Download Sea Level Rise

Global warming and
Sea Level Rise:
Best estimates by 2100
John King
Professor of Oceanography
Global Warming:
What is it?
• The increase in the measured temperature
of the earth’s oceans and near-surface air.
Measured temperature increases since 1860
Global annually averaged surface temperatures, based on NASA GISS surface temperature analysis
Global Warming:
What’s causing it?
• Human activities add CO2 and other gases
to the atmosphere.
• The increase of these gases causes
“The Greenhouse Effect.”
The Greenhouse Effect
Some of the energy is
reflected back into space.
Greenhouse gases in the
atmosphere trap some of the
heat. More gases = more heat.
Sun’s energy passes
through the
atmosphere, warming
the earth.
Indicators of human influence on the atmosphere
Changes in Temperature, Sea Level and Northern Hemisphere Snow Cover
Courtesy of IPCC, 2007
Global Warming:
Why does it matter?
Global warming causes climate changes that
will affect:
• natural ecosystems
•
availability of food and water
• global economies
• frequency of extreme weather events
• human health and lifestyle
Increased CO2 emissions = climate change
Rising Temperatures
Changes in Precipitation
Rising Sea Level
Increasing CO2
Global effects of climate change and sea level rise
Effects of Global Warming:
Rising temperatures
Rhode Island climate “migration”
Courtesy of the Union of Concerned Scientists
Rising Temperatures
Courtesy of the Union of Concerned Scientists
Global and Continental Temperature Change
Courtesy of IPCC, 2007
Changes in annual average temperature in the Northeast
Effects of Global Warming:
Rising sea level
Four contributions to sea level rise
1.
Thermal expansion of seawater
2.
Melting of glaciers and ice caps
3.
Ice sheet surface mass balance
•
4.
snowfall - melting
Ice sheet surface dynamical imbalance
•
increased flow rate
Projected globally averaged surface warming &
sea level rise at the end of the 21st century
Courtesy of IPCC, 2007
Sea Level Rise: Observed vs. Projected
Interval
Model Prediction
Observed
mm/year
mm/year
1993 - 2003
2.6
3.1
1961 - 2003
1.2
1.8
Sea Level Rise: Observed = Projected
projected
observed
2007 - IPCC sea level rise estimate
1.
Thermal expansion of seawater .......... 28 cm
2.
Glaciers and ice caps ......................... 12 cm
3.
Mass balance ..................................... - 3 cm
4.
Increased flow ................................... + 3 cm
Total: 40 cm
Range of Estimates: 18-59 cm
Sea Level Rise: New Estimates
Reference
By 2100
(feet)
Total Rise
(feet)
Overpeck,
et al., 2006
>3
13 - 20
Rahmsorf,
2007
1.6 - 4.6
---
Pfeffer,
et al., 2008
2.6 - 6.6
---
Increased sea level rise estimates for New England
Reference
Additions to global
rise predictions
Yin,
et al., 2009
+ 8 inches
Hu,
et al., 2009
+ 12 - 20
inches
Total global +
regional
2.3 - 8.3
feet
Greenhouse Gases in Ice Cores
Present day
From Brook, E. J., 2005. Science , 25 vol. 310. no. 5752, pp. 1285 - 1287
What does 3 feet of sea level rise look like?
Effects of Global Warming:
Rising sea level in Rhode Island
Quonochontaug Pond 5’ sea level rise:
Model by Nathan Vinhateiro, GSO-URI
Flooded areas shown with light blue shading
Quonochontaug Pond 5’ sea level rise detail:
Model by Nathan Vinhateiro, GSO-URI
Flooded areas shown with light blue shading
Quonochontaug Pond 5’ sea level rise detail:
Model by Nathan Vinhateiro, GSO-URI
Flooded areas shown with light blue shading
Planning Needs for Rhode Island
1.
Seamless digital terrain model


LIDAR survey of coastline
High-resolution bathymetry of coastal waters
2. Inundation model



Storm surge with wave regime superimposed
Better understanding of coastal erosion style
and rate
Expanded Rhode Island sea level and coastal
erosion monitoring program
Possible explanation for why human-induced
global warming is still “controversial”