Europe swelters even if Paris targets are met

If global temperatures reach 2°C above pre-industrial conditions, it becomes twice as likely that Europe will see a return of a heatwave similar to that of 2003, which led to 70,000 deaths. A 2°C rise also triples the odds of another year like 2016 – currently Europe’s hottest year on record.

These are the findings of a new paper released in Environmental Research Letters, which looks at how climate extremes in Europe will change if global temperatures hit 1.5°C and 2°C above pre-industrial temperatures.

“Extreme hot temperatures were always projected to be the first and strongest change in weather patterns with climate change, so an increase in extreme heat events was expected,” said lead author Dr Andrew King from the ARC Centre of Excellence for Climate System Science.

“But what is startling is the speed of the change. At 2°C, events like the 2003 heatwave could become so commonplace that they occur every second year.”

The authors also looked beyond heatwaves, examining how the number of record cold days and record precipitation events may change.

In terms of record cold events, the chance of them repeating dwindled close to zero even at global warming levels of 1.5°C above pre-industrial conditions.

Changes in rainfall across Europe were less clear-cut in terms of total precipitation over the course of a month. However, there appeared to be a 10% increase in the likelihood of record breaking one-day rainfall events.

To get their results the researchers looked at record events in the observational record, such as Europe’s hottest year on record, the 2003 summer heatwave, Britain’s coldest December on record in 2010 and some of the wettest months on record for Southern Europe and the British Isles.

They then compared the likelihood of these events recurring by modelling four different climates, a natural world without human emissions, the current world, a world where global temperatures had risen 1.5°C and a world where global temperatures had reached 2°C.

More than 10,000 model runs were used to produce the results.

“There were substantial differences in the number of these record heat events between a world 1,5°C warmer and a world 2°C warmer than today,” said Dr King.

“This clearly showed that strong action to keep global warming within the Paris Agreement targets has clear benefits in reducing the number of extreme events and the costs they have on our society.”

 

Paper: Climate extremes in Europe at 1.5 and 2 degrees of global warming. Environmental Research Letters.
Picture (top left): Paris by Grant Lemons (Unsplash).

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