• Keep Cool
  • Posts
  • This carbon removal pathway *rocks*

This carbon removal pathway *rocks*

$50M+ for enhanced rock weathering


Hey there,

Busy week! Time to tie a bow on it with some discussion of one of my favorite topics, carbon removal pathways not-named direct air capture. As always, in addition to that, read on for a round up of all the other notable deals and headlines that crossed my desk this week.

In today’s email:

  • This carbon removal pathway *rocks*

  • Climate tech fundraising announcements 

  • Climate tech and energy headlines

For some time, I've been curious about how to scale climate technologies in developing markets. Serendipitously, the team at Renewables.org is building a non-profit to help. On their site, you can invest in renewable energy projects across the world to accelerate the global energy transition and to advocate for equitable outcomes. Plus, you get paid back!

As part of Renewables.org's launch this holiday season, you can also gift renewable energy investments to friends, family (lovers?), and colleagues. Create impact in your gift card recipient's name, and they'll earn repayments as they generate low-carbon power across India and Africa. I got my first panel. Ready to get yours? Click below to explore Renewables.org


Sprinkle a bunch of crushed-up rocks on a field, and what do you get? A $50M+ deal, apparently. 

Cheeky intro aside, I’m not being dismissive. One of the biggest deals this week was in carbon removal. Specifically, Frontier, the advanced market commitment for carbon removals, entered into an agreement with Lithos Carbon, an enhanced rock weathering company. The specifics of the deal include Frontier paying $57.1M for Lithos to remove 154,240 tons of CO₂ between 2024 and 2028 (that’s revenue, not venture funding). Here’s why it matters.

Rock and roll* (*up your sleeves for a quick 0-1 on ERW)

Until now, most carbon removal funding, whether from Frontier, venture capitalists, or the U.S. government, has flowed into direct air capture. This week’s news is noteworthy because, well, enhanced rock weathering isn’t direct air capture! It’s a carbon removal pathway that is grounded in accelerating a natural carbon removal pathway rather than engineering a new one from scratch. 

Enhanced rock weathering (ERW) aims to accelerate a natural process that already removes carbon dioxide (CO2) from the atmosphere absent human intervention. The natural process in question is rock weathering. Independent of human tinkering, rock weathering already ‘moves’ a billion tonnes of carbon out of the atmosphere and into geological formations annually. That’s a scale that companies working on engineered carbon removal can only dream of today. 

A beach in Iceland with a lot of basalt (the columns) where, indubitably, a lot of rock weathering already happens (Shutterstock)

Scaling carbon removal is an order-of-magnitude challenge. Leveraging natural systems may make it easier. The basic idea behind ERW is to speed up the breakdown of certain types of rocks – like basalt – that absorb CO2 when elements like wind and rain 'weather' them out in nature. Here's more on the how's and why's:

  1. Choosing the rock: Basalt is often used for enhanced rock weathering at this stage, given its mineral composition. It contains olivine and pyroxenes that react with CO2 in the atmosphere to form stable carbonate minerals.

  2. Crushing the rock: The rock is crushed into small particles to increase its surface area, allowing for more reactions between the rock and CO2.

  3. Applying the rock: Crushed rock is spread over large land areas, such as agricultural fields or degraded lands. It can be applied to the surface, incorporated into the soil, or used as an additive in construction materials like concrete.

  4. Reaction with CO2: When crushed rock is exposed to the atmosphere, it reacts with carbon dioxide through a series of chemical reactions. The primary reaction catalyzes the conversion of CO2 into carbonate minerals and stable carbonate compounds as follows = CO2 + CaSiO3 (in the rock) → CaCO3 (calcium carbonate) + SiO2 (silica)

  5. Storage: Newly formed carbonate minerals are 'stable;' they can persist for long periods, storing carbon in a solid state for centuries or longer.

