690 likes | 820 Views
Melting Antarctic Ice: Hot Air or Chilling Reality?. Dr. David Vaughan Hot Science - Cool Talks Volume 47.
E N D
Melting Antarctic Ice:Hot Air or Chilling Reality? Dr. David Vaughan Hot Science - Cool Talks Volume 47 Produced by and for the Hot Science – Cool Talks Outreach Lecture Series of the Environmental Science Institute. We request that the use of any of these materials include an acknowledgement of Dr. David Vaughan and the Hot Science – Cool Talks Outreach Lecture Series of the Environmental Science Institute of the University of Texas at Austin. We hope you find these materials educational and enjoyable.
Melting Antarctic Ice: Hot Air or Chilling Reality? David G. Vaughan British Antarctic Survey
What goes on in Antarctica is important to the rest of the world
Menu Menu • Overview of Antarctica • Human fingerprints on the last wilderness • Archive of Planet Earth • Climate change in Antarctica • Sea-level rise – life’s a beach, why worry? • Antarctica and sea-level rise • Getting out there • Science and policy – where next?
which leaves just a fraction, an area no bigger that the home counties of England (US EQUIVALENT?), for colonisation by flora and fauna
Sea ice (frozen sea water only a metre thick) expands the area of Antarctica every year
Antarctica is the only continent that wasn’t explored in a temper!
Menu Menu – human fingerprints on the last wilderness • Overview of Antarctica • Human fingerprints on the last wilderness • Archive of Planet Earth • Climate change in Antarctica • Sea-level rise – life’s a beach, why worry? • Antarctica and sea-level rise • Getting out there • Science and policy – where next?
FOOTPRINT 1. Radioactive fallout from above-ground nuclear bomb testing in the 1950s remains as horizon in the ice Radioactive Fallout
Lead buried in the snow 1980 1970 1960 1950 1940 1930 1920 12 8 4 0 Concentration of Lead (ng / kg) 0 2 4 6 8 Firn depth / m Lead pollution Source: Wolff and Suttie
Ozone hole Ozone Hole Source: NASA/BAS
Menu Menu – archive of planet earth • Overview of Antarctica • Human fingerprints on the last wilderness • Archive of Planet Earth • Climate change in Antarctica • Sea-level rise – life’s a beach, why worry? • Antarctica and sea-level rise • Getting out there • Science and policy – where next?
The ice-core record Vostok Core (black) and Dome C Core (blue) The ice-core record Dome C Core Vostok Core (black) and Dome C Core (blue) Thousands of years before present Source: EPICA
Menu Menu – climate change in Antarctica • Overview of Antarctica • Human fingerprints on the last wilderness • Archive of Planet Earth • Climate change in Antarctica • Sea-level rise – life’s a beach, why worry? • Antarctica and sea-level rise • Getting out there • Science and policy – where next?
Climate change - World perspective Source: IPCCWorking Group I, Summary for Policymakers, 2007
0.59 oC -2.1 -2 -1.5 -1 -.5 -.1 .1 .5 1 1.5 2 2.9 oC Climate change - World perspective Trend in Average Annual Global Temperatures (1955 to 2005) Source: Hansen
Climate change in Antarctica Trends in mean annual temperature Climate change in Antarctica – trends in mean annual temperature Temperature trend (oC) Longitude Source: Vaughan et al., 2004
Antarctic Peninsula Antarctic Peninsula – trend in annual temperature Trend in annual temperature Mean annual temp (oC) Date Source: King et al., BAS
Trends in sea-ice duration around Antarctica and trends in mean annual temperature 1979-2000 Trends in sea-ice duration around Antarctica and trends in mean annual temperature 1979-2000 < -5 -5 to -4 -4 to -3 -3 to -2 -2 to -1 0 to 1 1 to 2 2 to 3 3 to 4 4 to 5 days Source: Connolley, BAS
1985/86 So what does this mean on the ground? 1994/95
Glacier retreat on the Antarctic Peninsula Glacier retreat on the Antarctic Peninsula Source: Cook et. al 2005
Ice shelf retreaton the Antarctic Peninsula 5th Mar. 2002 17th Feb. 2002 31st Jan. 2002 1995 Source: NSIDC, BAS
So what is the significance of the Antarctic Peninsula warming?
Menu Menu – seal-level rise – life’s a beach, why worry? • Overview of Antarctica • Human fingerprints on the last wilderness • Archive of Planet Earth • Climate change in Antarctica • Sea-level rise – life’s a beach, why worry? • Antarctica and sea-level rise • Getting out there • Science and policy – where next?
IPCC IPCC- 2007 “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.” Source: IPCCWorking Group I, Summary for Policymakers, 2007
HIGH Sea Level Asymmetry of Sea Level Change LOW Temperature change from present (Celsius) 4 2 0 -2 -4 -6 -8 -10 WARM COLD 400 350 300 250 200 150 100 50 0 Thousands of years before present (present = 1950) THEN NOW Time Source: Bindschadler
Impacts of sea level rise How many people suffer from coastal flooding today? 10 Million How many people will suffer from coastal flooding by 2080 with no sea level rise? 30 Million If the sea level rise is a conservative 44cm, how many people will suffer? 100 Million
Sea-level Rise in 500 years? Sea-level rise – 500 years!
1953 flooding of Norfolk and Lincolnshire. Norfolk coast - UK 1953 300 dead, 24,000 homes flooded
Careful here Source: NOAA
Menu Menu – Antarctica and sea-level rise • Overview of Antarctica • Human fingerprints on the last wilderness • Archive of Planet Earth • Climate change in Antarctica • Sea-level rise – life’s a beach, why worry? • Antarctica and sea-level rise • Getting out there • Science and policy – where next?
Antarctica and sea level Bed elevation Antarctica and sea level Source: BEDMAP
Antarctica and sea level Hydrostatic overburden Areas of Antarctica where ice is below sea level Source: Unpublished
Surface ice-thickness change 1992-2003 Current changes Source: Wingham et al., 2006
Antarctica and sea level Antarctica and sea level – satellite measurement of elevation change Satellite measurement of elevation change • Amundsen Sea sector • 0.043 mm / yr sea level rise (1991-2001) Source: Shepherd, Wingham and Mansley
Menu Menu – getting out there • Overview of Antarctica • Human fingerprints on the last wilderness • Archive of Planet Earth • Climate change in Antarctica • Sea-level rise – life’s a beach, why worry? • Antarctica and sea-level rise • Getting out there • Science and policy – where next?