To cap warming at 1.5°C, we need to capture and store carbon before it escapes into our atmosphere. And we need to remove what we can that’s already up there. Probably hundreds of billions of tons of it. Not as a hedge, but as a pillar of strategy. So says the Intergovernmental Panel on Climate Change, which concluded that "all analysed pathways limiting warming to 1.5°C" require carbon removal.

Because we can’t get to 1.5°C fast enough if we're only focused on electrifying buildings, transport, and industry. Those things must happen. But we're decades away from zero-carbon supply chains for steel and cement. Some buildings are too big and unwieldy (read: expensive) to electrify any time soon. And electrifying vehicles is going to take time because it’s hard– see the last Gist.

 

To be clear, I’m not talking about retrofitting coal and gas plants, or what we've known as Carbon Capture and Storage. Those projects may have a role, but they're also not the answer. For example, Royal Dutch Shell’s Carbon Capture facility in Alberta has since 2015 been a net emitter of carbon by 2.5 million tons.

Rather, I'm excited about the new wave of Carbon Dioxide Removal (CDR) technologies, plural. Startups are coalescing in these areas:

 

• Direct Air Capture (DAC):  Climeworks uses giant fans to pull carbon out of the air before turning it to stone. See Rhodium Group study here. A Geophysics Professor at Columbia suggests pairing wind turbines with air capture systems to bury surplus wind power in underwater basalt rock.
• Biomass: Charm Industrial last year surpassed 5,000 tons of carbon (more than 10x what DAC technology has captured to date) with its pyrolysis process, which converts biomass such as corn stalks into a liquid which, when injected into EPA-regulated wells, solidifies for permanent storage. Elegant in its simplicity, it could also be gasified and used to decarbonize steel production, aka the high stakes table of the CDR game.
• CO2 stored in commercial concrete: CarbonCure and CarbonBuilt inject CO2 into fresh concrete, reducing the inherent carbon intensity of one of the toughest commodities to decarbonize.
• Enhanced Carbon Mineralization: Heirloom uses minerals to produce oxides that naturally bind to CO2, and then exposes the rocks to the air to soak up carbon. If this all sounds a bit Dune to you, please know I fully support its Best Picture nomination.
• Ocean CDR: Ebb Carbon has developed a modular technology that assists the ocean's natural process of absorbing CO2 and forming bicarbonate, thereby reducing ocean acidification. Project Vesta adds the mineral olivine to ocean sand, thus rendering it sensitive to carbon absorption.

 

Other ideas have promise but haven't been tested or deployed at any scale. Carbon Plan keeps an awesome database of known CDR project proposals for those who want to nerd out.

 

Stripe, Microsoft and Shopify are currently leading the way with voluntary commitments to purchase carbon removal offsets, driving enough early demand to stimulate some venture capital. But these technologies won’t scale without new federal, state and ultimately global policy intervention with, at the minimum:

 

1. Tech neutral federal policy: Washington's most important carbon capture stimulant, an esoteric tax incentive named 45Q, was created by/for the fossil industry and effectively excludes technologies that aren’t directly connected to existing fossil infrastructure. 45Q must be revised to be technology neutral, to unleash a market for startups with superior technologies as they emerge, based on proven results. As Stripe's Hannah Bebbington put it the other day: "Stubborn on criteria, flexible on pathway."
2. State fuel standard pathways and procurement: We need a decade of state-based Low Carbon Fuel Standards (LCFS)’s that include new pathways for a range of CDR technologies. California, Washington and Oregon are moving in the right direction. State procurement policies could also help; last month a bill was introduced in New York directing the state to procure CDR in order to hit its emissions targets.
3. Advanced market commitments: A decade ago governments made advanced market commitments (AMCs) to buy pneumonia vaccines in large quantities. Carbon removal tech, like vaccines, is a tragedy of the commons problem well suited to this type of intervention. Companies with net zero pledges could start to bend the cost curve with an advance commitment on carbon removal. Governments should follow last week's 'first mover' commitment from the Biden Administration.

Finally, and I say this as a former climate negotiator and Treasury official, we need something more reliable than the wild west of ~120 unregulated voluntary offset markets that exist around the world. We need a workable method for crediting equal units of non-permanent carbon storage that will ensure the quality of the credit. Because a forest vulnerable to fire is not the same as a green concrete Taco Bell, which is not the same as theoretical thousand year bicarbonate ocean storage.

As Ryan Orbuch of Lower Carbon Capital puts it: