Reports & Papers

The authors of this discussion paper consider linkage among heterogeneous climate-change policies — moving beyond relatively simple linkage among emissions-trading systems — in the context of the emerging Paris-Agreement regime. A Harvard Project event at COP-23 will draw upon this paper.

Authors Christoph Böhringer and Thomas Rutherford evaluate the efficacy of imposing carbon tariffs on U.S. imports as an alternative to U.S. participation in the Paris Agreement. The authors warn that carbon tariffs on the United States could lead to a tariff war that ultimately hurts China, in particular, and the European Union more than the United States.

Martin Weitzman explores theoretically how international cooperation (democratic voting and/or negotiation) to set a global carbon price might incentivize mitigation and yield a global price that approximates an economically-efficient "social cost of carbon."

The 2015 Paris Agreement completed the transition to pledge-and-review as the core of the multilateral climate policy architecture. With ambitious long-term temperature goals and country-specific emission mitigation pledges set through 2030, the unfinished business coming out of the Paris talks is the design and implementation of the climate transparency mechanism. This paper reviews the poor transparency track record under the UN Framework Convention on Climate Change, and uses this performance to motivate engagement of non-stakeholders to enhance the rigor of the information and analysis of countries' emission mitigation efforts.

The Harvard Project releases a collection of expert briefs on the elaboration of the Paris Agreement.

Joseph Aldy examines competitiveness risks from domestic carbon pricing policies, as well as the risks posed by competitiveness policies (for example, border tax adjustments) intended to alleviate adverse impacts of carbon pricing. The paper presents two alternative frameworks for evaluating competitiveness policy options.

The emerging pledge and review approach to international climate policy provides countries with substantial discretion in how they craft their intended emission mitigation contributions. The resulting heterogeneity in mitigation pledges places significant demands for a well-functioning transparency and review mechanism. In particular, the specific forms of intended contributions necessitate economic analysis in order to estimate the aggregate effects of these contributions as well as to permit "apples-to-apples" comparisons of mitigation efforts. This paper discusses the tools that can inform such analyses as well as the institutional needs of climate transparency.

Uncertainty in the form of country-specific abatement-cost shocks, together with cross-border revenue flows from internationally-tradable permits, can lead to greater country risk from an international emissions-trading system than from the imposition of a uniform carbon price.