Source: IPCC
Source: IPCC
1. Reduced Biodiversity
(rapid change)
2. Sea level rise and coastal flooding
(melting ice and thermal expansion)
3. Expansion of tropical disease range
4. Soil Moisture Decreases and
Desertification ?
5. Increased frequency of heat illness
(problem for the elderly)
6. Increased frequency of severe events?
7. Engineering problem of thermokarst
(transportation and housing)
8. Affect on outdoor winter recreation
and winter tourism
1. Increasing NPP?
2. Increased food production?: CO2
fertilization, range & growing season
(depends on soil moisture/depth/nutrients)
3. Increased water-use efficiency
4. Increased nutrient-use efficiency?
5. High latitude warming
(positive and negative)
Source: IPCC
Source: IPCC
Ice core data
Temperature,
CO2 and CH4
are all in
phase
Are the gas
concentrations
a cause or an
effect of
warming or
both ?
Source: IPCC
HADCM3 Model Prediction
Global Circulation Model Projection:
Non-uniform spatial distribution of
global surface temperature increase
Free Air Carbon Dioxide Enrichment (FACE)
FACE Results:
NPP increases
(eg. 40% in cotton; 25%
for Sweetgum for 550
ppm vs. 370 ppm)
Carbon sink increase limited for forests: Increase in wood
production is short-lived; C goes mainly to fine roots and
leaves; affected by soil fertility
No effect on LAI
Stomatal conductance decreases (increased water-use
efficiency)
Lower leaf nitrogen concentration: need less or have less?
Carbon Sinks
But what are we doing to our sinks ?
http://news.bbc.co.uk/2/hi/americas/3609887.stm
Annual Atmospheric Increase
3.3(±0.2) PgC (billion metric tonnes)
Why ?
Emissions from fossil fuels
Changes in land use
Oceanic uptake
Missing carbon sink
+5.5(±0.5)
+1.6(±0.7)
- 2.0(±0.8)
- 1.8(±1.2)
Possible source: Underestimation of terrestrial uptake
Mid-latitude forest regrowth ?
Will the missing sink last ?
Source: Woods Hole Observatory
Source: IPCC
Meanwhile, we are detecting
stratospheric cooling !
Why ?
Ozone depletion
Tropospheric [CO2] increases
Interannual climatic variability at
the global scale
Caused by changing atmospheric and
oceanic circulation in the tropical
Pacific Ocean
Top La Nina December 1998; Middle Normal December
1993; Bottom El Nino Dec 1997
See http://www.cdc.noaa.gov/map/clim/sst_olr/sst_anim.shtml
Q. Is there a relationship between the
frequency and/or strength of El Nino
Southern Oscillation and climate
change ?
A. We don’t know.
However, effects might be exacerbated in a
warmer climate (higher sea levels would
enhance flooding, precipitation heavier
during enhancement, evaporation greater
during drought phases)
El Nino-related flooding in N. California
Mainly due to shifting winds