The effectiveness of international climate-change agreements

Have previous international agreements on climate change led to reductions in emissions?

Tenreyro and de Silva quantitatively assess countries’ compliance with the targets they stated in the Kyoto Protocol, the Copenhagen Accord, and the Paris Agreement. They also study the impact on Greenhouse-gas emissions of each of the agreements, as well as the various policies and laws enacted over time. The paper finally explores the indirect impact on economic outputs stemming from these actions.

Towards this goal they use the following data: a) For emissions they use historical data from the Climate Analysis Indicators Tool (CAIT) Climate Data Explorer compiled by the World Resources Institute which they combine with the pledges made by countries in each of the international agreements. In addition, to assess compliance against the targets, they use data from the Emission Database for Global Atmospheric Research (EDGAR) compiled by Crippa et al. (2019) in “Fossil CO2 and GHG emissions of all world countries – 2019 Report.” This database contains records of fossil CO2 emissions from 212 countries over the 1970 through 2018 period; b) For information on climate agreements they use the official documentation of the United Nations Framework Convention on Climate Change (UNFCCC), as well as processed information on the Copenhagen Accord and Paris Agreement from the CAIT Climate Data Explorer database; and c) Data on climate-related laws and policies were taken from the Grantham Research Institute’s Climate Change Laws of the World Database.

Their research indicates that compliance with emission-reduction targets has been mixed, with several countries undershooting their targets:

• Signing the Kyoto Protocol and the Copenhagen Accord have led to significant reductions in emissions, when compared to the control group of countries that did not sign these agreements;
• Signing the Paris Agreement does not appear to have yet had a significant reduction in missions;
• Carbon taxes and the introduction of emission-trading schemes (ETS) seem to have had the most material impact when compared to other policies;
• The impact of nationally enacted climate-related policies seem to have had an insignificant effect on GDP growth and inflation.

Climate-Change Pledges, Actions and Outcomes
Authors: Silvana Tenreyro, Tiloka de Silva
From: London School of Economics, University of Moratuwa

How can the Paris Agreement be made effective?

Dutta and Radner use a game theoretic setting to model the role international transfers play in ensuring that a Tragedy of the Common does not ensue with a global overaccumulation of Greenhouse-gas emissions. The main message of their paper is:

[T]he Paris Agreement can be made effective, if financial transfers are made to the developing world. The 2015 Agreement has taken a first step towards that goal – it included a commitment in principle to transfers and instituted a platform – the Green Climate Fund (GCF). However, actual meaningful commitments were postponed to at least 2020/21. The paper shows that if countries are required to make those commitments in 2020/21 and make them at the same time as they announce their nationally determined contributions (NDCs), then a Pareto-optimal outcome becomes incentive-compatible and both developed and developing countries are made better off.

The Paris Accord and the Green Climate Fund: A Coase Theorem
Authors: Prajit K. Dutta, Roy Radner
From: Columbia University, New York University