Heatwaves to become more frequent, longer and hotter due to climate change

Women going for a swim on Bull Wall in Dublin today. Photo: Brian Lawless/PA

Heatwaves like the one engulfing parts of Europe and the US will start earlier, become more frequent, and will be longer and hotter because of climate change, the World Meteorological Organisation (WMO) has warned.

The likes of Spain and France are experiencing intense heat in patterns rarely seen this early in the year, while nearly a third of the American population is under some form of heat advisory, it said.

"Although it is only mid-June, temperatures are more typical of those witnessed in July or August. The ongoing episodes follow a prolonged heatwave in India and Pakistan in March and April.

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"As a result of climate change, heatwaves are starting earlier and are becoming more frequent and more severe because of record concentrations of heat-trapping greenhouse gases," the WMO said.

People living in cities are even more vulnerable, according to its experts. "City dwellers are particularly susceptible because of the so-called urban heat island effect which magnifies heat impacts compared to the countryside where there is more vegetation," the WMO said.

According to the website Science Direct, so-called "heat islands" are urban or metropolitan areas that are significantly warmer than their surrounding rural areas due to human activities.

The UN advised in November last year that the world’s cities are warming at twice the global average rate. 

Milo Kinsella, Eli Harrison and Finton Deasy jump into Glandore Harbour after a day's sailing to cool off. Photo: Andrew Harris

The energy requirement for space cooling is predicted to triple from 2016 to 2050 as millions of households in developing countries acquire air conditioners in the coming decades, the UN's Environment Programme warned.

Overheated cities face disproportionate climate costs due to ‘heat island effect’ and the average city could warm as much as 4°C by 2100, it added. Similarly, the Red Cross warned in a report on heat islands in 2019 that "the urban poor frequently bear the brunt of this silent emergency".

It said:

In addition to threatening the lives and health of vulnerable populations, heatwaves have cascading impacts in other areas of society, such as reduced economic output, strained health systems and rolling power outages.

In relation to the current heatwaves, which have seen Irish holidaymakers caught up in ferocious temperatures unfamiliar to even the most heat-hardened, the Red Cross said simple measures could be taken to avoid serious health implications.

“Due to climate change, heat waves are on the rise globally — getting both hotter and longer. But they don't need to lead to tragedy. There are simple actions we can all take to protect ourselves, our neighbours, our family members and friends. 

"These include drinking water, resting in the shade, and avoiding outdoor activity in the hottest part of the day,” said Francesco Rocca, president of the International Federation of Red Cross and Red Crescent Societies (IFRC).

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