Two UN reports warn 1.5C overshoot will irreversibly damage Earth's ice

Two United Nations reports warned on Monday that letting global warming pass 1.5C would have "irreversible" consequences for glaciers, sea ice and the Earth's frozen regions, and called for urgent action.

The reports concern the cryosphere, the planet's frozen water and ground: ice sheets, mountain glaciers, sea ice and ground that stays frozen all year. One of the two said that overshooting the 1.5C limit "will bring large-scale and in many cases irreversible impacts" for those regions.

Dawn reported the warning from Paris. Its account listed the melting of glaciers and sea ice among the changes at stake in the frozen regions.

"Irreversible" is the reports' own word for the damage, as Dawn quoted it, and the threshold they set is a level of warming rather than a date.

The 1.5C figure is the stricter of the two goals written into the 2015 Paris Agreement, which Dawn described as landmark. That treaty commits governments to hold warming to well below 2C and to pursue efforts to keep it at 1.5C, in order to try to avoid the worst effects of climate change.

Dawn's report did not name the two reports or the UN bodies that issued them. It gave no estimate of how much ice has already been lost, no projection of the sea-level rise that further loss could cause, and no list of the governments or agencies that commissioned the work.

Both reports called for urgent action, Dawn said.