InVEST Tier 1 Carbon 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

Carbon Storage and Sequestration

Tier 1 Carbon Storage Model

Atmosphere

Soil type, moistureMicrobes, chemistry

SpeciesHarvested Wood Products

Aboveground biomass

Belowground biomass

Dead wood

Atmosphere

Land management

Land use history

Decay

Soil carbon

Climate

Tier 1 Carbon Storage ModelAtmosphere

Soil type, moistureMicrobes, chemistry

SpeciesHarvested Wood Products

Aboveground biomass

Belowground biomass

Dead wood

Atmosphere

Land management

Land use history

Soil carbon

Decay

5 pools x f(cost/ton) = Value

Climate

Sequestration and Value

2008

Future Value

Net Present Value

Δ in C

2058

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 theSocial cost of carbon: The price of current and

future damage caused by releasing a ton of carbon into the atmosphere

Approach to Valuation

Input Data

Required data:A land use / land cover (LULC) map

Table of carbon pools (metric tons / hectare)

Optional data:

• For calcuating C stored in harvested wood produtcs:– Map of timber harvest land parcels with data on– frequency of harvest– annual harvest amount – decay rate of wood products– density / volume factors

• Future land use map

• Economic data (carbon value / price, discount rate)

Input Data

• Local plot studies• Published analyses on similar regions• IPCC tables

Carbon Pool DataCarbon Pool Data

• Map of current carbon storage (Mg/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

Output

• Simple, requires relatively little data, thus also works for data-sparse regions

• Both biophysical (carbon storage / sequestration) and economic valuation modeling possible

Strengths

• 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.

Limitations

• Simplified carbon cycle

• Economic valuation assumes a linear trend in sequestration over time

Land cover transitions

T2

Stor

age

in B

iom

ass Reality

Model

T1

Forest(young)

Forest(old)

T2T1

Forest

• Land use planners: Compare consequences of future scenarios

• Ecosystem service tradeoffs

• Carbon market: First-pass analysis

• Not appropriate for precise cost-benefit analysis etc

Application

Gains and losses in carbon stocks from 2008 to 2058 in Sumatra, Indonesia

2008

Vision

Plan

Carbon gain

Carbon loss

2058

Dharmasraya district, Sumatra, IndonesiaCarbon gains and losses under alternative scenarios

Loss

Gain

2008 to Green Vision 2008 to Business as Usual Plan

Priority districts for investing in forest carbon projects

High priority districts have:

-High deforestation risk- Large biomass carbon stocks- Relatively lower agricultural value