Could this ocean carbon factory help save the world? Some scientists raise red flags CNN

Editor’s note: The CNN film “Blue Carbon: Nature’s Hidden Power” takes viewers from the mangroves of Vietnam to the salt marshes of France to investigate a powerful new ally in the fight to slow climate change. The series premieres on Sunday, April 21 at 9pm ET/PT.

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On a stretch of beachfront in western Singapore, a startup is building a factory that will convert carbon dioxide in the air and seawater into the same material as seashells, a process that will also produce green hydrogen, a much-hyped clean fuel.

When completed later this year, a cluster of low-rise buildings starting to take shape in Tuas will become the world’s largest ocean carbon dioxide removal plant, according to Equatic, a UCLA spinout.

The idea is that the plant will pull Taking water from the ocean, hitting it with an electric current, and passing air through it creates a series of chemical reactions that capture the carbon dioxide and store it as minerals that can be put back into the ocean or used on land.

This is a compelling vision of a potential solution In the face of a worsening climate crisis that has triggered unprecedented heat and Destructive extreme weather.Efforts to control global warming remain far off track, and Many scientists now warn that besides While rapidly reducing fossil fuels, the world also needs to eliminate the carbon pollution humans have already pumped into the atmosphere.

The factory in Singapore is the latest example of a series of uses of the oceans, which already absorb nearly 30% of humanity’s planet-heating pollution, as a tool to achieve this goal. Other projects include spreading iron pellets into the ocean to stimulate carbon dioxide-absorbing phytoplankton, sinking seaweed deep to lock in carbon, and spraying pellets into ocean clouds to reflect some of the sun’s energy.

But the carbon removal plan is controversial, criticized for being costly, unproven on a scale and distracting from policies to cut fossil fuels. When they involve oceans, complex ecosystems already under intense pressure from global warming, criticism is likely to become even louder.

Overall, there is a huge knowledge gap in ocean geoengineering, said Jean-Pierre Gatusso, a marine scientist at France’s Sorbonne University. “I’m very concerned about the fact that science is lagging behind industry,” he told CNN.

Equatics technology, which has been tested in small pilot projects in Los Angeles and Singapore, requires three main ingredients: seawater, rock and electricity.

Here’s how it works: The plant pumps in seawater and passes an electric current through it to separate the water into its four components: two liquids, an acid and a base, and two gases, hydrogen and oxygen.

The acidic water will be mixed with gravel to return the pH to the same level as seawater and then returned to the ocean.

Fans pump air into an alkaline stream, causing carbon dioxide to form solid calcium carbonate (the material that seashells are made of, and which look like fine sand) as well as dissolved bicarbonate.

Equatic says these solid and dissolved minerals could lock up carbon for at least 10,000 years, before being returned to the ocean or used on land. Seawater will also be sent back to the sea, ready to absorb more carbon dioxide from the atmosphere.

Gaurav Sant, founder of Equatic and professor of sustainability at UCLA, said it’s important that none of the processing occurs in the open ocean because it allows you to perfectly measure everything you do. This includes the electricity used by the plant as well as the amount of carbon sequestered.

Edward Sanders, chief operating officer of Equatic, which is building the plant in partnership with Singapore’s National Water Authority, said the $20 million plant will be fully operational by the end of this year and will remove 3,650 tonnes of carbon dioxide per year. This amount is equivalent to taking approximately 870 ordinary passenger cars off the road.

The goal is to expand CO2 removal to 100,000 tons By the end of the year in 2026, and increasing to millions of tons over the next few decades, Sanders told CNN. He said the plant could be replicated almost anywhere, stacked in modules like Lego bricks.

Sant told CNN that as the factory grows, they need to make sure there are no negative impacts. Whether you do it on a ton, a million ton or a billion ton scale, it makes a big difference. You need to measure, you need to monitor, you need to adapt.

The upfront costs are high, but the company says it plans to make money by selling carbon credits to polluters to offset their pollution and by selling the hydrogen produced in the process.

Equatic has signed an agreement with Boeing to sell 2,100 tons of hydrogen, which it plans to use to make green fuel and fund the reduction of 62,000 tons of carbon dioxide emissions.

For some critics, however, the risks far outweigh the benefits.

Lili Fuhr, deputy director of the Climate and Energy Program at the Center for International Environmental Law, criticized the use of speculative techniques at a time when climate change is already killing our oceans.

Fall told CNN that handling large amounts of seawater could kill marine life. We already know that power plants kill fish larvae and other marine life. She told CNN that each plant handles much more seawater than a power plant, and thousands of such plants would be needed to have a meaningful impact on the global climate.

James Niffenegger, a researcher at the National Renewable Energy Laboratory who authored a report on ocean carbon removal, said the impacts need to be monitored closely. He told CNN that artificial water flow on this scale would be massive.

The process could also disrupt the delicate balance of ocean chemistry, Niffenegger said. While there has been much research into the negative effects of ocean acidification, there has been far less research into what might happen when the ocean becomes more alkaline.

There are indications that the impact may be low, but we won’t know the potential of the solution until we start actually deploying such products, he added.

Then there’s energy demand, which is growing exponentially as the world transitions away from fossil fuels. Moving seawater would require vast amounts of renewable energy, which could be better used to replace fossil fuels in the first place, Full said.

Gattuso agreed, saying justice must be considered when precious electricity is used to remove carbon rather than being provided to those in need.

Equatic said it will filter the seawater to ensure that marine life does not enter the system, and the water discharged back into the ocean will have the same composition as normal seawater and comply with Singapore’s environmental guidelines.

The company also says the production of hydrogen can be used to power the process, meaning its overall energy consumption is lower than other carbon removal methods.

The Equatics project is part of a wider debate in which some fear a rush into geoengineering could cause untold damage to ecosystems, while others believe the climate crisis is so severe that the technology must be an option .

It’s clear whose side Equatic is on.

UCLA Santer said doing nothing is not a climate strategy, adding that being able to make decisions under uncertainty is critical. If we are serious about slowing the trajectory of climate change, Sant said, we need to be willing to act, and act quickly and at scale.