Other scientists have suggested a plastic sheath to keep the icy hydrate in place. Goldthorpe didn’t think that would be necessary, especially at the depths that he’s discussing. He believed the hydrate would at least form a crust that would keep it in place.
Harvard University geology, environmental science, and engineering professor Daniel Schrag disagreed. The hydrate would sooner or later dissolve, he said. But if it took hundreds or thousands of years to do so, that might be long enough to curb climate change or give scientists time to come up with better solutions to the problem.
For Schrag, the biggest issue with Goldthorper’s idea was logistical. Trenches are far away from power sources. The cost of capturing carbon dioxide, liquefying it, shipping it, and then pumping it into a trench are exorbitant, especially given the low cost of oil and natural gas.
“You are telling me that China is going to load its CO2 into tankers, go to the Sunda trench, and pump it down?” he asked. “Good luck with that.”
American power plants, oil and natural gas fields and other emitters could inject carbon dioxide underground at a cost of around $20 per ton of the stuff, said Schrag. Capturing it at the smokestack might cost two to four times as much, depending on estimates, he said. Today, power utilities and others have few economic incentives to invest in the technology to do either.
“The problem is not that we have good places to put it,” he said. “The problem is we don’t have a political will to impose a price on carbon high enough to make carbon capture viable.”
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Lastly, even if the hydrate stayed in trenches and it was affordable to put it there, scientists don’t know if they might harm fragile ecosystems at the bottom of the sea, Sabine added.
“We have not explored those trenches enough to know if there are life forms there,” said Sabine. “It is not safe to assume that these trenches are dead. There could be unique life forms that we don’t see in other places that live in these trenches.”
Still, Sabine felt Goldthorpe’s proposed was a useful exercise given how many folks reject the need to sequester carbon dioxide at all.
“It’s worth having these discussed even though I don’t agree with these conclusions,” he said. “There are a lot of people who don’t want these discussions to even happen. The problem is, the discussions are going to happen anyway, and if you don’t have it in the scientific literature and respond to it, you end up with discussions based on hearsay.”