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19241 |
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Date: August 28, 2024 at 19:57:25
From: mitra, [DNS_Address]
Subject: Scientists in Chile question if Antarctica has hit point of no return |
URL: https://www.reuters.com/business/environment/scientists-chile-question-if-antarctica-has-hit-point-no-return-2024-08-28/ |
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Nearly 1,500 academics, researchers and scientists
specializing in Antarctica gathered in southern Chile
for the 11th Scientific Committee on Antarctic Research
conference this week to share the most cutting-edge
research from the vast white continent.
Nearly every aspect of science, from geology to biology
and glaciology to arts, was covered but a major
undercurrent ran through the conference. Antarctica is
changing, faster than expected.
Extreme weather events in the ice-covered continent
were no longer hypothetical presentations, but first-
hand accounts from researchers about heavy rainfall,
intense heat waves and sudden Foehn (strong dry winds)
events at research stations that led to mass melting,
giant glacier break-offs and dangerous weather
conditions with global implications.
With detailed weather station and satellite data dating
back only about 40 years, scientists wondered whether
these events meant Antarctica had reached a tipping
point, or a point of accelerated and irreversible sea
ice loss from the West Antarctic ice sheet.
"There's uncertainty about whether the current
observations indicate a temporary dip or a downward
plunge (of sea ice)," said Liz Keller, a paleoclimate
specialist from the Victoria University of Wellington
in New Zealand that led a session about predicting and
detecting tipping points in Antarctica.
NASA estimates, opens new tab show the Antarctic ice
sheet has enough ice to raise the global mean sea level
by up to 58 meters. Studies have shown that about a
third of the world's population lives below 100
vertical meters of sea level.
While it's tough to determine whether we've hit a
"point of no return," Keller says that it's clear the
rate of change is unprecedented.
"You might see the same rise in CO2 over thousands of
years, and now it's happened in 100 years," Keller
said.
Mike Weber, a paleooceanographer from Germany's
University of Bonn, who specializes in Antarctic ice
sheet stability, says sediment records dating back
21,000 years show similar periods of accelerated ice
melt.
The ice sheet has experienced similar accelerated ice
mass loss at least eight times, Weber said, with
acceleration beginning over a few decades that kick off
a phase of ice loss that can last centuries, leading to
dramatically higher sea levels around the world.
Weber says ice loss has picked up over the last decade,
and the question is whether it's already kicked off a
centuries-long phase or not.
"Maybe we're entering such a phase right now," Weber
said. "If we are, at least for now, there will be no
stopping it."
KEEPING EMISSIONS LOW
While some say the climate changes are already locked
in, scientists agreed that the worst case scenarios can
still be avoided by dramatically reducing fossil fuel
emissions.
Weber says the earth's crust rebounds in response to
retreating glaciers and their diminishing weight could
balance out sea level rise, and new research published
weeks ago shows that a balance is still possible if the
rate of change is slow enough.
"If we keep emissions low, we can stop this
eventually," said Weber. "If we keep them high, we have
a runaway situation and we cannot do anything."
Mathieu Casado, a paleoclimate and polar meteorologist
at France's Climate and Environment Sciences
Laboratory, specializes in studying water isotopes to
reconstruct historical temperatures.
Casado said data from dozens of ice cores collected
throughout the ice sheet has allowed him to reconstruct
temperature patterns in Antarctica dating back 800,000
years.
Casado's research showed that the current temperature
rise in the last fifty years was clearly outside
natural variability, highlighting the role of industry
in producing carbon emissions that drive climate
change.
He added that the last time the Earth was this warm was
125,000 years ago and sea levels were 6 to 9 meters
higher "with quite a bit of contribution for West
Antarctica."
Temperature and carbon dioxide were historically at
equilibrium and balanced each other out, Casado said,
but we currently have much higher levels of CO2 and are
far from equilibrium.
Casado and other scientists noted the speed and
quantity at which carbon is being pumped into the
atmosphere is unprecedented.
Gino Casassa, a glaciologist and head of Chilean
Antarctic Institute, said that current estimates show
sea levels rising by 4 meters by 2100 and more if
emissions continue to grow.
"What happens in Antarctica doesn't stay in
Antarctica," said Casassa, adding that global
atmospheric, ocean and weather patterns are linked to
the continent.
"Antarctica isn't just an ice refrigerator isolated
from the rest of the planet that has no impact."
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Responses:
[19242] [19244] [19245] [19246] |
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19242 |
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Date: August 30, 2024 at 01:00:49
From: ryan, [DNS_Address]
Subject: Re: Scientists in Chile question if Antarctica has hit point of no... |
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i think it is pretty obvious it has...4 meters sea level rise in the next 75 years? and maybe even faster than that? the times, they are a-changin'...
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Responses:
[19244] [19245] [19246] |
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19244 |
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Date: August 30, 2024 at 14:44:54
From: mitra, [DNS_Address]
Subject: Re: Scientists in Chile question if Antarctica has hit point of no... |
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Sigh. yes.
It appears they want people to be free to choose a
positive future, if they say there is no hope, it's
over, it opens the sewer of desperate intentions,
radical acts and cold decisions.
Fear is a dog that won't be chained.
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Responses:
[19245] [19246] |
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19245 |
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Date: August 30, 2024 at 15:43:52
From: akira, [DNS_Address]
Subject: meanwhile Kamala says yeah, fracking, why not? and you'll vote for her |
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because the alternative is so much worse. But how much worse, really?
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Responses:
[19246] |
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19246 |
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Date: August 30, 2024 at 18:29:45
From: ryan, [DNS_Address]
Subject: Re: meanwhile Kamala says yeah, fracking, why not? and you'll vote... |
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i can't believe you have to ask...(and that is not what she said...you're starting to sound like b-ot...lol)
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Responses:
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