(Image: James Kirkham/ICCI)
It’s the time of year when the world’s top scientists give us the overview of the “State of the Cryosphere“, how the frozen regions of our planet are doing, against a background of runaway climate warming and record greenhouse gas emissions.
This time, the United Nations Environment Programme (UNEP) also commissioned a Report coordinated by the International Cryosphere Climate Initiative looking specifically at how the now inevitable overshooting of the 1.5°C Paris Agreement target will affect Earth’s ice sheets, permafrost, glaciers, sea ice and polar oceans.
Overshoot and the Cryosphere is a thematic companion report to UNEP’s recent Limiting Overshoot Report, the first of its kind from a UN agency. The State of the Cryosphere 2026, is this year titled The Cost of Overshoot, and builds on the UNEP-ICCI report.
The results of both are alarming.
Crossing 1.5°C bad news for ice
The UN has confirmed that the world will overshoot the 1.5°C temperature target because we have not succeeded in halting emissions and shifting to a low-carbon economy, in spite of all the warnings and the wealth of scientific data telling us we must.
The new reports show that this overshoot will bring large-scale, and in many cases irreversible, impacts from the Earth’s melting ice sheets, permafrost, glaciers, sea ice and polar oceans.
The reports set out the global impacts of ice loss with overshoot, exploring which ones are already locked in – and how more urgent climate action can still stop or slow the worst of this damage. With this year’s annual UN climate conference COP31 in Türkiye about to start on November 9th, this evidence is vital. Here’s hoping it will find the attention it deserves. If anyone has any doubts about the risks we run by going over the 1.5°C target, the effects it will have on our frozen regions, with all the implications for world as a whole, should be a convincing argument.
“There are no good outcomes in exceeding 1.5°C. To contain the global fallout and damage from ice loss in the world’s polar and mountain regions, overshoot needs to be kept to the absolute minimum. Temperatures must be returned to well below 1.5°C again as quickly as possible to reduce the risks,” said Dr. James Kirkham, coordinating lead author of Overshoot and the Cryosphere together with a team of over 80 polar and mountain scientists.
“Averting meltdown“, “containing fallout“ – stark language coming from scientists, who normally err on the side of caution – and a clear indication of where we stand.
“Every extra fraction of a degree and every year spent in overshoot means more devastating impacts”, added Kirkham, Chief Scientist at ICCI.
Abandon fossil fuels to avert the worst
A key message of the reports is that these losses can still be limited if overshoot is kept to a minimum by deep emissions reductions followed by scaled-up carbon drawdown. As I have discussed before on the Iceblog, removing carbon from the atmosphere is problematic and not yet available at scale. That makes it absolutely essential to have a faster transition away from fossil fuels. As the ICCI experts put it, “that means the difference between manageable losses — and a planet overwhelmed by serial disasters like that in Nepal in August“. And if we don’t prepare the way by the necessary emissions cuts, no carbon drawdown will save us.
In spite of the devastating impacts outlined in the reports, the authors stress that we can still do something about it. Both reports lay out practical solutions to limit peak temperature and come back down after overshoot. Renewable energy and battery technologies are booming, reliance on coal and oil is slowing, and climate policies have cut emissions in many places. Successful policies now need to be scaled up to reduce emissions by at least 5% per year, starting now, reaching net zero greenhouse gas emissions by mid-century. The reports emphasise that there can be no delay in phasing out fossil fuels to retain the possibility of bringing temperatures down in the future by drawing down carbon.
We owe it to future generations to do everything possible to both make preparations for adaptation measures to protect against outcomes we can no longer prevent – and to stop the damaging emissions which will make things even worse and more expensive and difficult to cope with in the future.
Safeguard ice for future generations
We can no longer prevent several metres of sea level rise over centuries to come, caused by the long-term retreat of polar ice sheets. But we can influence how fast this will happen. This matters greatly to coastal communities on the frontline of climate change today. By reducing emissions and slowing warming, we can slow down the rate of sea-level rise to an ‘adaptable’ level.
The scientists say we can potentially halt and partially reverse the loss of glaciers, snowpack and sea ice, which are of key importance in terms of water supply, stable mountains and coastlines and controlling the climate, regionally and globally. A return to 1.5°C and below would initiate some sea ice and glacier re-growth within decades to centuries, and could potentially re-establish healthy snowpack levels.
Already too hot for frozen regions
Even current levels of warming are already unsafe for the Arctic, the Antarctic, mountain glaciers and the polar oceans. The 2026 State of the Cryosphere describes new science and observations from the past year, such as Switzerland’s loss of 20% of its glacier ice in the past five years. Other impacts range from accelerating sea-level rise due to rapid ice loss, to increasing water shortages and mountain hazards as glaciers disappear and snow drought conditions spread.
Although returning to 1.5°C will slow ice loss, a truly ‘safe’ temperature target for Earth’s ice is now thought to be closer to 1.0°C or even below over the coming centuries.
“Overshoot is a problem facing us right now. Decisions made in the next few years will lock in the scale of damage, both for youth today and future generations,” said Gunjan Silwal, a young Nepali glacier researcher who will attend COP31. “The tragedy in Nepal is only a foretaste,” he says.
Return below 1.5°C a win-win
The pathway back to below 1.5°C requires ambitious and fast emissions reductions via fossil fuel phaseout – an “overshoot of ambition”, in the words of UN Secretary-General António Guterres – as well as deep reductions in methane and black carbon emissions. This would also deliver immediate benefits for resilience, health and food security, especially in mountain regions. Massive and rapid research and investment into sustainable, long-term and scalable carbon removal from the atmosphere will be needed to bring temperatures down after reaching net zero.
Given unavoidable losses however, adaptation must be a priority. Increased efforts and financing are desperately needed to meet growing adaptation needs, build resilience, and respond to loss and damage as a result of overshoot and the impacts of global ice loss.
Overshooting 1.5°C should never have been allowed to happen. There will be those who say we have missed the boat and it’s too late to do anything anyway.
Pam Pearson, ICCI Director, has this to say to them:
“When you miss an exit on the highway, you don’t abandon plans to get to where you really need to be – you take your first chance to turn back. Continuing full speed ahead just makes things worse,” said. “The road back to below 1.5°C may be difficult, but science and economics both provide a roadmap to a better future.”
Let’s send that message to the negotiators at COP31.
