A more limited rise in the oceans with a climate warming of 1.5 ° C

To halve the rise in ocean levels linked to the melting of ice over the course of the century, global warming should be limited to 1.5 ° C.

This is indicated by a study published this Wednesday in

Nature

.

Since 1993, melting ice has contributed at least half of sea level rise, and scientists have already warned that large areas of ice in Antarctica are melting faster than worst-case scenario forecasts.

To arrive at this 1.5 ° C threshold, around 50 researchers combined simulations of the melting ice covers of Antarctica and Greenland - which alone contain enough water to raise the level of the oceans. of 65 meters - as well as simulations of the 220,000 glaciers on earth.

An increase of 13 cm against 25

“Global ocean levels will continue to rise,” says lead author Tamsin Edwards of King's College London. But we can halve the contribution of melting ice if we limit global warming to 1.5 ° C compared to current commitments ”by states, which would lead to a rise in temperatures of around 3 ° C. The melting ice would thus contribute to making the oceans rise by 13 centimeters by 2100, against 25 centimeters according to current projections.

However, uncertainties remain regarding Antarctica.

"Greenland is very sensitive to atmospheric changes and therefore in a warmer world there will be more melting on the surface of the ice cover," explains Sophie Nowicki, of the Nasa Goddard Flight Center and co-author of the study.

In Antarctica, it's very complex.

A warmer world could mean more snowfall, but also more ice cap melting.

"

Planet

Arctic: Ice melts faster because of "heat bombs"

Planet

The melting of the world's glaciers is accelerating, in twenty years they have lost 4% of their volume

• Weather

• study

• Global warming

• Planet

• Ocean