Download Detection and attribution at the continental scale

LIVE INTERACTIVE LEARNING @ YOUR DESKTOP
NSTA Web Seminar:
Earth Then, Earth Now: Our Changing
Climate
Climate Change Jeopardy
Presented by Dr. Mike Winton, NOAA
Tuesday, March 31, 2009
Climate Change Jeopardy
Host: Mike Winton
of NOAA/GFDL
31 March 2009
The categories are
• Observations of change
• Basic greenhouse physics
• Climate models & what they tell us
• Climate change options
The earth’s surface is
warming
GISS Temperature
The heat that has warmed our climate
did not come out of the ocean
IPCC
Ice is declining globally
1993-2003 sea level rise
Antarctica
0.20 mm/yr
Greenland
0.21 mm/yr
Glaciers and
Ice Caps
0.77 mm/yr
Total
1.18 mm/yr
• Both Greenland and Antarctica are losing ice
• Glaciers are retreating globally
• Northern hemisphere snow cover has declined
• Northern hemisphere sea ice cover is declining
• Southern hemisphere sea ice cover is not declining
Sea level is rising (ice melt +
seawater expansion)
IPCC
Earth’s energy balance is the key
to long-term climate change
IPCC
Without the greenhouse effect
the earth’s climate would be …
A) The same
B) A wee bit cooler
C) Like the ice ages
D) Like a big ice ball
Without the greenhouse effect
the earth’s climate would be …
A) The same
B) A wee bit cooler
C) Like the ice ages
D) Like a big ice ball
The most important
greenhouse gas is?
A) N2 (78 % of the atmosphere)
B) O2 (21 % of the atmosphere)
C) H20 (<1 % of the atmosphere)
D) CO2 (0.038 % of the atmosphere)
The most important
greenhouse gas is?
A) N2 (78 % of the atmosphere)
B) O2 (21 % of the atmosphere)
C) H20 (<1 % of the atmosphere)
D) CO2 (0.038 % of the atmosphere)
Water vapor is a
climate feedback
Atmospheric CO2 is increasing
Global Warming Art
Atmospheric CO2 was stable
prior to the 19th century
IPCC
The CO2 increase is anthropogenic
CDIAC
We are perturbing the
Global carbon cycle
IPCC
Atmospheric carbon has a range of
timescales from short to very, very long
Global Warming Art
Our greenhouse gas emissions
have changed the heat budget of
the entire earth by?
A) About 0.01 %
B) About 0.1 %
C) About 1 %
D) About 10 %
Our greenhouse gas emissions
have changed the heat budget
of the entire earth by:
A) about 0.01 %
B) about 0.1 %
C) about 1 %
D) about 10 %
There are numerous anthropogenic
forcings of climate change
IPCC
We need global climate
models to help us sort this
out but they are …
A) Somewhat credible because they are based
on fundamental physical and chemical
principles
B) Not completely reliable since they have
significant disagreement with each other
C) Both
D) Neither
We need global climate models
to help us sort this out but they
are …
A) Somewhat credible because they are
based on fundamental physical and
chemical principles
B) Not completely reliable since they have
significant disagreement with each other
C) Both
D) Neither
What is a global climate model?
A GCM is a mathematical representation of the
major climate system components and their
interactions. The GCM equations operate on a
global grid and are solved on a computer.
Atmosphere
Land
Ocean
Concentrations of radiatively active species
Emissions of radiatively active species
Ice
Physical CM
ESM*
*Earth System Model
Climate model equations are solved
on global grids
Current model resolution
1980s
Atmosphere 2 deg.
1990s
2000s
OCEAN MODEL RESOLUTION: 1 deg.
Simulated vs. Parameterized
• Simulated processes: larger than grid-scale, based
on bedrock scientific principles (conservation of
energy, mass and momentum). Example: storms.
• Parameterized processes: smaller than grid scale,
formulations guided by physical principles but also
make use of observational data. Example: clouds.
Detection and attribution of climate
change using models
(2) Attribution: anthropogenic
forcing is that “something”
(1) Detection: something beyond
natural variability is happening to
the global climate
IPCC
Detection and attribution at the continental
scale
Climate models need
emissions to project future
climate change
IPCC
Projection: 21st century global
temperature rises further
IPCC
The hydrologic cycle intensifies
Sea level rises further
IPCC
Caveat: ice sheet dynamic response not fully modeled
Global warming impacts Option 1: Adapt
IPCC
Option 2: Mitigation stabilize
carbon emissions
Socolow, Scientific American 2006
• Conserve energy or produce it more efficiently
• Use alternative energy: solar, wind, bio, nuclear
• Sequester carbon
Emissions growth has powerful
socio-economic drivers
IPCC
Emissions growth has powerful socioeconomic drivers
The Rich
Emissions per capita
Rich emission level
The Rest Become Rich
The Rest
Population
Pop. increases
If we stopped emitting
greenhouse gasses the earth
would cool back down in?
A) 1 year
B) 10 years
C) 100 years
D) 1000 years or longer
If we stopped emitting greenhouse
gasses the earth would cool back
down in
A) 1 year
B) 10 years
C) 100 years
D) 1000 years or longer
Even if emissions were cut to zero,
temperature would fall very slowly
Solomon S. et.al. PNAS 2009;106:1704-1709
There are three options:
• Mitigation
– reduce carbon emissions
• Adaptation – adjust to climate change as best we can
• Geoengineering (e.g. continuously inject reflective
aerosols into stratosphere)
What option(s) are best
A) Mitigation
B) Adaptation
C) Mitigation and adaptation, not geoengineering
D) Adaptation and geoengineering, not mitigation
Summary: Climate change jeopardy is a
high stakes game with uncertain odds
Basic greenhouse physics
CO2 increase anthropogenic
Earth is warming
Warming is anthropogenic
Future carbon emissions
Future climate change
Impacts of future climate change
More certain
Less certain
Special Thanks to NOAA, SRS and
USFS for sponsoring this Web
Seminar!
http://www.elluminate.com
http://learningcenter.nsta.org
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