As the world races to head off worst-case climate change scenarios, there has been increasing focus on developing and advancing technologies to suck planet-warming carbon dioxide from the atmosphere.
Among the logistical hurdles with the technology, called carbon capture and storage, or CCS, is where to store the massive amounts of carbon gas underground once it’s been sequestered. One proven solution: the bottom of the ocean.
Congress recently helped to push that possibility forward. The $1.2 trillion infrastructure package that Congress passed and President Joe Biden signed into law late last year is expected to jumpstart U.S. carbon capture and storage. Along with earmarking more than $12 billion to advance CCS technologies, the law tasked federal regulators with creating a framework for companies to lease offshore areas and pump CO₂ into the ocean floor, thereby preventing it from reaching the atmosphere and further heating the planet.
There are many underground geological formations where carbon can be buried. The ocean floor is an appealing place for a number of reasons, including its availability and its distance from population centers and drinking water supplies. And the Gulf of Mexico is attractive given its vast network of existing oil and gas infrastructure, which could be utilized to pipe CO₂ offshore and forever store it in depleted oil and gas reserves and in deep saline aquifers.
The offshore provisions were quietly tucked into the bill during Senate negotiations and “caught many by surprise,” said Romany Webb, a senior fellow at the Sabin Center for Climate Change Law at Columbia Law School.
“It reflects both the urgency many people see around advancing CCS and also the fact that CCS is really, I think, one of the more bipartisan climate solutions,” she said. “It’s definitely an area to watch and something that I think there’s going to be a lot of focus on going forward.”
The law amended the 1953 Outer Continental Shelf Lands Act (OCSLA) to give the Bureau of Ocean Energy Management (BOEM) the authority to issue leases that “provide for, support, or are directly related to the injection of a carbon dioxide stream into sub-seabed geologic formations for the purpose of long-term carbon storage.” It also lifted a regulatory barrier by clarifying that carbon dioxide destined for deep sea storage does not qualify as an industrial material that would otherwise require a permit under the 1972 Marine Protection, Research and Sanctuaries Act, also known as the Ocean Dumping Act.
OCSLA has for decades governed fossil fuel and other development in U.S. waters. In 2005, it was amended to allow for offshore renewable energy activities, and BOEM previously concluded that it gives the agency the authority to permit CO₂ storage for enhanced oil recovery on existing oil and gas leases. Enhanced oil recovery a method of injecting CO₂ in order to extract hard-to-access oil and gas reserves.
Though the infrastructure law tasked BOEM and the Bureau of Safety and Environmental Enforcement with crafting new rules for carbon sequestration within one year, it did not allocate additional funding or resources for that effort. The agencies have said they are “well situated to oversee offshore CCS given their significant geological, environmental, and offshore energy regulatory experience,” but recently signaled there could be delays in finalizing regulations.
Thierry De Cort, chief of the geological and geophysical section of BOEM’s Office of Resource Evaluation, told Energy Intelligence last month that it would be “monumental” if the regulations were in place by November — a year after the infrastructure bill became law.
“If there’s regulations by November, there’s going to be nothing but problems,” he told the outlet at the Offshore Technology Conference in Houston. “The government never does that in a year.”
De Cort said there are a number of questions that still must be answered, including how far carbon dioxide could migrate once injected into the seabed and who will be responsible for long-term monitoring.
The proposed rule, once finalized, will be subject to public review and comment. As part of its ongoing work, BOEM analyzed depleted oil and gas reserves in the Gulf and identified 21 initial candidate sites for future CCS in shallow, nearshore waters.
Erik Cordes, an oceanographer and professor at Temple University who has done extensive work in the Gulf of Mexico, told HuffPost that offshore CCS has a lot of promise and is “an excellent way to repurpose” decommissioned oil and gas wells and other infrastructure.
It won’t be without risks. If CO₂ leaks from a seafloor storage site, it could acidify surrounding seawater, harming nearby coral by dissolving exposed skeleton, Cordes said. There’s also a risk of destabilizing deposits of methane hydrate, a solid, ice-like form of the potent greenhouse gas that is widespread in deep marine sediments.
But the bottom line, Cordes stressed, is “we need to do something, and fast” to combat climate change.
“This is a good, relatively low-cost option,” he said via email. “I’m not sure how much of a dent we can put into the total carbon budget, but every little bit helps. We have to try everything at our disposal — alternative energy, conservation, reforestation, CCS, etc.”
The push to scale up CCS in the U.S. comes on the heels of a series of sobering United Nations climate reports. Last year, the world’s premier climate research body made it clear that sucking CO₂ out of the atmosphere would prove key to averting catastrophic climate change. And in February, it warned that the window for reining in greenhouse gases in order to “secure a livable and sustainable future” is rapidly closing.
Two days after Biden signed the infrastructure bill, oil giant ExxonMobil gobbled up nearly 100 offshore leasing blocks in the Gulf of Mexico. The shallow water areas have largely been tapped of oil and gas reserves, leading many to speculate that Exxon was eyeing the site for carbon capture and storage rather than drilling.
The oil giant remained tight-lipped about its intentions, telling HuffPost that it would work with federal officials on its plans for the areas.
“ExxonMobil takes a long-term business view,” spokesperson Todd Spitler said in an email. “We are evaluating/analyzing the seismic/subsurface geology for future commercial potential.”
If Exxon’s plan was to use the site primarily for carbon capture, it likely would have sought additional approval, as the lease sale was specifically for oil and gas development. In the end, it didn’t matter: Those leases and others were later vacated when a federal judge ruled that the Biden administration failed to properly account for climate effects when it held its massive offshore auction in the Gulf late last year.
Exxon is leading an effort to build a $100 billion carbon capture hub in Houston. Thirteen companies, including oil giants Shell and Chevron, have partnered with Exxon on the planned project.
There are 27 commercial CCS facilities in operation globally, including 14 in the United States, and 106 more are in various stages of development, according to a report last year from the Australia think tank Global CCS Institute. None of the operating U.S. facilities is offshore.