Missouri, the state where I live, according to an Associated Press analysis, has increased its carbon dioxide emissions some 32% between 1990 and 2003, while the state's population grew no more than 13% by the A.P. reckoning. The primary reason seems to be the increasing use of coal as an energy source.
About half of America's electricity comes from burning coal at this point in time in the United States. It's "cheap" and plentiful. States also vary considerably in their greenhouse gas emissions, largely due to decisions to use coal an an energy source.
The state of Texas emits more CO2 than most countries do. On a per-person use, Wyoming, one of the least populous states, sends out more carbon dioxide than any other state in the U.S. Both of these states burn a lot of coal. Electricity is cheaper in these states than many others but of course pollution and greenhouse gases are not remotely interested in state boundaries and travel everywhere, including to those states that don't use coal an an energy source.
Idaho, on a per person basis, emits the least amount of CO2. California, the most populous state, has decreased its CO2 emissions more than 10% from 1990 to 2003, and New York has lowered its CO2 levels. These states have either outlawed the burning of coal or have sought alternatives to reduce its impact.
There is no particular reason to think that the U.S. will develop national energy standards anytime soon or that the world will develop global standards to reduce greenhouse gases in the next several years. Perhaps if we decide to put a value on clean air, water and biodiversity we may have a chance to get beyond infantile "voluntary" mechanisms in the U.S. and belligerent "entitlement" from countries like China and India.
In the meantime turn the pressure up.