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Milkywire’s Carbon Removal Portfolio

This report was last updated in November 2022.

Giving Green believes that donating to our top recommended nonprofits is likely to be the most impactful giving strategy for supporting climate action. However, we recognize that contributing to policy advocacy (as most of these nonprofits do) may not be tenable for all donors, especially businesses. Taking this into consideration, we recommend Milkywire specifically for businesses given its focus on carbon removal and more direct alignment with corporate net-zero ambitions. We believe Milkywire to be a high-impact option, but we are unsure of the extent to which its cost-effectiveness approaches that of our top nonprofits.


Overview of Milkywire

Theory of Change




Room for more funding

Key uncertainties/open questions


How to contribute to Milkywire’s carbon removal portfolio


  • Giving Green recommends Milkywire’s carbon removal portfolio as one of the top donation opportunities for businesses. 

  • Climate models indicate that emissions reductions alone may not be adequate to mitigate climate change; studies by the IPCC demonstrate a need for carbon removal to grow to the gigaton (billions of tons) scale by 2050 in order to limit warming to 2°C.

  • The carbon removal sector is in its early stages, both in terms of technological readiness as well as supply; available carbon removal supply is too expensive to create broad demand. 

  • Milkywire’s carbon removal portfolio provides a widely accessible, catalytic investment opportunity to enable future net-zero pledges by supporting the growth and development of carbon removal.

Overview of Milkywire

Milkywire is a platform [1] that hosts and manages the Climate Transformation Fund, a fund for businesses that consists of a portfolio of climate projects within three areas: restoring and protecting nature, carbon removal, and decarbonization.

Given that Giving Green has developed a distinct set of recommendations for top climate nonprofits, we restrict our recommendation of Milkywire to the carbon removal portion of the Climate Transformation Fund.

The fund is described as an “impact first approach…an alternative to traditional carbon offsetting solutions.[2] Klarna, a Swedish fintech company, has contributed $2.7 million to projects selected for the fund as part of its climate strategy. Other contributors include SilverLake, Pangaia, Wastebox and BioGaia. 

Projects in the carbon removal portion of the portfolio are assessed based on additionality, social and environmental sustainability, durability, scaling potential, and consideration for catalytic effect and co-benefits. [3] An independent advisory group consisting of experts in decarbonization solutions, equity issues, nature- and technology-based carbon removal solutions, and carbon markets provides feedback on the selection of projects; [4] Giving Green is part of this group. While the Milkywire team holds the decision-making power, it largely follows the guidance of the advisory group. [5]

Milkywire chooses carbon removal projects with medium- to long-term durability (100-1000+ years). As a result, it includes pathways such as biochar in addition to more permanent technological carbon removal like DAC and mineralization. Carbon removal included in the fund’s first cycle (2021) consisted of two biochar projects – Mash Makes and HUSK, two direct air capture (DAC) projects – Climeworks and Heirloom, and the Carbon Removal ClimAccelerator, an initiative to help European carbon removal start ups. During the next cycle (2022), Silicate – a company using returned concrete to capture CO2, and Inter.Earth – a company that removes and stores carbon through biomass burial, will be added to the portfolio.

Climeworks [6] and the Carbon Removal ClimAccelerator will no longer be included as these projects have a higher relative level of funding and consequently the impact of additional contributions is lower.

Milkywire divides its support for carbon removal projects into two categories, which it describes as  ‘research tons’ or ‘scale tons,’. Research tons support carbon removal projects that are in the earlier stages of the innovation cycle, while scale tons support projects that have been tested and are ready to grow supply.

Milkywire releases an annual report to provide updates on the progress of projects within the portfolio as well as how funds have been spent.

Our Take on Milkywire’s Theory of Change

Climate models indicate that in order to limit warming to 2°C, emissions reductions alone may not suffice; reaching net-zero in the necessary timeframe will likely require gigaton-scale deployment of carbon removal by midcentury. [7] Carbon removal may be especially useful in balancing emissions from hard-to-abate sectors like aviation, shipping, and industry. [8] In addition, it is our impression that removing more carbon than we emit via net-negative goals may be a important strategy to curb future climate damage. This is a view shared by some members of the private sector, [9] government, [10] and scientific community, [11] and would only be made possible through the development and deployment of carbon removal.

