Our impact
For almost 60 years, we have been building innovative solutions to the biggest environmental challenges — from the soil to the sky.
About us
Guided by science and economics, and committed to climate justice, we work in the places, on the projects and with the people that can make the biggest difference.
Get involved
If we act now — together — there’s still time to build a future where people, the economy and the Earth can all thrive. Every one of us has a role to play. Choose yours.
News and stories
Stay informed and get inspired with our in-depth reporting about the people and ideas making a difference, insights from our experts and the latest environmental progress.
  • Blogging the science and policy of global warming

    International climate diplomacy continues next week in Bonn, Germany, where negotiators and advocates will set the stage for the United Nations’ climate conference COP31 later this year in Antalya, Türkiye. London Climate Action Week – taking place later in June – will then gather the largest mobilization of UK and EU-based companies, finance institutions, and civil society groups focused on climate action.  

    These climate meetings arrive at a moment of profound complexity in our world: Conflict in the Persian Gulf is fueling rising energy prices and cost‑of‑living pressures on our households; fertilizer shortages are straining food security; and communities everywhere are bracing for an intense wildfire season and flooding due to one of the most intense El Niño seasons. Responding to these pressures, countries and companies are forced to make challenging economic and energy decisions in real time.  

    But it is precisely in moments like this where windows of opportunity open to make clean energy and resilient development the easy choice for countries seeking energy security and economic prosperity.  

    Transforming these fierce headwinds into momentum requires collaboration and whole-of-society-engagement to unlock and mobilize around emerging opportunities; climate diplomacy that delivers clarity and direction toward real-economy solutions; inclusive processes to drive finance for climate action; and putting people at the heart of climate solutions.  

    An all-hands approach to seize opportunity in times of crisis 

    Energy security remains top of mind for governments worldwide. The challenge now is to implement solutions that meet people’s immediate needs—energy affordability, reliability and access—while maintaining momentum toward deep cuts in climate pollution and building resilience that reduces our climate risk. 

    The recent dialogues on transitioning away from fossil fuels in Santa Marta, Colombia underscored both the risk of backtracking toward fossil‑based systems and the enormous opportunity that clean energy offers. 

    We won’t achieve a just energy transition by choosing between security and sustainability; we need actions that deliver both. And in times of crisis, we need to work together to find rare opportunities. 

    Right now, the world is reeling from a shortage of oil and gas supply. Meanwhile, enough natural gas to power Japan, South Korea and Australia for a year is being wasted through leaks and flaring at oil and gas infrastructure around the world, and instead leaked into the atmosphere as climate pollution. We can turn this wasted energy into energy that powers people’s lives—and avoids near-term climate harm—by tightening the screws and batting down the hatches, equipment maintenance and worker training. We can eliminate 70% of fossil-fuel methane emissions with affordable fixes and technologies that we have today. And that’s not only an energy security win today, but a leg up toward enabling a more orderly and equitable longer-term energy transition.  

    The world’s energy crisis is an opportunity to catalyze energy security and climate solutions—but it requires all hands on deck to seize the opportunity, and spaces like the Bonn climate meetings and LCAW provide the convening power required for enhanced progress and action. 

    Pulling the economic levers to make the climate choice the easy choice 

    London Climate Action Week will spark a gathering of stakeholders and leaders from the United Kingdom and across the European Union, including many from the private sector and finance who can play a major role in shaping the standards, financial tools and partnerships that enable climate action with lasting impact. This crowd gives us an opportunity to focus on one central question: How can we mobilize the money to drive a global climate transition? 

    EDF will engage across sectors to help unlock the real‑economy pathways needed to: 

    Putting people at the center of solution design and implementation 

    I’m a firm believer that a climate solution that only works for our atmosphere and fails to work for people is no solution at all. Conversely, solutions that center peoples’ experiences and livelihoods at the heart of their design are the ones most likely to succeed and deliver benefits for the long haul.  

    Climate diplomacy and climate solutions must be grounded in and informed by the lived realities of households, farmers, workers and communities. You can’t protect trees without the leadership of the community living near forest. We need to work directly with farmers to grow and produce food that feeds the world with less pollution. In the same way, we cannot transform our energy systems without the involvement of those directly involved in producing and using the energy. 

    This is how a climate solution can be truly sustainable: by putting people first. In this moment of geopolitical tension and economic crisis, that principle is more important to our work than ever.  

