Sea level rises from melting ice massively reduced by limiting global warming

Sea level rise caused by melting ice could be halved this century if the Paris Agreement target of limiting warming to 1.5°C is met.

A new study, from an international research team including University of Leeds scientists, explored the land ice contribution to sea level in the 21st century arising from the world’s glaciers and the Greenland and Antarctic ice sheets.

Researchers who worked on the paper, published in Nature, included Dr Christine McKenna, Professor Andrew Shepherd and Dr Chris Smith, all from the School of Earth and Environment.

The study used computer models and statistical techniques to make predictions about the latest socio-economic scenarios which could effect sea levels. The data will help to inform the sixth assessment report by the Intergovernmental Panel on Climate Change, which is due to be published later this year

If we take immediate and strong action on climate change, we could slow down future sea level rise.

The research predicts that if global warming is limited to 1.5°C, Greenland ice sheet losses would reduce by 70 per cent, and glacier losses by half, compared with current emissions pledges.

For Antarctica, the predictions are the same for different emissions scenarios, because it is currently unclear whether snow falling in the cold interior of the ice sheet will offset melting at the coasts.

However, under a 'pessimistic' storyline, with much more melting than snowfall, Antarctic ice losses could be five times larger.

Dr McKenna said: “These important results show that if we take immediate and strong action on climate change, we could slow down future sea level rise and reduce the impacts of coastal flooding.

“This is further motivation for governments and others to set stringent greenhouse gas mitigation targets.”

Global sea rise 

Glaciers and ice sheets are currently responsible for around half of global sea level rise, with most of the rest arising from expansion of the oceans as they warm.

Previous predictions had used older emissions scenarios, and could not explore uncertainty about the future as thoroughly due to the limited number of simulations.

This statistically-based study updates the scenarios, and combines all sources of land ice into a more complete picture that predicts the likelihood of different levels of sea level rise. 

Lead author Dr Tamsin Edwards, of King’s College London, said: “Ahead of COP26 this November, many nations are updating their pledges to reduce greenhouse gas emissions under the Paris Agreement.

“Global sea level will continue to rise, even if we halt all emissions now, but our research suggests we could limit the damage.”

Further information

Projected land ice contributions to twenty-first-century sea level rise is published in the journal Nature 5 May 2021.

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