The Georgetown Climate Center tracks federal climate and energy regulation that affects U.S. states. The Center also seeks to improve communication and coordination between states and federal agencies.
Currently, the Center is providing analysis and assistance to states and federal agencies in the wake of the EPA's endangerment finding and recent court rulings that call upon the federal government to regulate greenhouse gas emissions.
From Inside EPA (subscription only) :
In a Feb. 23 letter  to Senate Majority Leader Harry Reid (D-NV) and Senate Minority Leader Mitch McConnell (R-KY), environmental officials from the nine states argue a “resolution of disapproval” introduced by Sen. Lisa Murkowski (R-AK) that would invalidate EPA’s endangerment finding would also prevent the federal program for vehicle GHG standards from being finalized. Joining California Air Resources Board Chairwoman Mary Nichols on the letter are the heads of the environmental departments in Connecticut, Maine, Massachusetts, New Mexico, New York, Oregon and Rhode Island.
“As you know, under this program, EPA proposed federal GHG standards for vehicles that will be roughly equivalent to both the federal corporate average fuel economy (CAFE) standards and the GHG standards pioneered by California and adopted by 13 other states and the District of Columbia,” the letter states. “The existence of comparable federal GHG standards, in turn, would allow our states to accept compliance with the federal program as demonstrating compliance with the California program.”