    Looking Ahead 

    As the world moves from Bonn to Antalya, the stakes could not be higher. The decisions that countries and companies make in the midst of this moment of conflict and upheaval will shape not only the trajectory of global climate action but also the economic and energy security landscape for decades to come. 

    EDF will continue working with partners across governments, business and civil society to ensure that climate solutions are practical, investable and centered on people’s wellbeing. The path forward demands cooperation, creativity and courage—and we promise to bring all three to Bonn, London, and beyond. 

    Results were released today for the year’s second auction of the California-Québec carbon market, known as the Western Climate Initiative. This is the last auction before the California Air Resources Board votes on new regulations regarding the implementation of this program, at their hearing scheduled for tomorrow and Friday.

    If CARB approves the draft regulations as they are currently proposed, they’ll be voting to blow a hole in the emissions cap and threaten critical community and household investments that make Cap-and-Invest such a powerful tool for delivering results for the climate and families.

    May auction results

    What’s at stake at tomorrow’s CARB vote

    These results come at a tumultuous time for California’s landmark climate program. Since 2012, it has served as the state’s emissions backstop: a foundational policy to cap and reduce climate pollution, while generating critical revenue to invest in energy affordability, climate resilience, infrastructure and more.

    As detailed in our April blog, the creation of a Manufacturing Decarbonization Incentive (MDI) in CARB’s proposed update to program regulations creates a significant problem for the most essential part of this climate program: the cap on climate-warming emissions.

    When CARB votes, Board Members should make their approval of these regulations contingent on the removal of the MDI, and direct the CARB Executive Officer to issue a new 15-day package without this problematic new mechanism. Here’s why:

    1. The MDI blows a hole in the emissions cap.

    CARB has proposed creating exactly 118.3 million additional allowances to fund the MDI, the precise number of allowances they need to be removing from the cap to keep us on track for our 2030 targets. By both removing 118.3 million allowances from one part of the program, and then creating 118.3 million allowances in a new part of the program, CARB is essentially laundering pollution.

    While the MDI is intended to provide assistance to industries, like oil refineries, to encourage investment in decarbonization technologies, it is layered on top of already generous free allowance allocation in CARB’s draft regulations, and its design jeopardizes California’s ability to meet our 2030 emissions reduction targets. One analysis from UC Berkeley finds that when all these proposed benefits are taken together, refineries could receive free allowances “well in excess” of what they actually need for compliance. Free allocation of allowances from under the cap is a proven strategy to avoid emissions leakage, but the MDI above the cap is a step too far.

    2. The MDI threatens billions in revenue for households and communities.

    By creating additional allowances for a market where prices have been hovering at the price floor for a year, this proposal effectively stands to flood an already weak market with even more allowances, driving down demand further.

    The consequences are not theoretical: the Legislative Analyst’s Office issued a report in May, based on CARB’s own estimates, predicting that with these proposed revisions projected to cut Greenhouse Gas Reduction Fund revenue roughly in half, many critical programs that depend on GGRF funding — including AB 617 programs that fund clean air and safe drinking water — would be zeroed out. These findings build on analyses by the UC Santa Barbara Environmental Markets Lab and by Greenline Insights, which also predict huge losses in critical revenue for climate and affordability programs if this proposal is adopted. And that brings us back to today’s results:

    Today’s settlement price, which cleared above the February auction price by less than a dollar, reflects the ongoing downward trend in allowance prices and GGRF revenue seen by this market since February, 2024 when prices peaked at $41.76. In 2024, the May auction settled at $37.02 and generated $1.1 billion for the GGRF — over $330 million more than what’s expected from this auction. In 2025 alone, California lost out on more than $3 billion in cap-and-invest revenue as the rulemaking process dragged on. The prices we saw today are also still far lower than the price projections CARB used in their Initial Statement of Reasons, which estimated weighted average allowance prices of $68. Had allowance prices in this auction settled at that price, this auction would have raised over $1.8 billion in revenue for the GGRF.

    CARB can and must fix this when they vote tomorrow.

    Today’s results make the stakes of tomorrow’s Board vote impossible to ignore. By making their approval contingent on removing the MDI, CARB can strengthen this landmark program and permanently reduce emissions in line with our statutory 2030 goal while also shoring up critical climate and affordability revenue — in short, CARB can fulfill its duty to the law, to Californians, and to the climate.

