How much carbon dioxide removal do we actually need?

Sucking carbon from the sky is a key climate solution. But how much we lean on it depends on our political choices.

Ships pass in front of smokestacks belching smoke and steam into a cloudy sky. The light is hazy.
Laying a strong foundation that brings more people into the CDR fold will open up options for how it’s deployed, including how much we need.
Chris LeBoutillier / Unsplash

Silicon Valley’s favorite climate solution is still decades away from being deployed at scale, if it will ever be ready. Yet the moment carbon dioxide removal is having right now is really something to behold.

Over the past few weeks, the Intergovernmental Panel on Climate Change offered up an extensive chapter on sucking carbon from the sky, and Big Tech and venture capital committed more than $1.2 billion to it in two separate announcements last week. “There's never been a better time to start a carbon removal company!” Ryan Orbuch, Lowercarbon Capital’s carbon removal lead, tweeted while announcing the VC firm’s $350 million fund.

Indeed, there’s a lot of money out there and a lot of interest in a climate solution we know we’ll need in some form. But as we enter the era of exploring carbon removal in earnest, it’s worth asking just how much we need — and what “need” even means.

It’s a matter of scale

There’s no shortage of ways to pull carbon from thin air. Planting trees is perhaps the most basic way to do it, though even that comes with complications. There are exotic solutions, too, like growing kelp, adding crushed up rocks to soil, growing crops and building fanciful machines. Some companies turn that captured carbon into oil or rocks that can be stored underground while others reuse it for things like vodka. (Believe it.)

Yet all these efforts currently sequester a few thousand tons of carbon dioxide a year. All the money pouring into carbon dioxide removal — known as CDR in the climate world — would help scale up these nascent efforts or spark new ones. But right now, in a world where more than 36 billion tons of carbon dioxide were emitted last year, it’s the equivalent of using an eyedropper to bail out the Titanic.

We need a full-blown pump system in addition to a crew working 24/7 to repair the breach in the atmosphere’s hull if we’re going to keep from drowning. How fast that crew gets to work on the hull will be one of the deciding factors in how much CDR we need.

The IPCC report identifies the tools we need to do the repair work, including the usual climate solution suspects: renewable energy, battery storage, electric vehicles, reduction in energy demand and a slew of other tools we have available to us right now. The IPCC shows we need financing for stuff to increase anywhere from three to six times over current levels to get on the right track. Policies that support more rapid renewable deployment and provide people with options to live lower-carbon lifestyles — or in the case of the rich, forcing them to reduce their profligate carbon footprints — are also vital to ensuring this decade doesn’t put us further behind the eight ball. And the report makes it clear we need to rapidly phase out the use of fossil fuels.

All this will still only get us part of the way to staving off the worst impacts of climate change. The IPCC also shows that by midcentury, we’ll need to rapidly scale up CDR. Using modeling, the report calls for removing about 5.8 billion tons of carbon dioxide from the atmosphere by 2050 through a variety of techniques. That assumes we limit warming to 2 degrees Celsius, the main Paris Agreement target.

It’s also political

Choosing that as a target is a political choice, though. Another report from the IPCC published in 2018 showed the difference between 2 degrees and 1.5 degrees Celsius of warming is life and death for hundreds of millions of people as well as ecosystems throughout the world.

The IPCC isn’t the only game in town, however. Other groups have included carbon removal in their modeling. Another assessment from the United Nations pegged CDR needs at 10 billion tons a year by midcentury. Shell — yes, that Shell — puts it around the same total.

The underlying assumption in models calling for CDR is that we keep burning fossil fuels for longer. To revisit our boat analogy, the assumption is we take our sweet time repairing the breach, forcing us to rely on a more elaborate pump system we don’t have the instructions to even build in the first place.

Toly Rinberg, an applied physics doctorate student at Harvard, said that these high numbers are “weaponized by polluting interests” to constrain how we think of the future — and the present.

“People calling for 10 or 20 gigatons of removal per year, why are they doing that?” he asked. “It reduces political pressure to decarbonize.”

