Many climate philanthropies have the same North Star: reduce greenhouse gas emissions. The logic behind that is clear. Carbon dioxide, methane and other heat-trapping gases are the root cause of the climate crisis.
But many would-be grantees, particularly front-line activists and grassroots groups, say such an approach favors organizations whose technical solutions can be quantified in terms of emissions over groups whose organizing and power-building work can be as impactful but is often much harder to measure. This dynamic can also mean already well-funded groups with the scientific expertise to run such analyses triumph over those who lack the resources or capacity to do so.
Advocates have tried for years to make the case for funding the grassroots, including in reports such as CLIMA Fund’s “Soil to Sky” series, whose editions in 2019 and 2023 presented many examples of international movement success in the energy and food sectors. Other publications have looked at the emissions impacts of Indigenous-led movements and, earlier this year, surveyed climate justice groups from across the United States.
Yet those reports stopped short of attempting to calculate a dollars-per-ton figure to inform would-be donors, instead tallying how many total tons of greenhouse gases were averted, or could be, by the profiled movements and practices, and providing qualitative analysis. But now, apparently for the first time, there is a public report that makes the case in terms of grantmakers’ favored metric.
Released this week, “Changing the Game: Community-based strategies and climate mitigation,” reviews more than a dozen legislative victories, renewable energy projects and fossil fuel infrastructure battles and, for each of them, estimates the philanthropic cost per metric ton of CO2 emissions avoided by 2030.
“To date, there has been no systematic effort to compile and analyze the carbon impacts of these local and community-based climate strategies,” write authors Sam Greenberg, Arushi Desai and Jessica Kaplan, all of Redstone Strategy Group. “This report aims to fill that gap.”
The examples range from the Lilliputian (have you ever heard of Ohio’s Oak Run Solar Project?) to the legendary (the campaign to cancel Keystone XL) and, as those two examples show, span community support for the development of renewable energy as well as organized protest movements against oil pipelines — i.e., some of the profiled projects are what are typically thought of as climate justice efforts, while others seem better characterized by the report’s chosen term: “community-based strategies.”
Regardless, nearly all the per-ton costs are jaw-droppingly low. By my math, the median campaign profiled in the report had a cost of just $0.12 per ton of carbon dioxide emissions avoided through 2030. Even the average — which is dragged up by one more costly outlier — is only $1.40 per ton.
Not only does the report suggest that philanthropic backing for these efforts is remarkably cost effective, but that their impact on emissions is just one of the benefits they bring, as advocates have long argued. Such efforts build coalitions that can help ensure legislation is implemented, inform communities of new benefits, and advocate for the next campaign, potentially producing wins for communities well beyond carbon emissions avoided.
Commissioned in 2024, the report was based on a review of existing research and interviews with more than 40 experts and funders, and created for the MacArthur Foundation, Marin Community Foundation and the Equation Campaign, a Rockefeller-family-backed fossil fuel opposition regrantor. It arrives as many in climate philanthropy appear to be searching for a path forward after months of President Donald Trump’s environmental rollbacks and the recent passage of a Republican budget bill that erased major climate provisions from the Inflation Reduction Act.
What does it cost to avoid a ton of carbon emissions?
The report’s numbers suggest cost-effective community campaigns can come in all sizes. The Oak Run Solar Project, Ohio’s largest agrivoltaic project to date, is one of the smallest listed, and is projected to save 5.1 million metric tons of CO2 emissions by 2030 with the philanthropic cost coming to just $0.02 per ton.
Now consider a giant one: The cancellation of the Keystone XL pipeline will prevent the emission of between 168 million and 337 million metric tons of CO2 by the end of the decade, which, based on how much philanthropy spent, comes out to between $0.02 and $0.05 per ton.
(Of course, the Keystone XL campaign was powered by a lot more than just philanthropy, just as each of the report’s examples has a more complicated story, but the aim of the analysis is to consider the change won solely in terms of its philanthropic backing.)
That pair are among the lowest-cost-per-ton campaigns in the entire report, but it is telling that the full list includes only two projects that cost more than $1 per ton averted: A San Jose building code electrical policy whose calculated cost comes to $1.13 per ton and California’s Solar Multifamily Affordable Housing program, which the report finds cost between $10.30 and $22.43 per ton.
There are, of course, caveats. The per-ton dollar figures above are for emissions through 2030 (i.e., multiple years), do not include funding for national groups, and some are based on academic studies of how reduced oil supply results in reduced demand. There’s also the reality that many legislative and pipeline battles fail and the potential for selection bias by the authors.
