In a quarry surrounded by the rumble of heavy machinery, Jim Mann bends down and picks up a handful of small black stones.

“This is my magic dust,” he says with a smile, rubbing them gently between his fingers.

He is holding pieces of basalt. It is a hard volcanic rock that is not rare or particularly remarkable.

But through a process known as “enhanced rock weathering,” it could help cool our overheated planet.

UN scientists are now convinced that reducing greenhouse gas emissions alone will not be enough to halt dangerous levels of warming.

They say some carbon dioxide needs to be removed by actively removing it from the atmosphere.

Planting trees is the most natural way to do that, but it has its limitations; the CO₂ captured is released when the wood rots or burns, and there are limits to how many can be planted.

Another option is Direct Air Capture (DAC), where CO₂ is mechanically extracted from the atmosphere and stored underground.

It’s permanent, but does it make sense to build such an energy-intensive process as we try to move away from fossil fuels?

Improved rock weathering lies somewhere between the natural and the artificial.

It takes the natural but very gradual aging process and charges it up to remove carbon faster.

At first glance, the Orrock quarry in Scotland does not appear to be the source of a green solution.

I came to a quarry from Edinburgh, Scotland to see Jim, whose enhanced rock weathering company UNDO has just received $15.5 million in new investment and plans to expand its business.

All around us, the black hillside is constantly being eaten away, scraped away by huge bulldozers to make concrete and asphalt for the roads.

The scenery looks more like the scene of a post-nuclear apocalypse than a place where they’re trying to save the planet.

But the little bits of basalt rock that remain are prized by Jim’s party.

They have a useful property: when worn in the rain, they remove carbon dioxide from the atmosphere.

Basalt stone from the quarry has a very useful property.

For thousands of years, volcanic rocks and cliffs have removed carbon slowly as they erode in the rain.

Enhanced rock weathering uses small pieces to increase the surface area of ​​the rock that comes in contact with rain and therefore the amount of weathering and carbon removal.

Piled up in a quarry or in the form of a cliff, basalt wears away very slowly.

To maximize carbon removal, it must be spread over a wider area.

And that’s where local farmers come in, who help the planet and get free fertilizer in return.

In addition to capturing carbon, this has been demonstrated in tests basalt improves both crop yields as the quality of the grazing.

Half an hour’s drive from the quarry I see how it spreads over a field.

It does not require specialized equipment.

A trailer is loaded with 20 tons of basalt before being pulled up and down by a tractor, while a spinning wheel at the back scatters the small stones.

“It is free, which is very important for a farmerJohn Logan tells me with a smile as he lays out the basalt in his field. He had seen UNDO tests at a neighboring company.

“It seems that the grass will improve, so that can only be good for the cattle, because they eat better grass.”

According to UNDO, a trailer of 20 tons of basalt absorbs about 5 tons of CO₂

Some experts worry that such carbon removal techniques could distract people from the more pressing priority of reducing emissions and even be used as a justification for continuing to live our carbon-intensive lives.

“CO₂ reduction must come first,” says Jim as we watch the tractor zip around, guided by GPS, “but we also need to develop these technologies that can remove on a large scale.

“And the nice thing about what we’re doing with enhanced rock weathering is that it’s permanent.”

The numbers, it must be said, are overwhelming.

UNDO scientists calculate that it takes four tons of basalt to capture one ton of CO₂.

UNDO has plans to expand rapidly in the coming years and has attracted some serious fans.

Microsoft has agreed to pay 25,000 tons of basalt to spread across UK fields.

As part of the agreement, Microsoft will also help monitor the project and verify that it is working as intended.

Jim Mann calls stones that can help cool our planet his “magic dust.”

“The essential chemistry makes sense,” Steve Smith, an expert in carbon removal at the University of Oxford, told me.

“Measuring how much CO₂ would be removed and where it would eventually go is one of the main challenges, and there is currently no standardized system.”

In the end, Smith believes the idea could eventually become a standard part of how the land is worked.

“It’s something that can be integrated into the way we use the land now and that will provide a carbon removal benefit among other benefits,” he says.

There are still many questions about its distribution.

UNDO projects use by-products from local quarries, but if this expands massively, the energy and emissions required to break up the basalt and then transport and disperse it must be considered.

“At this point there is no downside, it’s a win-win situation for everyone involved.Jim Mann tells me.

UNDO plans to distribute 185,000 tons of basalt this year and hopes to remove one million tons of CO₂ by 2025.

It is still a drop in the ocean compared to emissions.

By 2022, it is believed to be downloaded around the world 37,000 million tons of CO₂ in the atmosphere.