Since 1995, the voluntary reporting system has collected data from U.S. companies, organizations and individuals on their greenhouse gases emissions and their actions to cut back on these emissions.

The department wants suggestions on how to improve the accuracy, reliability and verifiability of the information that is reported. Comments are due by June 5.

"Improving our greenhouse gas reporting system will benefit our environment without requiring a radical overhaul of our existing energy systems," said Energy Secretary Spencer Abraham.

The clear skies plan is the alternative to the international Kyoto Treaty to limit greenhouse gases, which President Bush announced last year the United States would not participate in because the treaty's tough requirements would hurt the U.S. economy.

Other countries, in particular European Union members, have criticized the Bush administration for pulling out of the Kyoto Treaty. They argue the United States is the world's biggest consumer of energy and producer of greenhouse gases and therefore should do more to scale back atmospheric warming emissions.