Assessing California’s progress toward its 2020 GHG limit

Sep 19, 2019

We present a retrospective analysis of California’s greenhouse gas emissions to assess how the state has achieved faster-than-expected emissions reductions, meeting its 2020 emissions reduction goal four years early in 2016, and to shed light on the successes and challenges encountered so far during climate policy implementation as California pursues deeper decarbonization goals.

We analyze the extent to which economic activity, climate policies, and market forces have affected California’s greenhouse gas emissions overall and in two key categories: electricity and light-duty vehicles. We also compare historical trends with business-as-usual and policy expectations from the 2008 Climate Change Scoping Plan. We find that the 2008-2009 recession played a major role in California achieving its 2020 emissions limit early. However, policy and market forces explain more of the reductions observed in recent years, particularly in the electricity sector, which has decarbonized more rapidly than expected. Meanwhile, GHG emissions from light-duty vehicles in recent years were rising, not falling, in contrast to expectations.

Download the preprint, supplemental information, and associated data analysis from a repository hosted by the Open Science Framework (DOI 10.17605/OSF.IO/FE25W).

preprint manuscript

Michael Mastrandrea *†, Mason Inman *, and Danny Cullenward *†§

* Near Zero

† Carnegie Institution for Science, Department of Global Ecology

§ Stanford Law School