Sign In or Create an Account.

By continuing, you agree to the Terms of Service and acknowledge our Privacy Policy

Podcast

The Next Big Climate Tool: Little Chunks of Rock

Inside episode four of Shift Key.

Rocks.
Heatmap Illustration/Getty Images

When we talk about carbon removal, we often focus on “direct air capture” facilities — big factories that suck carbon dioxide out of the ambient air.

But a simpler and easier way to remove carbon from the atmosphere may exist. It’s called “enhanced rock weathering” — grinding up rocks, spreading them out, and exposing them to the ambient air — and it works, essentially, by speeding up the Earth’s carbon cycle. Enhanced rock weathering recently got a major vote of confidence from Frontier, a consortium of tech and finance companies who have teamed up to support new and experimental carbon removal technologies.

Frontier’s members include Stripe, Meta, Alphabet, Shopify, and McKinsey & Company. It aims to buy nearly $1 billion of various forms of carbon removal in the next few years — an intervention meant to spur commercial and investor interest in the sector.

In this episode, Jesse Jenkins, an energy systems expert and professor at Princeton University, and I talk with Jane Flegal, a former Biden White House climate adviser and now the market development and policy lead at Frontier, about the promise of enhanced rock weathering and why Frontier just spent $57 million to do it.

Subscribe to “Shift Key” and find this episode on Apple Podcasts, Spotify, Amazon, or wherever you get your podcasts.

You can also add the show’s RSS feed to your podcast app to follow us directly.

Here is an excerpt from our conversation:

Jane Flegal: So enhanced weathering is a carbon removal process that speeds up a natural process which is weathering of alkaline materials. And so weathering happens naturally, it actually drives what makes the earth habitable in the first place. It just happens over very, very long periods. So essentially what happens is that rocks slowly erode when they come into contact with acid rain essentially and —

Robinson Meyer: Naturally acidic rain?

Flegal: Yeah, not like acid rain the way we think of it, rain that is acidic because it has some dissolved CO2. And so that acidic rainwater interacts with rocks and erodes them, and it results in CO2 being stored either as a solid carbonate or as a bicarbonate. So that happens naturally, again, on very long time periods.

Meyer: And I just want to interrupt before we go any further. What then happens, right, is that the CO2 winds up being dissolved as a bicarbonate. It goes into the ocean.

Flegal: Into the ocean.

Meyer: And then what happens? It’s turned into ...

Flegal: It sinks and becomes part of the Earth’s crust.

Meyer: Right. Or it gets turned into a shell, a creature’s shell, and then it sinks again.

Flegal: It is functionally stable. It is thermodynamically pretty much impossible to reverse.

Meyer: And you kind of said this, but I do want to draw it out: This is the carbon cycle. This is a central Earth science process. There’s nothing fancy about this.

Jesse Jenkins: The problem is it takes centuries to play out. It’s just moving on geologic time. But this idea of enhanced weathering means we can potentially speed that up, right?

Meyer: Sorry, I just want to — this is, like, the whole problem of climate change, right? The problem of climate change is that we take fossil fuels and carbon that’s stored in geological storage out of the ground on historic time scales, on decadal ... you know, every year we take millions of tons of it out of the ground, and then it would only be restored back to the ground by this extremely slow process.

Flegal: One way to think about carbon removal is, like, taking stuff out of the fast cycle and putting it into the slow cycle, basically. And essentially, you either inject CO2 underground, where it’s where it’s stable, or you turn it into salt. These are kind of the options.

And so enhanced weathering, to exactly this point, it’s enhanced for a reason, right? There’s regular old weathering, and then there’s the enhanced kind, which aims to speed up this process that typically takes millennia to years or days by either using more reactive materials than the normal rocks that would just weather naturally or increasing the surface area of the material that is exposed to CO2. So grinding up rocks into very, very fine fine powder and exposing that material to more favorable environments.

