If you’re reading this, chances are you care a lot about fighting climate change, and that’s great. The climate emergency threatens all of humanity. And although the world has started to make some progress on it, our global response is still extremely lacking.

The trouble is, it can be genuinely hard to figure out how to direct your money wisely if you want to reduce greenhouse gas emissions. There’s a glut of environmental organizations out there — but how do you know which are the most impactful?

To help, here’s a list of eight of the most high-impact, cost-effective, and evidence-based organizations. We’re not including bigger-name groups, such as the Environmental Defense Fund, the Nature Conservancy, or the Natural Resources Defense Council, because most big organizations are already relatively well-funded.

The groups we list below seem to be doing something especially promising in the light of criteria that matter for effectiveness: importance, tractability, and neglectedness.

Important targets for change are those that drive a big portion of global emissions. Tractable problems are ones where we can actually make progress right now. And neglected problems are ones that aren’t already getting a big influx of cash from other sources like the government or philanthropy, and could really use money from smaller donors.

Founders Pledge, an organization that guides entrepreneurs committed to donating a portion of their proceeds to effective charities, and Giving Green, a climate charity evaluator, used these criteria to assess climate organizations. Their research informed the list below. As in the Founders Pledge and Giving Green recommendations, we’ve chosen to look at groups focused on mitigation (tackling the root causes of climate change by reducing emissions) rather than adaptation (decreasing the suffering from the impacts of climate change). Both are important, but the focus here is on preventing further catastrophe.

And this work is particularly important right now, in a world where “climate attention has collapsed, political support has evaporated, and policy gains are under sustained assault,” Founders Pledge stressed in its assessment of today’s politically charged atmosphere. In November 2025, the prominent environmental group 350.org was forced to “temporarily suspend” its US operations because of severe funding challenges, according to a letter obtained by Politico. They are among the many groups in the climate movement now buckling under existential funding cuts, as the Trump administration attempts to dismantle longstanding climate regulations in the US. The war in Iran and the rising energy costs of data centers have only hastened the urgency for a clean energy transition.

At the same time, Founders Pledge argues that the climate community massively underinvested “outside the progressive bubble,” creating a movement that was not resilient to the shakeup that would come under President Donald Trump. “One of the main ways we were underprepared was the fact that climate philanthropy invested overwhelmingly on one side of the political spectrum,” the organization writes. Now, the experts say, it’s particularly important to invest in nonpartisan organizations dedicated to defending and expanding upon all of the progress made so far.

Arguably, the best move is to donate not to an individual charity, but to a fund — like the Founders Pledge Climate Change Fund or the Giving Green Fund. Experts at those groups pool together donor money and give it out to the charities they deem most effective, right when extra funding is most needed. That can mean making time-sensitive grants to promote the writing of an important report, or stepping in when a charity becomes acutely funding-constrained.

That said, some of us like to be able to decide exactly which charity our money ends up with — maybe because we have especially high confidence in one or two charities relative to the others — rather than letting experts split the cash over a range of different groups.

With that in mind, we’re listing below a mix of individual organizations where your money is likely to have an exceptionally positive impact.

What it does: The Clean Air Task Force is a US-based non-governmental organization that has been working to reduce air pollution since its founding in 1996. It led a successful campaign to reduce the pollution caused by coal-fired power plants in the US, helped limit the US power sector’s CO2 emissions, and helped establish regulations of diesel, shipping, and methane emissions. CATF also advocates for the adoption of neglected low- and zero-carbon technologies, from advanced nuclear power to super-hot rock geothermal energy.

Why you should consider donating: In addition to its seriously impressive record of success and the high quality of its research, CATF does well on the neglectedness criterion: It often concentrates on targeting emissions sources that are neglected by other environmental organizations, and on scaling up deployment of technologies that are crucial for decarbonization, yet passed over by NGOs and governments. For example, it was one of the first major environmental groups to publicly campaign against overlooked superpollutants like methane.

In recent years, CATF has been expanding beyond the US to operate in Africa, the Middle East, and elsewhere. This is crucial: About 35 percent of climate philanthropy goes to the US and about 10 percent to Europe, which together represent only about 15 percent of future emissions, according to Founders Pledge. And more recently, CATF has refocused its strategy to zero in on programs with broad nonpartisan political support to ensure those global efforts have staying power. This is part of why Founders Pledge is supporting CATF’s efforts and recommends giving to that organization. CATF is also one of Giving Green’s top picks.

You can donate to CATF here.

What it does: This Germany-based organization aims to promote innovation in Europe’s hard-to-decarbonize sectors by running key programs in, for example, zero-carbon fuels, industry, and carbon removal technologies.

Why you should consider donating: You might be wondering if this kind of innovation really meets the “neglectedness” criterion — don’t we already have a lot of innovation? In the US, yes. But in Europe, this kind of organization is much rarer. And according to Founders Pledge, it’s already exceeded expectations at improving the European climate policy response. Most notably, it has helped shape key legislation at the EU level and advised policymakers on how to get the most bang for their buck when supporting research and development for clean energy tech. Giving Green recommends this organization, too.