Why it matters

ERW is exciting owing to its potential scalability and its co-benefits, i.e., benefits it offers beyond its carbon removal potential. When I say scalability, I'm not inherently talking about cost, at least not yet. Scaling direct air capture, as a counterexample, requires the construction of new machines, a lot of low-carbon power, and other infrastructure, like CO2 pipelines and wells to inject CO2 underground. ERW doesn't require any of that. Considering how much agricultural land is already managed globally, if you could convince farmers to spread crushed up rocks on their fields as part of existing field management, you'd have an opportunity to scale more quickly. The rocks used, like basalt, are abundant, though crushing them can prove energy-intensive.

Of course, convincing any land managers to adopt practice change requires that it benefit them in straightforward, measurable, dollar-directed ways. That's where the co-benefits of ERW come in. Beyond carbon removal, ERW may offer:

  1. Crop and soil health: Rock weathering can release essential nutrients, such as calcium, magnesium, and potassium, into soil. These nutrients can enhance soil fertility, promoting healthier plant growth. This could benefit farmers and perhaps reduce the need for synthetic fertilizers, ideally reversing well-documented losses in crop nutrients.

  2. Acidification mitigation: The chemical reaction that drives absorption of CO2 by rocks can also help neutralize acidic soils.

  3. Water quality: Minerals released during rock weathering can also improve water quality by binding pollutants in water, helping decrease soil erosion and nutrient and pollutant runoff from fertilizers. 

  4. Biodiversity: Healthier soils equal more robust ecosystems and more diverse plant and microbial communities.

  5. Local economic benefits: If all of the above are borne out, then ERW could yield positive economic feedback loops for farming communities. 

If ERW can offer some or all of these other benefits, then it should be feasible to build coalitions of support with stakeholders who don't necessarily prioritize carbon removal or climate goals. That's important. Many farmers care about climate change. But they also run commodity market businesses; their priorities are focused on feeding people and keeping their businesses afloat. Getting them to support carbon removal without ever talking about carbon or splitting carbon credit revenue would be ideal. To the extent ERW doesn't have to hinge on CO2, that makes it more scalable.

And scale matters, through and through, because without it, carbon removal as a category makes little to no difference. The nascent carbon removal industry has removed < 1M tons of CO2 so far. Various IPCC scenarios include carbon removal capacity reaching the 10-20B tonne scale beyond 2040. Whether or not that 1,000-10,000xing of capacity proves possible, getting up the carbon removal capacity curve will require a) many carbon removal pathways and b) working with nature for some or many of them.

Here’s where I first encountered this chart from the IPCC over the weekend.

Still between a rock and a hard place?

You'll note I've barely talked about Lithos, the company with which Frontier entered into an offtake agreement this week. That's somewhat intentional; I think this story is much more about ERW than any individual actor. That said, the role Lithos now gets to play is one of leadership. It’s incumbent on them to deliver on the agreement they inked with Frontier in a sound way. This brings us into the heart of the challenge with ERW, namely measurement and modeling of what benefits and to what extent it delivers them.

ERW isn't as discreet or confined a system as a direct air capture machine, where you have a defined space in which all the carbon removal happens. Instead, what ERW proposes is inherently highly distributed; it’s hard to imagine ever tracking, on a square foot by square foot basis, how much carbon is being removed and what other benefits rock weathering confers to soils. Even when you take the time and develop the tools to study what happens on a square-foot-by-square-foot basis, soil spectroscopy is incredibly complex. 

Still, what you can do is take samples and model the rest. There’s nothing wrong with that, but it can make things ‘feel’ a bit more murky. And feelings matter in a market largely underpinned by the goodwill of corporate buyers.

As noted by Giana Amador, the executive director of Carbon Removal Alliance, in response to the discussed agreement and announcement:

Enhanced weathering is an underrated carbon removal pathway, though that's starting to change — especially with news like this. Enhanced weathering builds upon long-standing agricultural practices like liming and can improve soil pH in the process. Deployment on this scale matters. It can give us intel on how weathering performs across geographies, soil types, and climates. It also provides data to fuel more precise MRV in the future.

