Sea Level & Ice Sheets
This presentation is the property of its rightful owner.
Sponsored Links
1 / 19

Sea Level & Ice Sheets Concern about the Future of Inhabited Coastlines PowerPoint PPT Presentation


  • 47 Views
  • Uploaded on
  • Presentation posted in: General

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.

Download Presentation

Sea Level & Ice Sheets Concern about the Future of Inhabited Coastlines

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

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


Sea level history over the past 450,000 years

Source: Labeyrie et al (2003) In: Paleoclimate, Global Change and the Future, Springer.


Last interglacial

Global Sea Level

TODAY

Full Glacial

Lambeck et al., 2002, based on tropical & subtropical records


  • Ice from the Ocean makes ice sheets, so sea level drops

  • When Ice sheets melt, sea level goes up.


Antarctica

West

East


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 didn’t disappear during the Last Interglacial

.

  • IPCC2001: near 0

  • Cazenave & Nerem (2004): >0.15 mm/yr

  • Sterns & Hamilton (2007): 0.57 mm/y


Why Is Global Sea Level Rising Today?

Muir Glacier

  • 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

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


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


Should I Sell My Shore House?

Brazil

Atlantic City NJ


Observations(Tide Gauge and Satellite Altimetry Data)

  • Overall 10-20cm rise in 20th century

  • 20th 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


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)

2007

http://www.realclimate.org/images/sealevel_1.jpg


Recent Global Sea Level Rise Estimates

Slide from Rahmstorf web site

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)

WBGU

Delta Comm.

Rahmstorf

Data

Best Estimate = 80 cm of SL Rise by 2100, 1 m is not out of the question


Long Beach Island, NJ

Human stabilized

400 m

Natural movement

Courtesy N. Psuty


(from Day After Tomorrow)

Sea Level Rise – like this?

No !

Gradual sea level rise and storm events causing this?

Highly likely!

http://www.learnnc.org/lp/editions/cede_smsandvol/323


The Nile River Delta

1 m SL Rise would impact

6.1 Million people

4500 km2 cropland


Boston

http://www.geo.umass.edu/stategeologist/frame_maps.htm


  • Login