InVEST Carbon Storage And Sequestration Stacie Wolny

Transcription

1 InVEST Carbon Storage And Sequestration Stacie Wolny

2 Carbon Background Carbon dioxide is a greenhouse gas Terrestrial ecosystems store 4x more carbon than atmosphere Land use change can release carbon, or store it Whole world is impacted by release/storage anywhere

3 Carbon Background Climate change mitigation Reforestation Soil management Plantation practices Crop practices Carbon markets Reducing deforestation and forest degradation (REDD) Kyoto protocol

4 Existing models U.S. Forest Service has several, including: MC1 global vegetation dynamics FVS - tree growth and yield simulator FORCARB2 stock and change projections - Complex, often U.S.-centric CENTURY plant-soil nutrient cycling LPJml global managed vegetation and water balance - Very complex set of input parameters - More detail than many users need

5 InVEST Carbon Storage Model In the Tier 1 model we estimate carbon stock as a function of land use/land cover. Storage indicates the mass of carbon in an ecosystem at any given point in time. Sequestration indicates the change in carbon storage in an ecosystem over time. Valuation is applied to sequestration

6 Big Picture Climate Atmosphere Atmosphere Land use history Aboveground biomass Species Harvested Wood Products Dead wood Soil carbon Soil type, moisture Microbes, chemistry Belowground biomass Land management

7 InVEST Carbon Storage Model Climate Atmosphere Atmosphere Land use history Aboveground biomass Species Harvested Wood Products Dead wood Soil carbon Soil type, moisture Microbes, chemistry Belowground biomass Land management 5 pools x f(cost/ton) = Value

8 Sequestration and Value 2008 Δ in C 2058 Net Present Value

9 Approach to Valuation Net Present Value is a function of: Market discount rate Rate of change in the social value of carbon Social or market cost of carbon Carbon model is most appropriate for valuing the Social cost of carbon: What is the benefit to society from avoiding damage from CO 2 release?

10 Validation Mainly a lookup table: The better your table values are, the better the results will be. IPCC carbon pool values from literature review HWP methodology from IPCC 2006 Guidelines

11 Case study: Sumatra

12 Case study: Sumatra

13 Case study: Sumatra Current Vision - Current Plan - Current

14 Case study: Sumatra

15 Input Data Required data: Land use / land cover (LULC) map Table of carbon pools (metric tons / hectare)

16 Carbon Pool Data Carbon Pool Data Local plot studies Published analyses on similar regions IPCC tables

17 Storage in Biomass T1 T2 Land cover transitions Forest Reality T1 Forest (old) T2 Forest (young) Model

18 Optional Data Future land use map Economic data (carbon value, discount rate) Timber harvest land parcels - frequency of harvest - annual harvest amount - decay rate of wood products - density/volume factors

19 Output Map of current carbon storage (Mg C / cell) Map of future carbon storage - If future land use provided Carbon sequestration map = (future - present carbon storage) Map of economic value of carbon sequestered

20 Application Land use planners: Compare consequences of future scenarios Ecosystem service tradeoffs Carbon market: First-pass analysis Not appropriate for precise costbenefit analysis etc

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22 Post-analysis Example: Oregon climate change initiative Sumatra: Analyze by district

23 Limitations Simplified carbon cycle Economic valuation assumes a linear trend in sequestration over time Output is only as detailed and reliable as the land use classes and carbon pool data that are input. Carbon sequestration does not occur in an area unless the area s land use changes over time or wood is harvested.

24 Storage in Biomass Outlook Add some dynamics via time scale between current and future land uses Allow for an intermediate land use map Forest T1 T2

25 Equations - HWP yr_cur = Year of current land cover, t indexes the number of harvest periods, and ru indicates that any fraction should be rounded up to the next integer value. f = 1 e x x e yr_ cur start_ date x t Freq _ cur x x x ( log2 e / Decay _ cur x) measures how much of the carbon was typically removed from a parcel (Cut_cur x ) during a harvest period, that occurred some number of years ago: yr _ cur start _ datex t Freq _ cur x and still remains trapped in HWP as of the current year (yr_cur) and given the current decay rate (Decay_cur x ).

26 Equations - HWP Mass of harvested wood that has been removed from a parcel from Start_date to yr_fut:

27 Equations - Valuation Value of carbon sequestration over time: value_ seq x V sequest x yr _ fut yr _cur yr _ fut yr _ cur 1 t 0 1 r t 1 c t 100 V = value of a sequestered ton of carbon sequest x = amount of carbon sequestered on parcel x r = market discount rate c = annual rate of change in the price of carbon