WASHINGTON, D.C. — Thirty-one states, representing over 70 percent of the U.S. population, have banded together to create a Climate Registry, marking the largest national effort to take action on climate change.

The participating states see the creation of the Climate Registry, which is based on voluntary reporting of statewide emissions, as a necessary first step toward developing mandatory, federal regulations on global warming-causing emissions.

"This historic milestone establishes a critical and credible 'common currency' that will help us succeed as we move forward with efforts to reduce these missions,' said Connecticut's Governor, M. Jodi Rell.

California has already taken the lead on reducing carbon emissions -- the state has legislated a mandatory 25 percent reduction by 2020 -- and other states in the Registry have begun working on ways to lower their emissions as well. The Hawaii state legislature recently passed a bill similar to California's, and Washington state and the states that make up the Regional Greenhouse Gas Initiative have started to reduce the emissions caused by power plants in their states.

The list of founding member states and tribes thus far includes the states of Arizona, California, Colorado, Connecticut, Delaware, Florida, Hawaii, Illinois, Kansas, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, Utah, Vermont, Washington, Wisconsin, Wyoming and the Campo Kumeyaay Nation. Two Canadian provinces, British Columbia and Manitoba, have also committed to participate.

The Registry is a tool to measure, track, verify and publicly report GHG emissions accurately, transparently and consistently across borders and industry sectors. The Registry's proponents say it is is a critical first step in developing robust programs to reduce GHG emissions.

"You have to be able to count carbon pollution in order to cut carbon pollution," said Frances Beinecke, President of the Natural Resources Defense Council. "The Registry gives business and policymakers an essential accounting tool for tracking the success of the many emerging global warming emission reduction initiatives that are blossoming across the country."

The Climate Registry's members say creating local, voluntary programs are a necessary response to the reluctance of the federal governmnet to create mandatory or even voluntary greenhouse gas regulations.

"The Climate Registry is another example of how states are taking the lead in the absence of federal action to address greenhouse gas emissions in this country," said Arizona Governor Janet Napolitano.