    EDF and many others will be at the Board meeting in person to give comments — if you’re interested in tuning in or want to share your thoughts, you can find more information here.

    The Trump EPA is dismantling a series of clean air protections that reduce dangerous pollution from cars and trucks, power plants, oil and gas facilities, and other sources. And thanks to a policy quietly adopted earlier this year, the agency isn’t even bothering to estimate the overwhelmingly harmful health impacts of these actions.

    For instance, just last week EPA proposed delaying life-saving protections against soot and smog pollution from vehicles without an assessment of health impacts. EPA has also finalized weakened standards for smog from new gas-fired power plants and for greenhouse gas emissions from vehicles without those assessments.

    For decades, across both Democratic and Republican administrations, EPA has carefully evaluated the health impacts of its clean air rules when it considers the benefits and costs of regulations. That means considering the lives saved, avoided hospital and emergency room visits, and asthma attacks, along with the economic value of those benefits. And both EPA’s analyses and independent studies have consistently found that clean air programs yield enormous benefits, with a monetary value that vastly exceeds compliance costs to industry.

    Here’s one example: a Congressionally-mandated, peer-reviewed study of the benefits and costs of the Clean Air Act published in 2011 found that EPA’s clean air programs saved 160,000 lives in one year alone, with total benefits of approximately $2 trillion – about 30 dollars in economic benefits for every dollar spent on compliance.

    EPA has performed these analyses using rigorous and transparent approaches that have gone through scientific peer review, multiple rounds of independent assessment by outside experts, and numerous opportunities for public comment. Yet the Trump administration recently decided to abandon this analysis entirely, citing “uncertainty” about the health benefits of clean air rules. At the same time, the Trump administration has continued to quantify compliance costs to industry. This arbitrary approach introduces a bias against clean air regulation that flies in the face of EPA’s Congressional mandate to protect human health and welfare.

    The Trump EPA’s decision to devalue public health  

    EPA’s decision to abandon its decades-long practice of evaluating health impacts appeared for the first time in January of this year, in a brief discussion buried in an economic impact analysis for a final rule amending emissions standards for smog-forming pollution from new gas-fired combustion turbines.

    In that final rule, the Trump EPA weakened a subset of the standards based on cost concerns, and touted industry savings of $87 million relative to the previous 2006 standard. But the agency refused to assess the health impacts associated with the rule or estimate the economic value of those impacts, citing uncertainties in EPA’s analytical methods for ground-level ozone (“smog”) and particulate matter pollution.

    EPA did not cite any expert reports or data to support its abrupt decision to stop estimating health impacts. Nor did it explain why the agency’s well-established approaches to estimating those impacts – and addressing uncertainties – were no longer adequate. And despite acknowledging that the “costs presented in this RIA may be overestimates,” EPA did not treat its calculation of costs with the same skepticism as health benefits.

    The Trump EPA is now consistently refusing to quantify health impacts as it proceeds to dismantle other vital Clean Air Act protections. EPA failed to calculate the massive health consequences of its repeals of the 2009 Endangerment Finding and greenhouse gas standards for motor vehicles,  the Mercury and Air Toxics Standards for coal plants, the previously mentioned delay of criteria air pollutant standards for motor vehicles, and hazardous air pollutant standards for marine tank vessels. As a result, EPA is ignoring the massive health benefits of those rules – and is also keeping the public in the dark about the true costs of its attacks.

    The table below shows that just a subset of the protections EPA is rolling back adds up to hundreds of billions in benefits annually.

    Sources: Institute for Policy Integrity, Tracking the Damages of Regulatory Rollbacks; EPA, Final Regulatory Impact Analysis for the Reconsideration of the National Ambient Air Quality Standards for Particulate MatterEPA, Regulatory Impact Analysis for the Final Federal Good Neighbor Plan Addressing Regional Ozone Transport for the 2015 Ozone National Ambient Air Quality Standard. Health impacts listed for Particulate Matter Standards  for year 2032. U.S. EPA, Final Regulatory Impact Analysis for the Reconsideration of the National Ambient Air Quality Standards for Particulate Matter (2024)

    The strength of the science  

    The Trump EPA claims that it intends to pursue new methods for calculating health impacts at some indefinite point in the future but ignores the vast body of science underlying its prior methodologies. Notably, EPA’s methodologies  already account for uncertainty – in fact, there isn’t a single EPA benefits methodology that fails to do so.

