Why study
GLOBAL WARMING?
www.noaanews.noaa.gov/ stories/s412.htm
Photograph by Peter Essick
As Habitats Change
• Species distributions are changing
• Some animals are moving toward the
poles
• Some are moving up mountains
• Many are losing habitat, migration routes
Plants and Disease
• Agricultural crops
may be affected as
local weather and
seasons change
http://www.mindfully.org/Air/Global-Warming-Health20aug00b.GIF
• Insect population
explosions
• Invasive species
• Disease distributions:
malaria, cholera, etc
www.uaf.edu/.../2004/ ninilchik-beetles.html
Increased severe weather:
droughts, floods, hurricanes
http://magma.nationalgeographic.com/ngm/0409/feature3/zoom5.html
“More than a hundred million people
worldwide live within three feet of mean sea
level.” ~National Geographic fact
http://www.ourbangla.com/bangladesh/pg/flood/FLOOD_JESSORE_17_8AP_JWH_s0.jpg
Causes: Greenhouse gases
• Burning fossil
fuels
• Forest fires
• Volcanoes
• Deforestation
www.ctv.ca/.../
1038431872899_41?s_name=&no_ads=
www.unexplainable.net/.../ article_581.shtml
•Collapsing ground
from melting
permafrost
•Melting sea ice
http://climchange.cr.usgs.gov/info/assessment/tok.jp
eg
http://www.phenology.org.uk/standard/home/why/i
mages/polalbearsicemelt.jpg
http://www.ciel.org/Pictures/ice_arch.jpg
REDUCE CO2 Emissions!
• Clean Electricity /
Alternative Energy
• Smart Transportation
and Land Use
• Healthy Farms and
Forests
• Promote Conservation /
Restoration
• Make Greener Choices
So how do ecosystems respond
to elevated CO2?
• Study site:
Cheyenne, WY
• Treatments:
– Elevated CO2
– Heating
– Changing rainfall
patterns
• CO2 sink or
source?
CO2 (ppm)
CO2 uptake and respiration
590
580
570
560
550
540
530
520
510
500
0
50
100
150
Time (seconds)
200
250
300
Ecosystem respiration (umol/m^2/s)
What is happening belowground?
16
Pulse 1 Ecosystem respiration
A1
E1
C1
14
12
10
8
6
4
2
0
-2
0
2
4
Day of Pulse
6
8
0.2
NEE Pulse 1
0.1
0.0
-0.1
-0.2
-0.3
-0.4
A2
E2
C2
-0.5
-0.6
-2
0
2
4
Day of Pulse
6
8
Net Ecosystem Exchange (umol/m^2/s)
Net Ecosystem Exchange (umol/m^2/s)
CO2 fluxes…. Responses to rainfall
0.2
NEE Pulse 2
0.0
-0.2
-0.4
A2
E2
C2
-0.6
-0.8
-2
0
2
4
Day of Pulse
6
8