Can injecting climate-changing carbon dioxide into concrete mix help cut the huge emissions from concrete production?
By Sebastien Malo
NEW YORK, July 2 (Thomson Reuters Foundation) - Hawaiian officials have taken a concrete step to fight climate change: They plan to lock planet-warming carbon dioxide up in the concrete they use for road construction.
Hawaii's Department of Transportation will use carbon-injected concrete from now on when it constructs concrete projects - including a new structure to protect a highway tunnel from rockfalls, said the government body's spokeswoman Shelly Kunishige.
"It allows us to use less cement in our mixes. So we reduce the carbon footprint of our building," Kunishige said.
Honolulu city council members, meanwhile, in April adopted a resolution paving the way for the city to use the greener concrete, which locks up carbon dioxide captured from industrial emitters and uses it to replace some of the cement needed in concrete.
The state capital's resolution requests that city administrators "consider" using CO2-injected concrete in city and county infrastructure where concrete is used.
For now, bids put out by Honolulu won't call for the material, but won't restrict its use either, said Robert Kroning, head of the city's Department of Design and Construction.
"If it's much better then maybe we will start making it requirement," he said.
Cement, a key ingredient of concrete, releases 5% to 8% of global greenhouse gas during its manufacturing, according to the Global Cement and Concrete Association, a non-profit.
As governments and companies look to cut their planet-warming emissions, in line with Paris Agreement goals to limit global temperature rise to "well under" 2 degrees Celsius (3.6F), finding ways to make construction greener is key.
Companies have been experimenting with lower-carbon concrete - but now some, such as CarbonCure Technologies, are starting to make headway with public buyers.
The Canada-based company, which leads the field with 150 concrete producers supplying its product, sells carbon-injected concrete for the same price as traditional concrete, company officials said.
Chief executive Robert Niven said his company is in talks with half-a-dozen U.S. departments of transportation to use the material, as well as 10 countries in Asia and Europe and his home country, Canada.
Progress depends in part on more resolutions like that in Honolulu that pave the way for use of the new material, he said.
Government market signals "are so incredibly important," Niven said.
"That's what's going to get us to those climate-scale solutions. It's not more time in the laboratory," he added.
The U.S. market of people willing to pay for concrete combined with carbon dioxide was about $65 million in 2017, according to an estimate by Oakland-based Carbon180, a non-profit.
For the same year, the market size of ready-mix concrete manufacturing in the United States totaled nearly $33 billion, according to industry research firm IBIS World.
In Austin, Texas, sustainability officer Tom Ennis, after looking at Hawaii's example and crunching numbers to "vet the technology", began encouraging his city to purchase carbon-injected concrete as well.
The high-tech, low-carbon concrete "is a piece of the puzzle" toward reducing the city's emissions, Ennis said.
Last month, Austin's environmental commission approved a motion that recommends "supporting the development of pilot programs" to use the greener concrete.
The city council must now take the idea on board if it is to move forward, Ennis said.
Legislation to pave the way for the use of the material also is being explored in at least two other states - New York and New Jersey, said Julio Friedmann, a senior research scholar working on energy policy at Columbia University.
The New York bill in its current draft form calls for up to 5% of carbon dioxide captured direct from the air to be sequestered in concrete the state purchases.
So-called "direct air capture", using still-expensive devices that pull carbon dioxide directly from the atmosphere, is an emerging field with only a handful of players, including Global Thermostat.
That company's technology is being used to absorb carbon dioxide directly from the air at a pilot plant in California and a commercial-size plant operating in Alabama, a company spokeswoman said.
"I don't believe we will ever get to a place where we get to the net zero (carbon emissions) ... if we don't green the construction industry," said Robert Carroll, the New York lawmaker behind that state's bill.
The International Energy Agency says capturing carbon will be needed to limit a global rise in average temperatures to below 2 degrees Celsius (3.6F) above pre-industrial times by 2060.
Carroll said he may introduce his bill - possibly the first of its kind in the nation - later this summer or in the fall. (Reporting by Sebastien Malo @sebastienmalo, Editing by Laurie Goering. Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers climate change, humanitarian news, women's and LGBT+ rights, human trafficking and property rights. Visit http://news.trust.org/climate)
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