Carbon dioxide emission volumes, trends, and sources vary substantially by state, according to a report released
The report's data, obtained from the Dept. of Energy's Energy Information Administration, cover the years 1990-2007, with an additional breakout for 2004-2007. You can check the states you cover in a variety of ways, such as by source type (e.g., commercial, residential, electricity generation, transportation), fuel type (coal, natural gas, oil), or per capita.
For one-third of the states, the trend for total emissions is downward from 2004-2007, and four of the states (CT, DE, MA, NY) and DC have slightly lower totals in 2007 than 1990, due in part to various measures each jurisdiction has taken.
The report has a number of limitations, such as the exclusion of greenhouse gases other than CO2 that account for about 17% of total greenhouse gas effects, but it offers a user-friendly way to get at some of the facts about localized and national emissions.