These startups hope to spray iron-rich particles above the ocean to fight climate change

Commercializing ‘climate repair’

Despite the concerns and unknowns about this approach, the studies have already inspired a handful of entrepreneurs.

Fiekowsky cofounded an earlier startup, Methane Oxidation Corp., that planned to use iron particles to restore methane concentrations to preindustrial levels, according to a spring 2021 application for funding from Stripe, the online payments company. It shuttered, but several of the listed team members moved on to Blue Dot Change. 

That startup has been self-funded to date, but it’s now working to raise money for research efforts and the development of the equipment that would release particles, Henkel-Wallace says. During the planned field trials, the team hopes to release a few grams of ferric chloride and then measure the methane inside and outside the particle plume using known optical techniques, he says. 

Henkel-Wallace hopes to develop the capacity to remove 100 million tons of methane per year by the end of 2027, which he says would require about 3,000 ships equipped with machines capable of emitting a few grams of particles per second.

He declined to talk in detail about the company’s business model, but he said it hopes to earn revenue from companies willing to pay for forms of “climate repair.” 

At least two other for-profit companies have also emerged in this space.

A Swiss company, AMR AG, is doing lab research now and hopes to raise $2 million to $3 million to move forward with field experiments. The plan is to slowly release several kilograms of ferric chloride nanoparticles from a decommissioned oil platform, monitor the effects on methane, and repeat the effort several times to confirm the results. If the method proves safe and effective, the company would move forward with large-scale releases by building towers up to 400 meters high, equipped with machines that could release tons of particles per hour.

Oswald Petersen, the founder and chief executive of AMR AG, says there’s no environmental risk to a field trial of the size they’re proposing. He notes that briefly running a truck engine would produce roughly the same amount of pollution, though of different kinds.

The other company is an Australian venture, Iron Salt Aerosol, that several years ago proposed carrying out field trials in the Bass Strait, a channel separating Victoria, Australia, from Tasmania. But it decided not to pursue the effort “because of concerns that it would be too difficult to attribute any observed changes in atmospheric chemistry to the [iron salt aerosol] activity, and that the overall political governance framework is not ready to support this form of geoengineering,” one of the founders, Robert Tulip, wrote in an email to MIT Technology Review.

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