Geoscience Reference
In-Depth Information
PRISONERS OF NATIONALISM
The fi rst set of obstacles is the result of economic nationalism. Na-
tional governments face a dilemma because the costs of emission reduc-
tions are national while the benefi ts from slowing climate change are
widely dispersed around the globe. This structure of local costs and
distant benefi ts gives strong incentives for free riding. Individual coun-
tries will benefi t from local inaction and global action to abate CO
2
emissions.
This is the celebrated “prisoner's dilemma,” which in this context
can be better called the “nationalist dilemma.” If each country seeks a
strategy that maximizes its national welfare, taking other countries'
policies as given, then the resulting abatement will be much smaller
than if each country took global benefi ts into account.
It is worth spelling out the logic here because it is such an impor-
tant factor in international global warming policies. Suppose that there
are fi ve identical countries and that an additional ton of CO
2
emissions
does $5 worth of damage to each of the countries. Each country would,
in a purely rational national calculation, reduce its emissions as long as
the cost of emissions reductions was less than $5 per ton. If all countries
follow this logic, the outcome is the “noncooperative equilibrium” of
game theory. In this equilibrium, the overall level of abatement comes
where the cost of abatement in each country would be $5 per ton.
But this is too little from a global perspective. A ton of country A's
emissions does $5 of damage to country A, but it also does the same
amount of damage to the four other countries. So the global damages
are $25 per ton, not $5 per ton. This means that the world as a whole is
abating too little. An additional ton of reductions would cost only $5,
but the total benefi ts would be $25.
Several empirical studies have examined how the nationalist di-
lemma dilutes the effectiveness of global warming strategies. On the
whole, they confi rm that rational nationalistic behavior toward climate
change would lead to a level of abatement substantially smaller than
would occur with national policies that take global welfare into ac-
count. For example, I used the regional DICE model to calculate a
