Carbon and Communities
description
Transcript of Carbon and Communities
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
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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– Increased danger of famine,
disease, social upheaval, and global conflict
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.
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– What are our emissions sources?– How can we reduce them?– Can we hope to balance the budget?– What role can forest conservation play?
County Area (km2)
Pop. density (#/km2)
Character
Coos, NH 4,740 7 Rural, forestedGrafton, NH 4,532 18 Rural, forestedTompkins, NY 1,273 76 Rural, small city, mixed ag and forestChittenden, VT 1,605 91 Rural, small city, forested
Worcester, MA 4,090 184 Suburban/exurban, medium city, forested
Baltimore County, MD 1,573 501 Suburban, mixed agriculture and forested
Essex, MA 1,297 567 Suburban, forestedMiddlesex, MA 2,133 688 Suburban, forestedBaltimore City, MD 206.7 3,055 Urban
County-level Carbon Budgets
Variation in- Climate - Topography- Population density- Land-use and Land Cover
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kg C
/pe
rson
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r
Per Capita CO2 EmissionsIndustrialCommercialResidentialTransport
Increasing Population Density
Net C Flux = Emissions - Sequestration
R2 = 0.99
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.
Net C Flux = Emissions - Sequestration
Net zero Emissions31 persons/km2
Northeast Population134 persons/km2
Conclusion:
- Forest and soil C sinks are large.
- Conserving forests would be a good idea if we want to slow climate change and offset future emissions.
- However, we cannot count on forests alone to balance the C budget. We will need to reduce emissions, too.
Does not include emissions from manufacture of imported goods or air travel.
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Wind
Fuelwood Harvesting
Space and Water Heating
Lighting
Computers and Appliances
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Fortunately, we can significantly reduce CO2 emissions at little long term cost.
- Rural areas will supply a large share of carbon offsets, including wind and biomass energy.
- Urban and suburban areas should concentrate on energy efficiency.
Energy efficiency technologies in urban and suburban areas.
Alternative energy in rural areas.
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Forest Preservation
Photovoltaics
Afforestation
Biofuel Crops
440%
------------- Increasing population density ------------->
Forest Preservation is the largest non-zero cost C mitigation opportunity for rural counties in the region.
Carbon markets could provide financial incentives to forest land owners, but there are several challenges to overcome.
Forest Preservation also provides non-carbon ecosystem services, such as wildlife habitat and diversity, water purification, recreation and scenic landscapes.
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
Potential Forest C Offset Markets• Emerging Option: allocate a portion of emission allowances to
fund conservation easements. • Specific protocols have been developed to address the issue of
permanence (RGGI, 2007). – Land must be under a legally binding permanent conservation easement– Land must be managed to maintain long-term carbon density in accordance
with environmentally sustainable forestry practices– Sequestered carbon is discounted by 10% prior to the award of CO2
allowances to account for potential reversals of sequestered carbon (alternatively, insurance can be purchased).
– Current model rule applies to afforestation.
• Non-RGGI options are also emerging for preservation of existing forest land.– Credit for avoided deforestation (based on predictive models) could meet
the requirement for additionality.– Potential federal funding to support conservation easements.
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– More difficult to measure
due to high spatial variability, but also less dynamic over short time scales.
Fahey et al. 2010
Challenges
• Measurement and projection of forest C at small scales can be costly.– We need a defensible method for allocating
conservation easement funding based on carbon benefit.
– The system must be inexpensive, standardized, and discourage dishonest accounting
Conclusions• Forests already offset a large portion of emissions in
the Northeast• Development threatens to change rural areas from net
C sinks to net C sources• The ecology of forest C is well understood• Carbon markets could provide financial incentives to
forest land owners, but we need a defensible easement-based approach that is inexpensive, standardized, and discourage dishonest accounting
• Land trusts can help retain C storage in the landscape by accelerating forest conservation and reducing forest loss in New England