This is CDR is an ongoing series of online events to explore the range of carbon dioxide removal solutions that are currently in development. And for six episodes, we’ve covered a bunch of emerging technologies that get carbon dioxide safely out of the atmosphere. But this week, we’re taking a look at a related question: what do we do with the stuff once we remove it?
It’s not a simple problem, but Dr. David Goldberg, a professor who studies climate at Columbia University, walks us through some potential solutions, with a particular focus on offshore geological storage. In the natural world, certain types of rock (basalt and peridotite, among others) react with CO2 dissolved in water, gradually mineralizing it in a process called mineral carbonation. Large deposits of this “ultramafic” rock can be found in offshore areas, and scientists are experimenting with injecting captured CO2 into these deposits and allowing it to gradually mineralize. Dr. Goldberg describes a decade-long mineral-carbonation experiment in Iceland that is now sequestering 10,000 tons of CO2 annually.
There are a few requirements here: one, ultramafic rock; two, water; and three, power. In the Iceland experiment, the carbon-injection equipment was built into a geothermal power plant, but in order to take this concept to a global scale, we’ll have to head offshore, where more ultramafic rock and, of course, more water are available. As far as power, we could replace the land-based power plant of the Iceland setup by integrating carbon-injection infrastructure with wind farms.
Dr. Goldberg points out that because of daily and seasonal variation in human energy use, wind farms often produce more energy than can actually be used, resulting in “negative pricing.” That energy could instead be directed to sequestering carbon, right on site.
It’s a fascinating idea, and you can learn much more about it by watching Dr. Goldberg’s presentation. Thanks for checking it out, and please come back next week for more This is CDR.