Abstract
It is suggested that trade measures should be used to induce exporters to adopt more ambitious climate policy and reduce global emissions. However, a tariff and the exporter's emission tax are likely substitutes, which would undermine the rationale for these trade measures. This paper examines incentives to regulate the climate under border carbon adjustment (BCA), defined as an import duty of a magnitude determined by the difference in emission taxes between trade partners. Unlike a tariff, a BCA can induce the exporter to adopt a higher tax, suggesting that the BCA and tariff are not equally effective at targeting global emission levels and that the features of the border measure matter in assessing the effectiveness of trade policy in targeting global emissions.