Note: This text is a summary of Giving Green webpage 2022 updates to Giving Green's approach and recommendations, and has been edited for brevity and target audience.

Summary

• What is Giving Green? Giving Green is a guide for individuals and businesses to make more effective climate giving decisions. From our 2020 launch up to the 2022 Giving Season, we conducted broad reviews on 20 climate change approaches and published 10 giving recommendations. We estimate we’ve directed around $3.6M to these recommendations. We’ve made some mistakes along the way and have continually refined our research approach and model.
• Our top recommendations: We think our top recommendations are the most important way we can have impact. Though there is inherent uncertainty in assessing and comparing the cost-effectiveness of many of these funding opportunities, we believe these recommendations represent organizations and initiatives that can be highly effective with additional philanthropic funding. They include a re-analysis of our previous recommendations, as well as new recommendations focused on food systems, nuclear energy, and decarbonizing heavy industry. Our top recommendations are Clean Air Task Force, Evergreen Collaborative, The Good Food Institute, Good Energy Collective, and Industrious Labs.
• Our research process: Over the past year, we estimate we spent around 6,000 hours searching for, identifying, evaluating, and publishing research on our recommendations. To identify our 2022 top recommendations, we conducted a broad assessment of the climate philanthropy landscape, identified promising strategies, developed a longlist of organizations working on each strategy, conducted “shallow dive” and subsequent “deep dive” research on a subset of these organizations, and published recommendations.
• Updates to our process and products: In addition to thinking about what we should research, we’re also continually making efforts to improve how we conduct and communicate our research. Our improvements focus on two guiding principles: increasing the quality and increasing the transparency of our research. Updates include: formalizing our theory of change and research prioritization; publishing mistakes we’ve made; increasing our reasoning transparency; increasing public-facing research; and expanding citations. We plan to focus more on this in the years to come.
• Key uncertainties and plans to address them: We aim to be highly transparent about the uncertainties we have in our approach and research. Some of our key overall uncertainties include: whether there is a better way to define and target human suffering due to climate change; how we should think about climate impact today versus tomorrow; within our top recommendations, identifying the most cost-effective giving opportunity; how to allocate our limited research capacity; and how to estimate Giving Green’s marginal value add.
• Our plans for 2023: We look forward to continuing to engage with the broader climate community to learn and share in the year ahead. As always, we will remain focused on our mission to reduce human suffering due to climate change. Though we will remain flexible and may revise plans, our current top priorities include: executing our plans to address key uncertainties, publishing an annual report, publishing additional information on earlier-stage climate landscape research, expanding research into new topics, and continuing to generally improve the quality and usefulness of our work.
• Appendix: (1) We formalized an organizational theory of change to help define and assess the ways in which Giving Green might be especially impactful. (2) Due primarily to uncertainty around room for more funding, we no longer include Carbon 180 as a top recommendation. (3) In line with our theory of change, we also have a set of recommendations targeted specifically at businesses.

What is Giving Green?

Giving Green is a guide for individuals and businesses to make more effective climate giving decisions. Our mission is to direct donors to highly impactful opportunities to reduce human suffering due to climate change (see Appendix: Our theory of change).

Since Giving Green officially launched in 2020, we’ve been busy. Over the past two years, we conducted broad reviews on 20 climate change approaches to educate ourselves and our readers, as well as provide direction for our recommendations research.^[1] We published 10 giving recommendations, including overall top recommendations (at the time, US policy change), recommendations for donors restricted to Australia opportunities, and carbon offsets/removal recommendations for businesses with net-zero goals.^[2] We estimate we’ve directed around $3.6M to these recommendations, with around 90% going to our top recommendations.^[3] We also did some light research to provide high-level guidance to investors.^[4]

Over this time, we’ve continually refined our research approach and model (see Appendix: Our theory of change). We’ve also made some mistakes. We’ve grown from a two- to six-person team, benefited from collaboration and engagement with a broad suite of stakeholders in the climate change space, and know that there’s plenty more work to be done. Below, we’re pleased to share our top recommendations, our research process, our key uncertainties, and our plans for 2023 and beyond.

