This article from BBC reports on the So. Cal. methane leak, the largest in US history. It’s not just the burning of fossil fuels that is the problem. In order to burn them we have to extract, transport and store them. Each step in the process exposes the environment to leaks, spills and waste disposal problems.It’s a dirty business from beginning to end. A tax on carbon at the source, and end to government subsidies and enforcement of pollution laws would bring the cost pop fossil fuels far above that of renewables.

http://www.bbc.com/news/science-environment-35659947