Climate
crisis to blame for dozens of ‘impossible’ heatwaves, studies reveal
Exclusive:
Analyses are stark evidence of how global heating is already supercharging
deadly weather beyond anything ever experienced by humanity
Damian
Carrington Environment editor
Mon 18 Nov
2024 06.00 GMT
At least 24
previously impossible heatwaves have struck communities across the planet, a
new assessment has shown, providing stark evidence of how severely human-caused
global heating is supercharging extreme weather.
The
impossible heatwaves have taken lives across North America, Europe and Asia,
with scientific analyses showing that they would have had virtually zero chance
of happening without the extra heat trapped by fossil fuel emissions.
Further
studies have assessed how much worse global heating has made the consequences
of extreme weather, with shocking results. Millions of people, and many
thousands of newborn babies, would not have died prematurely without the extra
human-caused heat, according to the estimates.
In total,
studies calculating the role of the climate crisis in what are now unnatural
disasters show 550 heatwaves, floods, storms, droughts and wildfires have been
made significantly more severe or more frequent by global heating. This
roll-call of suffering is only a glimpse of the true damage, however. Most
extreme weather events have not been analysed by scientists.
The new
database of hundreds of studies that analyse the role of global heating in
extreme weather was compiled by the website Carbon Brief and shared with the
Guardian. It is the only comprehensive assessment and provides overwhelming
proof that the climate emergency is here today, taking lives and livelihoods in
all corners of the world.
The studies
have examined the impacts resulting from about 1.3C of global heating to date.
The prospect of 2.5C to 3.0C, which is where the world is headed, is therefore
catastrophic, warn the scientists. They urge the world’s nations meeting at the
Cop29 climate summit in Azerbaijan to deliver deep and rapid cuts to carbon
emissions and to fund the protection desperately needed by many communities
against now-inevitable climate disasters.
The science
of determining the role of global heating in extreme weather events is called
attribution. In its early days, more than a decade ago, the relatively subtle
influence detected was likened to finding the fingerprints of climate change.
Today, the influence is so obvious that the researchers are instead like eye
witnesses to a crime.
“Some say
climate scientists shouldn’t paint a picture of doom and gloom. But we are
humans, we have feelings, we have children,” said Dr Joyce Kimutai at Imperial
College London, UK, part of the World Weather Attribution group and an adviser
with Kenya’s Cop29 delegation.
“The
increasing role of climate change in the intensities of extreme weather events
is definitely worrying,” she said. “And if this continues it’s really going to
be difficult for everyone. The climate crisis is not discriminating how it
affects people. It’s hitting every part of the world.”
Kimutai said
the attribution studies show the “critical need” for a huge increase in the
funding for protecting people from extreme weather, especially those
communities already vulnerable to heatwaves, floods and storms. She said levels
of funding were “strikingly and painfully insignificant compared with needs”.
Delivering at least a trillion dollars of finance is a key task for negotiators
at Cop29 in Azerbaijan.
“The sheer
weight of this evidence reinforces the impact that human-caused warming is
having today – not at some far-off point in the future,” said Robert McSweeney,
at Carbon Brief, who compiled the database.
The
impossibles
The
impossible extreme weather events, ie those with a vanishingly low probability
of happening without the turbocharge of human-caused global heating, are
particularly striking.
They show
that the burning of fossil fuels has so dramatically changed the climate that
heatwaves are hitting communities with a severity and frequency never seen
during the entire development of human civilisation over the past 5,000 years.
It is a new world, for which cities, hospitals, roads and farms are unprepared,
and a world that gets even more dangerous every day as carbon emissions
continue to be pumped into the atmosphere.
Nowhere is
safe. In the last two years, previously impossible heat struck from the
Mediterranean to Thailand, and from the Philippines to the highly vulnerable
populations inSahel in Africa at the end of Ramadan. In the two years before
that, both North America and Europe sweltered in unprecedented heat, along with
South Korea and even the icy Tibetan plateau.
The trail of
impossibly scorched earth stretches back even further: China and Russia and the
Arctic – where one town recorded 38C – in 2020, Europe again in 2019 and
swathes of the northern hemisphere in 2018.
The earliest
recorded impossible heatwaves were in 2016, when in fact the heat the entire
planet then endured could not have occurred without global heating. The oceans
have also suffered, with impossible marine heatwaves striking the Tasman Sea,
north-east Pacific and Arctic ocean in recent years.
Many other
extreme events have been made far more likely, heavily loading the weather
dice. The sweltering heat in northern India and Pakistan in May 2022 was made
100 times more likely, as was the torrential rain that caused appalling
flooding in Libya in September 2023 and the Amazon river basin drought in 2023.
The
consequences
Attribution
scientists are no longer only analysing the extreme weather events themselves
but also making the human cost tangible by estimating how much of the damage
caused would have been avoided if fossil fuel burning had not heated the world.
One study
has found that one in three newborn babies that died due to heat would have
survived if global heating had not pushed temperatures beyond normal bounds –
that is about 10,000 lost babies a year. The study assessed low and middle
income countries from 2001-2019.
Another
study of heat-related deaths in summer from 1991-2018 also found a deadly
impact of global heating in the 43 countries assessed. Extrapolating these
findings to a global figure is not straightforward, but an approximate estimate
given by the scientists is more than 100,000 deaths a year. Over the two
decades, that implies a toll of millions of lives due to the climate crisis.
The deadly
supercharging of extreme weather is not new – it has existed for at least 20
years, largely undetected. But more than 1,000 people who died prematurely in
the UK in the 2003 heatwave would have lived without global heating.
More
recently, the increased intensity of 2017’s Hurricane Maria, fuelled by climate
change, was the reason for 3,700 deaths in Puerto Rico, while 13,000 people
would not have been forced from their homes by Tropical Cyclone Idai in
Mozambique in 2019 without global heating.
Global
heating is destroying homes as well as lives. Hurricane Harvey would not have
flooded 30%-50% of the US properties that it did submerge in 2017 without
global heating.
It has
driven up the price tags of hurricane destruction by billions of dollars, such
as Hurricane Sandy in the US in 2012 and Typhoon Hagabis in Japan in 2019. Four
major floods in the UK would have caused only half the $18bn of wrecked
buildings were it not for human-caused climate change.
Adding to
this litany of destruction is the loss of crops in the US and Southern Africa,
with global heating responsible for taking billions of dollars worth of food
off people’s table. It is changing cultural events too, playing a major part in
the early flowering of the famous cherry trees in Kyoto, Japan, the earliest
date in more than 1,200 years of records.
The details
The 744
attribution studies collated by Carbon Brief used weather data to compare
extreme events in today’s heated climate with the same events in computer
models of the climate that existed before large-scale fossil fuel burning. This
comparison allows the scientists to calculate how much more likely and severe
the extreme event was today, revealing the role of human-caused global heating
in worsening the event.
Three-quarters
of the analyses of extreme weather events found global heating made them more
severe or more likely to occur. A further 9% were made less likely, as would be
expected as these were mostly extreme cold and snow events. The rest found
either no discernible influence of global heating or were inconclusive, in part
due to lack of sufficient data. The analysis includes studies published up to
the end of September 2024.
Major parts
of the world, outside Europe, North America and China, have been little studied
by attribution scientists, leaving the true impacts of the climate crisis
underreported. Issues include lack of long term weather data and scientific
capacity. There are particularly few in the Middle East and North Africa,
despite these regions being both among the hardest hit and the biggest fossil
fuel producers.
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