Transcript Sea-level rise: another face of climate change Prof. David G. Vaughan British Antarctic Survey.

Sea-level rise:
another face of
climate change
Prof. David G. Vaughan
British Antarctic Survey
Response to sea-level rise
Mitigation
Sea-level rise
Adaptation
Emissions of greenhouse
gases
Photo – flickr / Tc7
Sea-level rise by ocean warming
Sea-level rise by loss of mountain glaciers
Muir Glacier 1941 - 2004
W. O. Field, B. F. Molnia
Sea-level rise by loss
of polar ice sheets
Recent sea-level rise
3.2 mm/year
2.0 mm/year
0.8 mm/year
IPCC (2007) on sea-level rise
• 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}
Ice-sheet thickness change 2002-06
Pritchard et al., Nature, 2009
Ice-shelf retreat
around the Antarctic
Peninsula
Photo – Vaughan, Jan 2009
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
- 1.25 million people
- £80bn property
Flood defences in London
Interim Defences during Thames Barrier construction
1928 Flood + 1930 Flood Act
Late C19 update
to Flood Act
1879 Flood Act
Thames Barrier
Flood return at Thames Barrier
1
110
10
100
100
1000
Source: Dawson et al. (2005), Jones (2001), Environment Agency (2003a)
Population (Millions)
Coastal populations
300
200
100
0
20
40
60
Elevation (m)
80
100
Developing countries
Photo – Flickr / Dan..
Developed countries
th Thames
Science
prediction
The
100and
Barrier Closure
Photo – flickr / jkpaul
Cascade of uncertainty in sea-level rise projection
A role for science in 2010?
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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: www.ice2sea.eu