Rinberg, along with fellow applied physics doctorate student Andrew Bergman, took a different “bottom-up approach” in “Carbon Dioxide Removal Primer,” a book and website, published last year. Rather than modeling a bunch of scenarios where the oil keeps flowing, the analysis looked at what are known as “hard-to-abate” emissions. That is, sectors of the economy like air travel and cement manufacturing that are going to be tough decarbonization nuts to crack. That yields a far lower — and by Bergman and Rinberg’s own estimation, “conservative” — range of 1.5 to 3.1 gigatons of carbon we’ll need to remove from the sky each year.

What these ranges show is that the idea of what we “need” when it comes to CDR isn’t set in stone. Bergman told Protocol any attempt to say we “need” a certain amount of carbon being pulled from the sky “merges a political choice that's complicated with a technical limit that makes one sound like the other and that undermines our ability as a society to actually talk about the choices.”

The same is true in letting Silicon Valley dictate the terms of the nascent industry. “Right now, the trajectory of scalability of this industry is not on track to be in the public interest,” Rinberg said.

Bergman added that a way to get it on track would be startups having community members where CDR projects are sited on their actual board and not advisory boards or companies like Stripe and Microsoft that are buying carbon removal services voicing support for unionization efforts at startups or mandating certain labor practices.

Ultimately, laying a strong foundation that brings more people into the CDR fold will open up options for how it’s deployed, including how much we need. The same is true for the climate solutions we have available now. And the track record isn’t super great so far. But there’s never been a better time to turn a page.

Gavin Newsom shows crypto some California love

“A more flexible approach is needed,” Gov. Newsom said in rejecting a bill that would require crypto companies to get a state license.

Strong bipartisan support wasn’t enough to convince Newsom that requiring crypto companies to register with the state’s Department of Financial Protection and Innovation is the smart path for California.

Photo: Jerod Harris/Getty Images for Vox Media

The Digital Financial Assets Law seemed like a legislative slam dunk in California for critics of the crypto industry.

But strong bipartisan support — it passed 71-0 in the state assembly and 31-6 in the Senate — wasn’t enough to convince Gov. Gavin Newsom that requiring crypto companies to register with the state’s Department of Financial Protection and Innovation is the smart path for California.

Keep Reading Show less
Benjamin Pimentel

Benjamin Pimentel ( @benpimentel) covers crypto and fintech from San Francisco. He has reported on many of the biggest tech stories over the past 20 years for the San Francisco Chronicle, Dow Jones MarketWatch and Business Insider, from the dot-com crash, the rise of cloud computing, social networking and AI to the impact of the Great Recession and the COVID crisis on Silicon Valley and beyond. He can be reached at or via Google Voice at (925) 307-9342.

Sponsored Content

Great products are built on strong patents

Experts say robust intellectual property protection is essential to ensure the long-term R&D required to innovate and maintain America's technology leadership.

Every great tech product that you rely on each day, from the smartphone in your pocket to your music streaming service and navigational system in the car, shares one important thing: part of its innovative design is protected by intellectual property (IP) laws.

From 5G to artificial intelligence, IP protection offers a powerful incentive for researchers to create ground-breaking products, and governmental leaders say its protection is an essential part of maintaining US technology leadership. To quote Secretary of Commerce Gina Raimondo: "intellectual property protection is vital for American innovation and entrepreneurship.”

Keep Reading Show less
James Daly
James Daly has a deep knowledge of creating brand voice identity, including understanding various audiences and targeting messaging accordingly. He enjoys commissioning, editing, writing, and business development, particularly in launching new ventures and building passionate audiences. Daly has led teams large and small to multiple awards and quantifiable success through a strategy built on teamwork, passion, fact-checking, intelligence, analytics, and audience growth while meeting budget goals and production deadlines in fast-paced environments. Daly is the Editorial Director of 2030 Media and a contributor at Wired.

Slack’s rallying cry at Dreamforce: No more meetings

It’s not all cartoon bears and therapy pigs — work conferences are a good place to talk about the future of work.

