SAN FRANCISCO

Customers can enroll in the utility's ClimateSmart program, which helps figure the annual tonnage of carbon dioxide emissions related to the electricity use of a household or business. That carbon footprint can be offset, or neutralized, by paying a few dollars a month, PG&E says.

An average household's use produces 4.8 tons of carbon dioxide a year, which would come to $4.31 a month under the program.

The utility will spend the money on such projects as managing mature forests that absorb carbon dioxide or controlling greenhouse gas emissions from livestock manure, PG&E spokesman Keely Wachs said.

Only projects that have been approved by the state's California Climate Action Registry, a public-private entity that oversees voluntary carbon reductions, will be supported with customers' funds, he said.

PG&E intends to monitor projects and report to the state Public Utilities Commission, which must approve its payments to carbon-cutting projects.

"We want to be as transparent as possible,'' said Wachs.

At 10 a.m. today, a panel will discuss the benefits and drawbacks of carbon offsets at the Golden Gate Club in the Presidio, 135 Fisher Loop.

Participants include Peter Liu, initial founder and vice chairman of New Resource Bank, and Dan Kammen, professor in the Energy and Resources Group at UC Berkeley.

The trend of becoming carbon neutral to combat global warming has been controversial. Some see it as a way to establish a voluntary carbon market aimed at putting a price on greenhouse gas pollution while others view it as a way for people to keep up wasteful energy use with less guilt.