Transcript The “Known” Projections of human drivers

The Climate Change Group
The “Knowers”
Andy Bakun
Tom Corringham*
Dave Erickson
Mickey Glantz
Hey-Jin Kim*
John Moisan
Raghu Murtugudde
Ron O’Dor
Dave Pierce
Gino Passalaqua*
Nancy Knowlton
Art Miller
Joanie Kleypas
RSMAS/U Miami
UCSD, Economics
Oak Ridge Nat. Lab
Nat. Ctr Atmos. Res.
SIO
NASA
U Maryland
Census of Mar. Life
SIO
SIO
SIO
SIO
Nat. Ctr Atmos. Res.
*Able students
The “Known” Projections
of Climate Change
Ocean pH
Sea surface temperature
Sea level
Ocean stratification
Water cycle
glaciers and sea ice
best
known
runoff (region-dependant)
precipitation
Changes in ocean circulation/wind patterns/upwelling
Meridional overturning (thermohaline circulation)
Tropical cyclone activity
Dust delivery (and trace metals) to the oceans
least
known
Direct effect
of CO2
forcing
[CO32-] at 280 ppmv and 560 ppmv
Spatial differences in surface warming
The “Known” Projections
of Impacts on Biodiversity
Forcing
Impact on Biodiversity
Lowered pH
Decrease in calcification rates of organisms that
secrete shells → biodiversity
Increased SST
Poleward migration of tropical species;
Contraction of high latitude habitats
Sea level rise
Expansion and contraction of coastal habitat species
Increased stratification
Decrease in nutrient availability → shifts between
P-limited and N-limited systems
Loss of sea-ice extent
Reduction in sea-ice dependent communities
Increased coastal
upwelling
Potentially increases nutrient availability with
effects on community structure → biodiversity
Decreased thermohaline
circulation
Lowered nutrient supply to subarctic and tropical
systems → biodiversity
Predicted changes in “Ecosystem Domain Areas”
from Climate Models of 2040-2060
Highly productive
Weakly productive
Productive
Oligotrophic
Sarmiento et al., 2004
The Unknowns (and why)
Forcings:
1. Feedbacks of clouds on climate
2. Temporal and spatial variance in all physical variables
3. Tropical cyclone effects on ventilation (reduction of the
“dead zone”)
4. Effects of human behavior on climate change forcing (CO2,
land use, etc.)
Biodiversity:
1. Relationship between productivity and biodiversity in the
open ocean
2. Time-scales of biological adaptation to changes in forcings
3. Roles of species interactions in modulating biodiversity
4. Response of subsurface biodiversity to surface changes
The Unknowable,
and the significance of not knowing
1. Behavior of large-scale climate oscillations
– PDO/NAO/ENSO
– could have large overriding effects
2. Glacial/Polar ice collapse
– not likely, but would have huge impact
3. THC shutdown
– not likely, but would have large impact
4. Biological ‘surprises’
– e.g., coral bleaching, marine diseases; animal behavior
– can completely alter structure of marine biological community
Gaps in knowledge:
what do we need to know and why
Time-space patterns of “biodiversity”
1.
–
–
2.
baseline data on present-day or past biodiversity
retrospective studies or synthesis of existing data (COML)
Models
–
–
include intrinsic population variability necessary to assess
biodiversity
higher resolution modeling at ecosystem/community scales
3.
Development of downscaling, esp. in coastal
regions
4.
Physiological studies; genetic analyses of
plasticity of species’/populations’ environmental
tolerances
Is it possible to reverse the trajectory
of degradation?
NO… but it’s possible to slow the trajectory
• Stabilize emissions
– does not halt the increase in atmospheric
greenhouse gases
– DOES reduce the rate of change
• Reduce non-climate stresses
• Include projections of climate change as a
component of conservation design