Prof. David G. Vaughan British 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

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 , 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 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 cm But rise in last decade is 3.5 cm per year (10 times current), cf MWP1a

London million people - £80bn property

1879 Flood Act Late C19 update to Flood Act Late C19 update to 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)

Elevation (m) Population (Millions) Coastal populations

Developing countries Photo – Flickr / Dan..

Developed countries

The 100 th Thames Barrier Closure Science and prediction Photo – flickr / jkpaul

Cascade of uncertainty in sea-level rise projection Compounding 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. Vaughan Information: Coordinator: David G. Vaughan Information: