World’s climate scientists to issue stark warning
over global heating threat
IPCC’s landmark report will be most comprehensive
assessment yet as governments prepare for pivotal UN talks in November
Fiona
Harvey Environment correspondent
Sun 8 Aug
2021 18.00 BST
The fires,
floods and extreme weather seen around the world in recent months are just a
foretaste of what can be expected if global heating takes hold, scientists say,
as the world’s leading authority on climate change prepares to warn of an
imminent and dire risk to the global climate system.
The
Intergovernmental Panel on Climate Change (IPCC) will on Monday publish a landmark
report, the most comprehensive assessment yet, less than three months before
vital UN talks that will determine the future course of life on Earth.
Policymakers
have already previewed the findings, finalised on Saturday night, which have
been the subject of an intense two weeks of online discussion by experts around
the world, and represent eight years of work by leading scientists.
Doug Parr,
policy director at Greenpeace UK, said governments must take heed of the
warnings. “Practical, funded and deliverable plans [by governments] to keep us
below the supposedly safe limits [of heating] are almost non-existent. Urgent
climate action was needed decades ago – now we’re almost out of time. The UK
government has a huge responsibility as host of the UN climate talks to ensure
world leaders sign up to policies that not just put the brakes on the climate
crisis, but slam it into reverse.”
The IPCC,
made up of hundreds of the world’s foremost climate scientists, publishes
comprehensive assessments about every seven years, with this report the sixth
since 1988. This one will be different, however: previous work has shown that
the 2020s are a crucial decade, in which greenhouse gas emissions must be
halved in order to limit heating to 1.5C above pre-industrial levels,
established by previous IPCC reports as the threshold of safety, and the lower
of two goals in the 2015 Paris agreement.
Michael
Mann, distinguished professor of atmospheric science at Pennsylvania State
University, said this would be the last IPCC assessment that can make a real
difference in policy terms, before we exceed 1.5C and the ambitions of the
Paris agreement.
“Climate
change is now causing amplified weather extremes of the sort we’ve been
witnessing this summer – droughts, heatwaves, wildfires, floods, superstorms,”
he said. “The impacts of climate change are no longer subtle. We see them
playing out in real time in the form of these unprecedented extreme weather
disasters.”
In recent
months there have been fires in the US, heatwaves in northern latitudes, and
devastating floods in China and Europe. Scientists warn that this may become
the norm unless climate breakdown can be stopped.
Simon
Lewis, professor of global change science at University College London, said:
“The observations this summer show that some impacts [predicted in previous
IPCC assessments of the climate] seem to be underestimated, but we can’t know
if the devastation of summer 2021 is the new normal without a few more years’
data. But what we do know is if emissions continue to rise, then increasingly
severe climate impacts will occur.”
He warned
that the consequences would be severe. “What we need to keep in mind is that we
all live in places that have built up over decades and centuries to cope well with
a given climate. The really, really scary thing about the climate crisis is
that every single achievement of every human society on Earth occurred under a
climate that no longer exists,” he said. “The pressure is on for world leaders
to agree both detailed and achievable plans to cut emissions now, and plans to
adapt to climate impacts, when they meet in Glasgow in November.”
This year’s
weather observations are not included in the IPCC report, which draws on
science published in peer-review journals before this year, and since its last
comprehensive report in 2013. Mann said: “This is also a limitation. The IPCC
reports always seem to be playing catch-up with what we’re witnessing on the
ground. Our own work suggests that the models upon which [most IPCC
projections] are made still aren’t quite capturing some of the mechanisms that
are important here.”
Extreme
weather this year has also shown how vital it is that countries and communities
around the world take steps to cope with the impacts, said Richard Betts,
professor of climate impacts at Exeter University, and head of climate impacts
research at the Met Office. “We now need to live with the consequences of what
we have already done to the climate. We are hopelessly unprepared to deal with
increasingly severe extreme weather events, even though these have been
predicted by science for decades.”
Alongside
this effort, we should be cutting emissions much faster, he added. “We need to
take urgent action on reducing emissions if we want to stop this getting much
worse,” said Betts. “The longer it takes to bring this increase [in the buildup
of CO2 in the atmosphere], the greater the severity of climate change we will
be stuck with.”
Alok
Sharma, the UK minister who will preside over the UN’s Cop26 climate talks, to
be held in Glasgow this November, said on Saturday: “This is going to be the
starkest warning yet that human behaviour is alarmingly accelerating global
warming and this is why Cop26 has to be the moment we get this right. We can’t
afford to wait two years, five years, 10 years – this is the moment. [The
consequences of failure would be] catastrophic – I don’t think there’s any
other word for it.”
Rachel
Kennerley, international climate campaigner at Friends of the Earth, said: “The
world’s climate scientists are set to issue a stark warning that cannot be
ignored. The international community must rapidly deliver the speed and scale
of the action required to avoid catastrophic climate change. It’s time to end
our reliance on dirty gas, coal and oil, and invest in green jobs and building
the zero-carbon future we so urgently need.”
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