Transcript Climate Change: Evidence

Climate Change Theory
Climate Change Ecology
Main points:
1. Climate has never been stable.
2. Climate dynamics impact ecosystems
3. The climate is changing rapidly now.
4. Climate change has substantial implications
Delcourt and Delcourt 1987
Tim Tebow press conference
6 m earliest “humans”
100 m flowering plants
408 m. land plants
Delcourt and Delcourt 1987
THE HOLOCENE
(11,000-now)
Delcourt and Delcourt 1987
Climate Change Ecology
Main points:
1. Climate has never been stable.
•
Enormous variability over the long-term
2. Climate dynamics impact ecosystems
•
Species respond to climate dynamics
3. The climate is changing rapidly now.
4. Climate change has substantial implications
Margaret Davis...
SCIENCE !
Pollen (SEM)
Acer rubrum
Juniperus sp.
http://www.geo.arizona.edu/palynology
Ambrosia trifida
Margaret Davis: Roger’s Lake
Ecology (50:409-422), 1969
Pollen Viewer
http://www.geo.brown.edu/georesearch/esh/QE/Research/VegDynam/VegAnima/Viewer32/WebViewer.html
Climate Change Ecology
Main points:
1. Climate has never been stable.
•
Enormous variability over the long-term
2. Climate dynamics impact ecosystems
•
Species respond to climate dynamics
3. The climate is changing rapidly now.
4. Climate change has substantial implications
Longer term temps?
http://www.realclimate.org/
http://www.ipcc.ch/
Griffith Woods, KY
http://www.realclimate.org/
Potential influences on climate:
1) Sunspot activity
2) Volcanoes
3) Ocean current changes
4) Earth’s wobble
5) Atmosphere (greenhouse effect)
Sunspots!
Sunspots!
Sunspots!
No evidence of more volcanos
Sensitivity to Orbital Parameters
Milankovitch Theory
IPCC AR4 2007
A CO2 driver of Climate Change….
The Greenhouse Effect is fundamental to our
understanding of how Earth works:
http://earthguide.ucsd.edu/earthguide/diagrams/greenhouse/
Keeling Curve: Measured on Mauna Loa
On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground
Svante Arrhenius
The London, Edinburgh and Dublin Philosophical Magazine and Journal of
Science Series 5, Volume 41, April 1896, pages 237-276.
Early Climate Model
http://earthobservatory.nasa.gov/Featu
res/Paleoclimatology_IceCores/
Carbon Dioxide Concentration
900
Petit et al, Nature v.399 (6735), pp. 429-436. (1999)
CO2 range 700
in 2100 600
500
400
300
CO2 today
today
200
100
Homo sapiens sapiens
400000
300000
200000
100000
Age (years before present)
0
0
CO2 (ppmv)
800
http://climate.nasa.gov/
Climate Change Ecology
Main points:
1. Climate has never been stable.
•
Enormous variability over the long-term
2. Climate dynamics impact ecosystems
•
Species respond to climate dynamics
3. The climate is changing rapidly now.
4. Climate change has substantial implications
Climate Change, Theory