The US Energy Information Agency has released a collection of data on the last 15 years of carbon dioxide emissions. Accessed via Ars Technica, the report shows that overall emissions dropped in 41 states, but that factors including population density and weather make year-over-year stats vary widely. The complete report paints a picture of the changing energy landscape across the country, as well as the challenges faced in states such as Wyoming which incur high heating costs, long commutes, and are heavily reliant on fossil fuels.
More data can be found here.