Published: 2018-02-21 10:33:50 BdST
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.
Tourists walk near the spot where the natural arch known as the Azure Window used to stand before it collapsed into the sea last March after years of erosion, at Dwejra outside the village of San Lawrenz on the island of Gozo, Malta, Jan 25, 2018. Reuters
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, told Reuters.
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.
Maldives Environment Minister Thoriq Ibrahim, who chairs the 44-member Alliance of Small Island States, said Tuesday’s findings showed a need for faster action to cut emissions, especially by rich nations.
Residents look at an exposed erosion along the boardwalk of Macumba beach after waves washed away the sand in the weekend storm, in Rio de Janeiro, Brazil Oct 17, 2017. Reuters
Professor John Church, of the Climate Change Research Centre at the University of New South Wales, who was not involved in the study, said 100 million people now live within one metre of the high tide mark.
“More people are moving to live within the coastal zone, increasing the vulnerable population and infrastructure,” he said in a statement. “Adaptation to sea level rise will be essential.”