“We want people to be able to work in whatever way works for them with flexible schedules, in meetings and out of meetings,” Slack chief product officer Tamar Yehoshua told Protocol at Dreamforce 2022.

Photo: Marlena Sloss/Bloomberg via Getty Images

Dreamforce is primarily Salesforce’s show. But Slack wasn’t to be left out, especially as the primary connector between Salesforce and the mainstream working world.

The average knowledge worker spends more time using a communication tool like Slack than a CRM like Salesforce, positioning it as the best Salesforce product to concern itself with the future of work. In between meeting a therapy pig and meditating by the Dreamforce waterfall, Protocol sat down with several Slack execs and conference-goers to chat about the shifting future.

Keep Reading Show less
Lizzy Lawrence

Lizzy Lawrence ( @LizzyLaw_) is a reporter at Protocol, covering tools and productivity in the workplace. She's a recent graduate of the University of Michigan, where she studied sociology and international studies. She served as editor in chief of The Michigan Daily, her school's independent newspaper. She's based in D.C., and can be reached at

LA is a growing tech hub. But not everyone may fit.

LA has a housing crisis similar to Silicon Valley’s. And single-family-zoning laws are mostly to blame.

As the number of tech companies in the region grows, so does the number of tech workers, whose high salaries put them at an advantage in both LA's renting and buying markets.

Photo: Nat Rubio-Licht/Protocol

LA’s tech scene is on the rise. The number of unicorn companies in Los Angeles is growing, and the city has become the third-largest startup ecosystem nationally behind the Bay Area and New York with more than 4,000 VC-backed startups in industries ranging from aerospace to creators. As the number of tech companies in the region grows, so does the number of tech workers. The city is quickly becoming more and more like Silicon Valley — a new startup and a dozen tech workers on every corner and companies like Google, Netflix, and Twitter setting up offices there.

But with growth comes growing pains. Los Angeles, especially the burgeoning Silicon Beach area — which includes Santa Monica, Venice, and Marina del Rey — shares something in common with its namesake Silicon Valley: a severe lack of housing.

Keep Reading Show less
Nat Rubio-Licht

Nat Rubio-Licht is a Los Angeles-based news writer at Protocol. They graduated from Syracuse University with a degree in newspaper and online journalism in May 2020. Prior to joining the team, they worked at the Los Angeles Business Journal as a technology and aerospace reporter.


SFPD can now surveil a private camera network funded by Ripple chair

The San Francisco Board of Supervisors approved a policy that the ACLU and EFF argue will further criminalize marginalized groups.

SFPD will be able to temporarily tap into private surveillance networks in certain circumstances.

Photo: Justin Sullivan/Getty Images

Ripple chairman and co-founder Chris Larsen has been funding a network of security cameras throughout San Francisco for a decade. Now, the city has given its police department the green light to monitor the feeds from those cameras — and any other private surveillance devices in the city — in real time, whether or not a crime has been committed.

This week, San Francisco’s Board of Supervisors approved a controversial plan to allow SFPD to temporarily tap into private surveillance networks during life-threatening emergencies, large events, and in the course of criminal investigations, including investigations of misdemeanors. The decision came despite fervent opposition from groups, including the ACLU of Northern California and the Electronic Frontier Foundation, which say the police department’s new authority will be misused against protesters and marginalized groups in a city that has been a bastion for both.

Keep Reading Show less
Issie Lapowsky

Issie Lapowsky ( @issielapowsky) is Protocol's chief correspondent, covering the intersection of technology, politics, and national affairs. She also oversees Protocol's fellowship program. Previously, she was a senior writer at Wired, where she covered the 2016 election and the Facebook beat in its aftermath. Prior to that, Issie worked as a staff writer for Inc. magazine, writing about small business and entrepreneurship. She has also worked as an on-air contributor for CBS News and taught a graduate-level course at New York University's Center for Publishing on how tech giants have affected publishing.

Latest Stories