Scientists believe climate disruption will bring more extreme weather, and humans are making things worse
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A flooded street in Bad Münstereifel, western Germany, after heavy
rain hit parts of the country. Photograph: Ina Fassbender/AFP/Getty Images |
Are the European floods linked to the climate crisis?
Almost certainly. Scientists have long predicted climate disruption will lead to more extreme weather, such as heatwaves, droughts and floods. Human emissions from engine exhaust fumes, forest burning and other activities are heating the planet. As the atmosphere gets warmer it holds more moisture which brings more rain. All the places that recently experienced flooding – Germany, Belgium, the Netherlands, London, Edinburgh, Tokyo and elsewhere – might have had heavy summer rain even without the climate crisis, but the deluges were unlikely to have been as intense.
But there have always been floods and heatwaves. What is the evidence that
humans are making them worse?
First, more records
are being broken more often; the world’s seven hottest years in recorded history have all come since 2014.
Second, scientists can now use statistical analysis and computer models to
calculate how much more likely particular weather events have become as a result
of the extra stress that humans have put on the climate system. For example,
human emissions made the
deadly “heat dome”
in Canada and North America last month at least 150 times more likely and the
prolonged heatwave in Siberia last year
more than 600 times more probable. Richard Betts, the head of climate impacts research at the Met Office Hadley
Centre, says such calculations
take away the argument
that “extreme weather happens anyway, so we don’t need to worry about it”. There
has not yet been an attribution study for the latest floods in Europe because
the analysis takes several days.
Some reports suggest the floods may be linked to a disruption of the jet
stream. Is that confirmed?
This is an important unknown. Climate scientists are looking at this as one of
several possible explanations for the previously unimaginable spike in some
recent records. The 24-hour rainfall at
Cologne’s Stammheim station
on Wednesday of 155mm (6.1in) smashed the city’s previous daily rainfall high of
95mm. Two weeks ago,
temperatures at Lytton
beat the previous Canadian daily heat record by a staggering 5C. These numbers
are outside worst-case scenarios, which could be the result of freak bad luck or
knock-on effects from other areas of climate disruption. One theory is the loss
of ice in the Arctic has made the jet stream more erratic. There is not yet a
scientific consensus on this topic, but experts are increasingly concerned the
world could be in for a bumpier ride than previously thought.
Will the UK have more floods and heatwaves?
Yes. The flash floods
in London, Edinburgh and elsewhere last week were unusual compared with the past, but
they will be more common in future. Over the course of this century, the Met
Office Hadley Centre
predicts
“warmer, wetter winters and hotter, drier summers along with an increase in the
frequency and intensity of extremes”. If emissions are not cut, it says severe
heatwaves, such as that of 2018, would be likely every other year by 2050.
Although summers would generally be drier, there would be an increase in
intensity of heavy rainfalls.
Why do so many news reports about extreme weather underplay the climate
connection?
In some media organisations, this appears to be part of a deliberate strategy to
undermine climate science and the political impetus to reduce emissions. Habit
also plays a part. For decades, journalists have depicted heatwaves as a good
news story to be casually illustrated with pictures of sunbathers, ice creams
and swimming pools. Excess caution can also make reporters timid about making
the link with the climate crisis. On Wednesday, the climate scientist Ed Hawkins
took the BBC to task
for this and for failing to keep up with the science. From now on, he suggested
journalists use the phrase: “Experts say that climate change is already
increasing the frequency of extreme weather events, and many single events have
been shown to have been made worse by global warming.”
Links
- Europe Flooding Deaths Pass 125, and Scientists See Fingerprints of Climate Change
- European Floods Are Latest Sign of a Global Warming Crisis
- The Extent of Flooding in the Hardest-Hit Areas of Europe
- Hundreds Missing and Scores Dead as Raging Floods Strike Western Europe
- ‘It’s all wrecked’: German town stunned by flood damage
- Death toll exceeds 150 as Germany and Belgium hit by devastating floods
- Aftermath of Germany and Belgium floods – in pictures
- Climate scientists shocked by scale of floods in Germany
- Merkel and Biden express sympathy for German flood victims – video
- Germany floods: stranded residents rescued by helicopter from rooftops – video
- At least 58 dead in Germany as heavy rains bring catastrophic flooding
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