Geoscience Reference
In-Depth Information
8,000
Net benefits through 2050
Net benefits after 2050
7,000
6,000
5,000
4,000
3,000
2,000
1,000
0
-1,000
-2,000
Rich
Middle
Poor
Global
Figure 44.
The temporal trade-off in climate-change policies. The bars show net
benefi ts (equal to damages plus abatement costs, all discounted at market interest
rates) for country groups for two time periods. The left solid bars are the net benefi ts
for the fi rst half century, while the light shaded bars are the net benefi ts for the balance
of the period through 2200.
world. Net benefi ts here are the negative of costs, which include both
damages and abatement costs, discounted back to 2010 at market inter-
est rates. While these numbers are primarily illustrative because there
was no specifi c agreement, the results are similar to those calculated for
other policies. Countries are categorized as rich, middle income, and
poor based on their per capita incomes. The net benefi ts before 2050
and the net benefi ts for the period 2050-2200 are compared.
5
The left solid set of bars, all below the zero axis, shows the estimated
net losses for the period 2010-2050. For example, the Copenhagen
Accord has near-term net costs for rich countries of approximately $1
trillion. The global cost is about $1.5 trillion.
The second, light shaded set of bars, which are uniformly positive,
shows the net impacts for the period 2050-2200, again discounted to
2010. The net benefi ts for the rich countries are $1.3 trillion, which does
offset the fi rst- period costs. For other groups, the benefi ts after 2050 are
