On a 98-degree day in Houston, I was shivering. Inside the expansive George R. Brown Convention Center, during the two-day North America Carbon Capture Technology Expo, an overabundance of cold air poured from vents overhead. About three thousand attendees had gathered there from across the globe, showcasing and viewing technology that they promised would save us from climate disaster.

The expo, held in mid-June, had the eager energy of a high school science fair, only it was for adults who represent potentially billions of dollars of capital. Conference speakers frequently threw around words like “electrolyzer” and “seismicity.” They casually alluded to imminent “catastrophic climate change,” uttering that phrase without any apparent anxiety, as though they were forecasting the weather and not humanity’s demise. Indeed, a buzz of opportunism ran through the event. According to estimates, the worldwide carbon-capture market is expected to grow from about $2 billion this year to about $7 billion in 2028. “There’s growing recognition in the private sector that climate change isn’t scary from a business proposition,” said Matt Kittell, a senior investment officer with the U.S. Department of Energy’s Loan Programs Office. “You can solve this problem in a way that makes money.”

Carbon capture is exactly what it sounds like: harmful carbon dioxide emissions are captured, either from the atmosphere, which is known as direct-air capture, or at industrial facilities as they burn fuel, where it’s called point-source capture. Point-source capture traps CO2 from flue gas—that plume of exhaust billowing from a smokestack—before it’s released. The exhaust is “scrubbed,” isolating the CO2, which can be recycled and sold. Captured carbon is already going into any number of products, including concrete, carpets, lab-grown diamonds,  sparkling water, and even vodka. But it’s mostly stored underground in a process called sequestration. 

A handful of start-ups set up booths at the expo, alongside small and midsized oil and gas firms, including Houston-based liquefied natural gas company NextDecade. They, in turn, were flanked by industry giants, such as the London-based, $261 billion Shell. Most of the 29 booths were nondescript—engineers and sales directors stood in front of colorless cardboard displays featuring overhead views of pipelines. Some booths were more elaborate, with interactive computer models and free company merch—pens, totes, baseball caps, bowls of candy. Air Liquide USA, the Houston-based division of a €23 billion Paris-based multinational, had arguably the nicest setup: a barista made complimentary espresso drinks to order.

At one booth, I met Petri Laakso, the CEO of Soletair Power, a Finnish company that aims to turn buildings into “carbon sinks.” Laakso told me buildings account for nearly 40 percent of all carbon emissions worldwide. This includes both operational emissions—that is, emissions from the energy it takes to heat, cool, and power the structures—as well as the emissions produced from building materials and construction. As he related this to me, I couldn’t help but wonder about the volume of carbon dioxide emitted because of the George R. Brown Convention Center’s aggressive cooling system.

Soletair has designed methods to offset such building emissions by capturing carbon in a variety of ways. One of its products looks like a shipping container and employs fans to suck in air surrounding a building. A chemical process inside the unit separates the CO2, which is then compressed and stored. Laakso told me the technology is being marketed to companies looking to get ahead of stricter government regulations of carbon emissions. In New York City, for example, most buildings larger than 25,000 square feet will need to meet emissions limits by 2024 or face penalties. “You can avoid those penalties by doing negative emissions with technologies like what we’re doing,” Laakso said.

Another of Soletair’s prototypes hooks up to a building’s ventilation system and captures carbon dioxide produced by people—their breath—inside commercial buildings. Capturing that kind of carbon isn’t going to save the planet, but it might save workers from falling asleep on the job. “You can really feel, when you have this system in the meeting room or in the office, that the air is much more refreshed,” Laakso said. As part of his pitch, he cited a Harvard study that found that as workers gather and exhale in a typical room, carbon dioxide levels can double from their normal concentrations, leading to drowsiness and reduced productivity.

I asked Laakso whether a bunch of office plants might filter carbon in the same way. They won’t, he explained, noting that the average person produces more than two pounds of carbon dioxide daily—far more than a plant is capable of processing in that same time.  A mature tree, for instance, can only absorb fifty pounds of carbon dioxide per year, and Soletair claims its prototype can capture more than double that in one day.

Maybe Laakso’s pitch got in my head, or the attendees’ aggregate exhalations actually made me tired—either way, by afternoon, I joined a long queue for Air Liquide’s espresso station. When I headed outside to take a break and warm up, I spotted a man with white hair vaping nearby and wearing a T-shirt that read, “Yo quiero freedom.” Also gathered at the convention center that week was the Texas GOP. Unlike many of those Republicans, everyone at the carbon-capture expo seemed to agree that climate change is real and must be addressed.

Devin Shaw, a business manager and carbon-capture specialist at Shell, made a presentation stating that current carbon-capture products around the world have the capacity to catch 40 million tons of CO2 annually. That figure needs to grow, he proclaimed, to 5.6 billion tons by 2030 to prevent catastrophic climate change. But trapping 13,900 percent more carbon over the next eight years will require either more government mandates to do so or the creation of a more profitable market for that carbon—or, quite likely, both.

Which might explain why attendees flocked to Kittell, of the Energy Department. He had what they needed—money. Kittell was spreading the word about billions in new federal dollars that could help offset the risks of investing in capturing carbon dioxide. “CO2 is a waste product,” Kittell told me. “It’s not oil; it’s not gas; there’s no real value, to a large scale today, of CO2 on the other end of the pipeline.” As part of the $1 trillion bipartisan infrastructure bill passed last year, the federal government now has billions in loan guarantees, as well as direct funding, to offer carbon-capture projects. That might be one reason why enthusiasm for the industry seems to be picking up steam. Trans-Global Events, the company that organized the Houston expo, told me it welcomed about double the number of attendees it had expected.

Still, critics of carbon capture ultimately see it as enabling continued reliance upon fossil fuels. In fact, much of today’s captured carbon is used to help extract the maximum amount of oil from wells. “It’s almost like dry-cleaning the oil from the rock,” Stuart MacKenzie, CEO of Calgary-based Gas Liquids Engineering, told me. Critics also worry about sequestration, an environmentally risky practice. Such injection of liquefied CO2 underground can trigger earthquakes that could end up releasing the stored CO2.

At the expo’s conclusion, I returned to my hotel room, where the thermostat had been set to 66 degrees—freezing. From my window, I could see the smokestacks of oil refineries. Down below was the hotel pool. It was shaped like Texas and huge. Along its perimeter, swimmers bobbed in inflatable plastic doughnuts while Houston’s heat wave beat down on them. The forecast was for hotter temperatures ahead.