The world blew past historic CO2 levels earlier this year, passing the milestone of 400 parts per million for the first time in recorded history. Much of the focus of climate change researchers has been slowing or stopping the current trajectory, but some go further and say we should try to take carbon out of the air and reverse the trend
And what if, when we took it out of the air, we turned it into a valuable material? Even better.
Ultra-strong, ultra-light carbon nanotubes can be used for building bikes and planes, storing energy, and even cleaning up oil spills. But the material is usually expensive to make. The new method makes it much cheaper.
With the right mix of materials and a little electricity, researchers at George Washington University were able to suck carbon dioxide out of the air and turn it into carbon nanofibers. The method can run on solar power, so it serves as a carbon sink. If machines were spread over a large area–10% of the size of the Sahara Desert–the scientists calculated that they could remove enough carbon in the atmosphere to return to preindustrial levels in about a decade.
That’s obviously a huge undertaking, but the researchers are convinced that it’s possible. “A massive amount of CO2 has been added to the air in the past two centuries of industrialization, and the response to remove that CO2 to mitigate climate change will also take a massive effort,” says Stuart Licht, a chemistry professor at George Washington University. “I am optimistic that this is a viable means to remove that CO2, particularly as the carbon nanofiber product is valuable, providing an economic impetus to confront climate change.”
The technique can be used anywhere. “We’ve demonstrated the process works effectively both directly from the air, and also using gas containing the water vapor and higher concentration of carbon dioxide typical in smoke stack emissions, such as in coal power plants,” Licht says, noting that it’s even easier to do at power plants.
Unlike some other geoengineering methods–like burying carbon–this technique would put pollution to use, and might make it valuable enough that it pays for itself. Right now, the market for carbon nanotubes is relatively small, but that’s partly because of the cost of typical production. In theory, the material could be used to replace almost our entire infrastructure–imagine roads, buildings, power lines and trains made from climate pollution, along with products like smartphones or clothing.
Though the lab has only tested the tech at a small scale, they believe that it would be easy to scale up industrially.