Cement is terrible for the climate. California just passed a law to fix that

California has taken on a major source of climate change pollution: the carbon emitted from cement used in the construction of buildings and highways. Last week, Governor Gavin Newsom (D) signed SB 596, which will require carbon emissions per ton of cement produced to be cut by 40 percent below 2019 levels by 2035.

“California is now the leader in driving decarbonization of the cement industry,” said state Senator Josh Becker (D), lead sponsor of the legislation. 

The law instructs the California Air Resources Board to develop a net-zero emissions strategy for cement by 2045. It also tasks CARB with creating a metric to easily compare the climate impact of different types of cement. No such metric currently exists.

Passage of the bill marks the first time the state has required specific reductions of an economic sector, said Becker, a first-term legislator and vice chair of the Joint Legislative Committee on Climate Change Policies.

Cement is the primary ingredient in concrete — and the most carbon-intensive one. Cement production is responsible for 7 to 8 percent of all carbon dioxide emissions globally. If the cement sector were a country, it would rank fourth in the world as a climate polluter.

Bob Epstein, a co-founder of the cleantech entrepreneur group E2, said the law is significant because it creates an incentive for cement companies to innovate. ​“Proving that [it] can be done in California [and] it can be copied in India and China and the other large cement consumers” is important, he said.

Cement manufacturers in California, which have committed to reaching carbon-neutrality by 2045, worked with Becker on the bill’s language. The legislation was passed with bipartisan support.

However, a second bill proposed by Becker, addressing the broader issue of concrete, did not pass. Becker said he plans to reintroduce it in the next legislative session, so it will have another chance beginning in January 2022. SB 778 is a government procurement or ​“buy-clean” bill that would gradually push the state to use contractors that produce lower-carbon concrete. Governments are the largest buyers of concrete, so they have the power to drive change in the industry.

Check out our previous in-depth coverage of both bills.