Negative-Emission Technologies Could Help Remove CO2 from the Atmosphere

Adverse effects of cumulative emissions of greenhouse gases at constant increasing rates have been predicted by climate researchers. The fact that any solution will require sharp decreases in emissions from sources like coal-fueled power plants and automobiles has been accepted by professionals.

However, an article published in Chemical & Engineering News (C&EN), the weekly newsmagazine of the American Chemical Society, states that negative-emission technologies (NETs) that have the potential to remove CO₂ from the atmosphere could help in resolving this issue.

It has been reported by the United Nations Environment Programme that every year, 50 billion tons of greenhouse gases, chiefly CO₂, are discharged into the atmosphere. Freelance contributor Jeff Johnson has written that researchers have estimated that, if scaled up, NETs could achieve approximately 30% of the required CO₂ emission reductions. But many challenges are faced by NETs in being used cost-effectively at a global scale.

NETs capture CO₂ by streaming air through a liquid or solid sorbent, which in turn releases the concentrated gas when heated later. Despite the previous use of this approach by power plants, so far, it has not been applied at significantly dilute levels of CO₂ in the atmosphere. In addition, since the current technology amounts to $200–$1000 per metric ton of CO₂, researchers aim to develop novel sorbents that can reduce energy expenses and release CO₂ at lower temperatures.

However, the challenges never end there––once the gas is extracted, scientists ought to find a solution to get rid of it, which is achieved by injecting CO₂ as a supercritical fluid into geological formations deep within the earth, where porous, permeable rock may be capable of storing the gas for many years. According to experts, current oilfield injection technologies ought to be drastically increased to have any influence on global CO₂ emissions.