Climate change is among the most complex problems on the foreign policy agenda. Even with a mounting consensus that humans are causing a change in the world’s climate, experts are divided on the severity of the problem and the necessity and nature of policy responses. Practically any course of action implies that today’s societies will incur costs as they deviate from the status quo, and any benefits of their efforts will accrue mainly in the distant future. Such intergenerational bargains are always hard to strike. Compounding the difficulty is the reality that this problem is truly global in scope. A few nations—led by the United States, which is responsible for one-quarter of the effluent that is linked to global warming—account for most emissions. Yet in a global economy some measure of global coordination will be required to ensure that some do not ride free on the efforts of others. This issue thus involves all the factors that make it hard to construct successful foreign policy: highly complex yet uncertain scientific knowledge, widely diverging interests, and the need for effective international arrangements.
