Half of Greenland and vast areas of Antarctica are destined to melt if global warming continues at the same pace until the end of the century, scientists warned on Thursday.
Their research shows that the loss of so much ice will trigger dramatic rises in sea levels, ultimately swamping low-lying islands and coastal regions and threatening the flood defenses of cities such as London.
The last time so much ice was lost from the poles -- in a period between ice ages 129,000 years ago -- global sea levels rose between 4m and 6m.
Experts believe many coastal regions would suffer long before sea levels rose significantly, because even a minor rise will make storm surges more devastating and increase the risk of flooding.
The warning comes from climate scientists who combined historical records of Arctic and Antarctic ice melting with advanced computer models capable of predicting future environmental conditions.
They found that if nothing is done to put the brakes on climate change, Greenland, the west Antarctic ice sheet and other expanses of polar ice will be warmed beyond a "tipping point" after which their melting is inevitable.
Jonathan Overpeck, director of the Institute for the Study of Planet Earth at the University of Arizona, and Bette Otto-Bliesner, at the US National Center for Atmospheric Research in Colorado, looked back in history to find a time when sea levels were higher than they are today.
They identified a period when glacial melting increased sea levels by several meters.
They used a computer model of the environment to work out how warm the world must have been to trigger the mass melting and concluded that the Earth was between 3oC and 5oC warmer than it is today.
Using the same model, the scientists spun the clock forward to see when climate change is likely to make the world as warm again.
"We showed that that level of warming will come later in this century unless we act on carbon emissions," Overpeck said.
"An Arctic warming of 3oC to 5oC is enough to cause 4m to 6m of sea level rise," he said.
If temperatures do rise as the scientists predict, the ice at the poles will not be lost immediately. Enough ice is likely to melt within the next 100 years to raise sea levels by a meter, but ultimately the fresh water pouring into the North Atlantic would slow down the Gulf stream by a quarter.
"These ice sheets have melted before and sea levels rose. The warmth needed isn't that much above present conditions," said Otto-Bliesner.
The major concern is that unless climate change slows down significantly, the eventual loss of polar ice and subsequent 6m rise in sea levels will become unavoidable.
"There has been an increasing number of observations from the ice sheets suggesting they are responding faster to climate change than anticipated," Overpeck said.
"Now along come our results showing these kinds of changes occurred in the past and lead to large ice sheet retreat and sea level rise," he said.
A 1m rise in the sea level would see the Maldives disappear, make most of Bangladesh uninhabitable and put cities such as New Orleans "out of business," according to Overpeck.
The research was published in two papers in the US journal Science on Thursday.
‘TAIWAN-FRIENDLY’: The last time the Web site fact sheet removed the lines on the US not supporting Taiwanese independence was during the Biden administration in 2022 The US Department of State has removed a statement on its Web site that it does not support Taiwanese independence, among changes that the Taiwanese government praised yesterday as supporting Taiwan. The Taiwan-US relations fact sheet, produced by the department’s Bureau of East Asian and Pacific Affairs, previously stated that the US opposes “any unilateral changes to the status quo from either side; we do not support Taiwan independence; and we expect cross-strait differences to be resolved by peaceful means.” In the updated version published on Thursday, the line stating that the US does not support Taiwanese independence had been removed. The updated
‘CORRECT IDENTIFICATION’: Beginning in May, Taiwanese married to Japanese can register their home country as Taiwan in their spouse’s family record, ‘Nikkei Asia’ said The government yesterday thanked Japan for revising rules that would allow Taiwanese nationals married to Japanese citizens to list their home country as “Taiwan” in the official family record database. At present, Taiwanese have to select “China.” Minister of Foreign Affairs Lin Chia-lung (林佳龍) said the new rule, set to be implemented in May, would now “correctly” identify Taiwanese in Japan and help protect their rights, the Ministry of Foreign Affairs said in a statement. The statement was released after Nikkei Asia reported the new policy earlier yesterday. The name and nationality of a non-Japanese person marrying a Japanese national is added to the
AT RISK: The council reiterated that people should seriously consider the necessity of visiting China, after Beijing passed 22 guidelines to punish ‘die-hard’ separatists The Mainland Affairs Council (MAC) has since Jan. 1 last year received 65 petitions regarding Taiwanese who were interrogated or detained in China, MAC Minister Chiu Chui-cheng (邱垂正) said yesterday. Fifty-two either went missing or had their personal freedoms restricted, with some put in criminal detention, while 13 were interrogated and temporarily detained, he said in a radio interview. On June 21 last year, China announced 22 guidelines to punish “die-hard Taiwanese independence separatists,” allowing Chinese courts to try people in absentia. The guidelines are uncivilized and inhumane, allowing Beijing to seize assets and issue the death penalty, with no regard for potential
‘UNITED FRONT’ FRONTS: Barring contact with Huaqiao and Jinan universities is needed to stop China targeting Taiwanese students, the education minister said Taiwan has blacklisted two Chinese universities from conducting academic exchange programs in the nation after reports that the institutes are arms of Beijing’s United Front Work Department, Minister of Education Cheng Ying-yao (鄭英耀) said in an exclusive interview with the Chinese-language Liberty Times (the Taipei Times’ sister paper) published yesterday. China’s Huaqiao University in Xiamen and Quanzhou, as well as Jinan University in Guangzhou, which have 600 and 1,500 Taiwanese on their rolls respectively, are under direct control of the Chinese government’s political warfare branch, Cheng said, citing reports by national security officials. A comprehensive ban on Taiwanese institutions collaborating or
RSS