A new international study led by the King’s College London has predicted that sea level rise from the melting of ice could be halved this century if the Paris Agreement target of limiting warming to 1.5°C is met.
The study, led by Dr Tamsin Edwards, reader in climate change at King’s, explored the land ice contribution to sea level rise in the 21st century arising from the world’s glaciers and the Greenland and Antarctic ice sheets.
The findings of the study were published in a paper entitled Projected land ice contributions to twenty-first-century sea level rise and published in the Nature journal. The work involved more than 80 scientists from around the world.
The study used a large number of computer models combined with statistical techniques, making predictions for the latest socio-economic scenarios to inform the Intergovernmental Panel on Climate Change’s Sixth Assessment report which will be published later this year.
Dr Edwards said, “We used a larger and more sophisticated set of climate and ice models than ever before, combining nearly 900 simulations from 38 international groups using statistical techniques to improve our understanding of uncertainty about the future.”
The research predicted that if global warming is limited to 1.5°C, Greenland ice sheet losses would reduce by 70%, 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.
“Antarctica is the wildcard of sea level rise: difficult to predict, and critical for the upper end of projections. In a pessimistic storyline, where Antarctica is very sensitive to climate change, we found there is a 5% chance of the land ice contribution to sea level rise exceeding 56cm in 2100 even if we limit warming to 1.5°C. Coastal flood management must therefore be flexible enough to account for a wide range of possible sea level rise, until new observations and modelling can improve the clarity of Antarctica’s future,” Dr Edwards added.
“Global sea level will continue to rise, even if we halt all emissions now, but our research suggests we could limit the damage: if pledges were far more ambitious, central predictions for sea level rise from melting ice would be reduced from 25cm to 13cm in 2100, with a 95% chance of being less than 28cm rather than the current upper end of 40cm. This would mean a less severe increase in coastal flooding,” she concluded.