You can donate to Future Cleantech Architects here.

What it does: The Good Food Institute works to make alternative proteins (think plant-based burgers) competitive with conventional proteins like beef, which could help reduce livestock consumption. It engages in scientific research, industry partnerships, and government advocacy that improves the odds of alternative proteins going mainstream.

Why you should consider donating: Raising animals for meat is responsible for more than 10 percent and perhaps as much as 19 percent of global emissions. These animals belch the superpollutant methane. Plus, we humans tend to deforest a lot of land for them to graze on, even though we all know the world needs more trees, not less. Yet there hasn’t been very much government effort to substantially cut agricultural emissions. Giving Green recommends the Good Food Institute because of its potential to help with that, noting that “GFI remains a powerhouse in alternative protein thought leadership and action. It has strong ties to government, industry, and research organizations and continues to achieve impressive wins. We believe donations to GFI can help stimulate systemic change that reduces food system emissions on a global scale.”

You can donate to the Good Food Institute here.

What it does: When Bill Gates shuttered the policy arm of his climate philanthropy Breakthrough Energy last year, the US lost a unique advocate for innovation at a pivotal moment in the country’s energy transition. Or did it? Not long after the closure, a group of veteran Breakthrough Energy staff launched the Innovation Initiative — part of a new organization called the Clean Economy Project — as part of a push to ensure the US continues on the right path in its energy transition, regardless of which party is in power.

Why you should consider donating: This newly formed project may still be in its infancy, but its work builds upon years of deep experience advocating for clean energy innovation across the political spectrum. Founders Pledge helped seed the new organization with an early grant because “we see the Innovation Initiative as the best bet for donors who want to support federal energy innovation policy advocacy at a moment when this ecosystem needs coordination and strategic leadership,” they said, noting that even small-scale support for such efforts can spur massive payoffs in the space: “Relatively modest advocacy investments can influence billions” in federal spending for research and development “that accelerates breakthrough technologies with global spillover effects.”

You can learn more about the Innovation Initiative here. To donate, send an email to giving@cleanecon.org, with the subject line “Donating to Innovation Initiative.”

What it does: This nonpartisan nonprofit works with American conservatives to enact decarbonization policies, with the goal of reaching net-zero emissions by 2050. DEPLOY/US partners with philanthropic, business, military, faith, youth, policy, and grassroots organizations to shape a decarbonization strategy and generate policy change.

Why you should consider donating: In case you haven’t heard of the eco-right, it’s important to know that there are genuine right-of-center climate groups that want to build support for decarbonization based on conservative principles. These groups have a crucial role to play; they can weaken political polarization around climate and increase Republican support for bold decarbonization policies, which are especially important now, with Republicans in control of the White House and Congress. Right now, these right-of-center groups remain “woefully underfunded compared to both the opportunity and necessity of correcting a large ideological blindspot of the climate movement that has come to bite in 2025” and beyond, Founders Pledge writes, adding that DEPLOY/US is uniquely positioned to insulate climate policy against the shifting winds of politics.

You can donate to DEPLOY/US here.

What it does: Founded by Todd Moss in 2013, Energy for Growth Hub aims to make electricity reliable and affordable for everyone. The organization hopes to end energy poverty through climate-friendly solutions.

Why you should consider donating: While Energy for Growth Hub is not a strictly climate-focused organization — ending energy poverty is its main goal — it’s still a leader in the clean energy space. The organization will use your donation to fund projects that produce insight for companies and policymakers on how to create the energy-rich, climate-friendly future they’re dreaming of. In June 2025, the World Bank announced an end to its ban on funding nuclear power projects after a sustained lobbying effort from Energy for Growth Hub alongside other think tanks and policy wonks. “We all know that Washington is broken. People complain that it’s impossible to get stuff done,” Moss wrote in his Substack in response. “But then, actually quite often, stuff does get done. And sometimes, just sometimes, things happen because people outside government come together to push a new idea inside government.”

You can donate to Energy for Growth Hub here.

What it does: This US-based nonprofit hopes to unlock the power of heat — geothermal energy — lying beneath the Earth’s surface. Launched in 2022, Project InnerSpace seeks to expand global access and drive down the cost of carbon-free heat and electricity, particularly to populations in the Global South. The organization maps geothermal resources and identifies geothermal projects in need of further funding.

Why you should consider donating: Most geothermal power plants are located in places where geothermal energy is close to the Earth’s surface. Project InnerSpace will use your donation to add new data and tools to GeoMap, its signature map of geothermal hot spots, and drive new strategies and projects to fast-track transitions to geothermal energy around the world. The group also began funding community energy projects through its newly launched GeoFund last year, starting with a geothermal-powered food storage facility in Tapri, India, which will offer local farmers more power to preserve their crops.

You can donate to Project InnerSpace here.

