The rise of Direct Air Capture

Hi everyone,

For years, one of the more futuristic climate solutions has been carbon removal. Where we don’t just reduce emissions, but pull carbon dioxide back out of the atmosphere. Now, thanks to a mix of scientific breakthroughs, startup funding, and growing urgency, that idea is moving from theory to reality.

At the centre of it is a clever bit of tech called Direct Air Capture (DAC). It’s a surprisingly simple concept: build machines that capture carbon directly from the air, concentrate it, and either store it safely underground or use it in new ways.

The big question is can it scale fast enough to help?

Why Do We Need Carbon Removal?

Even if we stopped burning fossil fuels today and didn’t emit any further carbon, we’d still need to deal with the carbon we’ve already dumped into the atmosphere over generations. The IPCC says limiting global warming to 1.5°C will require removing billions of tonnes of CO₂ this century.

And while nature does a great job through forests, wetlands and oceans, it’s not enough. Nor is it always permanent. That’s where engineered carbon removal comes in.

What Is Direct Air Capture?

DAC is a bit like industrial-scale air purification. Big fans pull in air, which is then passed through filters or chemical solutions that bind with the CO₂ molecules. The captured CO₂ is then concentrated and either stored or used to make end products!

It’s not new science, but making it affordable, scalable, and energy-efficient has taken years of engineering breakthroughs.

Who’s Doing It?

A few companies have emerged as early leaders in this space:

Climeworks
They’re the first to run a commercial DAC plant with permanent carbon storage. Their facility in Iceland, called Orca, captures about 4,000 tonnes of CO₂ a year. That’s a tiny amount, but a start and proves the technology works.

Their next plant, Mammoth, is ramping up now and aims to remove 36,000 tonnes per year. Climeworks also recently signed a $500 million carbon removal deal with Microsoft.

Heirloom
Heirloom is taking a different approach, using limestone to absorb CO₂ from the air, then regenerating it in a closed-loop process. Their tech is cheaper and more modular, promising faster deployment.

In 2023, they launched the first U.S. DAC plant connected to permanent storage and were part of the U.S. Department of Energy’s $1.2 billion DAC Hub initiative.

Carbon Engineering
Carbon Engineering focuses on large-scale DAC for the production of synthetic fuels. Their goal is to capture 1 million tonnes per year in future facilities.

The catch

On paper, DAC is one of the most exciting pieces of sustainable technology. But today, it’s expensive and energy-hungry.

Current estimates put the cost at between $600–$1000 per tonne of CO₂ removed. For it to be viable as a large-scale option, we need to get that number down to about $100–$150 per tonne.

That gap is closing, but it needs a lot more investment and innovation.

Another factor in scaling it is that DAC only makes sense if it’s powered by renewables. Otherwise, we’d be solving one problem and creating another.

That’s why Iceland (with its geothermal grid) and future hubs in Texas and Louisiana (solar and wind) are attractive locations for DAC at scale.

Where Does the Carbon Go?

There are two main options:

Storage
Some companies work with partners like Carbfix, who inject the CO₂ into basalt rock deep underground, where it mineralises and stays locked away for millennia.

Utilisation
Others turn it into:

• Synthetic aviation fuel

• Low-carbon concrete

• Recycled plastics

• Carbonated beverages (yes, really)

While reuse can be climate-positive, only permanent storage counts toward net-zero goals, because reuse typically re-releases the CO₂ later.

Not everyone is on board with DAC. Critics argue that it’s a distraction and that we should focus everything we can on cutting emissions now, not banking on unproven future fixes.

But even the sceptics often agree that at some point in the future, we’ll need some level of carbon removal. The key is to treat it as a complement, not a substitute, for reducing fossil fuel use.

The technology works. The challenge now is to scale it up, drive the costs down, and ensure we’re using clean energy to run it all.

DAC won’t solve climate change alone, but it might help clean up the mess we’ve already made.

Catch you next week,
James