This paper analyses two unilateral policies available to countries that want to rapidly curb carbon emissions in the global economy, but do not own any fossil fuel resources. If fossil fuel owners do not cooperate in CO 2 emission reduction efforts, the only strategy to reduce their fossil fuels' use is to exploit the interconnectedness of production given by international trade. We compare a Pigouvian approach, namely a subsidy for renewable energy prices, and a Coasian supply-side strategy, buying extractive rights over fossil fuel deposits abroad. Using a dynamic North-South trade model with endogenous innovation, we show how these policies, designed to prevent an environmental disaster, have different cost and welfare profiles. If fossil fuel deposits can be purchased at their market price, the supply-side policy achieves the highest welfare. If instead the fossil fuel owners require a full compensation for their income loss, subsidies for renewable energy inputs can result in higher welfare, but only if the resource-rich region has less advanced technologies for green energy production than the countries implementing the policy.