SACRAMENTO — If a new California climate bill passes, contractors vying for state-funded infrastructure bids will have something besides dollars and cents to add to their bottom line: the “social cost” of greenhouse gas emissions created by their projects.

Its sponsors say the measure would be the first of its kind in the nation and would give companies an incentive to offer the best deal for the environment, not just the lowest price.

“By focusing the buying power of California’s budget, of which approximately $10 billion goes to infrastructure each year, AB 262 will help ensure a thriving market exists for low-carbon industrial products,” said Assemblyman Rob Bonta, D-Oakland, who is sponsoring the bill along with Susan Talamantes Eggman, D-Stockton.

How would it work?

First, bidders would have to fill out a disclosure form about greenhouse gases emitted in the manufacturing and transport of industrial materials to be used in the project, such as cement, steel and glass. Using a formula from California’s secretary of government operations, agencies would calculate a social cost that would figure into the bid’s bottom line.

The new rules also would apply to California State University and the University of California, which have separate purchasing laws.

Assembly Bill 262 has the backing of clean-air and environmental justice advocates, of course. But its list of supporters also includes the United Steelworkers District 12 — which represents steelworkers in the western United States — and Gerdau Steel, a large steelmaker with operations throughout North and South America. As of late Wednesday, California’s major business organizations had not taken a position on the bill.

“California has been a leader in fighting climate change,” Bonta said, “and AB 262 will further demonstrate our resolve by requiring our state government to consider whether products were made in clean or dirty factories when making infrastructure purchases.”