Heat deaths to mount as world risks warmest summer on record

Scientists and diplomats have warned of a rise in heat deaths as large parts of the world struggle with extreme weather in what is at risk of becoming the hottest June to August period on record.

Selwin Hart, UN special adviser on climate change, told the Financial Times that countries urgently needed to take action to protect people from extreme heat, which he labelled a “silent killer”. He warned that the recent spate of high temperatures was “just a sign of things to come”.

Germany’s climate envoy Jennifer Morgan said climate change was fuelling extreme weather around the world and putting “the most vulnerable segments of the population at risk”.

India is currently grappling with its longest heatwave on record, while the US has issued heat warnings affecting more than 100mn people across more than 20 states in recent days.

Temperatures across parts of southern Europe including Turkey, Italy, Cyprus and Spain have lingered close to 40C this month, while the thermometer hit almost 50C in some Middle Eastern countries such as the United Arab Emirates, two months before the region usually hits its peak temperatures for the year.

Several tourists have been reported dead in Greece as the country was hit by its earliest heatwave on record this month. Meanwhile extreme heat was blamed for more than 1,300 deaths among people taking part in the Hajj pilgrimage as temperatures hit 50C in Saudi Arabia last week.

A report from Copernicus, the European earth observation programme, and the World Meteorological Organization this year found that deaths linked to hot weather in Europe had risen by 30 per cent over the past two decades. It warned of the “profound impact of heat stress on public health”.

Scientists found there were almost 62,000 heat-related deaths across the continent in 2022, the report said. Globally an estimated 490,000 people died of heat-related deaths from 2000 to 2019, according to WMO data.

The June-August period last year was the hottest season on record, while each of the past 12 months have been the warmest on record globally, as a combination of the naturally occurring El Niño weather phenomenon and climate change drove up global temperatures.

Friederike Otto, senior lecturer in climate science at Imperial College London, said that with each fraction of a degree of warming, “dangerous heat is hitting larger regions of the world for many more days of the year”.

“The deadly heatwaves we’re seeing around the world clearly indicate that our climate is warming to dangerous levels,” she said.

She added that “this summer could become the hottest ever recorded, even with El Niño fading and shifting to La Niña”, the corresponding weather phenomenon that typically leads to a cooling of the earth’s surface temperatures.

Copernicus said this month the latter part of the European summer was likely to be warmer than average.

“Human-caused climate change is making heatwaves more frequent and more intense, increasing the likelihood of several events happening concurrently in various parts of the world at a given point in time,” said Julien Nicolas, senior climate scientist at Copernicus.

A study published by academics from the University of California, Berkeley, and Princeton this year said that the strong El Niño at the end of 2023 meant there was a 68 per cent chance of existing records for temperature and humidity being broken across the tropics this year.  

Summer temperatures are typically higher in the months following an El Niño event, which occurs when water in the eastern equatorial Pacific Ocean warms up more than normal.

The WMO said this month that there was now a 70 per cent probability of the opposite La Niña phenomenon occurring between August and November this year, which typically helps to cool global surface temperatures.

But Hart argued the record temperatures over the past year should “inspire urgency” to address the “root cause of the climate crisis”, the high emissions caused by the continued burning of fossil fuels.

He added: “In many of the big cities, even in rich countries, the economically disadvantaged, the poor, the disabled, those are often the silent victims of heatwaves.”

Data visualisation by Jana Tauschinski

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Good design can mitigate effects of city hotspots / From Dima Zogheib, Associate Director, Cities, Planning and Design, Arup, London W1T, UK