Our top recommendations

We think our top recommendations are the most important way we can have impact. Though there is inherent uncertainty in assessing and comparing the cost-effectiveness of many of these funding opportunities, we believe these recommendations represent organizations and initiatives that can be highly effective with additional philanthropic funding.

For those interested in maximizing their impact across current and future top recommendations, we recommend donating via our Giving Green Fund. Our current top recommendations are (in alphabetical order):

• Clean Air Task Force
• Evergreen Collaborative
• Good Energy Collective
• The Good Food Institute
• Industrious Labs

Re-evaluation of previous US policy recommendations

Historically, we focused our limited research capacity on US policy recommendations.^[5] We re-evaluated these recommendations primarily based on (a) a shifting opportunity landscape, (b) a shifting political landscape, and (c) organization-specific changes. For past recommendations focused on passing US federal policy, we also specifically re-evaluated whether and how these organizations planned to shift strategies in light of the recently passed Inflation Reduction Act and Bipartisan Infrastructure Law.^[6] Given that the Republican party regained control of the House in the November 2022 midterm elections, we placed additional emphasis on organizations that could continue to be successful without a Democratic trifecta.^[7] For organization-specific changes, we paid close attention to criteria that might have changed over the past year, such as whether an organization’s success may have crowded in additional funding and reduced its overall room for more funding.

Re-recommendation: Clean Air Task Force

Clean Air Task Force (CATF) is a nonprofit that advocates for public policies that (1) invest in climate-protecting technologies (e.g., low-emission energy sources), (2) curb fossil fuel emissions, or (3) enact pollution regulations. Although it continues to lead on US policy advocacy, it has also scaled its work on technology innovation and commercialization to a global level.

We recommend CATF because of its strong track record of policy accomplishments at the national level (including policies with bipartisan support), its growing international model, its focus on relatively neglected issue areas, the strength of its staff, and its ability to productively absorb additional funds in coming years.^[8] We previously recommended CATF in 2021 and 2020. For more information, see our deep dive research report and recommendation summary.

Re-recommendation: Evergreen Collaborative

Evergreen Collaborative is a left-of-center insider policy advocacy group that was founded by former staffers of Washington State Governor Jay Inslee’s 2020 presidential campaign. Since its founding, Evergreen Collaborative has focused its efforts on supporting policies that aim to power the economy with 100% clean energy, invest in jobs, support environmental justice, transition the US from fossil fuels, and influence US leadership to confront climate change.

We first recommended Evergreen Collaborative in 2021, and focused our initial analysis on its federal legislative work.^[9] Evergreen successfully advocated for many initiatives that were included in the Inflation Reduction Act (IRA) such as clean energy tax credits, the green bank, and environmental justice block grants. Following the passage of the IRA, Evergreen Collaborative is now planning to work on bill implementation, state-level policy, and influencing the Biden Administration and federal agencies to take further action on climate. We think Evergreen Collaborative will be impactful in these areas, given its track record of success, organizational strengths, strategic approach, and emphasis on aligning its work to what is most politically tractable. For more information, see our deep dive research report and recommendation summary.

New top recommendations

Thanks to additional research capacity, we also expanded our recommendations to include new efforts we view to be especially promising: food systems, nuclear energy, and decarbonizing heavy industry. In general, these recommendations continue to focus on two overlapping strategies we consider to be highly cost-effective: policy advocacy and technology. In cases where these recommendations have a geographic focus, we assessed whether these efforts might result in global impact, e.g., by developing model regulation that could be replicated elsewhere or advancing technology that could be scaled worldwide.

Food systems: The Good Food Institute

Currently, livestock emissions play an outsized role in food emissions and are expected to increase in the future. Our take is that shifting demand from carbon-intensive conventional meat to alternative proteins (APs), such as plant-based and cultivated meat, could significantly lower GHG emissions. The Good Food Institute (GFI) is a nonprofit that seeks to make APs competitive with conventional meat in terms of price and taste. It supports AP development through scientific research, policy advocacy, and corporate engagement in the US and abroad.

