Washington Report: The Coming Debate About Concrete and Climate Change

by Craid Piercy, ACPA Washington Advocate

The second of two Democratic presidential candidate debates in June will be best remembered for Senator Kamala Harris’s “leg-sweep” of Joe Biden over his opposition to school busing in the 1970s. However, it was an exchange between moderator Rachel Maddow and former Colorado Governor John Hickenlooper later in the evening which made my ears perk up.

In response to a question from Maddow on climate change, Hickenlooper said, “If you look at the real problem, CO2, the worst polluters in CO2 is China, is the United States, and then it’s concrete and its exhalation.”

Yes, you read that right, the concrete industry just got called out in the U.S. political debate on climate change.

The fact that cement production is a carbon intensive process is not news; it’s been common knowledge in the industry for some time. However, the media has finally caught on and is running stories with headlines like, “Climate change: The massive CO2 emitter you may not know about” (BBC, 12/17/2018) and “Cement Produces More Pollution Than All the Trucks in the World” (Bloomberg, 6/22/2019).

So, is concrete the new climate villain? Let’s take a look at the arguments.

Technically, Hickenlooper is not wrong. If cement production was a country, it would be the third largest emitter of carbon dioxide, after China and the United States. Over four billion tons of cement are produced annually around the world, generating around eight percent of global carbon dioxide emissions. Each ton of cement requires 4.7 million BTU of energy to produce. The International Energy Agency expects direct carbon emissions from the cement sector to increase four percent by 2050. As John Vidal, environment editor of the Guardian, wrote in February, “The cement industry has transformed the world and enriched both itself and mankind. But it now threatens to tip the environment into uncontrolled warming.”

On the other hand, concrete is the most widely used manmade material in the world. It is strong, long-lasting and highly resistant to fire and water. It can be made with recycled materials like coal fly ash and crumb rubber, and both its costs of production and maintenance are low compared to other building materials.

Concrete also has a compelling environmental case. Pound for pound, it requires only 10 to 30 percent of the energy needed to make structural steel. In addition, because it is produced locally, the CO2 emissions from transporting concrete to the job site are lower than steel or wood.

Concrete also absorbs a significant amount of CO2 out of the air after it is cast. According to a Nature Geoscience Report, from 1930 to 2013, the world’s concrete absorbed more than 16 billion tons of CO2, 43 percent of the total carbon emitted when limestone was converted to lime in cement kilns. In fact, several companies are commercializing new concrete production methods which actually sequester CO2 from fossil energy plants!

More than 50 percent of cement sector emissions are linked to producing clinker. However, according to Columbia University’s Earth Institute, “Less carbon-intensive fuels … can reduce cement emissions by 18 to 24 percent from 2006 levels by 2050.”

Finally, roughly 90 percent of the average building’s carbon footprint comes from operational energy use, and because concrete buildings are more energy efficient, they contribute to lowering overall energy demand for heating and cooling.

Yes, concrete production has a CO2 emissions footprint, but so do other building materials. The timber industry has been very successful touting its climate-friendly credentials to the public in recent years. However, an April 2019 study by the International Institute for Sustainable Development found that current life cycle assessments for construction “do not track or account for ‘biogenic carbon’ from the extraction and end-oflife stages of wood building products,” which may “represent up to 70 percent of total lifecycle emissions.”

Ultimately, Hickenlooper’s debate comment is likely to fade into obscurity, but with so many Democrat candidates now embracing the Green New Deal, the larger climate change debate will no doubt feature prominently in the 2020 elections. Its focus will likely remain on energy generation, with the fossil fuel industry playing the main villain, but the concrete industry could get dragged into it. We—trade associations, companies, employees—all must be ready to respond at a moment’s notice. We have a good story to tell.