The US carbon capture industry would directly remove carbon emissions from ambient air and help meet the country’s 2050 net zero emissions target. 

The US Department of Energy (DOE) has announced a USD$3.5 billion investment in direct air carbon capture technologies, which could help drastically reduce planet-warming greenhouse gas emissions in the atmosphere.

Carbon capture or removal refers to negative carbon dioxide (CO2) emissions or the process of absorbing and storing carbon durably in another form – often in geological, terrestrial, or ocean reservoirs. Carbon capture occurs naturally via carbon sinks like oceans and forests, but they are unable to keep pace with humanity’s rapid growth and emissions from fossil fuels. Even if we stopped burning fossil fuel today, there is still too much carbon in the atmosphere to completely stall global warming. 

Direct air capture technologies could help speed things up, and will be “unavoidable” to limit global temperature rise and net zero emissions, according to the Intergovernmental Panel on Climate Change. 

As the name suggests, direct air capture sees large facilities capture CO2 directly from the ambient air; plants use enormous fans to draw in the air, from which the carbon is then removed using chemicals such as alkaline solvents or sorbents. Following this, the CO2 is isolated through heat and then either sequestered in the ground or utilised for carbon-neutral products like fuels or chemicals. 

US President Joe Biden pledged to halve carbon emission by 2030 and to achieve net zero by 2050. Due to political gridlocks in Congress and the war in Ukraine, the country’s decarbonisation process and renewable transition has not progressed far. To diversify climate action, the Biden administration is looking to dramatically scale up direct air removal and the carbon capture industry.

Last week, the DOE released a notice of intent for developers for four direct air capture hubs using $3.5 billion from the bipartisan infrastructure law. Each hub must be capable of removing at least a million tons of CO2 per year, which is equivalent to taking 200,000 fossil fuelled-powered vehicles off the road. The hubs also need to be able to permanently store the CO2 and not use the captured CO2 to produce more fossil fuels.

“The UN’s latest climate report made clear that removing legacy carbon pollution from the air through direct air capture and safely storing it is an essential weapon in our fight against the climate crisis,” US Secretary of Energy Jennifer M. Granholm wrote in the statement. “President Biden’s Bipartisan Infrastructure Law is funding new technologies that will not only make our carbon-free future a reality but will help position the U.S. as a net-zero leader while creating good-paying jobs for a transitioning clean energy workforce.”

The plan is for at least two of the hubs to be located in “economically distressed communities in the regions of the United States with high levels of coal, oil, or natural gas resources.” But the US agency will also be looking for regions with other kinds of heavily polluting industries; allowing projects to share the same pipelines could potentially help cut down costs.

Iceland is currently home to the world’s largest direct air capture plant. Built by Zurich-based Climeworks, the facility removes about 4,000 tonnes of carbon dioxide every year, or 10 metric tons every day – approximately what 500 trees could remove in a year. The captured carbon is then stored underground and turned into stone. 

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