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

Marketing “climate repair”

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

Fiekowsky co-founded an earlier startup, Methane Oxidation Corp., which planned to use iron particles to restore methane concentrations to pre-industrial levels, according to a spring 2021 funding request from Stripe, the online payment company. It closed, but several of the team members listed switched to Blue Dot Change.

This startup has been self-funded so far, but is now scrambling to raise funds for research efforts and the development of equipment that would release particles, Henkel-Wallace said. During planned field tests, 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 tonnes of methane per year by the end of 2027, which it says would require around 3,000 ships equipped with machines capable of emitting a few grams of particles per second.

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

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

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

Oswald Petersen, founder and managing director of AMR AG, says there is no environmental risk for a field trial of the size they are offering. He notes that running a truck engine briefly would produce roughly the same amount of pollution, although of a different nature.

The other company is an Australian company, Iron Salt Aerosol, which several years ago proposed to carry out field trials in the Bass Strait, a channel separating Victoria, Australia, from Tasmania. But he decided not to pursue the effort “for fear that it would be too difficult to attribute the 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.