I resonate especially with the second half of her quote. Lithos is now in an enviable position as far as clarity of future revenue is concerned. At the same time, they have a responsibility to the entire ERW field to deliver carbon removal in a credible, well-substantiated way, which will be no small feat.

The net-net (tl;dr)

Frontier is sort of becoming a de facto, binary 'stamp' (or Stripe?) of approval for carbon removal. They don't say they are. But, like the U.S. government with its DAC Hubs program, everyone else in this space is watching them. I’m glad that they aren’t just funding DAC. There are so many other carbon removal pathways that, like ERW, may well rock! At the same time, neither Frontier nor the U.S. government can or should carry the carbon removal space on their own. Just because these actors aren’t funding, say, good ol’ reforestation, doesn’t mean those options don’t matter.

The other note I’ll end on is that even as this entire section was ostensibly about ‘carbon’ removal, the allure of ERW should attune us to the benefit of broadening our aperture beyond ‘carbon.’ ERW has many potential positive impacts, ranging from improved soil health to reductions in nitrogen oxide emissions by reducing the need for synthetic fertilizers. CO2 is less than half of the climate change story. Solutions that speak to that are the ones you’ll see me increasingly focus on.


Large funding rounds

🤖 Gecko Robotics, based out of Pittsburgh, raised $100M in extended Series C funding to develop robots and software for inspecting large industrial assets like boilers and power plants. US Innovative Technology and Founders Fund led. More here. (U.S., Industry)

⚛️ X-energy, based out of Rockville, MD, raised an additional $80 million in Series C funding from its founder and Ares Management for its small modular nuclear reactor and fuel design business. X-energy has now raised a total of $235M in Series C funding. It had previously considered going public via a SPAC but has since canceled those plans. More here. (U.S., Energy)

Medium-sized funding rounds

🥛 Ripple Foods, based out of Berkeley, CA, raised $49M to make pea-based milk. More here. (U.S., Food & Agriculture)

⛏️ Nth Cycle, based out of Burlington, MA, raised $37M in Series B funding and $7M in non-dilutive funding for its metals refining and recycling business. VoLo Earth Ventures led. Caterpillar also invested. More here. (U.S., Industry)

🔋 AM Batteries, based out of Chelmsford, MA, raised $30M in Series B funding round to manufacture dry electrode equipment for lithium-ion batteries on its pilot production line in Massachusetts. Toyota Ventures led. More here. (U.S., Industry)

🌾 AgroSpheres, based out of Charlottesville, VA, raised $25M in Series B funding for its sustainable crop protection solutions. FMC Ventures, Lewis and Clark AgriFood, Ospraie Ag Science, Bidra Ventures, and Cavallo Ventures invested. More here. (U.S., Food & Agriculture)

💦 Ionomr Innovations, based out of Vancouver, Canada, raised $20M in Series A-4 funding to develop and manufacture polymer and ion-exchange membrane technologies for hydrogen applications. NGIF Cleantech Ventures and Pallasite Ventures led. More here. (U.S., Industry)

🔩 Cambium, based out of El Segundo, CA, raised $19M in Series A funding for its advanced material innovation business. While primarily targeted at defense applications, Cambium also produces advanced materials for other high-performance fields like renewable energy and transportation. 8VC led. More here. (U.S., Materials)

📊 Actility, based out of Paris, raised $17.3M in equity funding for its low-power industrial IoT connectivity technologies. More here. (France, Industry) 

💦 Blue World Technologies, based out of Aalborg, Denmark, raised ~$12M for its fuel cell development business for the maritime industry. Maersk Growth, the Export and Investment Fund of Denmark, and Cycle Group invested. More here. (Denmark, Transportation)

Smaller funding rounds

🌳 Pachama, based out of San Francisco, raised $9M in extended Series B funding to use satellites to substantiate carbon credit claims from nature-based solutions and to build software for carbon credit buyers to manage their portfolios. T Capital, Lowercarbon Capital, and Positive Ventures led. More here. (U.S., Carbon Markets)

🌱 PlantSwitch, based out of Sanford, NC, raised $7.7M in equity funding to make plant-based plastics. NexPoint Capital led. More here. (U.S., Materials)

