Evaluation of the Influence of 2008 Scoping Plan to Carbon Emissions in California by DID

Abstract

Global warming has been a crucial issue these years as the development of human society and technologies. The main factor is the greenhouse gas emissions, including water vapor, methane, carbon dioxide and nitrous oxide in the earth atmosphere. There are many countries with different kinds of policies to reduce greenhouse gas emissions to slow down the speed of global warming and protect the world environment, such as the California 2008 Scoping Plan. Difference-in-Difference is an estimation method to evaluate the effectiveness of a policy change on a group of individuals. This study selects the transportation sector as the indicator of carbon emissions in California and uses the data from 2004 to 2014 in all 51 states in the U.S. to estimate the influence of 2008 Scoping Plan on carbon emissions in California. The result shows the policy had a positive effect on reducing the carbon emissions in the transportation sector in California, which means that the Scoping Plan is worth continuing to implement and improve to achieve the goal of decreasing greenhouse gas emissions to protect the global environment.