Growing evidence from Antarctica suggests that even if countries hit the lower target for temperature increases set by the Paris Agreement, it may not be enough to prevent some countries from suffering catastrophic damage caused by ice-sheet melting
As countries gather in Bonn, Germany, to finalise the first evaluation of Paris climate-agreement pledges — known as the Global Stocktake — scientists have joined an unusual new grouping of countries urging “2°C is too high”, a warning that, based on the most recent science of the world’s ice, even moderate levels of global warming will place 3.5 billion people in harm’s way.
The 20-nation Ambition on Melting Ice group, formed at the 2022 UN climate conference in Egypt, includes countries not just from polar and mountain regions (Iceland and Chile co-chair the group), but also countries like Liberia, Vanuatu and Senegal that are highly vulnerable to sea-level rise caused by melting glaciers and ice sheets. Together with leading scientists, these countries point to fresh research on global impacts from the world’s ice sheets, glaciers and permafrost. It indicates the original Paris Agreement goal of 2°C is unacceptable. Even the lower 1.5°C limit could be too high.
The AMI countries met with other interested governments and stakeholders in Bonn on Friday, hearing from a wide range of scientists alarmed that both observations and projections are pointing to devastating and, most of all, permanent impacts from global ice melt, even if temperature rise is kept well below 2°C. Growing evidence from Antarctica, for example, points to thresholds closer to 1.5°C, especially in more vulnerable west Antarctica.
“We are on the edge of a cliff,” said Chris Stokes, a glaciologist at Durham University who spoke at the event in Bonn. “The latest science over the last two to three years tells us the threshold beyond which ice loss from the Antarctic will become irreversible over centuries to millennia is much lower than we thought. If we keep on as we are now, we could trigger runaway feedbacks within the next few decades, with sea-level rise from ice sheets accelerating much, much faster than we feared.”
Carlos Fuller, a negotiator from Belize who attended the workshop on the “cryosphere”, the term scientists use for the part of the climate system that includes snow, ice, permafrost and other forms of frozen water, said: “Knowing what we know today, 2°C should not even be on the table. Indeed, even 1.5°C may be too high.”
The message mirrored in a paper published in Nature last week concluding that “the world has already passed the safe and just climate boundary, which is set at 1°C above pre-industrial temperature levels, as tens of millions of people are already harmed by the current level of climate change”.
The figure of 3.5 billion is the number of people the IPCC, the UN agency responsible for assessing the science related to global warming, says live in regions highly vulnerable to even moderate sea-level rise from ice sheets, or at least seasonally dependent on water from glaciers and snow.
“This science is jaw-dropping,” said Izabella Koziell, the deputy-director of Icimod, an eight-nation Himalayan group based in Nepal, a prominent AMI member. “We cannot continue emissions at these levels and expect any mountain community to survive.”
Icimod also includes Pakistan, a country that saw 10% of its land put under water last year by the triple factors of ice melt, rain replacing snowfall and sea-level rise.
The scientists noted that real-time field observations of the Greenland ice sheet and mountain-glacier loss are running above the upper range of the latest IPCC projections, known as AR6.
“The scale of the change we are seeing should be a wake up call for every policy maker at this conference,” said James Kirkham, an Antarctic scientist formerly with the British Antarctic Survey and now working with the AMI group. “I was in Antarctica three months ago and the ice sheet looks unrecognisable compared to even just a few years ago because kilometres of ice have been lost. The term ‘glacial pace’ has taken on a completely different meaning.”
Ms Koziell said: “The damage is happening here and now, this is not about future impacts. Melting glaciers and erratic snowfall disrupting water supplies, widespread flooding juxtaposed with heat and drought, disruption of the monsoon — it’s the reality of 2 billion people in the Hindu Kush Himalayan region today. We simply must cut emissions now, even while we adapt for tomorrow.”
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