We recommend GFI based on its accomplishments, organizational strengths, strategic approach, and cost-effectiveness.^[10] We believe GFI has substantial room to grow in its three programmatic areas and across its various offices, and that it will increase the likelihood of alternative proteins going mainstream. Since AP production is still in its early stages, we plan to continue to monitor APs’ climate impact and look forward to following GFI’s efforts in this space. For more information, see our deep dive research report and recommendation summary.

Nuclear energy: Good Energy Collective

Good Energy Collective (GEC) is a policy research organization that supports “advanced” nuclear reactors, which are designed to be safer, cheaper, and more versatile than traditional reactors. Nuclear power can decrease GHG emissions if it replaces or avoids dirtier energy sources. For example, it can reduce emissions by complementing renewables because, unlike wind and solar power, nuclear power can produce steady electricity regardless of seasonal or environmental factors. GEC advocates for progressive US policies that support equitable advanced reactor deployment, and engages with local communities to ensure there’s broad support for advanced nuclear.

We believe GEC fills a neglected niche in increasing advanced reactor deployment, and that it can effectively absorb additional funding. Although GEC primarily focuses on the US, it also has an international diplomacy workstream. We believe its work could have global implications if scaled advanced nuclear power in the US gives other countries the policies, technology, and/or general confidence to also make advanced nuclear part of their clean energy portfolio. We believe GEC has substantial growth potential and that with increased funds, GEC could become more effective by adding staff and scaling its community engagement efforts. For more information, see our deep dive research report and recommendation summary.

Decarbonizing heavy industry: Industrious Labs

Heavy industries like steel and cement are the literal building blocks of the global economy. They account for around one-third of greenhouse gas emissions, but have not been a major focus of governments or philanthropists. Industrious Labs is a new organization dedicated to decarbonizing global heavy industry. In collaboration with partner organizations, Industrious Labs advocates to corporations to make low-carbon commitments, and applies legal and political pressure to governments to ensure there’s regulation and public funding to speed up the transition.

As a new organization, Industrious Labs has a limited track record but big ambitions. We are excited about its potential for impact because it’s focused on a highly neglected area, its leadership has a track record of success, and we think its comprehensive industry-specific strategies will pull on the right levers to drive industry’s transition. We also think Industrious Labs has substantial growth potential. It’s building dedicated teams for each of its industry-specific campaigns, and there is considerable room to deepen existing campaigns and add new sectors. For more information, see our deep dive research report and recommendation summary.

Our research process

Our research process: Over the past year, we estimate we spent around 6,000 hours searching for, identifying, evaluating, and publishing research on our recommendations.^[11] To identify our 2022 top recommendations, we conducted a broad assessment of the climate philanthropy landscape, identified promising strategies, developed a longlist of organizations working on each strategy, conducted “shallow dive” and subsequent “deep dive” research on a subset of these organizations, and published recommendations. For more information, see Our Research Process section of 2022 updates to Giving Green's approach and recommendations.

Updates to our process and products: In addition to thinking about what we should research, we’re also continually making efforts to improve how we conduct and communicate our research. Our improvements focus on two guiding principles: increasing the quality and increasing the transparency of our research. Updates include: formalizing our theory of change and research prioritization; publishing mistakes we’ve made; increasing our reasoning transparency; increasing public-facing research; and expanding citations. We plan to focus more on this in the years to come. For more information, see Updates to our process and products section of 2022 updates to Giving Green's approach and recommendations.

Our key uncertainties and plans to address them

We aim to be highly transparent about the uncertainties we have in our approach and research. Some of our key overall uncertainties include: whether there is a better way to define and target human suffering due to climate change; how we should think about climate impact today versus tomorrow; and within our top recommendations, identifying the most cost-effective giving opportunity. We detail our uncertainties and plans to address them below:

Is there a better way to define and target human suffering due to climate change?

• Uncertainty: We currently use atmospheric GHG levels as a rough proxy for human suffering due to climate change. We think this is an imperfect indicator, but is relatively easy to objectively define, measure, and understand. There may, however, be ways to improve the accuracy of this proxy. For example, we might consider using climate damage functions or general estimates of the social cost of carbon.^[12] Other climate change organizations compare funding opportunities based on broader outcomes (e.g., Founders Pledge focuses on “climate damage”), which gives us some confidence we may be able to better define and use our actual outcome of interest when making recommendation decisions.^[13]

• Plan: We plan to consider ways in which we might better define our outcome of interest as part of our uncertainty regarding how we should think about climate impact today versus tomorrow (see below).

