A top EU environment official has warned that adapting to rising sea levels could cost Britain billions of pounds.
Jacqueline McGlade, who leads the European Environment Agency, said it would be a "significant problem" for coastal areas of the UK and urged the government to act now.
Her warning comes amid growing signs that melting glaciers and ice sheets - especially in the Arctic - are causing oceans to rise faster than expected.
A report just last month predicted that a fifth of Canada's Arctic glaciers will have disappeared by 2100, adding 3.5cm to sea levels.
In the latest of his reports on the changing Arctic, our Science Editor Lawrence McGinty follows two glaciologists at work on the Norwegian archipelago of Svalbard:
Scientists have put forward a range of estimates about how quickly sea levels will rise in the coming decades.
Estimates in the 2007 IPCC report - the official forecast used by the UN - put the figure at between 18cm and 59cm by 2100.
Since then, further research has shown that glaciers in the Arctic are melting faster than expected, prompting some scientists to predict that seas could rise by as much as a metre by 2100.
If such a dramatic rise was to materialise, the Thames Barrier would be engulfed by storm surges once in a decade on average, rather than once every thousand years as at present.
Scientists believe melting glaciers currently contribute around half of the rise in sea levels.
Growing evidence of rapid melting in the Arctic region suggests this contribution could increase.
Dr David Vaughan heads the EU-funded Ice2Sea programme which is working to fill in some of the gaps in the data in order to produce more accurate predictions:
ITV News' Science Editor Lawrence McGinty is filing a series of special reports from the Arctic all week.