| Construction begins on direct air capture company Climeworks' Mammoth plant in Hellisheiði, Iceland, in 2022. The technology is one of several "novel" approaches to CO2 removal defined in a recent report. |
The scaling up of nascent technologies that vacuum up CO2 from the atmosphere is an "urgent priority" for governments to limit global warming by midcentury, according to a recent report.
A team of international researchers found that engineered — as opposed to nature-based — approaches to capturing carbon must increase by a factor of 30 by 2030, and by a factor of 1,300 by midcentury.
The "State of CDR" report, led by Oxford University's Smith School of Enterprise and Environment and the Berlin-based Mercator Research Institute on Global Commons and Climate Change, claims to be the first to estimate the global rate of carbon dioxide removal, or CDR, which refers to a range of methods to capture CO2 from the atmosphere and store it. According to that estimate, CDR has scaled to a capture rate of about 2 gigatonnes of CO2 per year, almost entirely through "conventional" methods, such as planting trees.
Only 0.1% of that carbon is captured using what the authors call "novel," or technology-based, methods. These include innovations such as direct air capture, which uses a machine that fans CO2 out of the air and turns CO2 into rock through a process known as carbon mineralization. Another technique, bioenergy with carbon capture and storage, involves converting organic matter into fuel in a process that emits CO2 and burying those emissions underground.
The findings expose a "substantial shortfall" between current CDR deployment and what is necessary to meet the goals of the Paris Agreement on climate change, according to the report. "CDR is not something that we can do, it's something that we must do," Jan Minx, a researcher with the Mercator institute, said in a Jan. 19 briefing.
To close that gap, governments must support "rapid growth" of novel CDR technologies as conventional methods require finite land resources, the report said. "We're really still at the very beginning with these kinds of technologies," Minx said.
Who pays?
Industry watchers have debated whether CDR should belong in the public or private sector. Some U.S. policymakers, including Democratic lawmakers and a former U.S. energy secretary, have called for federal procurement of CDR, which they liken to other public goods such as waste management.
So far, however, the private sector owns the largest-scale deployments of CDR technologies, including direct air capture.
Climeworks AG, which owns the only commercially operating direct air capture plant worldwide, recently removed its first CO2 for corporate customers following a successful audit of its Iceland operations.
The U.S. government has also sought to spur private-sector investment in direct air capture through tax credits and a $3.5 billion grant program launched by the U.S. Department of Energy. And a subsidiary of Occidental Petroleum Corp. began construction in 2022 on a plant capable of vacuuming up to 1 million tonnes of CO2 per year in Texas's Permian Basin. The company has said it expects the facility to receive tax credits for the CO2 captured.
According to the report, the current project pipeline for direct air capture is still a fraction of what it needs to be to avert the worst impacts of climate change. But an uptick in patents may be a leading indicator of future investment.
While patents across all CDR technologies are on the rise, "direct air capture has been the most important patenting area," Greg Nemet, a professor at the University of Wisconsin-Madison, said in the briefing. "It's interesting to juxtapose this with our deployment data, where we don't actually see much direct air capture deployment."