Carbon removal as a sector is quite varied both in terms of the types of pathways as well as the technological readiness of each pathway. In addition, not much carbon removal is available, [12] and that which is available is too expensive to create broad demand. In fact, we have only reached about 0.0062% of a projected 10 gigaton by 2050 deployment goal, and only around 4% of the carbon removal purchases ever made have been delivered. [13] Much of the carbon removal sector remains in the R&D phase, and projects that have higher technological maturity are still navigating economic viability and the logistics for deployment at scale. In short, the current market is young, small, [14] and relatively uncertain. 

As a reflection of this, Milkywire supports carbon removal through “research tons” or “scale tons,” depending on the technological readiness of a particular pathway or project. Through this approach, Milkywire aims to catalyze the development of carbon removal projects and pathways and enable carbon removal to become cheaper so that it can be scaled effectively as a climate mitigation tool. Milkywire is not prescriptive regarding the number of research vs scale tons for any given year; in this way it can remain agile and reflect the most current needs of the quickly evolving carbon removal market.

Below, we discuss and evaluate each of the assumptions related to Milkywire’s theory of change. For each of the assumptions identified, we rank whether we have high, medium, or low certainty. [15] Importantly, a number of the stages of Milkywire’s theory of change are not amenable to easy measurement or quantification, or are expected to occur in the future but have not occurred as of yet. For each assumption, we assess whether the best available evidence, primary or secondary, suggests whether the assumption will plausibly hold or not.

We have high certainty that Milkywire will help advance carbon removal research, development, and demonstration (RD&D) as it intentionally directs funds towards projects in earlier stages of innovation.

We have medium certainty that Milkywire will catalyze more mature technologies to scale. While the fund will purchase scale tons to incentivize increased supply, these purchases are decided upon annually; we believe that longer-term demand certainty at this stage may be important for the timely scale-up of carbon removal deployment.

We have low certainty regarding the extent to which Milkywire will influence the price trajectory of carbon removal. We believe the magnitude of Milkywire’s impact will depend on its ability to secure substantially more investment, how strategically the research tons are distributed to improve existing technologies, and the quantity of scale tons that are funded.


Project-level additionality is satisfied if a project would not have happened without the sales of offsets. This requirement tends to be satisfied by projects run by non-profits who solely rely on offset revenue in order to operate. However, it can be very difficult to determine for projects with multiple revenue streams such as those undertaken by carbon removal companies. We have high confidence in Milkywire’s assessment of additionality in its process of selecting carbon removal projects. 

In terms of the larger carbon removal sector, we believe Milkywire’s carbon removal portfolio to be additional in that we find it to be a uniquely accessible, catalytic investment opportunity for businesses. As far as we are aware, it is the only opportunity for businesses to contribute to both research and scale tons without requirements on the minimum size of the contribution or length of the contract. This is distinct from other aggregators of private sector investment for carbon removal such as Frontier (also recommended by Giving Green), First Movers Coalition, and South Pole. Additionally, in contrast to Frontier, Milkywire’s medium to long term durability criteria enables the inclusion of a broader array of carbon removal pathways such as biochar into its portfolio.


Projects selected by Milkywire must demonstrate that they do not cause social or environmental harm. In addition, “projects are given a higher priority if they create benefits for people in poverty, or if they help ecosystems in other ways beyond storing more carbon.” [16] In order to ensure that this criteria is faithfully evaluated during the selection process, the advisory board includes experts in equity issues. 


We tried to develop a quantitative model for cost-effectiveness, but decided that it would not be useful given our high uncertainty regarding assumptions and estimates for parameters that we deem central to Milkywire’s theory of change. In particular, given that we are providing this recommendation in the specific context of a business looking to make an investment toward carbon removal, we believe that Milkywire is highly likely to be relatively cost-effective as we think that supporting its model of funding research and scale tons across pathways will have higher impact than purchasing tons from just one carbon removal project. We find the emphasis of catalytic investment over quantity of tons purchased to be a notable value-add considering the early stage of the carbon removal market at present. For reference on how we have attempted to account for catalytic potential, see our cost-effectiveness analysis model in the context of DAC.

Room for more funding

Investment in carbon removal remains orders of magnitude away from the trillions of dollars [17] needed to achieve and sustain gigaton-scale deployment by midcentury. [18] We have confidence that Milkywire is positioned to absorb more funding effectively by increasing support of selected carbon removal projects and/or expanding the list of selected projects. 

Key uncertainties/open questions

  1. We are uncertain to what extent, if any, the absence of longer-term purchase agreements will affect Milkywire’s impact on growing the carbon removal market.

  2. We are uncertain that the investment from Milkywire’s carbon removal portfolio will result in sufficient reduction in cost and scaling of deployment to substantially contribute to climate change mitigation.

