’s population could be left outside the climate niche, posing what the researchers call an “existential risk”.