Transcript Human causes for climate change

Climate Change
The story line
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Earth’s energy budget
More energy?
Warming?
What else?
What about the future?
So what?
The
climate
system
Involves the exchange
of energy and moisture
that occur among the:
• Atmosphere
• Hydrosphere
• Solid Earth
• Biosphere
• Cryosphere
(ice and snow)
Natural causes for climate change
• Greenhouse gases
• Solar variation
– Long term increase
– 11-year cycle (0.08%)
• Orbital variations
• Volcanism
• Plate tectonics
Human causes for climate change
• Long-lived greenhouse gases
– CO2, Methane, N2O
• Aerosols
• Land use
• Aviation contrails
More Energy?
Warming yet?
What else?
Larsen B ice shelf broken up
Jan 31, 2002
March 7, 2002
Contributions to Sea Level Rise
What about the
future?
How good are climate models?
• Simple climate model
• Earth system models of
intermediate complexity (EMICs)
• Atmosphere-ocean global
circulation models (AOGCMs)
Temperature increase for different
levels of CO2 concentration
IPCC SRES Scenarios
• A – Economic growth
– A1: more integrated and convergent world
with stabilizing population at 9 billion
– A2: more divided and fragmented world with
increasing population
• B – Ecologically friendly
– B1: more integrated world with stabilizing
population
– B2: more divided and fragmented world with
slower rate of population growth
Emission Scenarios
Projected global surface warming
and sea level rise at 2100
So what?
A tale of an island
Cape May County, New Jersey
Risk Zones
0 - 3 ft.
3 - 6 ft.
6 - 9 ft.
above 9 ft.
Roads
Limited Access
Highways
Secondary Roads
Other
Highway Ramp
Atlantic County, New Jersey
Risk Zones
0 ft. and below
0-3 ft.
3-6 ft.
6-9 ft.
above 9 ft.
open water
Roads
Limited Access
Highways
Secondary Roads
Other
Highway Ramp
Mid-Atlantic States: MA-VA
• About 1,000 square miles of land area lies below 3
feet
• Within this area, about 70 square miles are
developed land
• About 388 thousand people live in this high risk zone.
• Nearly 3,000 miles of roads are exposed to such high
risk of inundation.
• Southern states have more area, people and facilities
lying in high risk zones because of gentler terrain and
more development along the coast
• CARA website
Do Warmer Seas
mean worse Hurricanes?
Sea surface temperature of the Gulf of Mexico, 8/28/2005
Total power dissipated by tropical cyclones compared to
September North Atlantic sea surface temperature
(Emanuel, 2005)
Disruption of ocean circulation?
Shifts in Agriculture
Extreme Weather Events
Human Health
• More heat-related deaths
• Spread of tropical
diseases into temperate
areas
• Increase of vector-borne
diseases: malaria, west
Niles, Lyme disease
• Disruption of water and
food supply
Species distribution and diversity