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WATER THREAT

Rising sea levels: Indian coastal cities at risk too

TIMES NEWS NETWORK 

New Delhi: Days before the Copenhagen conference on climate change kicks off, a major study by a group of 100 international scientists has said that sea levels are likely to rise by as much as 1.4 metres (more than 4 feet) by the end of this century. That’s twice as much as previously predicted in IPCC’s fourth assessment report of 2007.
    If these projections come true, most areas in low-lying island nations like the Maldives would go under the sea. Based on earlier studies, the UN’s environmental panel has already warned that sea levels would be high enough to make the Maldives uninhabitable by 2100. The new study also significantly enhances the threat to the Indian coast — and cities like Mumbai, Chennai and the low-lying Kolkata. The report released by the Scientific Committee on Antarctic Research (SCAR) is the first comprehensive review of the impact of global warming on Antarctica. 
Sea levels could rise by over 4 feet
(1.4m) by 2100, according to the study of
Antractica. This is more than twice the
projection made by IPCC in 2007 
Islands like Maldives and Mauritius under grave threat of going under. Indian coast at risk, including cities like Mumbai, Kolkata and Chennai The report is based on evidence from 100 scientists from 13 countries IPCC ’07 REPORT Climate Change: Coastal Cities Heading For Trouble 
    Amajor study by a group of 100 international scientists has said that sea levels are likely to rise by as much as 1.4 metres by the end of this century. That’s twice as much as the 2007 assessment report by the Intergovernmental Panel on Climate Change (IPCC).
    The IPCC’s 2007 report had projected that sea-levels could rise by 18cm to 59cm by 2099. Subsequent studies of glacial melts in Greenland and Antarctica had raised fears that sea rise could be much higher than that.
    “We can see the west Antarctic glaciers are shrinking at a rate fast enough to contribute to a sea level rise of 1.4 m by 2100, but it will be no more than that,’’ executive director of Scientific Committee on Antarctic Research (SCAR) Colin Summerhayes told reporters at a media briefing in London.
    “Anybody who lives in coastal cities needs to be slightly worried by projections of 1 metre or more,’’ Summerhayes said. Since 1870, global sea level has risen by about 20cm at an average rate of 1.7 mm/year. But in recent decades, the rate has risen sharply to 2.5mm/year, according to the latest figures. The rise in sea level is mainly a result of thermal expansion of the ocean due to global warming as well as increased water inflows from melting glaciers and ice caps.
    The reports says that central Antarctica, that has so far been protected from warming due to a hole in the ozone layer, will also see the full effects of greenhouse gas increases as the ozone hole heals. 
    The scientists found that there has been significant thinning of the west Antarctic ice sheet and 90% of glaciers across the Antarctic peninsula had retreated over recent decades. But the bulk of the Antarctic ice sheet has shown little change over recent decades.
    However, the report says, historically, small-scale climate variability has caused rapid ice loss, shifts in ocean and atmospheric circulation in the continent. This shows Antarctica is highly sensitive to even minor climate changes. It says studies of sediments under recently lost ice shelves suggest ice shelf loss in some regions is unprecedented during this time scale.