The landmark 2015 decision by the Hague District Court in Urgenda v. The Netherlands represents the first time a national court has expressly used the international environmental law (IEL) principle of common but differentiated responsibilities and capabilities (CBDRs) of the climate regime as a complementary tool to interpret the scope of a state’s climate obligations under domestic law. This article highlights that despite the marked engagement of national courts with IEL in recent decades (including engaging with principles such as sustainable development, polluter pays, intergenerational equity, and precaution), until this decision CBDRs had remained outside the purview of environmental law jurisprudence at the national level. The article examines how the Hague Court used CBDRs to help address two common barriers to climate liability: causation and the ‘political question’ doctrine. The article argues that the Court was able to find normative content in a core element of the climate-related CBDRs: the ‘leadership’ role of developed countries in climate action. This core element has remained remarkably consensual throughout the contested history of CBDRs in the climate regime – a history that has gained a new chapter with the signature of the Paris Agreement in December 2015. The article concludes that Urgenda v. The Netherlands may serve as a starting point for a more productive and extensive use of CBDRs in climate litigation, provided litigants make more explicit use of the persuasive authority of the principle.

Liability for causing or failing to mitigate climate change has long been proposed as an alternative, or backstop, to lagging international cooperation. Thus far, there has been very limited success in holding governments or individuals responsible for the emission of greenhouse gases (GHGs) that are considered the primary cause of anthropogenic climate change. The recent landmark decision in Urgenda Foundation v. Government of the Netherlands (Ministry of Infrastructure and the Environment) breaks with this tradition. In June 2015, the Dutch District Court (The Hague) held that the current climate policies of the government are not sufficiently ambitious for it to fulfil its duty of care towards Dutch society. The judgment, and the accompanying order for the government to adopt stricter GHG reduction policies, raises important questions about the future of climate change liability litigation, the separation of powers between the judiciary and the legislature, and the effect of litigation on international climate change negotiation and cooperation.

We develop a model of international agreements to price a transboundry externality and provide a new heuristic to aid in interpreting negotiation behavior. Under conservative assumptions, a country’s net benefits will be positive under an efficient pollution price if its share of global damages is less than half its share of worldwide abatement costs. We solve for a permit allocation scheme consistent with that heuristic such that every region will have positive net benefits in an agreement to price the pollution externality at the globally efficient level. We then apply this framework to climate change using regional data from Integrated Assessment Models and test the feasibility of a global climate change treaty. The results indicate that several regions have positive net benefits from a globally efficient price on carbon, including Western Europe, South Asia (including India), and Latin America. We then solve for a permit allocation scheme that should produce worldwide agreement on a climate treaty. Using the same model, we show that differential carbon taxes aimed at producing universal agreement would produce tax rate differences of an order of magnitude. We also argue that shares of global GDP might be an appropriate proxy for exposure to climate damages and find that a global climate treaty would be cost-benefit justified for all countries without transfers when that assumption is used.