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

Overview  Global forests and forestry  Forests and the carbon cycle  Climate change and forests: Impacts Mitigation Adaptation

 Forests comprise  4 billion ha (30% of land surface, 434 billion m 3 )  89% natural (36% primary and 53% modified) Source: FAO Global Forest Resource Assessment 2005 Global forests Forest Other wooded land Other land Water

Global forests: recent changes  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 >0.5% decrease per year>0.5% increase per yearChange rate <0.5% per year Change 2000 – 2005  Greatest forest loss in low-income, low-latitude countries  Average annual net loss: Brazil – 3.1 million ha Indonesia million ha  Average annual net gain: China – 4.0 million ha

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  Less than half of human emissions stay in atmosphere 3.2 ± 0.1 GtC/yr Airborne fraction 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 WG Reduce emissionsIncrease sinks  Mitigation = reduced emissions and/or increased sinks  Forests/forestry can have significant impacts on future atmospheric C concentrations

Climate change and forests: impacts From IPCC AR4 WG Projections of surface temperatures (relative to ) Emission scenario: B1 A – 2029 (short term)2090 – 2099 (long term) Increasing GHGs Climate change Impacts on forests Increasing temperatures Feedbacks?

Climate change and forests: impacts (short term)  CO 2 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 Increased productivityIncreased disturbance

Current IPCC 1995, GFDL + MAPSS models Temperate grasses Grasslands Deserts Savanna Tropical seasonal forests Tropical moist forest Wetland, mangrove etc Agricultural land Ice Tundra Boreal forests 2 x CO 2 Climate change Restricted distributions, esp. northern hemisphere Climate change and forests: impacts (long term)

 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

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  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 WG st assessment report 2 nd assessment report 3 rd assessment report Observed Constant from 2000 Emissions scenarios Adaptation = adjustments in ecological, social, and economic systems in response to the effects of climate change. (Smit et al. 2000)

Forests and adaptation  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) “…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) A portfolio of adaptation and mitigation measures can diminish the risks associated with climate change. Opportunities?