The move is part of California's growing effort to try to control climate changes and reduce the risks of environmental damage to the state's economy, businesses and resources.

California air-quality regulators have adopted the nation's first-ever regulations to reduce car emissions linked to global warming, and a new state energy plan pushes for more energy efficiency, conservation and renewable resources like wind and solar power to build up electricity supplies.

The CPUC will hold a conference Feb. 23 to begin identifying "best practices" regulated companies can take to save energy and cut emissions that could lead to regulations.

The measures may include more fuel-efficient fleet vehicles, new efficiency standards for buildings and appliances, and improved power plant operations, Michael Peevey, president of the CPUC, said.

The US is the world's biggest emitter of greenhouse gases, accounting for roughly 25 percent of global emissions, but with less than 5 percent of the world's population, according to a CPUC paper prepared for the meeting.

FOSSIL FUELS

The major industrial contributors of greenhouse gases are transportation -- about 50 percent -- and electricity production -- 25 to 30 percent -- from power plants fired by fossil fuels.

California, the nation's most populous state, depends on natural gas, hydroelectricity and nuclear energy to run its power plants, but it also imports coal-fired electricity from big plants in Nevada, Utah, Arizona, New Mexico and other Western states.

Plants fueled by coal emit about twice as much carbon dioxide, the leading global warming pollutant, as gas-fired plants, according to the Natural Resources Defense Council, an environmental policy group.

The Bush administration refused in 2001 to ratify the Kyoto Protocol to reduce global warming, which goes into effect Feb. 16, saying it was too costly.

The CPUC, in December, approved long-term power procurement plans for utilities to ensure California has enough electricity to serve growing demand, ordering that energy efficiency and conservation should come first.

The regulators also directed the utilities to factor in a "carbon adder" when they plan to purchase electricity supplies. It is a financial tool to measure the cost to generate electricity by coal and gas versus the cost of renewable resources and energy savings.