Forests and Carbon in the US Michael G. Ryan USDA Forest Service Rocky Mountain Research Station

Transcription

1 Forests and Carbon in the US Michael G. Ryan USDA Forest Service Rocky Mountain Research Station Richard A. Birdsey, USDA FS, NRS Christian P. Giardina, USDA FS PSW Mark Harmon, Oregon State University Linda Heath, USDA FS, NRS Skee Houghton, Woods Hole Research Center Robert Jackson, Duke University Duncan McKinley, AAAS Brian Murray, Duke University Mark Nechodom, USDA Diane Pataki, University of California, Irvine Ken Skog, USDA FS, Forest Products Lab National Forests Climate Change Workshop Washington, DC, January 2010

2 Forests and Carbon Remind everyone of basics before we start Where we are, how we got there, where we might go Two very different ideas of forest carbon futures for US A couple of radical ideas

3 Synthesis of Science Issues in Ecology ESA synthesis for policy and managers; Ecological Applications Review paper Questions What human actions influence forest carbon sinks and can these sinks be enhanced? What are the risks, uncertainties, tradeoffs, and co-benefits of using forests and forest products in proposed carbon mitigation strategies?

4 US forests and wood products offset 12%(FS- EPA) 19%(SOCCR) of fossil-fuel emissions North America Mt = (10 12 g) CCSP, The First State of the Carbon Cycle Report (SOCCR): The North American Carbon Budget and Implications for the Global Carbon Cycle. From SOCCR Report:

5 10% is Huge! To get another 10%: Convert entire US auto fleet to hybrid gas mileage Convert 1/3 current Ag land to forests.

6 US Forest Carbon Balance : Forest Disturbance on a Massive Scale-the Industrial Revolution? In 1915, emissions from forests were 760 million tons C per year Birdsey, R., K. Pregitzer, and A. Lucier Forest carbon management in the United States: Journal of Environmental Quality 35: Photo courtesy of University of Washington Libraries, Special Collections, KIN084.

7 US Forest Carbon Balance 1950 to 2008: Forest Regrowth on a Massive Scale In 2000, sequestration by forests was ~200 million tons C per year Birdsey, R., K. Pregitzer, and A. Lucier Forest carbon management in the United States: Journal of Environmental Quality 35: Photo by Mike Ryan

8 Will the sink continue? Recovered only ~40% of pre-industrial forest C. But, all of the agricultural land east of Mississippi used to be forest not likely to return. Increased N and CO 2 increase sink? Increased disturbance reduce sink?

9 Forest Carbon Biology Basics

10 Forest carbon has a cycle: after disturbance, loss and recovery Photo by National Park Service Photo by Mike Ryan Photo by Dan Kashian Photo by Mike Ryan

11 Ecosystems that regenerate forests after disturbance (harvesting, fire, bugs) will recover all of the carbon lost, given time

12 What happens with no regeneration? Example: Hayman Fire, Colorado, 2002 Photo by Merrill Kaufmann, USFS

13 The larger the landscape, the more stable the carbon seems Figure from Mark Harmon

14 Forest Biology Bottom Line Disturbance does not cause C loss, unless forest does not regenerate Carbon is best evaluated over large scales of space and time Photo by Mike Ryan

15 Timing is important for economics and our descendents: YNP

16 Can forests do more to slow the rate of CO 2 increase in the air? Photo by Mike Ryan

17 Concepts: Leakage Changes outside system caused by changin management inside Example: Longer rotations -> greater imports and lower carbon elsewhere Photo by Mike Ryan

18 Concepts: Additionality Flowchart for proving additionality! Would carbon offset happen without the intervention? Don t pay for something that would happen anyway Difficult, legalistic, not simple! Photo by Mike Ryan

19 Large Dichotomy in Literature Forests can do more!

20 Disturbance will lower C

21 Keep forests as forests: Avoid deforestation Development, conversion to ag use. Important for US, not just tropics Large potential, low risk, but difficult to credit Many co-benefits. Possible Leakage

22 Reforestation and Afforestation Moderate potential, low risk Benefits - Increased biodiversity and soil erosion control More water use, Loss of ag production Uncertainties low when reestablishing forests Bugwood,Org

23 Management: Decrease Outputs (Increase rotation, decrease removals) Large potential in areas with active forest management, moderate risk Increase structural and biodiversity Increased risk of disturbance loss Leakage? Lower economic return Bugwood.org

24 Management: Increase Inputs (Increase growth) Reforestation/regeneration, fertilization, genetics, silviculture, species selection High potential, moderate risks: Additionality, full GHG accounting, potential maladaptation Increased wood production, keeps forests as forests Lower biodiversity, lower water yield and quality

25 Biofuels Substitution Forest biomass energy: large potential, but requires: Intensive management over a large area Large economic subsidies. Carbon savings from substitution in the U.S. depends on wood use by the non-residential building sector.

26 Combined Benefits Depend on Start Afforestation Harvest Old Growth

27 Avoided deforestation: Highest potential, lowest risk Potential decreases; Risk or uncertainty increases with other options

28 Largest Sources of Uncertainty Current Estimates: Changes in soil C and dead wood Land use changes Disturbance area Future Estimates Pace of disturbance, regeneration, recovery Sink saturation

29 A Couple of Radical Ideas Additionality or CRP Model? FS Focus on Regeneration?

30 Take Home Forest Carbon is a cycle: Forests recover what is lost in disturbance if they regenerate We have a large sink, but it may not last Need to focus on retaining forests in addition to using them to store more C. NRS Global Change

31 Further Reading Ryan, Michael G Forests and Carbon Storage. (June 04, 2008). U.S. Department of Agriculture, Forest Service, Climate Change Resource Center. Effects of climate change on agriculture, land resources, water resources and biodiversity State of the Carbon Cycle Report Carbon and Yellowstone Fires: Kashian_Romme_Tinker_Turner_Ryan_2006_Bioscience_56_ pdf and Publications/Final_Report_JFSP_ pdf US Greenhouse Gas Inventory: Jackson, R.B., Schlesinger, W.H., Curbing the U.S. carbon deficit. Proceedings of the National Academy of Science 101, Jackson, R.B., Jobbagy, E.G., Avissar, R., Roy, S.B., Barrett, D.J., Cook, C.W., Farley, K.A., le Maitre, D.C., McCarl, B.A., Murray, B.C., Trading water for carbon with biological sequestration. Science 310, Birdsey, R., Pregitzer, K., Lucier, A., Forest carbon management in the United States: Journal of Environmental Quality 35,