Forest Ecosystems: Tools to address climate change impacts and adaptation Brent Sohngen

1. Forest Ecosystems: Tools to address climate change impacts and adaptation Brent Sohngen Department of Agricultural, Environmental & Development Economics, Sohngen.1@osu.edu The views expressed are those of the presenter and should not be attributed to either UNDP or USAID. Furthermore, it is strongly recommended that both the PowerPoint slides and the videos of the presentation of content included herein are viewed in conjunction in order that statements appearing in the PowerPoint slides are not interpreted out of context.

2. Model for measuring economic effects in forestry Adaptation of Forests and People to Climate Change. 2009. Alexander Buck, Pia Katila and Risto Seppälä. (eds.). IUFRO World Series Volume 22. Helsinki. 224 p.

3. Ecosystem impacts that affect forestry • Productivity changes • Will forests grow faster or slower with climate change? Where will the changes occur? • CO2 fertilization (e.g., Norby et al., 2006). • Warmer and wetter increases growth; while warmer and drier slows growth. • Some current evidence that historical climate change and CO2 change have increased productivity to date (e.g., Myneni et al., 1997; Boisvenue and Running, 2006; McMahon et al., 2010).

4. Ecosystem impacts that affect forestry • Disturbance • Forest fires increase and reduce standing stock (Westerling et al., 2006; Marlon et al., 2012) • Tropical regions potentially experience increases in emissions • Species/biome shifts • Prasad and Iverson; Woodall et al. (2009)

5. How do ecosystem models work? Focus on measuring changes in carbon stock as a function of various ecological processes affecting carbon Time Total C = 50 Total C = 65 Per hectare basis: TotalCt = TotalCt-1+ NPPt-1 – decompt-1 - disturbancet-1 For all hectares, adjust for forest area.

6. Ecosystem measurement: DGVM

7. DGVM Output • MC1 model (MAPPS and Century Model) • Bachelet et al. • Spatial • Intertemporal • Differs by climate scenario • A2, A1b scenarios • CSIRO, Hadley, MIROC models

8. Shift in potential forest areaExample for single climate scenario MIROC A1b 2005

9. Shift in potential forest areaExample for single climate scenario MIROC A1b 2095

10. Shift in total carbonMIROC A1b 2005

11. Shift in total carbonMIROC A1b 2095

12. Ecosystem Adaptation: Net Primary Productivity 2015-2095 (% change relative to 2005) A2 A1B

13. Ecosystem Adaptation: Area Change 2015-2095 (% change relative to 2005) A2 A1b

14. Ecosystem Adaptation: % burned per year 2015 - 2095 A1b A2

15. Ecosystem Adaptation: Total carbon change 2015-2095 (% change relative to 2005) A1b A2

16. Variation across climate models

17. Incorporating humans: Economic modeling Adaptation of Forests and People to Climate Change. 2009. Alexander Buck, Pia Katila and Risto Seppälä. (eds.). IUFRO World Series Volume 22. Helsinki. 224 p.

18. Economic models of forests • Must: • Manage stocks of trees (harvesting/replanting) • Respond to land use change (conversion/regenerate) • Account for prices (either endogenously or exogenously) • Many important trends influencing forests already underway • Increasing use of non-indigenous short-rotation species. • Growing demand in developing world, particularly Asia. • Demand rising both for traditional forestry and energy. • Rising opportunity costs for land leading to land use change. • Efforts to protect forests from land use change. • Climate change adds perturbations to this complex management picture.

19. Ecosystem measurement: DGVM

20. Integrating ecosystem impacts into forestry models • Productivity: shift the yield of forests over time in response to climate change • Shift occurs slowly

21. Integrating ecosystem impacts into forestry models • Disturbance: Stock is lost instantaneously through fires, or other non-human disturbance. • Increasing evidence these changes occur worldwide. VCa Va

22. Global Forest and Land Use Model • Maximize PV of CS minus costs • Single global demand • 250 ecosystem and management types differentiated by costs. • Land rents account for competition with other uses (rising land rents induce land use change). • Climate Scenarios • Adjust yield function • Adjust equation of motion • Impose constraints on available land area.

23. Adaptations Incorporated • Manage existing stock by • changing rotations (e.g., harvest early if dieback occurring) • salvage • Adjust where species grow: • Replant new species if growing and economic conditions (e.g., prices) warrant. • Manage future stock by • Changing rotations • Changing management & investments

24. Analysis • Climate Change: • A2, A1b scenarios • CSIRO, Hadley, MIROC models • Ecological Analysis: DGVM • MC1 model (MAPPS and Century Model) • Economic Analysis: • Global Land Use Model

25. Economic Results: Prices Change in price range = -7% to +2% Hadley & Miroc have mostly lower prices (7% max)

26. Economic Results: Forest areaRelative to baseline

27. Economic resultsChange in output relative to baseline

28. Example: China • Why do economic and ecological results diverge? • Effective yield increase more modest than NPP gains projected by ecosystem model

29. Example: China • Markets only use some of the new land available.

30. Example: China • Dieback is increasing…

31. Example: China • Output changes most in NE (down) and South (up)

32. Economic results: welfare(million US$/yr)

33. Annual Producer WelfareComparison of A1b and A2 averages

34. Annual producer effectsRange across climate scenarios

35. Economic model estimates of carbon flux

36. Challenges for conservation • Shifting biomes • Large potential effects across the range of ecosystems • Declining forestland area • Particularly in tropics • Changing productivity and disturbance

37. Shifts in potential forest area MIROC A1b 2005

38. Shifts in potential forest area MIROC A1b 2095

39. Implications for Conservation Harris et al., 2008

40. China: Change in forest area and carbonMIROC A1b Forest Area Forest Area Forest Carbon Forest Carbon

41. SE Asia change in forest area and carbonMIROCA1b Forest Area Forest Carbon

42. Issues to consider • Costs of maintaining existing ecosystems • Harvest, replant, etc. • Opportunity costs (other uses) important. • Costs of establishing new forests • Length of time to establish a new forest • Protected area management • When to give up?

43. Conclusions • Climate change has relatively modest impacts on global forest prices and outputs. • Although large changes in forest management occur and regional effects are large. • Output falls in most of Asia, albeit modestly in most areas. • Lower prices lower investments. • Large range across ecosystem scenarios • Carbon flux is positive in initial periods. • Large implications for conservation based on protected areas.