ISLAMABAD: Heatwaves will become so extreme in certain regions of the world within decades that human life there will be unsustainable, the United Nations and the Red Cross said on Monday.

Extreme-heat event that would have occurred once in fifty years in a climate without human influence is now nearly five times as likely as under 2 centigrade of warming.The report, “Extreme Heat: Preparing for the Heatwaves of the Future” says there are clear limits beyond which people exposed to extreme heat and humidity cannot survive. There are also likely to be levels of extreme heat beyond which societies may find it practically impossible to deliver effective adaptation for all.

Extreme heat is a silent killer whose impacts are certain to grow, posing huge challenges to sustainable development and creating new emergency needs that will demand a humanitarian response, according to the report, jointly released by UN Office for the Coordination of Humanitarian Affairs (UNOCHA), the International Federation of Red Cross and Red Crescent Societies, and the Red Cross Red Crescent Climate Centre.

On current trajectories, heatwaves could meet and exceed these physiological and social limits in the coming decades, including in regions such as the Sahel, and South and South-West Asia. The impacts would include large-scale suffering and loss of life, population movements and further entrenched inequality. These impacts are already emerging.

The impacts of extreme heat are hugely unequal in both social and geographic terms. In a heatwave, the most vulnerable and marginalised people, including casual labourers, agricultural workers, and migrants, are pushed to the front lines. The elderly, children, and pregnant and breastfeeding women are at higher risk of illness and death associated with high ambient temperatures.

There is compelling evidence that the world’s lowest-income countries — those least responsible for climate change — are already experiencing disproportionate increases in extreme heat. The combined effects of warming, ageing and urbanization will cause a significant increase in the number of at-risk people in developing countries in the coming decades.

Projected future death rates from extreme heat are staggeringly high — comparable in magnitude by the end of the century to all cancers or all infectious diseases — and staggeringly unequal, with people in poorer countries seeing far greater levels of increase.

Cities are at the epicentre of vulnerability to heatwaves. Informal and off-grid settlements, which share many characteristics with camps in humanitarian settings, are at particularly high risk. Analysts project a 700 per cent global increase in the number of urban poor people living in extreme-heat conditions by the 2050s.

Extreme heat will also increasingly undermine agriculture and livestock systems, degrade natural resources, damage infrastructure and contribute to migration. The International Labour Organisation projects that economic losses related to heat stress will rise from $280 billion in 1995 to $2.4 trillion in 2030, with lower-income countries seeing the biggest losses.

To prevent a future of recurrent heat disasters, aggressive steps are needed now. The single most important arena for action is in slowing and stopping climate change. Limiting global warming to 1.5°C rather than 2°C could result in up to 420 million fewer people being frequently exposed to extreme heatwaves and around 65 million fewer people being frequently exposed to ‘exceptional’ heatwaves.

Published in Dawn, October 11th, 2022