This episode of Shift Key is sponsored by Advanced Energy United, KORE Power, and Yale …

Advanced Energy United educates, engages, and advocates for policies that allow our member companies to compete to power our economy with 100% clean energy, working with decision makers and energy market regulators to achieve this goal. Together, we are united in our mission to accelerate the transition to 100% clean energy in America. Learn more at advancedenergyunited.org/heatmap

KORE Power provides the commercial, industrial, and utility markets with functional solutions that advance the clean energy transition worldwide. KORE Power's technology and manufacturing capabilities provide direct access to next generation battery cells, energy storage systems that scale to grid+, EV power & infrastructure, and intuitive asset management to unlock energy strategies across a myriad of applications. Explore more at korepower.com — the future of clean energy is here.

Build your skills in policy, finance, and clean technology at Yale. Yale’s Financing and Deploying Clean Energy certificate program is a 10-month online certificate program that trains and connects clean energy professionals to catalyze an equitable transition to a clean economy. Connect with Yale’s expertise, grow your professional network, and deepen your impact. Learn more at cbey.yale.edu/certificate.

Music for Shift Key is by Adam Kromelow.

Yellow

You’re out of free articles.

Subscribe today to experience Heatmap’s expert analysis 
of climate change, clean energy, and sustainability.
To continue reading
Create a free account or sign in to unlock more free articles.
or
Please enter an email address
By continuing, you agree to the Terms of Service and acknowledge our Privacy Policy
Politics

Can Offshore Wind Survive the Tax Credit Purge?

Empire Wind has been spared — but it may be one of the last of its kind in the U.S.

Sharks circling a wind turbine.
Heatmap Illustration/Getty Images

It’s been a week of whiplash for offshore wind.

On Monday, President Trump lifted his stop work order on Empire Wind, an 810-megawatt wind farm under construction south of Long Island that will deliver renewable power into New York’s grid. But by Thursday morning, Republicans in the House of Representatives had passed a budget bill that would scrap the subsidies that make projects like this possible.

Keep reading...Show less
Politics

Carbon Capture May Not Have Been Spared After All

The House budget bill may have kept the 45Q tax credit, but nixing transferability makes it decidedly less useful.

The Capitol.
Heatmap Illustration/Getty Images, Climeworks

Very few of the Inflation Reduction Act’s tax credits made it through the House’s recently passed budget bill unscathed. One of the apparently lucky ones, however, was the 45Q credit for carbon capture projects. This provides up to $180 per metric ton for direct air capture and $85 for carbon captured from industrial or power facilities, depending on how the CO2 is subsequently sequestered or put to use in products such as low-carbon aviation fuels or building materials. The latest version of the bill doesn’t change that at all.

But while the preservation of 45Q is undoubtedly good news for the increasing number of projects in this space, carbon capture didn’t escape fully intact. One of the main ways the IRA supercharged tax credits was by making them transferable, turning them into an important financing tool for small or early-stage projects that might not make enough money to owe much — or even anything — in taxes. Being able to sell tax credits on the open market has often been the only way for smaller developers to take advantage of the credits. Now, the House bill will eliminate transferability for all projects that begin construction two years after the bill becomes law.

Keep reading...Show less
Green
Politics

The GOP Tax Bill Is a Dangerous Gamble at a Precarious Moment

House Republicans have bet that nothing bad will happen to America’s economic position or energy supply. The evidence suggests that’s a big risk.

The Capitol.
Heatmap Illustration/Getty Images

When President Barack Obama signed the Budget Control Act in August of 2011, he did not do so happily. The bill averted the debt ceiling crisis that had threatened to derail his presidency, but it did so at a high cost: It forced Congress either to agree to big near-term deficit cuts, or to accept strict spending limits over the years to come.

It was, as Bloomberg commentator Conor Sen put it this week, the wrong bill for the wrong moment. It suppressed federal spending as America climbed out of the Great Recession, making the early 2010s economic recovery longer than it would have been otherwise. When Trump came into office, he ended the automatic spending limits — and helped to usher in the best labor market that America has seen since the 1990s.

Keep reading...Show less
Yellow