A US developer has unveiled plans for the world’s largest direct capture facility which could suck millions of tonnes of carbon dioxide from the air by the end of the decade. By 2030, ‘Project Bison’ hopes to capture 5 million tonnes of CO2 per annum, roughly the equivalent of 5 million return flights between London and New York. Humans emit 43.1 billion tonnes of carbon dioxide every single year. This gas acts like a heat blanket, trapping warm air inside the atmosphere and raising global temperatures. The solution to this problem is to stop producing greenhouse gases. Carbon capture is no substitute for rapid decarbonisation, which requires countries to swiftly phase out fossil fuels and electrify industries like agriculture and transport. Even though it may not be a silver bullet and the technology is still in its infancy, carbon removal can help minimise the impact of the carbon that’s already in the air. Currently, the world is able to capture 40 million tonnes of CO2 a year, roughly 0.1 per cent of 2019’s global emissions. There are 26 commercial carbon storage facilities in the world, with at least another 30 planned. There are several methods of capturing and storing carbon. Project Bison, run by US company CarbonCapture Inc, will be a direct air capture (DAC) system, extracting CO2 straight from the atmosphere. Plants and trees do this every day through photosynthesis. DACs emulate the process through a series of chemical reactions. First, a fan pulls air into an ‘air contactor,’ where it passes over thin plastic surfaces covered with potassium hydroxide solution, which chemically binds with the carbon dioxide molecules, trapping them in the liquid as carbonate salt. Through further chemical processes, the salt is turned into pellets and then into pure gas, ready to be stored deep underground. Solutions will inject the gas into ‘deep saline aquifers.’ To minimise the project’s energy footprint, the system will be electrified. The company says the project should start operating at the end of 2023. In its first year, it will suck 10,000 tonnes out of the atmosphere. “Project Bison starts small, but grows fast,” says a company press release. “By 2030, Project Bison is scheduled to have rolled-out five megatons of annual capture and storage capacity. At that point, we expect it will be the largest single atmospheric carbon removal project in the world.” DAC isn’t cheap. Removing CO2 from the atmosphere takes a lot of energy, and can cost up to $600 per tonne. However, Project Bison is aided by the recent Emissions Reductions Act passed by the US congress. For every tonne of CO2 it traps, CarbonCapture will sell ‘carbon credits’ to companies looking to offset their emissions.