How should we think about climate impact today versus tomorrow?

• Uncertainty: Currently, we don’t have a well-developed process for comparing the tradeoffs between current and future climate mitigation opportunities, as well as climate suffering. This is especially relevant when comparing funding opportunities targeting (a) short-lived climate pollutants versus (longer-lived) CO2 and (b) near-term GHG reductions versus expected future GHG reductions (e.g., business opportunities to purchase carbon removal credits today versus donating to Frontier’s advance market commitment).^[14] In our cost-effectiveness analyses, we also use a global warming potential of 100 years, which (though widely used) implicitly overweights GHG that have substantial impact within a 100-year period (e.g., refrigerants).^[15] As an initial attempt to explore part of this uncertainty, we wrote a preliminary short-lived climate pollutants report in April 2022, which we think is fairly simplistic and doesn’t take into account some new evidence.^[16] We also don’t currently include a formal discount rate for future removed/avoided tCO2e. This may not actually be the best approach if, for example, we think it’s more important to reduce GHG atmospheric levels as soon as possible to avoid tipping elements.^[17] On the other hand, reducing GHG atmospheric levels in a long-term worst-case scenario may actually be more important if we’re trying to avoid a scenario of going from 3 degrees to 4 degrees of warming, which we think is likely to cause more human suffering than going from 2 degrees to 3 degrees of warming.^[18] Overall, we currently make many qualitative implicit judgment calls on climate impact today versus tomorrow.

• Plan: We plan to make additional progress on this, but don’t expect to comprehensively formalize our thinking for two reasons. First, we think the majority of funding opportunities we investigate focus on relatively similar climate change reduction timelines. Second, it’s our impression that there is so much uncertainty regarding longer-term climate forecasts that it could be relatively intractable to have a higher-confidence opinion than we currently have. However, we plan to spend some additional time collecting our thoughts on this in 2023, including making updates to our short-lived climate pollutants report, better understanding the latest evidence on tipping elements, and improving our assessment of the relative neglectedness of different climate change scenarios.

Within our top recommendations, what is the most cost-effective giving opportunity?

• Uncertainty: We currently have five top recommendations, and think some of these recommendations are probably more cost-effective than others. However, we’re uncertain about the specific cost-effectiveness of each recommendation and, thus, which recommendation is technically the most cost-effective giving opportunity.
• Plan: We think it’s unlikely we’d make so much progress on this that we would be able to recommend a single giving opportunity above others. Our current recommendations represent a range of giving opportunities that we think generally have similar levels of cost-effectiveness within a range of uncertainty.^[19] Though some of this uncertainty is inherent to the types of recommendations we make (e.g., it’s extremely difficult to understand what impact Clean Air Task Force had on the Global Methane Pledge), we plan to explore more ways to reduce relative uncertainty. For example, we may try to improve the rigor with which we compare the credibility of theories of change and/or improve our cost-effectiveness analyses.^[20]

Where should we allocate our limited research capacity?

• Uncertainty: We have limited research capacity, and aren’t certain where it makes sense to allocate our research time. This depends on (a) how much financing we can influence in a given space and (b) how many tCO2e can be removed or avoided due to that financing. For example, we estimate our top recommendations avoid roughly one tCO2e per dollar donated. By contrast, we estimate a one-ton offset purchase via Tradewater costs around $17. As a rough heuristic, it might make sense to focus more research capacity on high-quality offset recommendations if we believe we can influence more than 17 times as much money as for our top recommendations.
• Plan: We don’t think it’s useful to try to improve a direct quantitative comparison such as the one above, as there are other factors that are difficult to quantify. For example: the marginal impact of an additional recommendation in the same sector (e.g., decarbonizing heavy industry), the longer-term cost-effectiveness of early-stage funding for relatively expensive initiatives (e.g., direct air capture), or the potential longer-term upside of reaching a broader audience by researching high-interest topics (e.g., forestry offsets). However, we plan to more generally consider heuristics and guiding principles for how we allocate research capacity, which we hope will allow us to be more thoughtful and transparent about how we allocate research capacity. In mid-2023, we expect to make deliberate decisions about how much to focus on top recommendations versus other expectations for the 2023 giving season.

