Deforestation Prediction for Different Carbonprices - Earth Science: New Methods and Studies - page 71

⎧
⎪
⎪

⎫
⎪
⎪

⎡ ⎤

⎛
⎜

frac llp ⋅ dec llp frac slp ⋅ dec slp ⎞

⎟ ⋅

DV i = BM i ⋅ (22)

( ) − epc i ⋅ ( ⋅ ( ) + frac sb

pw i ⋅ C 2 W ⋅ 1 − HL i 1 + r + 1 − frac sb

⎢
⎢

⎥
⎥

dec llp + r dec slp + r

⎣ ⎦

()

fr i

r + 1

( ) ⋅ pca i ⋅

IP i = BM i + BMP i

1

(23)

()

fr i

r + 1 −

There exist several ways of how fi nancial transfers can be handled. Two mecha-
nisms are realized in equation (21). One is to pay the forest owner to avert from the de-
forestation, the other is to introduce a carbon price that the forest owner gets money by
storing carbon and paying for releasing it. The introduction of a carbon price focuses
the money transfer to the regions where a change in biomass takes place. Payments
to avoid emissions from deforestation can be transferred to cover all of the globe's
forests, target to large “deforestation regions” or individual grids.

Deforestation Rate
Once the principle deforestation decision has been made for a particular grid cell (i.e.,
the indicator variable Defor i = 1) the actual area to be deforested within the respective
grid is to be determined. This is done by the auxiliary equation (24-25) computing the
decrease in forest share. We model the deforestation rate within a particular grid as
a function of its share of forest cover, agricultural suitability, population density and
gross domestic product. The coefficients c 1 -c 6 were estimated with a generalized lin-
ear model of the quasibinomial family with a logit link. Values significant at a level of
5% were taken and are shown in Table 1. The parameters of the regression model were
estimated using R (R Development Core Team, 2005). The value of c 0 was determined
upon conjecture and directly influences the maximum possible deforestation rate. For
our scenarios the maximum possible deforestation is set to 5% of the total land area
per year. That means, a 0.5° × 0.5° grid covered totally with forests cannot be defor-
ested in a shorter time period than 20 years.

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0 Defor = No

(24)

Fdec i = FS i Ftdec i > FS i ∧ Defor = Yes

Ftdec i Ftdec i ≤ FS i ∧ Defor = Yes

Table 1. Coefficients for equation (25)--Deforestation speed.

Coef Estimate Std. Error

Pr(> ltl)

C 0 0.05 _ _

C L -1 .799e+OO 4.874e-O1 0.000310

C 2 -2.200e-O1 9.346e-02 0.019865

C 3 -1 .663e-O 1 5.154e-02 0.001529

C 4 4.029e-02 1.712e-02 0.019852

C 5 -5.305e-04 1.669e-04 0.001789

C 6 -1.282e-04 3.372e-O5 0.000206