Presentation on theme: "Sea Level & Ice Sheets Concern about the Future of Inhabited Coastlines Presented by Beth Caissie (thanks to Ken Miller, Rutgers, for many of his slides)"— Presentation transcript:
Sea Level & Ice Sheets Concern about the Future of Inhabited Coastlines Presented by Beth Caissie (thanks to Ken Miller, Rutgers, for many of his slides)
Sources: Petit et al. (1999) Nature 399, 429-436 and National Oceanic and Atmospheric Administration (NOAA), USA
Source: Labeyrie et al (2003) In: Paleoclimate, Global Change and the Future, Springer. Sea level history over the past 450,000 years
Lambeck et al., 2002, based on tropical & subtropical records TODAY Last interglacial Full Glacial Global Sea Level
Why Is Global Sea Level Rising Today?. Melting Ice Caps and Glaciers: Melting land ice adds to ocean volume (sea ice does not) Greenland is thinning today, but didnt disappear during the Last Interglacial IPCC2001: near 0 Cazenave & Nerem (2004): >0.15 mm/yr Sterns & Hamilton (2007): 0.57 mm/y
Muir Glacier 1941, William Field 2004, Bruce Molnia From the Glacier photograph collection. Boulder, Colorado USA: National Snow and Ice Data Center/World Data Center for Glaciology. http://nsidc.org/data/glacier_photo/repeat_photography.html Glacial Retreat Most glaciers world-wide are in retreat Alpine glaciers contribute 0.6 mm/yr to sea level rise Why are some advancing? Increased snow Why Is Global Sea Level Rising Today?
Thermal Expansion: ocean has gained heat Warmer water less dense global 20th century warming ~0.6°C 1.6 mm/yr sea-level rise
Brazil Atlantic City NJ Should I Sell My Shore House?
Overall 10-20cm rise in 20th century 20 th century average rate of sea level rise: 1.7±0.3mm/yr 1950-2000 1.8±0.3mm/yr 1993-2003 accelerated to 3.1±0.7 mm/yr Observations (Tide Gauge and Satellite Altimetry Data)
Sea-Level Forecast: IPCC 2007 40 cm (1.25 ft) rise by 2100 1 m (3.3 ft) by 2200 IPCC 2007 error: 20-60 cm (does not include ice sheet melting) http://www.realclimate.org/images/sealevel_1.jpg 2007
Recent Global Sea Level Rise Estimates Delta Comm. WBGU Data Data: Church and White (2006) Scenarios 2100: 50 – 140 cm (Rahmstorf 2007) 55 – 110 cm (high end, Delta Committee 2008) Scenarios 2200: 150 – 350 cm (high end, Delta Committee 2008) Scenarios 2300: 250 – 510 cm (German Advisory Council on Global Change, WBGU, 2006) Slide from Rahmstorf web site Best Estimate = 80 cm of SL Rise by 2100, 1 m is not out of the question
Human stabilized Natural movement 400 m Long Beach Island, NJ Courtesy N. Psuty
http://www.learnnc.org/lp/editions/cede_smsandvol/323 Sea Level Rise – like this? No ! Gradual sea level rise and storm events causing this? Highly likely! (from Day After Tomorrow)
The Nile River Delta 1 m SL Rise would impact 6.1 Million people 4500 km 2 cropland