Transcript Data from IPCC AR4 WG1 2007

Climate Change and Forestry
Allan L. Carroll, Ph.D.
Senior Research Scientist
Natural Resources Canada
Canadian Forest Service
Pacific Forestry Centre
Victoria, Canada
Overview
 Global forests and forestry
 Forests and the carbon
cycle
 Climate change and
forests:
• Impacts
• Mitigation
• Adaptation
Global forests
Forest
Other wooded land
Other land
Water
 Forests comprise 4 billion ha (30% of land surface, 434 billion m3)
 89% natural (36% primary and 53% modified)
Source: FAO Global Forest Resource Assessment 2005
Global forests: recent changes
Change 2000 – 2005
 Greatest forest loss in
low-income, low-latitude
countries
 Average annual net loss:
Brazil – 3.1 million ha
Indonesia - 1.9 million ha
 Average annual net gain:
China – 4.0 million ha
>0.5% decrease per year
>0.5% increase per year
Change rate <0.5% per year
 Forest loss due to:
•
•
Expansion of settlements, infrastructure, unsustainable logging practices
Sources of carbon
•
•
Afforestation, landscape restoration, natural forest expansion
Sinks of carbon
 Forest gain due to:
Source: FAO Global Forest Resource Assessment 2005
Carbon implications of global forest cover change
 Forests: both large sources and sinks of carbon
 The global forest sector:
•
•
Emissions from deforestation 1.6 Gt C/yr
Equivalent to 20% of anthropogenic GHGs
 Forests affect and are affected by climate change
•
Outcome determines mitigation/adaptation potential
How forest affect the carbon cycle
3.2 ± 0.1 GtC/yr Airborne fraction
Atmosphere
 Less than half of
human emissions
stay in atmosphere
Biosphere
6.4 ± 0.4
1.6 ± 0.9
2.6 ± 0.1
Fossil fuel Land-use change Land uptake
(esp. forests)
Reduce emissions
Data from IPCC AR4 WG1 2007
2.2 ± 0.4
Ocean uptake
Increase sinks
 Mitigation = reduced
emissions and/or
increased sinks
 Forests/forestry
can have significant
impacts on future
atmospheric C
concentrations
Climate change and forests: impacts
Projections of surface temperatures (relative to 1980-1999)
2020 – 2029 (short term)
2090 – 2099 (long term)
Emission scenario:
B1
A2
Increasing
GHGs
Climate
change
Increasing
temperatures
Feedbacks?
From IPCC AR4 WG1 2007
Impacts on
forests
Climate change and forests: impacts (short term)
Increased productivity
 CO2 fertilization
 Higher temperature
(inc. growth rate)
 Nitrogen mineralization
 Longer growing season
 Range expansion
Increased disturbance
 Size/severity of forest
fires, wind damage, floods
 Rate/severity/range of
native insect and disease
impacts
 Invasive species
 Feedbacks
Climate change and forests: impacts (long term)
Restricted distributions, esp. northern hemisphere
Current
2 x CO2
Temperate grasses
Grasslands
Deserts
Savanna
Tropical seasonal forests
Tropical moist forest
Wetland, mangrove etc
Agricultural land
Ice
Tundra
Boreal forests
IPCC 1995, GFDL + MAPSS models
Forests and mitigation
 Forests and forestry cannot solve the problem of fossil C
emissions, but they can contribute to the solution
 Reduced deforestation, increased afforestation could more
than offset global carbon emissions from the transportation
sector (Stern 2006)
Forests and mitigation: management options
 Maintain (or increase) forest area
• Reduce deforestation, increase afforestation
 Increase stand-level carbon density
• Partial harvest systems, reduce residue
burning, reduce regeneration delays, species
selection
 Increase landscape-level carbon density
• Lengthen rotations, inc. conservation areas,
protect against disturbance
 Increase stored C in wood products,
reduce fossil C emissions through
product substitution and bioenergy
• Longer-lived products, recycling, biofuels,
salvage
Forests and adaptation
Adaptation = adjustments in ecological, social, and economic systems in
response to the effects of climate change. (Smit et al. 2000)
1st assessment report
2nd assessment report
3rd assessment report
Observed
Constant from 2000
Emissions scenarios
From IPCC AR4 WG1 2007
 Continued warming
even with emissions
held at 2000 levels
 Impacts greatest at
higher latitudes
 Increasing need for
adaptation to
accompany
mitigation efforts
Forests and adaptation
“…more extensive adaptation than is currently occurring is required to
reduce vulnerability to future climate change. There are barriers, limits
and costs, but these are not fully understood.” (IPCC AR4 WG2 2007)
Opportunities?
 Technological
(e.g. assisted migrations, increased resilience)
 Behavioral
(e.g. altered ecosystem service requirements)
 Managerial
(e.g. altered forest practices)
 Policy
(e.g. planning regulations)
A portfolio of adaptation and mitigation measures can diminish
the risks associated with climate change.