Climate Change and Forestry

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Climate Change and Forestry
Allan L. Carroll, Ph.D.
Senior Research Scientist
Natural Resources Canada Canadian Forest
Service Pacific Forestry Centre Victoria, Canada
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Overview

• Global forests and forestry
• Forests and the carbon cycle
• Climate change and forests
• Impacts
• Mitigation
• Adaptation

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Global forests

• 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
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Global forests recent changes
Change 2000 2005

• Greatest forest loss in low-income, low-latitude
  countries
• Average annual net lossBrazil 3.1 million
  haIndonesia - 1.9 million ha
• Average annual net gainChina 4.0 million ha

• Forest loss due to
• Expansion of settlements, infrastructure,
  unsustainable logging practices
• Sources of carbon
• Forest gain due to
• Afforestation, landscape restoration, natural
  forest expansion
• Sinks of carbon

Source FAO Global Forest Resource Assessment 2005
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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

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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 Fossil fuel
2.2 0.4 Ocean uptake
1.6 0.9 Land-use change
2.6 0.1 Land uptake(esp. forests)
Data from IPCC AR4 WG1 2007
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Climate change and forests impacts
Projections of surface temperatures (relative to
1980-1999)
Increasing GHGs
From IPCC AR4 WG1 2007
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Climate change and forests impacts (short term)
Increased productivity
Increased disturbance

• CO2 fertilization
• Higher temperature(inc. growth rate)
• Nitrogen mineralization
• Longer growing season
• Range expansion

• Size/severity of forest fires, wind damage,
  floods
• Rate/severity/range of native insect and disease
  impacts
• Invasive species
• Feedbacks

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Climate change and forests impacts (long term)
Current
IPCC 1995, GFDL MAPSS models
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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)

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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

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Forests and adaptation
Adaptation adjustments in ecological, social,
and economic systems in response to the effects
of climate change. (Smit et al. 2000)

• Continued warming even with emissions held at
  2000 levels
• Impacts greatest at higher latitudes
• Increasing need for adaptation to accompany
  mitigation efforts

From IPCC AR4 WG1 2007
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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)

• 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.