Uncertainty and Forecasts of
Landscape to Global
Vegetation Changes Related to
Climate Change
Ronald P. Neilson1*, James M. Lenihan1, Dominique
Bachelet2, Raymond J. Drapek1, John Wells2
1USDA
Forest Service, Pacific Northwest Research Station,
Corvallis, OR, USA
2Oregon State University, Corvallis, OR, USA
Assessments of Future Climate Change
Begin with Uncertainty
CO2 and SO2 in the 21st Century
A2
A1B
B1
Future Scenarios are Based on Socio-Economic ‘Storylines’
This Presents a Paradigm for
All Future Management Considerations
Source: IPCC TAR 2001
Variations of the Earth’s Surface Temperature:
1000 to 2100
Uncertainty is due to both
Emissions Scenarios and
Climate Models
(not to mention
Vegetation Models!)
• 1000 to 1861, N.
Hemisphere, proxy data;
• 1861 to 2000 Global,
Instrumental;
• 2000 to 2100, SRES
projections
But note the slope of Past
Compared to Future Temperature Change
The Low End of Some Models
Is as High as
The High End of Other Models
CSIRO MK3
A2
A1B
B1
Temperature difference:
2070-2099 vs. 1961-1990
MIROC MEDRES
The Uncertainties are Often Percent Change Precipitation:
Greater Between Climate Models 2070-2099 vs. 1961-1990
Than between Emissions Scenarios!
CSIRO MK3
A2
A1B
B1
MIROC MEDRES
Simulated Historical Vegetation
MC1 (MAPSS-CENTURY, v.1)
0.5o
Resolution
50m Resolution
Multi-Scale Assessment
2.5’ Resolution
Percent Change in Total Ecosystem Carbon
CSIRO_MK3 A2
What will happen to Timber and Carbon Markets?
The West Sequesters Carbon!
Percent Change in Biomass Burned
CSIRO_MK3 A2
Fire Increases Across the Western U.S.,
But, Look at the Boreal Forest
MAPSS Simulated Vegetation Distribution
Current Climate
Future Climate
(CGCM1)
Future Woody and Grass Expansion in the West
Enhance Carbon Storage, and
Catastrophic Wildfire, But…
Absolute Change
(Kg/m2)
Where is all the Excess Wood
From Fire Suppression / Exclusion?
Percent Change
MC1 Simulation of
Fire Suppression
Average Biomass Burned
Historical (1950-1999)
This includes NO
Fire Suppression or Exclusion
Average Biomass Burned
CGCM2a (2050-2099)
In the Future
The West gets Woodier, and
It burns a lot more!...
But, look at the East!
A California Assessment
Requested by the Governor
Three
Future
Scenarios
1
Three
Future
Scenarios
2
Three
Future
Scenarios
3
Percent Change In Annual Area Burned (2050-2099),
Compared To The 20th Century
PCM-A2
GFDL-B1
GFDL-A2
Even Across Models, there Appear to be
Intrinsic Regional Sensitivities
Interdecadal Climate Variability
Can Obscure the Long Term Change
A.
PERCENT CHANGE
15
ANNUAL TOTAL AREA BURNED
12
9
6
3
0
-3
Multiple Scenarios can help ‘Bound’ the Uncertainties
PERCENT CHANGE
B.
PCM-A2
GFDL-A2
GFDL-B1
ANNUAL TOTAL BIOMASS BURNED
16
12
8
4
0
-4
-8
2000
2010
2020
2030
2040
2050
YEAR
2060
2070
2080
2090
2100
Simulated Annual Global Mean
Surface Temperatures
Ensemble Simulations,
Doing Experiments,
May be the Only Way
To Bound Uncertainties
Over the Next Few Decades
Current Climate
But, before closing…
HADCM2SUL
Let us not Forget that Species Migrations
Including Diseases, Insects, Vertebrates and Plants
Could Flood Our Ecosystems
Management Implications
(personal musings)
• Management Goals face an uncertain Future
– The Future will NOT echo the Past
• Instead,… Manage Change, per se
– Desired function will supercede ‘Desired future condition’
• Improve resilience of ecosystems to rapid change
– Keep forest density below water-limited carrying capacity
– Plant diversity rather than homogeneous monocultures
• Fire, Carbon and other policies may be antithetical
demanding creative management of change