Crews pour concrete on a bridge over Interstate 69 in southern Indiana, circa 2002.(Indiana Department of Transportation)
This story was reported by Floodlight, a nonprofit newsroom that investigates the powerful interests stalling climate action.
Concrete built much of the modern world. It paves highways, shelters millions, and forms the foundations of countless buildings.
But cement, the crucial powder that serves as the binder in concrete, has become one of the planet’s biggest climate threats, generating about 8 percent of the world’s carbon dioxide emissions. And now, efforts to curb its pollution are facing new political headwinds.
Moves to decarbonize the cement industry picked up speed during the administration of President Joe Biden, which channeled billions of dollars in Inflation Reduction Act (IRA) money toward reducing the carbon footprint of concrete and other construction materials.
The Trump administration has reversed course. In January, the Environmental Protection Agency canceled 21 grants aimed at reducing greenhouse gas emissions from concrete, cement and other construction materials, according to a spreadsheet compiled by the Sierra Club from EPA records. “There’s definitely concern that the momentum is broken,” said Yong Kwon, senior campaign advisor for Sierra Club’s Industrial Transformation Campaign.
The EPA didn’t respond to Floodlight’s questions about why it canceled those grants. Instead the agency’s press office sent a two-sentence response:
“As with any change in Administration, the agency is reviewing each grant program to ensure it is an appropriate use of taxpayer dollars and to understand how those programs align with Administration priorities. The agency determined that the grant application no longer supports Administration priorities, and the awards have been cancelled.”
Prized for its strength, durability and versatility, concrete is the second-most used substance on Earth, behind only water.
But the explosive growth in its use has also heightened concerns about a warming planet. Carbon dioxide emissions from cement production have nearly tripled over the past 30 years. If the cement industry were a country, it would be the world’s fifth largest carbon polluter. Global demand is expected to soar by 50 percent by 2050.
Cement serves as the glue in concrete, binding together aggregate materials like sand and gravel. Key to giving cement its strength and hardening ability is a manufactured substance known as clinker. But in the process of making clinker, cement factories release massive amounts of carbon dioxide.
Some emissions result from the kilns used in the manufacturing process. Those kilns, commonly fired by fossil fuels in the United States, typically reach about 2,700 degrees Fahrenheit—roughly a quarter of the sun’s surface temperature. The chemical process used to convert limestone into lime, a key compound required for clinker, generates even more carbon dioxide.
Many of the efforts to reduce the cement industry’s carbon footprint have focused on reducing or replacing clinker with other materials, such as slag from the blast furnaces used to make iron, and fly ash, a byproduct of coal combustion in power plants.
“I think certainly industry, American industry, sees this as an opportunity to broaden its horizons.”
Other companies are using alternative fuels to power kilns. But that’s far more common in Europe than domestically. “Today, the US lags behind Europe and other parts of the world in adopting low-carbon approaches,” according to a 2023 report about low-carbon cement by the Department of Energy. “The EU uses alternative fuels for about 50 percent of primary energy consumption in cement, compared to just about 15 percent in the US.”
The Biden administration had begun funding an array of cement decarbonization efforts.
Last year, the DOE awarded $1.5 billion in grants to six projects designed to curb carbon emissions by the cement industry. It’s not yet clear whether any of that money will be held up under the Trump administration. The department did not respond to Floodlight’s emailed questions about the status of those grants.
The IRA, Biden’s massive climate law, also provided $2.2 billion for the purchase of low-carbon construction materials for planned federal buildings.
As of January, about $1.6 billion of that money had not yet been spent, according to the IRA Tracker, a joint project of Columbia Law School’s Sabin Center for Climate Change Law and the Environmental Defense Fund. It’s unclear how much or whether any of the remaining money will be spent on green materials.
But a bipartisan effort in Congress could advance efforts to decarbonize the cement industry. The so-called Impact Act, passed by the House last month on a vote of 350-73, would establish a DOE program to support production of low-emission cement, concrete and asphalt.
A second House bill, now under consideration, would provide grants to states to encourage the purchase of green cement, concrete and asphalt. The Senate has introduced similar legislation that includes features from both House bills.
Rep. Valerie Foushee—a North Carolina Democrat who, along with Republican Max Miller of Ohio, sponsored both House bills—told Floodlight she understands there’s support for the legislation in the Senate, too.
“This opportunity for a bipartisan, bicameral way of reducing carbon emissions for the production of cement, concrete, and asphalt is very important, and this is a good time to do it,” Foushee said. “The time is now. We have the opportunity.”
Caught between Congress and the Trump administration, DOE is receiving “mixed signals” on decarbonizing the cement industry, according to Harry Manin, the Sierra Club’s deputy legislative director on industrial policy and trade.
“While there are incredible headwinds under this administration … there still seems to be some awareness by some Republicans that it would be to our advantage to continue down this path,” Manin said. “And I think certainly industry, American industry, sees this as an opportunity to broaden its horizons.”
Politics isn’t the only obstacle in reducing the industry’s impact on global warming.
Creating demand for low-carbon cement and concrete is challenging, partly because those products are more expensive, experts told Floodlight.
Another hurdle: Some low-carbon concrete takes longer to cure, according to Lionel Lemay, executive vice president of structures and sustainability for the National Ready Mixed Concrete Association. In a construction industry where time is money, that makes it a tougher sell, he said: “In reality, the demand for low-carbon concrete is still relatively low.”
Builders and other customers also want to know that low-carbon cements will be as reliable as conventional cement.
“It’s a pretty risk-averse industry,” said Ben Skinner, who focuses on cement for RMI, a nonprofit research group that works to reduce emissions. “And for good reason. If these buildings do fail, there’s serious consequences that may involve physical injuries.”
Given the uncertainty about what will happen with federal support for decarbonization over the next four years, much of the focus is now on efforts by private industry and the states.
A number of them—including New York, Minnesota, and Colorado—have created “buy clean” programs to prioritize the purchase of construction materials with a lower carbon footprint. Said Kwon of the Sierra Club: “State governments have a huge role to play now.”
The Portland Cement Association, a leading trade group, is among those whose EPA grants were canceled.
“Regardless of administration, our goal is carbon neutrality by 2050—that has not changed,” Bohan said. “That will be achieved.”
Will the industry really decarbonize without government help and pressure?
The National Ready Mixed Concrete Association also got word earlier this year that it lost its EPA funding. The association was planning to use its $9.6 million grant to help concrete producers develop “environmental product declarations” so government agencies and other customers could identify which products have a low-carbon footprint.
The grant would have boosted demand for low-carbon products, Lemay said. But the Trump administration’s EPA canceled it along with 48 others. “That just means that we’re not going to have the benefit of the federal government accelerating our progress,” Lemay said. “That would have helped. Clearly.”
