Probably you missed it, but last week there was a fascinating interview on the NPR program Talk of the Nation. The segment featured a scientist named David Goldberg, who answered questions about his research concerning the plausibility of storing massive amounts of carbon dioxide in basalt formations deep below the earth’s oceans.
In a paper that is available online and will be published in an upcoming issue of The Proceedings of the National Academy of Sciences, Goldberg and his colleagues write about how a basalt formation off of the coast of Oregon and Washington could potentially store anywhere from 120-150 years of carbon produced by the United States in its cavities (assuming current U.S. emission rates do not increase).
While initially I was extremely skeptical of this idea (because I thought that it might cause all kinds of unintended ecological havoc), by the end of the interview, I was somewhat more optimistic.
The idea of storing carbon dioxide under the ocean reminds me of a rather naive idea I once had as a kid. I thought that a good way to rid the earth of our human waste would be to rocket it into space in huge bundles. Then a giant incinerator in space would burn the garbage. Every time I see a bumper sticker that says “Earth First: We’ll destroy the other planets later,” I chuckle as I am reminded of what a silly idea shooting our litter into space would be.
The Basic Science Behind Storing CO2 Under the Ocean
The aforementioned NPR interview does an excellent job of explaining how carbon would be stored underneath the ocean in basalt rock formations. Essentially, the CO2 would need to be pumped into fissures in the rocks in pressurized liquid form. It would become trapped inside for a long period of time, reacting with iron, calcium, and sea water in the rocks to make chalk (known more technically as carbonates).
Laboratory reactions indicate that this process would most likely occur quickly and would not influence the oceans in a negative way or allow the carbon to escape easily. According to Goldberg, in its liquid form CO2 is denser than sea water and would subsequently be more likely to sink than rise while trapped within the basalt formations. The formations in discussion are part of the Juan de Fuca Plate, and are close to 10,000 feet below the ocean off of the coast of Oregon and Washington.
Goldberg says that this particular formation has the advantage of potentially holding about ten times more carbon than other areas of this kind underneath the ocean. He therefore thinks that research efforts should be focused here. But he readily admits that there are other challenges that might derail this potential solution to help alleviate global warming. He explains that a pilot study is needed to see if assumptions are correct that carbon can be stored safely and efficiently this far below the ocean. He and his fellow researchers are currently seeking funding to commence this introductory research.
What Are Some of the Other Challenges and Alternatives to Storing Carbon this Way?
The process of storing carbon in such ways that it won’t enter the atmosphere is known as carbon sequestration. What Goldberg and his fellow researchers are proposing is referred to as geochemical trapping. If it is discovered that the basalt formations below Oregon and Washington’s coastal areas can in fact store carbon dioxide safely, there is still the issue of transporting the CO2 from destinations on the ground in the U.S. all the way to the depths of the ocean.
Goldberg admits that creating and financing this infrastructure would be a necessary precursor to making carbon sequestration and geochemical trapping a reality. But he suggests that if his research and those of others is fast-tracked, then perhaps it is achievable. He is right in that the research has to begin somewhere though.
When asked by NPR’s interviewer about how this idea was different or better than storing CO2 in empty oil wells, he replied that while the strategy he is researching would be more inconvenient, it would represent a component to global warming alleviation that would be far more significant in magnitude to any storage that old oil wells might provide. He wisely cautions listeners, however, by saying that his idea would just be one of various solutions and actions needed to address global warming and climate change, not a silver bullet to relieve us of attempting to reduce our greenhouse emissions.
You can listen to the NPR interview by clicking here. Your thoughts on this potential method of combating global warming are appreciated.