OSLO: Sea levels will rise between 0.7 and 1.2 metres in the next two centuries even if governments end the fossil fuel era as promised under the Paris climate agreement, scientists said on Tuesday.

Early action to cut greenhouse gas emissions would limit the long-term rise, driven by a thaw of ice from Greenland to Antarctica that will re-draw global coastlines, a German-led team wrote in the journal Nature Communications.

Sea level rise is a threat to cities from Shanghai to Lon­don, to low-lying swathes of Florida or Bangladesh, and to entire nations such as the Maldives in the Indian Oce­an or Kiribati in the Pacific.

By 2300, the report projected that sea levels would gain by 0.7-1.2 metres, even if almost 200 nations fully meet goals under the 2015 Paris Agreement, which incl­ude cutting greenhouse gas emissions to net zero in the second half of this century.

Ocean levels will rise inexorably because heat-trapping industrial gases already em­­itted will linger in the atmosphere, melting more ice, it said. In addition, water naturally expands as it warms above four degrees Celsius (39.2F).

The report also found that every five years of delay be­­yond 2020 in peaking global emissions would mean an extra 20 centimetres (8 inch­­es) of sea level rise by 2300.

“Sea level is often communicated as a really slow process that you can’t do much about ... but the next 30 years really matter,” lead author Matthias Mengel, of the Pots­dam Institute for Climate Impact Research, said.

Governments are not on track to meet the Paris pled­ges. Global emissions of carbon dioxide, the main greenhouse gas emitted by burning fossil fuels, rose last year after a three-year plateau.

And US President Donald Trump, who doubts that human activities are the prime cause of warming, plans to quit the Paris deal and instead promote US coal, oil and natural gas.

Published in Dawn, February 21st, 2018