What it does: Opportunity Green aims to cut aviation and maritime shipping emissions through targeted regulation and policy initiatives. The UK-based nonprofit was founded in 2021, and since then has aimed to encourage private sector adoption of clean energy alternatives.

Why you should consider donating: Aviation and maritime shipping are an enormous source of global emissions, but receive little attention because international coordination is difficult around the issue, and there are few low-carbon fleets and fuels readily available. Even so, in a few short years, Opportunity Green has managed to gain significant influence in EU and international policy discussions around shipping emissions, while also helping to bring the perspective of climate-vulnerable countries into the fray. In 2024, the group launched a major legal filing against the EU to challenge its green finance rules. “We think Opportunity Green is a strategic organization with broad expertise across multiple pathways of influence to reduce emissions from aviation and shipping,” Giving Green notes. “We are especially excited about Opportunity Green’s efforts to elevate climate-vulnerable countries in policy discussions.”

You can donate to Opportunity Green here.

The past several years have seen an explosion of grassroots activism groups focused on climate — from Greta Thunberg’s Fridays for Future to the Sunrise Movement to Extinction Rebellion. Activism is an important piece of the climate puzzle; it can help change public opinion and policy, including by shifting the Overton window, the range of policies that seem possible.

Social change is not an exact science, and the challenges in measuring a social movement’s effectiveness are well documented. While it would be helpful to have more concrete data on the impact of activist groups, it may also be shortsighted to ignore movement-building for that reason.

The environmentalist Bill McKibben told Vox that building the climate movement is crucial because, although we’ve already got some good mitigation solutions, we’re not deploying them fast enough. “That’s the ongoing power of the fossil fuel industry at work. The only way to break that power and change the politics of climate is to build a countervailing power,” he said in 2019. “Our job — and it’s the key job — is to change the zeitgeist, people’s sense of what’s normal and natural and obvious. If we do that, all else will follow.”

Of course, some activist groups are more effective than others. And it’s worth noting that a group that was highly effective at influencing climate policy during the Biden administration, such as the Sunrise Movement, will not necessarily be as effective today.

“Overall, our take on grassroots activism is that it has huge potential to be cost-effective, and we indeed think that grassroots movements like Sunrise have had really meaningful effects in the past,” Dan Stein, the director of Giving Green, told Vox. But, he added, “It takes a unique combination of timing, organization, and connection to policy to have an impactful grassroots movement.”

One umbrella charity that’s more bullish on the ongoing impact of activism is the Climate Emergency Fund. It was founded in 2019 with the goal of quickly regranting money to groups engaged in climate protests around the globe. Its founders believe that street protest is crucially important to climate politics and neglected in environmental philanthropy. Grantees include Just Stop Oil, the group that made international headlines for throwing soup on a protected, glassed-in Van Gogh painting, and Extinction Rebellion, an activist movement that uses nonviolent civil disobedience like filling the streets and blocking intersections to demand that governments do more on climate.

If you’re skeptical that street protest can make a difference, consider Harvard political scientist Erica Chenoweth’s research. She’s found that if you want to achieve systemic social change, you need to mobilize 3.5 percent of the population, a finding that helped inspire Extinction Rebellion. And in 2022, research from the nonprofit Social Change Lab suggested that, in the past, groups like Sunrise and Extinction Rebellion may have cost-effectively helped to win policy changes (in the US and UK, respectively) that avert carbon emissions.But the words “in the past” are doing a lot of work here: While early-stage social movement incubation might be cost-effective, it’s unclear whether it’s as cost-effective to give to an activist group once it’s already achieved national attention. The same research notes that in countries with existing high levels of climate concern, broadly trying to increase that concern may be less effective than in previous years; now, it might be more promising to focus on climate advocacy in countries with much lower baseline support for this issue.

There are plenty of ways to use your skills to tackle the climate emergency. And many don’t cost a cent.

If you’re a writer or artist, you can use your talents to convey a message that will resonate with people. If you’re a religious leader, you can give a sermon about climate and run a collection drive to support one of the groups above. If you’re a teacher, you can discuss this issue with your students, who may influence their parents. If you’re a good talker, you can go out canvassing for a politician you believe will make the right choices on climate.

If you’re, well, any human being, you can consume less. You can reduce your energy use, how much stuff you buy, and how much meat you consume. Individual action alone won’t move the needle that much — real change on the part of governments and corporations is key — but your actions can influence others and ripple out to shift social norms, and keep you feeling motivated rather than resigned to climate despair.

You can, of course, also volunteer with an activist group and put your body in the street to nonviolently disrupt business as usual and demand change.

The point is that activism comes in many forms. It’s worth taking some time to think about which one (or ones) will allow you, with your unique capacities and constraints, to have the biggest positive impact. But at the end of the day, don’t let the perfect be the enemy of the good: It’s best to pick something that seems doable and get to work.

Update, April 22, 2026, 6:30 am ET: This story was originally published on December 2, 2019, and has been updated annually.