Filtering greenhouse gases for a new source of fuel and a cooler planet

Geoengineers want to cool the earth by removing the greenhouse gas carbon dioxide from the atmosphere. It's a long shot, but if it works, it will mean a new source of fuel and a cooler planet

Johann Grolle
August 22, 2018

Geoengineers want to cool the earth by removing the greenhouse gas carbon dioxide from the atmosphere. It’s a long shot, but if it works, it will mean a new source of fuel and a cooler planet

Canadian clean-energy firm Carbon Engineering’s pilot air contactor, constructed from the same set of cooling tower components and design philosophy that will be used at commercial scale Photo: Carbon Engineering

Steve Oldham plans to save the world, and he’ll get $25m if he succeeds. The adventurer and billionaire Richard Branson has offered this sum as prize money to the one person who can show a practical way to filter the manmade greenhouse gases that heat up the earth from the atmosphere.

The demands are high: If you want to win Branson’s Virgin Earth Challenge, you have to find a method of capturing and “sinking” (absorbing and storing) a billion tonnes of carbon annually. This corresponds to almost 10% of annual carbon dioxide emissions worldwide.

To most experts, such a thing is pure idiocy. To Oldham, it’s a challenge he’s keen to tackle. As the CEO of Canadian clean-energy firm Carbon Engineering (CE), he’s proud that his company has been selected as one of the 11 Virgin Earth Challenge finalists.

“Our big advantage is that we not only have a PowerPoint presentation, but a real existing facility,” he said, pointing to a barn-like building in the middle of an industrial wasteland on Howe Sound, a fjord north of Vancouver, Canada. A fan hums in front of it, blowing 140,000 cubic meters of air per hour through a dense pack of honeycomb-like plastic foils. A liquid that absorbs carbon dioxide from the passing air trickles through this “contactor”.

The tower of the “pellet reactor”, into which this liquid releases its carbon load onto small calcium grains, protrudes from the barn roof. These then release the gas again via the heat from a kind of roasting oven. In this way, the CE system can “fish” around a tonne of carbon dioxide from the air every day.

Although CE’s engineers have proven that it is technically possible to filter the air, they’re not equipped to save the world just yet – there is a big difference between a tonne and a gigatonne.

But doubts don’t dampen Oldham’s enthusiasm. He hopes to build a second complex where technicians will convert the carbon dioxide obtained together with hydrogen into fuel. Oldham promises that commercial production will begin in three years.

Carbon Engineering’s project is one of a handful of small initiatives worldwide trying to create a new industry. Their task is to direct the planet’s climate, which has gone out of balance.

This industry was born on the green table of climate protectors. In its strategy papers, it has grown into a multibillion-dollar business, although in reality it does not yet exist.

A large part of the work of climate researchers consists of playing through complex scenarios on supercomputers. They determine how many greenhouse gases people have pumped into the atmosphere over various periods of time, and then calculate how the climate has reacted.

In order to draw practical conclusions from these business games, politicians demanded clear guidelines: How much can global warming be tolerated? At what point will the heat be unacceptable? A threshold value of two degrees Celsius was agreed. With the Paris climate agreement, most of humanity has committed to not exceeding this value.

Climate researchers were faced with a problem: In their climate models, the world temperature usually rises by three, four or even five degrees Celsius. Even with strict measures, it would be difficult to meet the two-degree target, so researchers installed a backdoor with negative emission technology (NET). The logic: if curbing emissions alone is not enough, then humanity must begin to capture the carbon dioxide that has escaped into the atmosphere.

Scientists have calculated around 900 scenarios for the latest report of the UN Intergovernmental Panel on Climate Change (IPCC). In 116 of these 900 scenarios, the two-degree target is achievable. But if you take a closer look, you will notice that in 101 of these 116 projections, at some point in the second half of the century, carbon dioxide suddenly disappears as if by magic – the NET industry has started its work. It is this very industry that Oldham wants to create.

Rendering of a facility that would use Carbon Engineering’s proprietary Air to Fuels process to manufacture roughly 250 barrels per day of clean-burning synthetic fuel Photo: Carbon Engineering

The task is enormous. Because air consists of 78% nitrogen and 21% oxygen, only 0.04% is carbon dioxide. Producing such a trace gas in large quantities is an enormous challenge.

The easiest way is reforestation. Forests absorb carbon dioxide and bind it in the form of biomass. The problem is that every hectare of land can be planted only once. The total amount of carbon that can be neutralized in this way is therefore limited.

Another possibility is to raise fast-growing plants and then burn them. The resulting carbon dioxide could be pumped into the underground and thus removed from the atmosphere. The advantage is that energy that can still be used as a byproduct of carbon disposal is produced during combustion – but there’s a huge space requirement. To achieve a noticeable climate effect, a large portion of the world’s farmland would have to be planted with energy grasses.

Other researchers want to follow nature’s example. Nature removes carbon dioxide from the atmosphere during the weathering of rock – over millions of years. Climate engineers hope to drastically accelerate this process by spreading the finely milled rocky wastes from platinum, nickel or diamond mines. But that would come at a huge cost and considerable degradation of landscapes.

Oldham’s approach of fishing carbon dioxide directly from the air is the most radical. He and his team at CE want to prove that this is possible at a reasonable price. They were able to raise $30 million for their project – with the biggest contributions from American software billionaire Bill Gates and the Canadian oil magnate Murray Edwards.

The company was founded nine years ago by David Keith, professor of applied physics at Harvard University. The climate protection community knows him as an enfant terrible: the gangly Canadian loves to provoke. He intrepidly promotes exploring all possibilities of so-called geoengineering.

Technically, it is possible to counteract global warming with comparatively little effort, said Keith. A few grams of sulphur sprayed in the stratosphere could cool the planet by as much as it heats up with a ton of carbon dioxide. Given the planet’s current massive emission of greenhouse gases, Keith considers it irresponsible to not investigate such options.

But even Keith admits: If mankind would consider such an artificial cooling of the earth, it would be little more than planetary patchwork. The human-induced climate catastrophe can be repaired in the long term only if its cause is tackled – in other words, the greenhouse gases.


Oldham is targeting road traffic, one of the major climate pests. The efforts of the climate protectors were aimed at electrifying the vehicles as quickly as possible. “But why switch to a different drive when you can also make the proven climate-compatible?” Oldham wondered.

Fuel synthesized from atmospheric carbon dioxide is carbon neutral. This means that its combustion releases only as much greenhouse gas as its production consumes. Such fuel has a massive competitive advantage, especially in the important California market, thanks to the legislation there. Oldham thinks he can make a profit.

His plan is to sell licences for his process to oil companies. Two possible locations for the first petrol factories, he said, have already been selected – one in British Columbia and the other in the US. If it were possible to start gasoline synthesis within three years, as envisioned, this plant could produce “up to 2,000 barrels a day” as early as 2021, Oldham claimed.

© 2018 Spiegel Online distributed by The New York Times Syndicate
This article was published in the August 2018 edition of Southeast Asia Globe magazine. For full access, subscribe here.

Read more articles