Status: Published
Citation: Aldy, J., W. Pizer, M. Tavoni, L. Aleluia Reis, K. Akimoto, G. Blanford, C. Carraro, L.E. Clarke, J. Edmonds, G.C. Iyer, H.C. McJeon, R. Richels, S. Rose, F. Sano. 2016. Economic tools to promote transparency and comparability in the Paris Agreement. Published in NATURE CLIMATE CHANGE 6: 1000–1004.
The Paris Climate Agreement resulted in pledges to reduce greenhouse gas emissions from most of the World’s countries. This study evaluates the comparability of the ambition reflected in the emissions reduction pledges. The study analyzes the pledges using four global economic-energy models. Each model estimates the cost to countries of achieving the emissions reduction pledges. Taken together, the set of results across models provides an indication of uncertainty about costs. The study finds that the country pledges are not comparable and represent different levels of effort, with wealthier country pledges having higher costs and representing greater relative ambition. By comparing costs to that associated with the long-run climate objective of limiting global warming to 2°C, the study also concludes that the combined level of effort associated with the pledges is insufficient. Finally, the study notes that the large differences in country costs imply that there are opportunities for countries to work together to reduce emissions and lower the societal costs of their combined pledges. The study informs strategic planning with insights regarding the potential stringency and implications of future climate policies in the U.S. and internationally and potential policy designs that affect the cost of compliance.
Link to Journal article: Nature Climate Change.