What is Giving Green’s marginal value add?

• Uncertainty: Currently, we use money directed as a rough proxy for our impact. However, this doesn’t clearly (a) explain how we estimate, in the absence of Giving Green, the counterfactual impact of money influenced by Giving Green and (b) estimate the ultimate tCO2e removed/avoided.
• Plan: In 2023, we plan to publish an annual report that details how we estimate our marginal impact, estimates of pessimistic/optimistic/best guess impact scenarios, as well as provide an estimate of tCO2e removed/avoided due to Giving Green.

Our plans for 2023

We look forward to continuing to engage with the broader climate community to learn and share in the year ahead. As always, we will remain focused on our mission to reduce human suffering due to climate change. Though we will remain flexible and may revise plans, our current top priorities include: executing our plans to address key uncertainties, publishing an annual report, publishing additional information on earlier-stage climate landscape research, expanding research into new topics, and continuing to generally improve the quality and usefulness of our work. For additional information, see Our plans for 2023 section in 2022 updates to Giving Green's approach and recommendations.

Interested in supporting Giving Green?

As a nonprofit organization, Giving Green relies on donations from its readers. If you appreciate our research and would like to support our operations, you can donate to us here. Donations to Giving Green help us grow as an organization and support our research and communications.

Questions and feedback?

To guide our search for effective climate giving, we strive to uphold four values: truth-seeking, humility, transparency, and collaboration. We’d love to hear your questions and feedback in the comment section below. You can also email us directly.

Appendix

Our theory of change

Organizational theory of change

Giving Green’s mission is to direct donors to highly impactful opportunities to reduce human suffering due to climate change. However, we don’t have a formalized definition of what human suffering means in practice, since it’s hard to define and measure, and is generally open to interpretation. As a proxy, we use greenhouse gas (GHG) atmospheric levels as our outcome of interest. We think this is a useful proxy because it’s easily measurable and, we think, generally leads us to the same conclusions we would’ve made if we tried to directly focus on reducing human suffering due to climate change. However, we’re uncertain about this and plan to explore ways in which we might improve this proxy (see Our key uncertainties and plans to address them).

At a high level, Giving Green’s theory of change follows a five-step process. We produce high-quality recommendations, supporters make donations based on these recommendations, and recommended organizations increase their activities. These activities remove or avoid atmospheric GHG, which subsequently reduces human suffering due to climate change. See Figure 1 for a high-level illustration.

Figure 1. Giving Green organizational theory of change

Research prioritization

So what does our theory of change imply for how we should prioritize our research, given limited research capacity? We think there are two ways our research and recommendations can be especially impactful: (1) Direct funding to highly cost-effective giving opportunities and (2) in high-interest giving areas, reallocate funding from low-impact opportunities to higher-impact opportunities.

We think directing funding to highly cost-effective giving opportunities is the most important research Giving Green can focus on, since it’s our impression that these organizations are able to do substantially more with each dollar than some of the most well-known philanthropic opportunities. These are our “top recommendations”.

Since high-interest areas attract substantial attention and financing, we also think focusing on these areas can have a positive impact. Our current high-interest research includes: carbon removal opportunities for businesses, carbon offsets for businesses, and Australia-specific recommendations.^[21]

For both our top recommendations and high-interest areas, we think donors sometimes have restrictions or self-imposed preferences that cause them to give less (overall and/or to specific initiatives) than they would otherwise give. For example, a business with net-zero goals might donate $10,000 to our Frontier carbon removal recommendation, but would never donate to our US policy recommendations due to fears of being perceived by customers as political or partisan. An Australia-based donor may be more likely to give to Australian nonprofits for tax-deductibility reasons. We also consider this when prioritizing some research areas above others.

We’re uncertain about the tradeoffs we make when deciding how to prioritize research (see Key uncertainties). We plan to reassess our approach in 2023 to ensure our research capacity is focused on where we can have the most impact.

