Sunday 18 August 2019

Heatwaves to be more common - and to cause food shortages

Climate researcher Martha Vogel
Climate researcher Martha Vogel
Claire Murphy

Claire Murphy

Last summer's heatwave would not have happened without greenhouse gas pollution, and further extreme temperatures will mean food shortages, environmental researchers have warned.

Scientists have identified that if global temperatures keep rising we could experience extreme heatwaves every two out of three years.

But the warmer temperatures are not to be celebrated - ultimately it will lead to food shortages and higher prices for consumers, the researchers have warned.

The new study from the ETH Zurich Institute for Atmospheric and Climate Science investigated data from 1958 to 2018 and measured the widespread heatwave last year, which affected 17 countries.

On an average day from May to July last year, 22pc of agricultural land and populated areas in the northern hemisphere were simultaneously hit by extremely high temperatures, according to the research presented in Vienna.

Climate researcher Martha Vogel said that the hot summer temperatures last year "could not have occurred without human-induced climate change".

"Without the climate change that can be explained by human activity, we wouldn't have such a large area being simultaneously affected by heat as we did in 2018," Ms Vogel said. The research further found if global temperatures increase by 1.5C above pre-industrial levels, a quarter of countries in the northern hemisphere will experience a summer as hot as 2018 every two out of three years.

The researchers warned that the rising temperatures will ultimately have a negative impact on agriculture.

"If in future more and more key agricultural regions and densely populated areas are affected by simultaneous heatwaves, this would have severe consequences," said Ms Vogel at the European Geosciences Union press conference.

The researchers investigated model simulations to project how heatwaves could develop by the end of the century.

They identified large-scale heatwaves first appeared in the northern hemisphere in 2010, then in 2012, and again in 2018.

Prior to 2010, however, the researchers did not find any instances of such large areas being affected simultaneously by heat.

Lead researcher Professor Sonia Seneviratne said that if large agricultural areas are affected by a heatwave, this could have a knock-on effect on harvests - which would ultimately drive up food prices for the consumer.

"Ultimately, extreme events affecting large areas of the planet could threaten the food supply elsewhere, even in Switzerland," said Ms Seneviratne.

"If multiple countries are affected by such natural disasters at the same time, they have no way to help one another."

The paper resulting from this study is currently in review for an academic publication.

Irish Independent

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