Climate Change and Forestry

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

2. Overview • Global forests and forestry • Forests and the carbon cycle • Climate change and forests: • Impacts • Mitigation • Adaptation

3. Forest Other wooded land Other land Water 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

4. 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 Greatest forest loss in low-income, low-latitude countries Average annual net loss:Brazil – 3.1 million haIndonesia - 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 Change 2000 – 2005 Global forests: recent changes Source: FAO Global Forest Resource Assessment 2005

5. 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

6. Mitigation = reduced emissions and/or increased sinks • Forests/forestry can have significant impacts on future atmospheric C concentrations Reduce emissions Increase sinks 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 1.6 ± 0.9 Land-use change 2.6 ± 0.1 Land uptake(esp. forests) 2.2 ± 0.4 Ocean uptake Data from IPCC AR4 WG1 2007

7. 2020 – 2029 (short term) 2090 – 2099 (long term) Emission scenario: B1 A2 Climate change Increasing temperatures Impacts on forests Feedbacks? Projections of surface temperatures (relative to 1980-1999) Climate change and forests: impacts Increasing GHGs From IPCC AR4 WG1 2007

8. 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 Increased productivity Increased disturbance Climate change and forests: impacts (short term)

9. Restricted distributions, esp. northern hemisphere 2 x CO2 Climate change Temperate grasses Grasslands Deserts Savanna Tropical seasonal forests Tropical moist forest Wetland, mangrove etc Agricultural land Ice Tundra Boreal forests Climate change and forests: impacts (long term) Current IPCC 1995, GFDL + MAPSS models

10. 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)

11. 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

12. 1st assessment report 2nd assessment report 3rd 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 • 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

13. Opportunities? 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.