But even if you adjust by a factor of five, 10 or even 20, many would still appear to be cost effective, at least in comparison to one major philanthropic campaign by one of the most metrics-driven grantmakers in philanthropy.
While it is hard to find per-ton analyses of most climate funding, the report notes that Bloomberg Philanthropies’ American Cities Challenge helped 25 cities reduce emissions by 74 million tons from 2020 to 2030, through a combination of providing municipalities with expert support and funding local groups, at a cost of $70 million. That comes to $0.94 per ton, which is within the ballpark of the efforts profiled by this report, though very much on the high side. (Bloomberg, which was among the groups consulted on the report, did not respond to a request for comment by press time.)
Yet another proof philanthropic dollars work best as a catalyst
At a time when many billionaire donors seem to be eager for climate moonshots, the report provides a potent reminder of just how cheap philanthropic nudges for community efforts and movement-building can be compared to the actual cost of mitigation.
For instance, the direct air capture industry has long set its sights on achieving a $100 price tag for sucking a ton of carbon out of the sky. Yet even now, Fortune 500 firms like JPMorgan Chase are paying nearly twice that much for long-term deals, top carbon removal companies are aiming to bring cost to $250 to $350 per ton, and some in the industry argue for dispensing with that price target altogether.
To be clear: Removing carbon is not the same as mitigating emissions (not to mention that the IPCC verdict is unequivocal that carbon dioxide removal is needed). The report’s figures are also the cost of the philanthropic nudge, not the work itself. The comparison is imprecise, but it is a reminder that dollars not spent on mitigating carbon today will — based on the best available projections — likely be worth pennies on the dollar in terms of removing carbon tomorrow.
Similarly, the costs of the strategies the report profiles come out favorably versus the actual cost of installing wind and solar. An analysis of 2018 energy data by professors from Yale and Harvard found onshore wind and utility-scale photovoltaic installations both cost between $20 and $40 per ton of avoided carbon dioxide emissions, while advanced nuclear was nearly $60 per ton. (Those figures have likely declined in the intervening years, but probably not to a few cents per ton.)
In other words, backing local passions — whether for renewable energy or against fossil fuel infrastructure — is far more effective than philanthropy building solutions itself.
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Groups doing this work feel validated, even if their impact goes further
For groups funding or engaging in community organizing and campaigns, such data offers a new type of validation for approaches whose impact they have long witnessed firsthand.
The Climate and Clean Energy Equity Fund, for instance, works on state and local campaigns across the United States. “We’ve long known that investing in organizing and power-building delivers deep and lasting change, and now the data is catching up,” said Andrea Mercado, president and CEO, in a statement. “The Changing the Game report affirms what we see every day.”
Most of the Climate and Clean Energy Equity Fund’s current backers do not need numbers to appreciate its impact, but the team has encountered donors who prefer data and appreciate seeing the report’s attempt to provide a quantitative evaluation, though the numbers do not capture the full picture.
“There’s tension sometimes with people who like to see data, who like to see very hard numbers, and this work is very much existing in the qualitative,” said Arianne Ortegaray, director of development at the fund.
At least one national organization felt similarly. Mini Saraswati, senior director for campaign strategy at the Sierra Club, which was involved in at least two of the campaigns featured in the report but was not in its preparation, said its national advocacy has always relied on members and supporters at the local level.
“The analysis offers compelling evidence that investing in community-driven advocacy is both just and highly effective in reducing emissions at scale, and we hope that this report can serve as a springboard for more robust, equity-centered and long-term approaches to measuring impact campaigning,” she said via email.
For Lindley Mease, executive director of CLIMA, whose reports are one precursor to this analysis, it is critical that funders continue to broaden their aperture.
“While mitigation is necessary, solely focusing on mitigation risks sidelining more comprehensive, community-led solutions that address root causes and deliver broader benefits,” she said. “That’s why research like this is important.”
She urged funders not just to consult or engage communities, but fund solutions originating among populations that are facing flooding, fires, famine and other front-line climate impacts.
“Grassroots climate solutions — those coming from the communities most impacted by the climate crisis — are not only effective, they’re inherently democratic, locally grounded and globally significant,” she said. “In this moment, mitigation funders have an opportunity to back strategies that are both deeply transformative and measurably impactful.”
Michael Kavate covers climate philanthropy and billionaire donors. He welcomes feedback, disagreements, tips and questions.
Correction (July 30, 2025): An incomplete version of the Climate and Clean Energy Equity Fund’s name was used in an earlier version of this story.