No longer including as a top recommendation: Carbon180

Based on our re-evaluation, we decided to no longer include Carbon180 as a top recommendation. Our assessment is that Carbon180 has been highly effective in advancing its mission and securing additional funding, which suggests marginal donations may be less cost-effective relative to our other recommendations. Our impression is that carbon removal, in general, has also gained substantial philanthropic attention over the past year, and we believe it will continue to be a major focus of climate donors. In particular, we think the recent passage of the Infrastructure Investment and Jobs Act and Inflation Reduction Act increased the visibility of and financial support for carbon removal projects, and may pave the way for additional philanthropic support for carbon removal advocacy. We could be wrong if Carbon180 has longer-term room for more funding, recent carbon removal policy support increases the leverage of philanthropic dollars, or carbon removal becomes less of a philanthropic and government focus in the years to come. We plan to continue to monitor this, and are looking forward to following Carbon180’s progress. For more information, see our deep dive research report.

Our recommendations for businesses

Businesses are increasingly interested in determining how they can reduce climate change.^[22] However, businesses often have unique giving criteria (e.g., they may have net-zero goals or avoid donations that could be interpreted as partisan). We believe there is an opportunity to help businesses re-allocate funding from low-impact opportunities to higher-impact opportunities.

We wrote a white paper outlining various high-impact corporate climate strategies that businesses can adopt, either through making investments in decarbonizing their own operations or donating to impactful organizations. We followed a similar research process to that of our top recommendations, and additionally conducted user research to ensure our recommendations would be applicable to business-specific criteria and preferences. In order of priority, we recommend businesses (a) consider cost-effective opportunities to directly reduce their own emissions, (b) donate to our top recommendations, (c) donate to carbon removal funds, and (d) purchase high-quality carbon removal or offset credits. Our specific recommendations for businesses include making catalytic investments in carbon removal though the Frontier or Milkywire funds; buying carbon removal from Mash Makes, Charm Industrial, or Climeworks; or buying high-quality carbon offsets from Tradewater or BURN.

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1. Rough estimate, calculated by reviewing topics listed under Giving Green’s “Research” dropdown menu as of 2022-10. See US Policy Change | Giving Green's Research; Australian Policy Change; Carbon Offsets & Removals | Giving Green's Research; Investments | Giving Green's Research. ↩︎

2. See Recommendations | Where to Give | Giving Green for a current list of our recommendations. ↩︎

3. To estimate the influence of our recommendations, we gather information from a few different sources: recommended organizations (e.g., Clean Air Task Force), donation platforms that use our advice (e.g., Sweden’s Ge Effektivt), and donors, themselves. We then estimate how much of the donation is directly attributable to Giving Green (i.e., how much of the donation would have occurred in the absence of Giving Green). We also make pessimistic and optimistic guesses, which currently give us a range of $1.3M-$4.9M. In 2023, we plan to publish our first annual report, which will outline our methodology and estimates in more detail (see What’s next). ↩︎

4. See Investments | Giving Green's Research. ↩︎

5. For example, see Giving Green's Approach to Policy Change Recommendations (Wayback Internet Archive 2022-11-01). ↩︎

6. This is primarily based on 10+ conversations with policy stakeholders, among whom there was broad consensus that no major climate change legislation will pass until 2025 at the earliest; Inflation Reduction Act: https://www.congress.gov/bill/117th-congress/house-bill/5376/text; Infrastructure Investment and Jobs Act: https://www.congress.gov/bill/117th-congress/house-bill/3684/text. ↩︎

7. Our assessment of whether an organization could continue to be successful was based on a mix of quantitative and qualitative analysis. We conducted interviews with experts (including politicians, political staff, and climate philanthropists), used proxies (e.g., whether the organization participates in a coalition self-identifying as bipartisan), and assigned scores to organizations’ bipartisan engagement. To assess the likelihood of no Democratic trifecta, we primarily relied on FiveThirtyEight 2022 election forecasts. ↩︎

