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https://www.positive.news/environment/were-likely-to-breach-1-5c-what-happens-next-is-still-in-our-hands/>
"For almost a decade, keeping global warming below 1.5C has been one of the
defining goals of global climate action. Now, for the first time, the UN
Environment Programme (UNEP) has concluded that the world is likely to breach
that threshold within the next few years, while also making clear that crossing
it does not mean temperatures have to remain there or that further efforts to
limit warming become futile.
Published on Wednesday, UNEP’s
Limiting Overshoot report describes what it
calls an “overshoot, peak and decline” pathway, in which temperatures rise
beyond 1.5C before peaking as greenhouse gas emissions fall towards net zero,
then begin to decline if humanity succeeds in removing more carbon dioxide from
the atmosphere than it releases.
Under the most ambitious scenario examined by UNEP, warming would peak at
around 1.8C by the middle of the century. By contrast, policies currently in
place would put the world on course for around 2.6C of warming by 2100,
according to the report, which underlines why every fraction of a degree
avoided continues to reduce the scale of harm.
Climate scientists have long warned that 1.5C is not a line separating a safe
world from one in which further action becomes pointless. Risks increase as
temperatures rise, so a world that reaches 1.6C is less dangerous than one that
reaches 1.7C, while spending a shorter period above 1.5C would also reduce the
damage compared with remaining there for decades.
“The 1.5 limit is not ‘some magical climate cliff’ where it’s just game over,”
Andrew Weaver, a climate scientists at the University of Victoria, Canada, who
was not involved with the report, told the
Associated Press. “Every tenth of
a degree we avoid still means less damage.”
Although 2024 was the first individual year in which average global
temperatures exceeded 1.5C above pre-industrial levels, the Paris agreement
threshold is assessed over a longer period rather than a single unusually hot
year. Sustained warming is now estimated at around 1.4C, meaning the world has
not yet formally crossed the threshold, although UNEP now believes doing so is
likely within the next few years.
The report argues that the response should be to keep any overshoot as low and
as short as possible, rather than treating the breach as evidence that the
original goal should simply be abandoned. “Decisions, science and, most
importantly, mindsets need to shift to seeing 1.5C as a goal we’ll be
approaching from above rather than below,” said Mirey Atallah, chief of UNEP’s
adaptation and resilience branch and coordinator of the report."
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