🌾 Carbon Robotics, based out of Seattle, raised $7M in extended Series C funding (adding to an earlier $35M raise) for its robotic systems that identify, weed, and thin vegetable crops using lasers. More here. (U.S., Food & Agriculture)

🌞 Sunsave, based out of London, raised ~$7M in seed funding for its rooftop-solar-as-a-subscription service. Norrsken VC led. More here. (U.K., Energy)

🚲 Velca, based out of Madrid, Spain, raised ~$5.8M in Series A funding to make electric motorcycles and e-bikes. Sherry Ventures led. More here. (Spain, Transportation)

🪵 Cambium Carbon, based out of Baltimore, MD, raised $5.3M in seed-plus funding to connect manufacturers and other businesses with sources of timber that would otherwise end up in landfills. MaC Venture Capital led. More here. (U.S., Industry) 

🥩 Farmless, based out of Amsterdam, Netherlands, raised ~$5.3M in seed funding to manufacture alternative proteins via precision fermentation. World Fund and Vorwerk Ventures co-led. More here. (Netherlands, Food & Agriculture)

🧱 Strong by Form, based out of Madrid, raised ~$5.3M in seed funding to make biocomposite and wood-based materials for construction. CMPC Ventures led. More here. (Spain, Materials)

♻️ Up Catalyst, based out of Tallinn, Estonia, raised ~$4.4M in seed funding to turn waste or captured CO2 into carbon nanomaterials. Extantia led. More here. (Estonia, Materials)

🥩 Meatiply, based out of Singapore, raised $3.8M in a first close of seed funding for its specialized muscle cell regeneration technology designed to create cultivated meat products. AgFunder and Wavemaker Partners led. More here. (Singapore, Food & Agriculture)

🍇 Carbon Maps, based out of Paris, raised ~$3.3M in pre-seed funding for its food supply chain analytics platform. Back Market and Daphni invested. More here. (France, Food & Agriculture) 

🌱 Lignovations, based out of Klosterneuburg, Austria, raised ~$2.4M to “develop and manufacture innovative materials from lignin.” Borregaard invested. More here. (Austria, Materials)

🦊 BioFluff, based out of New York and Paris, raised ~$2.4M in seed funding to make plant-based alternatives to luxury furs and textiles. Astanor Ventures led. More here. (U.S., Materials) 

🔋 Innovasion Labs PINC, based out of Turkey, raised $2M in funding for its lithium-ion batteries in which the anode and cathode are intertwined rather than side by side, which purportedly reduces charge time by reducing ion flow distance. Angel investors, including an executive at GS Yuasa, led the round. More here. (Turkey, Energy)

💦 Digital Paani, based out of Gurugram, India, raised $1.2M million in seed funding for its IoT wastewater treatment platform. Enzia Ventures led. More here. (India, Industry)

💦 Ki Hydrogen, based out of London, raised $1.1M in pre-seed funding to electrolyze waste biomass to produce green hydrogen. More here. (U.K., Industry)

🔋 LIND, based out of Kinross, Scotland, raised ~$1.1M in seed funding for its large-scale battery technologies designed to operate at elevated temperatures. Green Angel Ventures, Scottish Enterprise, and the University of Strathclyde invested. More here. (Scotland, Energy) 

Other funding rounds

In private equity funding and corporate rounds: 

EnergyRe, based out of Houston and New York, raised $1.2B from Glentra Capital, Novo Holdings, and Danish pension fund PKA for its renewables, energy storage, and transmission development business. More here. (U.S., Energy)

In acquisitions:

💵 CalSTRS, the Californian State Teachers Retirement System based out of Sacramento, acquired a minority stake in Just Climate, a London-based climate investment firm. CalSTRS previously invested in Just Climate's $1.5B industrial decarbonization fund. More here. (U.S., Funds)

In grant funding:

🔋 Nanoramic, based out of Wakefield, MA, received a $47.5M grant from the DOE to build a lithium-ion battery electrode manufacturing plant in Bridgeport, CT. More here. (U.S., Industry) 

