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– 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?

CountyArea (km2)

Pop. density (#/km2)

Character

Coos, NH 4,740 7 Rural, forested

Grafton, NH 4,532 18 Rural, forested

Tompkins, NY 1,273 76 Rural, small city, mixed ag and forest

Chittenden, VT 1,605 91 Rural, small city, forested

Worcester, MA 4,090 184Suburban/exurban, medium city, forested

Baltimore County, MD 1,573 501Suburban, mixed agriculture and forested

Essex, MA 1,297 567 Suburban, forested

Middlesex, MA 2,133 688 Suburban, forested

Baltimore City, MD 206.7 3,055 Urban

County-level Carbon Budgets

Variation in- Climate - Topography- Population density- Land-use and Land Cover

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000kg C

/per

son/y

ear

Per Capita CO2 EmissionsIndustrial

Commercial

Residential

Transport

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.

0%

50%

100%

150%

200%

250%

300%

350%

Miti

gati

on P

oten

tial (

% o

f em

issi

ons)

"Zero Cost" Mitigation Opportunities

Wind

Fuelwood Harvesting

Space and Water Heating

Lighting

Computers and Appliances

1,050%

------------- Increasing population density ------------->

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.

0%

20%

40%

60%

80%

100%

120%

140%

160%

180%

200%

Miti

gati

on P

oten

tial (

% o

f em

issi

ons)

"Non-zero Cost" Mitigation Opportunities

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