Global warming caused by humans fuelled more than a third of excess deaths triggered by high temperatures between 1991 and 2018, research reveals.
The elderly and those with underlying health problems like asthma are at higher risk of disease and early death as rising temperatures bring stronger and more heatwaves.
The study looked at 43 countries to calculate the number of deaths caused by temperatures above the ideal for human health, which varies across locations.
Researchers simulated past weather conditions with and without emissions triggered by human activity, to separate the health impact linked with human activity from natural trends.
Thirty-seven per cent of all heat-related deaths in places looked at were attributable to human activity. But Iran, Kuwait, the Philippines, Thailand and Central and South America had the most climate-change-triggered excess heat deaths at more than 50%.
In the UK, where the overall impacts are smaller compared with most other countries, deaths attributable to anthropogenic or human-caused climate change compare with the overall estimate.
“The impacts are large, time is running fast, and our predictions are conservative,” said Brunel University London’s Dr Ariana Zeka. “And this is considering countries where these impacts will be largest were not included in the analysis,” added the environmental epidemiologist.
The team, led by London School of Hygiene & Tropical Medicine with Brunel and The University of East Anglia, published their report in the journal Nature Climate Change. It comes ahead of the [United Nations climate conference] COP26 in November.
The proportion of unnecessary heat-related deaths is set will grow as climate change worsens, but data from Africa and the Middle East and from Asia are needed to calculate at what rate. Although it is certain the people who'll suffer most are the ones causing the least damage, other impacts such as sea level rise, livelihoods and food and water security will also hit the poorest the hardest.
Last year, despite a 7% fall in fossil fuel burning because of coronavirus lockdowns, global temperatures were 1.2°C above pre-industrial levels. This is uncomfortably close to the 1.5°C target set by the UN. Even half a degree above this is thought to significantly worsen the risks of drought, floods, extreme heat, poverty and threats to security for hundreds of millions of people.
Extracting and burning fossil fuels for transport and energy cause the worst environmental damage. These findings call for shifting to renewable energy on a global scale, urges Dr Zeka. “This requires both a rapid political response coordinated at global and local level. Societal attitudes and awareness of our daily activities must also change, and fast.”