Title: Observing Climate with Satellites: Are We on Thin Ice
1Observing Climate with Satellites Are We on
Thin Ice?
Compton Tucker NASA/Goddard Space Flight Center
Greenbelt, Maryland
- Solar forcing - Orbital forcing
- Ice / Sea level
- CO2 - CH4 - O3 - N2O
- Temperature data -- direct proxy
- Cryosphere
2Climate Feedback
- Given a climate forcing (e.g. orbital variation
or CO2 increase) ? initial warming - Amplifying loops (positive feedback) magnify the
warming - Diminishing loops (negative feedback) magnify the
cooling
3Milutin Milankovitch 1879-1958
Solar and orbital drivers of climate
Orbital variations 0.3 W/m2 globally, 5-10
W/m2 far N.
4Orbital DynamicsFg G( m1m2)/r2
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8North America last glacial maxima
9Western Europelast glacial maxima
10Ice core dataAntarctica 440k 800k year
records Greenland 120k year record
11Equilibrium Climate from Ice Core Data
385 ppm
- Estimate climate forcing (W/m2) from atmospheric
composition changes
J. Hansen
12Data and Sum CKY 1 7 lt 10,000 years
13S modes 9 to 13 20k, 40k, 100k, 400k, 400k
years
14Temperature leads greenhouse gas forcing by 700
years
GHG Fe 1.15Fa(CO2)1.4Fa(CH4)
Hansen et al. 2007
15Temperature, albedo, greenhouse gases, and sea
level
Hansen et al. 2007
16Ice Core Summary
- Earths climate remarkable sensitive
- Orbital variations 0.3 W/m2
- Albedo greenhouse gas feedbacks
- Lags in system -- oceanic processes
- GHG emissions put us in danger zone
- Temperature - albedo - sea level
17Present Inter-Glacial Period(very stable)
18Proxy Surface Temperatures (great recent
contention)
- Bore Holes
- Ice Cores
- Tree Rings
- Coral Cores
- Glacier Lengths
- Sediment Cores, etc.
19Land Ocean Temperature Data
8 warmest years 1998 and 2001-2007
NASA/GISS
20Warming greatest at high latitudes
Amplification of warming due to decrease of
albedo (melting of snow and ice)
21Proxy surface Temperature data density circa 1500
AD
22Proxy surface Temperature data density circa 1000
AD
23Greenland ice core high resolution/distinct
layers
24Coral d18O/16O TemperatureReconstruction
25Bore Hole Locationsdifferent physics (thermal
diffusivity) 10s of years time steps
26Bore Hole Temperature Reconstructions
27Mann, Bradley, Hughes (1998)The hockey
stick surface temperature
28Proxy data used by Mann et al. 1998
29National Research Council USA June 2006 Report
30Satellite Era1970s ---gt now
31Why NASA?
- NASA builds, launches, and operates satellites to
study the earth, our solar system, and the cosmos
32NASAs Hubble Space Telescope
33Hubble Images
34NASAs Earth-viewing Satellites
35OCEAN
36OCEAN
37Ocean Photosynthesis
38Solar Climate Forcing
39Solar Climate Forcing
1. Variation in total solar energy output ---gt
earth warms or cools 2. Variation in ultraviolet
solar output ----gt earth warms or cools 3. Sun
influences cosmic rays --gt clouds --gt earth
warms or cools (see Henrik Svensmark -- however
no microphysical mechanism has been identified)
40ICE
41Arctic Sea Ice Trends
1979 summer minima
42Arctic Sea Ice Trends
1979 summer minima
43Arctic Sea Ice Trends
44Photo by K. Steffen, U. of Colorado
45Sea Level Rise from thermal expansion water
from melting glaciers
60 thermal expansion 40 glacial melt
20 cm (7 inches) in a century
46Gravity Recovery Climate Experiment
500 km orbit 220 km separation Distance accuracy
?0.001 mm
47Greenland Ice Mass Flux from GRACE mascon
solution
Ann. Amp. 162 ? 14 Gt
NASA GSFC mascon solution, update to Luthcke,
S.B., H.J. Zwally, W. Abdalati, D.D. Rowlands,
R.D. Ray, R.S. Nerem, F.G. Lemoine, J.J. McCarthy
and D.S. Chinn, Recent Greenland Ice Mass Loss
by Drainage System from Satellite Gravity
Observations, Science 314, 1286 (2006)
(10.1126/science.1130776).
48Greenland Ice Mass Flux from GRACE mascon
solution
Losing 154 Gt of ice per year ! (update to
Luthcke et al. Science 2006) 154 Giga-ton
154,000,000,000 metric tons 1 metric ton
2,205 lbs. 154 Giga-ton 168 km3 of ice or 40.3
mi3 of ice Nearly 2.5 times the amount of water
in the Chesapeake bay ! Nearly 10 times the
average annual flow of the Colorado river ! 0.43
mm/yr to global sea level rise.
NASA GSFC mascon solution (update to Luthcke et
al. Science 2006)
Photo Credit Roger Braithwaite
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51Atmospheric CO2 measurements
52Atmospheric CO2 since 1740
385 ppm now
Different d CO2 slopes reflect
d time techno-economic conditions
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55Florida without Greenlands ice sheet
56Carbon-Dioxide Levels
- ppmv parts per million by volume
- Carbon-dioxide levels recover slowly
57Alternatives to Fossil Fuels for World
Electricity
- Hydroelectric is 16, Nuclear is 14
- Wind is the leader of the new alternatives, up
10? in 10 years - 100 GW capacity (1 of world electricity
production) - 1/3 of new US capacity in 2007
- Solar photovoltaics, ten years behind wind
- 8GW capacity
- Distributed generation, Caltech is installing 1MW
58Nevada Solar One
Photo Schott Glass
59King Hubbert
- Geophysicist at the Shell lab in Houston, Texas
- In 1956, he wrote a paper with predictions for
the peak year of US oil production
60Hubberts Peak
Optimistic ultimate
1970
Hubberts ultimate
- BBLS barrels
- CUMULATIVE PRODUCTION past production
- ULTIMATE cumulative production plus future
production
61US Oil Production
62Cumulative Plot for US Oil
Fit is 29Gb future production EIA reserves
21Gb USGS/MMS assessment 189Gb
- EIA Energy Information Administration of the
DOE - Reserves are resources that could be economically
produced
63Rate Plot for US Oil
Dashed curve is previous normal
- Growth Rate annual production/cumulative
production - Ken Deffeyes developed this approach
64Trends for Alternatives
- These are the compound growth rates for the last
ten years - The comparable growth rate for world electricity
has been 3.6 - No production trends yet for fossil-fuel
alternatives like oil shale and methane hydrates.
Previous predictions of imminent substantial
production have been wrong.
65Photo Schott Glass