⚛️ General Fusion, based out of Richmond, Canada, received ~$3.7M in grant funding from Canada's Strategic Innovation Fund to develop its ‘Magnetized Target Fusion’ demonstration project. More here. (Canada, Energy)

New funds

💵 Congruent Ventures, based out of San Francisco, raised $275M for its third flagship fund. Congruent is one of the top venture firms in climate tech investing. More here. (U.S., Funds)

💵 Revaia, based out of Paris, raised ~$160m in a first close of the firm's second fund, which will target sustainability startups raising growth stage rounds (Series B funding and after). More here. (France, Funds)

💰 Circulate Capital, based out of Singapore, raised $76M for a new fund to invest in companies tackling plastic pollution and other climate challenges across Asia. More here. (Singapore, Funds)

💰 Kvanted, based out of Helsinki, Finland, raised ~$76M for a new fund targeting 'industrial technology' companies. More here. (Finland, Industry) 

💰 Vanagon Ventures, based out of Munich, raised ~$32M for the firm's first fund, with which it will focus on early-stage B2B sustainability companies. More here. (Germany, Funds)


🔌 Milestones: Annual U.S. EV sales surpassed 1M for the first time this year.

🔋 Grid-scale batteries down under: The Victorian government (a state in Australia) will invest $245M to take a stake in a 600 MW, 1.6 GWh battery energy storage project being developed west of Melbourne as part of the Melbourne Renewable Energy Hub. Tesla is providing batteries, while Samsung will supply other electrical systems. Completion is slated for late 2025; today, this would be one of the world's largest such facilities.

⚛️ Next-gen nukes: The world's first first high-temperature gas-cooled reactor began commercial operations this week. China Huaneng Group Co.'s 200 MW unit got approval after first operating for 168 consecutive hours.

In addition to bringing the decommissioned Palisades nuclear power plant in Michigan back online, new owner Holtec announced plans to seek federal approval to build two additional 300 MW small modular reactors alongside the existing 800 MW plant. The target date for the first new unit to come online is mid-2030; Holtec aims to reenergize the existing unit by 2025.

💵 Fusion funding: The DOE announced it will create three laser-driven nuclear fusion research hubs. The Lawrence Livermore National Laboratory, Colorado State University, and the University of Rochester received a total of $42M, which they'll split over four years

📢 COP 28: Exxon Mobil, Saudi Arabia's Aramco, and 50 other major private and public global oil companies pledged to reduce methane emissions from their operations to "near zero" by 2030 and to reduce flaring of natural gas. Some companies also pledged financial support to a new 'Global Flaring and Methane Reduction Partnership', which has raised ~$255M so far and which the World Bank will help run, to support developing countries and their oil companies' efforts to reduce methane leaks and fugitive methane emissions. 

📜 State-level policy: Massachusetts' Department of Public Utilities issued a new order this week designed to wean the state off of fossil fuels for home heating. Specifically, utilities can't charge customers for new gas infrastructure if there are viable non-gas alternatives. 

California is also considering new legislation to require homeowners to replace broken air conditioning units with heat pumps as early as 2026 (paywall). Elsewhere, Illinois' governor signed legislation ending a three-decade moratorium on the development of nuclear reactors in the state. Smaller nuclear reactors (< 300 MW) will also be newly allowed in 2026. 

🚫 so good news: The Potsdam Institute for Climate Impact Research released a comprehensive and sobering report on climate tipping points (i.e., reinforcing feedback loops that more warming could trigger).

🌞 Closing on good news: While offshore wind has had a rough year, Ørsted's South Fork Wind project (planned to offer 132 MW of capacity to Long Island) began producing power this week, making it the first utility-scale offshore wind project in U.S. federal waters to log this milestone.

Avangrid also announced that it installed the first five turbines (65 MW of a planned 806 MW total) at Vineyard Wind 1 in Massachusetts.


– Nick

Join the conversation

or to participate.