14 may 2013

Sea levels in Europe could rise up to 1m by 2100, say scientists

By Pilita Clark, Environment Correspondent, The Financial Times, May 14 2013

Cities around Europe could face sea level rises of a metre or more by the end of the century when storm surges are factored in, according to research that helps address some of the biggest uncertainties about climate change.

A mix of melting ice sheets, warming oceans, storm surges and other drivers mean places such as Sheerness, at the mouth of London’s Thames river, face rises reaching just under 1 metre by 2100 – enough to overwhelm the capital’s existing flood protection barriers – though the risk is relatively low and any increases would be intermittent.

Denmark’s seaport of Esbjerg could experience even higher rises of up to 1.15 metres, according to a four-year programme of study by scientists from 24 leading EU institutions, known as Ice2Sea.

The work was done to try to fill in some of the gaps left after the last big report by the Intergovernmental Panel on Climate Change, the UN body set up to produce regular assessments of the latest state of climate knowledge.

Its 2007 report identified a number of shortcomings in scientists’ ability to predict how ice sheets contribute to sea level rises as they flow towards the coast, break away as icebergs and eventually melt into the sea.

Scientists are relatively confident about how warming oceans and melting mountain glaciers drive sea level rises but have been far less certain about the impact of ice loss from the ice sheets resting on Greenland and Antarctica.

The Ice2Sea work, which has been submitted to the IPCC for its next big report, due in September, suggests this continental ice loss could contribute between 3.5cm and 36.8cm to global average sea level rises up to 2100. There is also a small chance this rise could be as high as 84cm by the end of the century, but the probability is less than 5 per cent.

Though it will not be known for sure how this will affect the projections in the IPCC’s new report for overall sea level rises, it could push it up by about 10cm to 69cm, the Ice2Sea scientists say.

The EU-funded research, which focuses on consequences for Europe, shows sea level rises are likely to differ around the world, sometimes by tens of centimetres. The overall increase around European coastlines is expected be 10-20 per cent less than the global average, though regional variations mean some parts face much higher rises.

The flood barriers built to protect London, for example, are only expected to be breached once in 1,000 years. But a 1 metre rise in the Thames Estuary means “you would take that level of protection down from one in 1,000 years down to one in 10 years”, said the programme co-ordinator Professor David Vaughan, of the British Antarctic Survey.

“Obviously, one in 1,000 is probably acceptable to most people who live in London, 0.1 per cent per year. One in 100 years is maybe not acceptable. One in 10 years is clearly not acceptable.”

A 1 metre rise would be more than five times the 18cm increase in sea levels estimated for the whole of the 20th century, said another study contributor, Professor Jonathan Bamber of Bristol University.

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