This approach addresses one of the big risks of just willy-nilly burying CO₂: that the gas will somehow escape and a) re-enter the carbon cycle via the atmosphere or b) create a Lake Nyos (Cameroon, 1986) scenario which released naturally trapped CO₂ and killed over 1700 people and thousands of head of livestock. Solidifying the CO₂ as part of the entombment has had its attractions since the Al Gore days:
I too have heard the siren song of carbon capture and storage.
There are two ways to use carbon once it is captured (still theoretical because of price but the cost is dropping, see below), either sequester it and remove it from the carbon cycle or reuse it in a closed loop hydrocarbon fuel infrastructure.
From 2007: "Can baking soda curb global warming?":
I have a fascination with calcium carbonate. But, being flexible, I am willing to consider the bicarbonate of various metals.
Some scientists have proposed compressing carbon dioxide and sticking it in underground caves as a way to cut down on greenhouse gases. Joe David Jones wants to make baking soda out of it.And a few months earlier:
Jones, the founder and CEO of Skyonic, has come up with an industrial process called SkyMine that captures 90 percent of the carbon dioxide coming out of smoke stacks and mixes it with sodium hydroxide to make sodium bicarbonate, or baking soda. The energy required for the reaction to turn the chemicals into baking soda comes from the waste heat from the factory."It is cleaner than food-grade (baking soda)," he said.The system also removes 97 percent of the heavy metals, as well as most of the sulfur and nitrogen compounds, Jones said.
... Right now I'm looking at calcium carbonate. Literally. Got a hunk of limestone. CaCO3. That's sequestered carbon, right?. Hmmm.
Make a green pitch, wrap it in recycled fiberboard; et voila! Return of the Pet Rock, eco-version! And seashells, same stuff, calcite. There's the hook! Mom, you're going to Miami Beach.
And many, many more. Use the 'search blog' box if interested.
The cost of the carbon capture stage is still exorbitant but who knows what advances are ahead?
From UnDark, February 19:
It’s a contentious idea, but advocates say storing CO2 under the seafloor could help address climate change—if it works.
In 2010, as the Deepwater Horizon rig sank and millions of gallons of oil gushed into the Gulf of Mexico, Kate Moran’s phone rang in Washington, D.C. At the time, she was assistant director in President Barack Obama’s Office of Science and Technology Policy, and government officials recognized that she brought years of ocean drilling experience. Within a matter of days, and guided by her understanding of deep ocean geochemistry, the government rapidly deployed resources and experts to manage the crisis, overseeing controlled burns, remote undersea vehicles, even air and sea traffic control systems. “It was remarkable,” Moran said recently of the mobilization. “Unbelievably remarkable.”
That memory looms large as Moran leads a project to mitigate the environmental impacts of fossil fuels on a much larger scale. Now president and CEO of the research institute Ocean Networks Canada, she is also the principal investigator for Solid Carbon, a project overseen by the institute that aims to permanently remove greenhouse gases from the atmosphere by entombing carbon under the seafloor.
“You can do big things in the ocean — the oil industry does,” Moran said, expressing dismay that governments have not marshaled resources like they did for Deepwater Horizon. “So why not look at a system where you could have essentially an independent system offshore that actually removes CO2 from the atmosphere and puts it away forever?”
In addition to transitioning away from fossil fuels, climate science experts are increasingly convinced that greenhouse gases will need to be removed from the atmosphere to avoid cascading impacts of climate change. A new global climate deal from the United Nations climate conference, COP28, doesn’t require countries to completely phase out fossil fuel use, but rather relies on investments in renewable energy and carbon removal techniques to mitigate the impacts of greenhouse gases. National climate plans, too, increasingly depend on carbon removal.
But it’s a gamble: Removing enough carbon dioxide on a large scale hasn’t been fully tested. And the slower the transition away from fossil fuels, the more carbon removal will be needed to reach goals and avoid catastrophes.
“My students always say, ‘But don’t we have to try?’ And the answer is absolutely,” said David Goldberg, a professor at Columbia University’s Climate School who designed the Solid Carbon plan with Moran.
Effective carbon removal is essentially a two-step process: first, remove the carbon dioxide from the air, and then somehow keep it from returning for at least several decades and ideally much longer. Forests and other plant life remove and store carbon dioxide naturally, but it risks returning through decomposition or fires. Solid Carbon would use machinery that filters out carbon dioxide both from sources of emissions, as well as directly from the air. The next step is finding a way to permanently store the trapped carbon dioxide.
Researchers at Solid Carbon are turning to basalt, a volcanic rock that easily reacts with acids like carbon dioxide, to turn the greenhouse gas into a carbonate rock under the seabed. Storing carbon in geologic formations like this is expected to be the most long-lasting method among options to keep carbon dioxide out of the atmosphere. Under the Cascadia Basin off the coast of Vancouver Island lies the most extensively studied ocean basalt. What’s more, it’s colossal: large enough in theory to store carbon from all global annual emissions many times over.
Solid Carbon offers a glimpse into the enormous scale that would be required to impact emissions. In one version of its plan, dozens of floating rigs on the Pacific Ocean would be coupled with many more wind turbines to funnel compressed, carbon dioxide nearly 2 miles under the sea. But that would only remove less than 1 percent of what climate scientists predict will be needed by 2050. If carbon removal techniques are to make any dent in emissions, they will need to scale up multiple magnitudes....
....MUCH MORE
I know Professor Moran is all over the earthquake risk but for readers who are unfamiliar with the area here's a little map of the Cascadia Subduction Zone from Kids Fun Science:
When The Megaquake Hits, The Living Will Envy The Dead
Okay, a bit of hyperbole in the headline but let's go with 10,000 dead, 30,000 injured and 2,000,000 people displaced and dependent on handouts.
We've had three posts on the Cascadia Subduction Zone, a couple links below.
There have been a few cat bonds issued over the years that cover Cascadia, they seem to be underpriced for the risk.*
