Despite efforts to curb carbon dioxide emissions, the Keeling Curve still ticks higher up each year, reflecting increased concentration of carbon dioxide in Earth's atmosphere. A new carbon-sucking power plant may allow scientists to tackle that problem with "negative emissions" technology.
The idea of removing carbon from the atmosphere is by no means revolutionary. Plants capture CO2 and use it for photosynthesis. Forests can therefore act as huge carbon sinks, as can peat bogs, animals and the ocean.
The removal of natural carbon sinks could be significant. World Carfree Network estimates that as much as 15 percent of carbon-emissions come from deforestation. By comparison, about 14 percent are said to come from vehicles, Scientific American reports.
Efforts to 'regreen' the planet have been taken up by conservationists and regular citizens alike. Initiatives range from planting vertical gardens on skyscrapers to providing aid for communities to protect the forests they live in. According to Futurism, scientists are even developing drones that could plant up to 100,000 trees a day.
While developments in planting and forest conservation are helpful, carbon-emissions cannot be offset by revegetation alone. According to The Guardian, scientists say that negative-emissions technologies will need to be up and running by the 2030s to stay under the 2-degree warming limit set by the Paris Climate Agreement.
"If you're really concerned about coral reefs, biodiversity [and] food production in very poor regions, we’re going to have to deploy negative emission technology at scale," said Bill Hare of the science and policy institute Climate Analytics.
Artificial carbon sequestration has been around for a bit, but talks of ramping up the scale are curtailed by the realistic costs of developing and implementing the technology. One carbon-capture method that may be introduced in the next Intergovernmental Panel for Climate Change report involves planting trees and using their energy for wood, then pumping the emissions underground.
A new geothermal power plant in Iceland presents a cheaper alternative.
Switzerland's Climeworks, one of three leading companies exploring direct capture of carbon from air, partnered with Reykjavik Energy and energy project CarbFix to turn its geothermal power plant into the world's first negative emissions plant, Quartz reports.
Geothermal power plants are very low-energy to begin with, producing about 3 percent of the emissions of a typical coal-fired plant. Reykjavik Energy managed to reduce that number in 2014, when CarbFix developed a way to mix the carbon emissions with water. The carbonated water was then pumped underground.
In 2016, scientists discovered that the water had mineralized in Iceland's basalt rocks over a period of just two years. On a geologic time scale, that's practically light speed. The $30 cost per metric ton is equally as impressive.
In October 2017, Climeworks installed one of its air-capture units near the geothermal vents and connected it to CarbFix's underground system. The plant now captures all emissions and stores it in a mineralized rock that will last for millions of years.
The method proves that direct air carbon capture can be performed for much less money than previously believed, but it is still very small scale. Right now it is sequestering the same amount of CO2 emitted by a standard U.S. household each year. The ability to use the same method for carbon plants in larger countries is a long way away -- but the door has been opened.