US Forest Greenhouse Gas Inventories and RPA Carbon Assessments Linda S. Heath USDA Forest Service, FIA Northern Research Station Forest Carbon Accounting and Research Durham, NH 1
Climate mitigation is a game of tradeoffs Forest carbon changes over time Energy from wood or oil or coal or? Imports/exports of products Public lands, private lands 2
To manage carbon and GHGs, we must monitor them United Nations Framework Convention on Climate Change: Greenhouse Gas Emissions and Sinks Inventories early1990s Like 140 other nations, the US ratified the UNFCCC and promised, by law, to report their GHG emissions and sinks annually. 3
US GHG inventory covers all sectors, key sources and sinks US EPA lead agency National-level Base year 1990 Annual Sectors: Energy; Industrial Processes; Solvent & other product use; Waste, Agriculture; Land Use, land use change, and forestry GHGs: CO 2 ;CH 4 ;N 2 0; PFC, HFC, & SF 6 4
Guidance for GHG inventories evolves Intergovernmental Panel on Climate Change (IPCC) Guidelines for National Greenhouse Gas Emissions and Sinks (1994-1996) IPCC Good Practice Guidance for Land Use, Land Use Change and Forestry (2001-2003) 2006 IPCC Revision Guidelines. Volume 4: AFOLU: Agriculture, Forestry, and Other Land Use 5
Aims/principles of NGHGI guidance apply at many scales Transparency -- users can replicate and assess info Consistency -- change real, not due to methods differences Comparability Completeness -- all sources/sinks considered, entire geographic land-base Accuracy -- neither over or underestimating as far as can be judged --uncertainties reduced as far as practicable 6
Main equations Carbon stock = area * carbon/area Activity type equation: number of animals *emission per animal 7
System boundaries are key for analyzing climate mitigation activities A true story: Finland then and now All managed lands and related activities? All carbon pools (above, belowground)? Fate of carbon beyond the forest Trade (imports/exports) Substitution? Co-benefits Resolution 8
Managed land definition is key Affected by direct human intervention Includes providing social functions for personal, community or societal benefits All forest land in lower 48 states is considered managed for the purposes of the US GHG inventories 9
Definition of managed under debate Unmanaged lands are largely considered inaccessible due to remoteness or to limited commercial value or both One possible outcome of managed lands in Alaska blue managed 10
Forest carbon Monongahela National Forest, WV 11
Forest Inventory & Analysis (FIA) Strategic objectives National design standards Standardized estimation Data released at prescribed intervals A national database with user-friendly access Nationally consistent state reports (5 years) Peer review/publication of outputs/procedures
FIA Data include: Use of remote sensing Ground plots Harvested wood & products --Utilization Studies --Timber Products Output Ownership survey National Inventory & Monitoring Applications Center 13
% contribution to GHG inventory for land use change and forestry all owners 11% 4% 0% 1% Forest Ecosystem Forest Products 12% Settlements Croplands 72% Grasslands Other Source: EPA (2008), Inventory of US GHG emissions and sinks (all are net sinks, no non-co 2 ) 14
About 1/3 of net sequestration within US forests are on NFS forest lands While about 1/5 of forestland area is in NFS ownership. CAVEATS: implicit disturbance, products 15
Focus of capacity Inventory? Activity accounting? Life cycle assessment? 16
The RPA Forest Assessment is the reason the FS is the provider of US forest GHGs Originally used the FORCARB model linked to the RPA timber assessment models, and HARVCARB for harvested wood products Advantages: C= [f(biomass/ac)=f(volume/ac)]*acres The Climate Action Report needs projections Special analysis Needed to start in 1990 17
New RPA models due 2010 Plot level resolution, 5-10 year projections, will include explicit fire disturbance Vs older system: region level resolution, 5 or 10 year projections Both based to great degree on FIA and economic data 18
C stock change differences between 2007 RPA scenarios & base, National Forest only --forest land only 120 Carbon difference -Tg 100 80 60 40 20 0 Base 01Climate,CO2 02Climate,noCO2-20 Note: these are Cumulative differences 19
Carbon stock change differences between 2007 RPA scenarios & base, all owners Productive forestland only 2000 1800 1600 Carbon difference -Tg 1400 1200 1000 800 600 400 200 Base 01Climate,CO2 02Climate,noCO2 M&RPlant M&Rplant+01Climate M&Rplant+02Climate 0 1990 2000 2010 2020 2030 2040 2050 20
Privately owned, productive forest land, Base scenario (2007RPA) Age class distribution in terms of area (Mha) Area (Millions of ha) 18 16 14 12 10 8 6 4 2 0 0 2 4 6 8 10121416 0 2 4 6 8 10121416 Age class (e.g., 2=20 years) 21
Natl Forest System, productive forest land, Base scenario Age class distribution in terms of area 16 Area (Millions of ha) 14 12 10 8 6 4 2 0 0 2 4 6 8 10 12 14 16 0 2 4 6 8 10 12 14 16 Age class (e.g., 2=20 years) 22
Summary of items to consider System boundaries Managed land definitions Geographic and temporal scale Acceptable levels of uncertainty/scope Relationship to other efforts Improve as we go, how often update analysis Management affects carbon whether we manage for carbon or not 23
THANK YOU! 24