May 20, 2025

1.5C is too high for polar ice sheets

Mass loss from ice sheets in Greenland and Antarctica has quadrupled since the 1990s.  It’s now the main source of global mean sea-level rise from the cryosphere.

The stability of ice sheets is critical to predicting sea level rise. A new synthesis published in Communications Earth and Environment brings together multiple lines of evidence to show that +1.5C is too high, and that even the current increase (about 1.2C) – if sustained – is likely to generate several metres of sea-level rise over the coming centuries. This would cause extensive loss and damage to coastal populations. The authors argue that avoiding this requires a global average temperature cooler than present.

Journalists came to this online briefing to hear the authors present their work and answer their questions on the threats of polar ice melt.

Speakers included:

Prof Chris Stokes, Glaciologist, Durham University

Prof Jonathan Bamber, Director of the Bristol Glaciology Centre, University of Bristol