Despite delegates’ efforts at this month’s climate summit in Glasgow, the world is on a collision course with potentially catastrophic levels of global warming. Some countries and corporations are now relying on innovative technology to remove carbon from the atmosphere.
With the announcement of a new “Carbon Negative Shot” effort, the US Department of Energy (DOE) unveiled an ambitious new goal to make those technologies, known as carbon dioxide removal (CDR) technologies, cost-effective and scalable.
The government wishes to lessen the cost of CDR significantly this decade — to less than $100 per tonne — so that it can be implemented at a large enough scale to remove “gigatons,” or billions of tonnes of carbon dioxide from the atmosphere. That is a significant amount of CO2 pollution.
According to the DOE, sequestering one gigaton of carbon dioxide would be equivalent to removing the decay from 250 million vehicles — the entire light-duty fleet of the United States — in a year. Still, there are significant barriers to defeat before the DOE can do so, as CDR technologies are still in their initial development steps.
CDR refers to a set of measures targeted at lowering CO2 levels to prevent it from trapping heat in the atmosphere. Trees and plants can help us with this by removing CO2 from the air. Although it hasn’t been widely adopted, there’s also “direct air capture” technology, which uses carbon-sucking equipment to replicate the process. The United States will almost certainly need large-scale direct air capture systems to reduce adequate heat-trapping pollutants.
The world’s largest direct air capture facility, which can only remove 4,000 tonnes of CO2 per year, went online earlier this year in Iceland. It is nearly the same as the annual emissions from 790 passenger automobiles. International Energy Agency says just 19 direct air capture plants are operating worldwide, and they can only catch a tiny portion of the DOE’s goals.
One of the primary reasons why technology hasn’t progressed further is cost. Companies like Microsoft pay around $600 per tonne of CO2 captured by the Iceland plant. In the fiscal year 2020, the corporation emitted the equivalent of 11,164,000 metric tonnes of carbon dioxide.
Microsoft would have to pay about $6.7 billion to remove only one year’s worth of pollution at the cost of $600 per tonne. However, the price isn’t the only issue. CO2 is trapped in direct air capture facilities using filters or chemical solutions. The filter or chemical solution must be heated to extremely high temperatures — between 100 and 900 degrees Celsius — to release the trapped CO2 and properly store it.
That necessitates a significant amount of effort. According to a 2019 research published in the journal Nature Communications, the machines that extract carbon from the air might use up to a quarter of the world energy supply by 2100, creating a catch-22. If such energy is derived from the combustion of fossil fuels, it may exacerbate the problem it is attempting to remedy.
(Using utterly renewable energy to reach the extremely high temperatures required for the chemical solution method of direct air capture is still technically impossible.) That’s probably why the DOE wants to make sure that “emissions emitted while running and creating the removal technology are accounted for,” as it stated in its release today. Finally, the DOE wants to secure CO2 storage sites that can be monitored for 100 years. To protect humanity from sinking deeper into climatic calamity, it should be kept sequestered for much longer.