8. Clean Air Task Force is a 501(c)(3) tax-exempt organization in the United States. CATF has partnered with other organizations to accept tax-deductible donations from Canada, Germany, Switzerland, and the UK, and non-tax-deductible donations in Sweden. Please see their website, linked below, for detailed information. We are only offering an opinion on CATF, and not on CATF Action. ↩︎

9. Evergreen Collaborative is a 501(c)(3) tax-exempt organization in the United States. As Giving Green is part of IDinsight, which is itself a charitable, tax-exempt organization, we are only offering an opinion on the charitable activities of Evergreen Collaborative, and not on Evergreen Action. ↩︎

10. The Good Food Institute is a 501(c)(3) tax-exempt organization in the United States. GFI has partnered with organizations in Canada, Germany, the UK, the Netherlands, and Switzerland to provide tax-beneficial donation options. Giving Green is only offering an opinion on the charitable activities of GFI's 501(c)(3) entity. ↩︎

11. This is roughly based on 2.5 FTE from January through May 2022, and 4.5 FTE from June to mid-November 2022. Calculation: ((2.56)+(4.55.5))*148 [hours per month] = 5,883. ↩︎

12. For example, Diaz and Moore 2017 summarizes climate damage modeling approaches and their limitations. Halstead’s 2022 “Climate Change & Longtermism: new book-length report” includes a review of evidence estimating the social cost of carbon. ↩︎

13. “This leads to what might be a surprising conclusion -- the goal of high-impact climate philanthropy is not to maximize emissions reductions but to minimize climate damage.” Navigating the changing landscape of climate philanthropy | Founders Pledge. ↩︎

14. “[Short-lived climate pollutants] persist for a short time in the atmosphere but can be extremely potent in terms of their global warming potential compared to long-lasting greenhouse gases such as CO2.” World Bank: Short-Lived Climate Pollutants, 2014. ↩︎

15. “The Global Warming Potential (GWP) was developed to allow comparisons of the global warming impacts of different gases. Specifically, it is a measure of how much energy the emissions of 1 ton of a gas will absorb over a given period of time, relative to the emissions of 1 ton of carbon dioxide (CO2). The larger the GWP, the more that a given gas warms the Earth compared to CO2 over that time period. The time period usually used for GWPs is 100 years.” Understanding Global Warming Potentials | US EPA. “The time period usually used for GWPs is 100 years” Understanding Global Warming Potentials | US EPA. For additional information on refrigerants, see our refrigerants report. ↩︎

16. For example, it doesn’t take into account emerging evidence on “tipping elements” (e.g., McKay et al 2022) or how reducing short-term warming could “bend the curve” on longer-term warming (e.g., Carmichael et al 2013). ↩︎

17. For example, McKay et al 2022 suggests that some tippling elements may be likely to occur within relatively low temperature increases. We haven’t investigated this literature in detail, and it’s our understanding that the exact likelihood and expected damage of tipping elements is highly debated. “Current global warming of ~1.1°C above pre-industrial already lies within the lower end of five [climate tipping point] uncertainty ranges.” McKay et al 2022. ↩︎

18. For more on probabilities of temperature increases, see Raftery et al 2017, Figure 3. ↩︎

19. As a heuristic, we consider something to plausibly be within the range of cost-effectiveness we would consider for a top recommendation if its estimated cost-effectiveness is within an order of magnitude of $1/tCO2e (i.e., less than $10/tCO2e). ↩︎

20. Examples of ways we might try to improve our CEAs: conduct higher-quality sensitivity checks; include (better) leverage and funging estimates (for an explanation of these terms, see: Revisiting leverage - The GiveWell Blog); improve the precision/accuracy with which we estimate policy advocacy influence. ↩︎

21. See Our key uncertainties and plans to address them for additional commentary on why we view these research areas to be high-interest, and why we might be wrong about allocating limited research capacity to these topics. ↩︎

22. For example, a 2021 McKinsey report found that the number of corporate net-zero commitments doubled between 2019 and 2020, and estimated that the carbon credit market could increase by a factor of 15 by 2030 to around $50 billion. For additional information, see McKinsey: A blueprint for scaling voluntary carbon markets to meet the climate challenge, 2021. ↩︎