Seas have risen 2.5 times faster than during the 20th century

Since 2005 seas have risen 2.5 times faster than during the 20th century mainly due to melting of ice sheets, and will likely jump four-fold again by 2100 if carbon emissions continue unabated, the UN warned on Wednesday.

But capping global warming at under two degrees Celsius -- the cornerstone goal of the Paris climate treaty -- could stabilise the rate of increase and hold the line at a metre above today's watermark, even two centuries from now, the Intergovernmental Panel on Climate Change (IPCC) said.