A rise in global temperatures exceeding 1.5°C above pre-industrial levels could trigger irreversible changes across the Earth’s cryosphere—including glaciers, polar ice sheets, permafrost, and sea ice—scientists warn in a new report supported by the United Nations Environment Programme (UNEP).
Sea-news.az reports citing UN sources, that the study—compiled jointly by UNEP and 80 experts from the International Cryosphere Climate Initiative (ICCI)—emphasizes that even a temporary overshoot of the Paris Agreement temperature threshold could result in multi-century consequences for Earth’s climate system.
According to scientific projections, continuing current climate policies could drive global warming to 2.8°C. Such a scenario would lead to the near-total disappearance of near-surface permafrost, accelerated ice loss, and substantial global sea-level rise.
The state of the Greenland and Antarctic ice sheets raises particular concern. Ice loss in these regions is currently occurring roughly six times faster than during the 1990s. Even bringing global temperatures back down to 1.5°C would not fully arrest this ongoing thaw.
The report details that a 2.8°C global temperature increase could reduce existing glacier mass in the Alps, Iceland, and Scandinavia to under 10 percent. Under a scenario limiting warming strictly to 1.5°C, between 20 and 35 percent of glacier mass would be preserved.
Severe impacts are anticipated in the Hindu Kush Himalaya mountain region, whose glaciers provide freshwater to nearly a quarter of the world’s population. If current policies persist, only 41 percent of the region’s ice mass may remain, whereas a 1.5°C scenario would preserve approximately 83 percent.
Lead author James Kirkham, a glaciologist with the International Cryosphere Climate Initiative, noted that snow and ice respond rapidly to subtle temperature increases, yet recovery of deeply damaged cryospheric systems takes centuries or even millennia.
The authors stress the critical imperative to minimize the duration of any 1.5°C overshoot by rapidly reducing greenhouse gas emissions and scaling up carbon dioxide removal from the atmosphere. Over the long term, experts urge returning global warming below 1°C by 2150.
The report warns that cryospheric loss will not remain isolated to polar and alpine zones, but will severely impact global water security, ecosystems, and the livelihoods of hundreds of millions of people worldwide.