  3. Although we are aware that co-benefits are taken into account during the selection process, we are unsure to the extent to which they are weighted in the final decision making.


Setting net-zero and, eventually, net-negative goals are important, but we do not believe that they are achievable at present [19] given the current state of technology, infrastructure, systems, and policies in place today. Therefore, we think that supporting the change and advancement to make these goals possible is among the most effective ways to contribute directly to robust climate action and, when possible, should be favored over ton-ton accounting; investment in emerging yet valuable technologies like carbon removal is one such way to contribute. We believe that Milkywire’s carbon removal portfolio provides a widely accessible catalytic investment opportunity to enable future net-zero pledges by supporting the growth and development of carbon removal.

How to contribute to Milkywire’s carbon removal portfolio

Given that Milkywire’s theory of change centers around spurring innovation in the carbon removal field and lowering prices for the future, it encourages businesses to contribute to its carbon removal portfolio outside of any net-zero framework. [20] Businesses will be able to contribute directly through a forthcoming direct link where credit card payments are accepted; for bank transfers email partnerships [at] milkywire [dot] com.

We thank Robert Höglund, Climate Transformation Fund Manager at Milkywire, for a series of conversations that informed this document.


[1] Donations to Milkywire are distributed to projects through the WRLD Foundation, a registered nonprofit

[2] An impact-first approach opens possibilities to support pioneering solutions.”

[3] See Requirements and Criteria

[4] In the selection, we have worked with an advisory group to help us choose the most impactful and sustainable climate projects for the portfolio.”

[5] In the selection, we have worked with an advisory group to help us choose the most impactful and sustainable climate projects for the portfolio. Final decisions on chosen projects are made by Milkywire but the ambition is to follow the advisory group’s guidance as far as possible.”

[6] Giving Green recommends Climeworks as a carbon removal supplier; see here for our recommendation.

[7] “All available studies require at least some kind of carbon dioxide removal to reach net zero;  that is, there are no studies where absolute zero GHG or even CO2 emissions are reached by deep emissions reductions alone.” IPCC Sixth Assessment Report, Chapter 3

[8] These difficult-to-decarbonize energy services include aviation…production of carbon-intensive structural materials such as steel and cement…To the extent that carbon remains involved in these services in the future, net-zero emissions will also entail active management of carbon.” Davis et al. 2018.

[9] While the world will need to reach net zero, those of us who can afford to move faster and go further should do so.“

[10] “I believe that it’s important for all the developed countries to talk about, not net zero, but about removing more carbon from the atmosphere than they are adding — net negative is what they need to talk about.” Minister Singh, IEA-COP26 Net Zero Summit

[11] “The world will be net negative once removal exceeds emissions. If it takes us more than a decade or two to lower the level of CO2, we definitely will have overshot our targets and will need to maintain net negative emissions for decades into the future. Therefore, time is of the essence.”

[12] There is an extremely limited supply of reliable, permanent carbon removal available, and what exists is extremely expensive.” Stanford Social Innovation Review. Racing to Net-Zero: A Captivating but Distant Ambition (2022)

[13] As of August 30, 2022; see for live updates.

[14] “The market for durable carbon removal does not exist. Yet. What we have is a heterogenous space consisting of hundreds of companies with ideas on how to remove carbon.”

[15] We describe our certainty as low/medium/high to increase readability and avoid false precision. Since these terms can be interpreted differently, we use rough heuristics to define them as percentage likelihoods the assumption is, on average, correct. Low = 0-70%, medium = 70-90%, high = 90-100%.

[16] “Sustainable from a social and local environmental perspective. The deployment of the project does not cause harm to people or local ecosystems…Projects are given a higher priority if they create benefits for people in poverty, or if they help ecosystems in other ways beyond storing more carbon.”

[17] “The carbon-removal market will probably need to reach $1 trillion a year, Ransohoff told me, a figure that places it well outside any company’s reach.”

[18] The carbon-removal industry is tiny, with less than $5 million in revenue last year. That figure will need to reach about $1 trillion by midcentury, scientists say.”

[19] “All available studies require at least some kind of carbon dioxide removal to reach net zero;  that is, there are no studies where absolute zero GHG or even CO2 emissions are reached by deep emissions reductions alone.” IPCC Sixth Assessment Report, Chapter 3

[20] Milkywire encourages donating to its wider Climate Transformation Fund as a first option, but accepts donations earmarked for carbon removal.

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