Environmental Economics

From greenh-gas@mailer.eia.gov:

These estimates of energy-related carbon dioxide (CO₂) are based on the State Energy Data System. The state data include a summary table with total energy-related CO₂ by state beginning in 1990, a table with emissions by fuel in 2012 and a table with emissions by sector in 2012. Detailed tables for individual states provide emissions by fuel and sector for data beginning in 1980. Documentation for methodology is also included on the page. 

See the all State tables at:

http://www.eia.gov/environment/emissions/state/state_emissions.cfm

There must be a research opportunity in there somewhere.