Prof. David G. VaughanBritish Antarctic Survey

Sea-level rise: another face of climate change

Mitigation

Sea-level rise

Adaptation

Response to sea-level rise

> 500 yrs

< 200 yrs

Photo – flickr / Tc7

Emissions of greenhouse gases

Sea-level rise by ocean warming

Sea-level rise by loss of mountain glaciers

W. O. Field, B. F. Molnia

Muir Glacier 1941 - 2004

Sea-level rise by loss of polar ice sheets

Recent sea-level rise

0.8 mm/year

2.0 mm/year

3.2 mm/year

• Models used […] do not include the full effects of changes in ice sheet flow, because a basis in published literature is lacking. The projections include a contribution due to increased ice flow from Greenland and Antarctica at the rates observed for 1993-2003, but these flow rates could increase or decrease in the future. For example, if this contribution were to grow linearly with global average temperature change, the upper ranges of sea level rise for SRES scenarios shown in Table SPM-3 would increase by 0.1 m to 0.2 m. Larger values cannot be excluded, but understanding of these effects is too limited to assess their likelihood or provide a best estimate or an upper bound for sea level rise. {10.6}

IPCC (2007) on sea-level rise

Ice-sheet thickness change 2002-06

Pritchard et al., Nature, 2009

Photo – Vaughan, Jan 2009

Ice-shelf retreat around the Antarctic Peninsula

IPCC 2007 sea-level rise projections

Possible future sea-level rise

Continuation of a 1% per year increase in rate, until 2100 gives 53 cm

Acceleration to 2.5% per year increase in rate, until 2100 gives 1.4 m cmBut rise in last decade is 3.5 cm per year (10 times current), cf MWP1a

London- 1.25 million people - £80bn property

1879 Flood Act

Late C19 updateto Flood Act

1928 Flood + 1930 Flood Act

Interim Defences during Thames Barrier construction

Flood defences in London

Thames Barrier

Flood return at Thames Barrier

Source: Dawson et al. (2005), Jones (2001), Environment Agency (2003a)

1 10 100 10001 10 100 1000

Elevation (m)

0 20 40 60 80 100

300200100

Popu

lati

on

(Mill

ions)

Coastal populations

Developing countries

Photo – Flickr / Dan..

Developed countries

The 100th Thames Barrier Closure Science and prediction

Photo – flickr / jkpaul

Cascade of uncertainty in sea-level rise projection

Com

pounding of error

A role for science in 2010?

• Improved quantification of risk• Improved basis for sea-defence planning• Support for coastal adaptation and management• (Avoidance of unwarranted expenditure)• Fuller evaluation of long-term impact of climate

change

Coordinator: David G. VaughanInformation: www.ice2sea.euCoordinator: David G. VaughanInformation: www.ice2sea.eu