Carbon and Communities

1. Carbon and Communities New Findings for the New England Landscape Presented by Steve M. Raciti Steve M. Raciti, Timothy Fahey, Charles Driscoll, Frederick J. Carranti, David Foster, Philip S. Gwyther, Brian Hall, Steven Hamburg, Jennifer C. Jenkins, Julian Jenkins, Christopher Neill, Scott Ollinger, Brandon W. Peery, Erin Quigley, Ruth Sherman, R. Quinn Thomas, Matt Vadeboncoeur, David Weinstein, Geoff Wilson, Peter Woodbury

2. Carbon as a Pollutant • CO2: most important greenhouse gas • 85% of U.S. emissions (based on warming potential) • 77% of global emissions • Potential impacts • Rising mean global temperature • Sea level rise • Extreme weather events • Species extinctions • Droughts, floods

3. Natural Carbon fluxes are large, but they are in relative balance. Anthropogenic activities have changed this balance, largely through fossil fuel combustion and land use change.

4. The Carbon Budget • Assembling C budgets for Northeastern Counties • Collaboration • Hubbard Brook Science Links Program • Hubbard Brook, Harvard Forest, Plum Island, & Baltimore LTERs • Carbon Budget = Emissions – Sequestration • Emissions: Carbon losses to the atmosphere • Sequestration: Removal of carbon from the atmosphere • Useful for decision-makers and conservationists • What are our emissions sources? • How can we reduce them? • Can we hope to balance the budget? • What role can forest conservation play in that balancing?

5. County-level Carbon Budgets • Variation in • Climate • Topography • Population density • Land-use and Land Cover

7. More people = more emissions. Regardless of differences in per capita emissions among counties. Boring data? Gets more interesting at the lower part of our graph… Does not include emissions from manufacture of imported goods or air travel. R2 = 0.99 Net C Flux = Emissions - Sequestration

8. Net zero Emissions 31 persons/km2 Northeast Population 134 persons/km2 Does not include emissions from manufacture of imported goods or air travel. • Conclusion: • Forest and soil C sinks are large. Protecting these sinks by conserving forests and minimizing conversion to development would be a good idea if we want to slow climate change. Net C Flux = Emissions - Sequestration

9. Note that maximum potential biomass may be under and over-predicted by the model and future changes in climate may increase or decrease carbon storage potential. There is increasing evidence that even old growth forests can continue to sequester carbon in biomass and soils, but at slower rates than younger forests. • However • These forest C sinks will slow down over time. • We’ll need to reduce emissions, while maintaining the C stored in forest trees and soils.

10. Fortunately… • We can significantly reduce CO2 emissions at little long term cost. • “Zero cost” = pays for itself via energy savings or revenue over the life of the strategy. • Rural areas will supply a large share of carbon offsets and alternative energy opportunities. Alternative energy in rural areas. Energy efficiency technologies in urban and suburban areas. ------------- Increasing population density ------------->

11. Forest Preservation is the largest C mitigation opportunity for rural counties in the region (among the opportunities we evaluated). Carbon markets could provide financial incentives to forest land owners, but there are several challenges to overcome. Note: Forest Preservation provides important additional non-carbon ecosystem services that enhance the benefits of this option. ------------- Increasing population density ------------->

12. Potential Forest C Offset Markets • Regional Greenhouse Gas Initiative (RGGI): Offsets must be “real, additional, verifiable, enforceable and permanent” • Additional: Cannot replace a management activity that would have happened anyway. • Verifiable: Data collection at regular intervals. • Permanent: Sequestered carbon should not be re-emitted to the atmosphere within the foreseeable future. • Enforceable: Contracts or other legal instruments should ensure compliance and exclusive ownership. • Emerging Option: allocate a portion of emission allowances to fund domestic conservation easements through state, regional or national programs.

13. The Ecology of Forest Carbon • Aboveground biomass (wood) and Soil Organic Matter are the largest pools. • Aboveground • Easiest to measure • Tree diameter + allometric equations • Root biomass • Can be estimated based on aboveground biomass • Soil organic matter • C sequestration is more difficult to measure due to high spatial variability. Fahey et al. 2010

14. Challenges • Measurement and projection of forest C at small scales can be costly. • We need an inexpensive, standardized system that discourages dishonest accounting • For easement option • we need a defensible method for allocating potential conservation easement funding based on estimated carbon benefit.

15. Forest Product Substitution • Can provide immediate emissions reductions • Substitute wood for other building materials • Displace fossil fuel energy with biomass energy (heating systems or power plants) • Again, we need standardized accounting approaches

16. Conclusions • Forests already offset a large portion of emissions in the Northeast • Development threatens to change rural areas from net C sinks to net carbon sources • Carbon markets could provide financial incentives to forest land owners, but we need inexpensive, standardized approaches for C accounting or a defensible easement-based approach • Land trusts can play an important role in retaining carbon storage by accelerating forest conservation and reducing forest loss in New England

17. Slide 24 11,000 11,000 Forests absorb large amounts of carbon relative to emissions in rural areas, but not in urban areas. 2,000 1,900 Courtesy: Hubbard Brook Research Foundation Raciti et al. In prep.