    As recently detailed by experts, EPA’s methodologies for quantifying health impacts and associated uncertainties have undergone multiple forms of peer review and independent expert review, including by the EPA Science Advisory Board, the EPA Clean Air Scientific Advisory Committee, the EPA Environmental Economics Advisory Committee, the EPA Science Advisory Board Council on Clean Air Act Compliance Analysis, and the National Academies of Science, Engineering, and Medicine. Through these multiple rounds of review, EPA has honed its approaches to account for uncertainties and conducted numerous sensitivity analyses.

    The most recent of these reviews came in 2024, when a panel of EPA’s Scientific Advisory Board issued a report reviewing the agency’s Environmental Benefits and Mapping (BenMAP) software tool and the Technical Support Document for Estimating PM2.5- and Ozone-Attributable Health Benefits (TSD). This tool and support document set forth the agency’s framework for estimating health impacts of ground-level ozone across the United States. Notably, the Scientific Advisory Board’s review found that EPA’s analyses are “scientifically robust and appropriate for regulatory analyses.” And although the report provides specific recommendations to EPA on how to refine its framework to further address uncertainties, the data and evidence largely reflect that EPA’s methodologies may be understating health harms. (see report at pages 48 to 51)

    EPA’s consideration of health impacts follows executive orders, Congressional directives and court opinions  

    EPA’s long-standing consideration of health impacts is consistent with federal policies and judicial rulings requiring agencies to fully and even-handedly consider both the benefits and costs of their actions.

    In 1981, President Ronald Reagan issued an executive order mandating that agencies prepare analyses of the costs and benefits of significant regulations and proceed with regulation only when benefits outweighed costs. In response to that directive, the EPA began developing economic models to estimate the health impacts of its air regulations with input from air and water quality modelers, health scientists, economists, and other experts.

    In 1993, President Clinton replaced the Reagan-era executive order with a revised framework that maintained the required cost-benefit analyses but also required that regulations justify the costs rather than strictly outweigh them. Subsequent Democratic and Republican administrations retained this cost-benefit framework for decades and have used it to review the rigor of EPA’s assessments of health impacts.

    In 2000, Congress passed the Regulatory Right-to-Know Act, which requires that the Office of Management and Budget submit an annual report estimating benefits and costs of significant rules. Based on these executive orders and the Regulatory Right to Know Act, the Office of Management and Budget drafted guidance (known as Circular A-4) to guide federal agencies on best practices for cost-benefit analysis.

    Circular A-4 supports full consideration of costs and benefits, including quantification and monetization of those benefits where possible. In addition, it provides best practices for meaningfully analyzing uncertainty when quantifying impacts. When reviewing EPA rules, Office of Management and Budget examiners have historically carefully reviewed EPA’s health benefits assessments to make sure they conform to the guidance provided in Circular A-4 on cost-benefit assessment.

    Congress further mandated that EPA calculate the impacts of clean air regulations on public health, the economy, and the environment as part of the 1990 amendments to the Clean Air Act. In that provision, Congress explicitly directed that EPA “consider all of the economic, public health, and environmental benefits” of Clean Air Act rules. Further, Congress specifically instructed EPA not to overlook such benefits by assigning them a zero value as a “default.” The statute states, “where numerical values are assigned to such benefits, a default assumption of zero value shall not be assigned to such benefits unless supported by specific data.“ (42 U.S.C. 7412 (b) This statutory directive shows that Congress appreciated the importance of quantifying and valuing health impacts and other benefits of regulations, and wanted EPA to put forward its best estimates of those benefits rather than use uncertainty as a basis for overlooking their value.

    Courts have likewise found that it is arbitrary and unlawful for agencies to assign no value to pollution reduction benefits from regulations simply because those benefits are subject to uncertainty. Further, courts have held that agencies cannot focus on the costs of regulations to the exclusion of benefits – they must fairly account for both. (See Center for Biological Diversity v. Nat’l Highway Traffic Safety Admin., 538F.3d 1172, 1189 (9th Cir. 2008); Public Citizen v. Fed. Motor Carrier Safety Admin., 374 F.3d 1209, 1219 (D.C. Cir. 2004); American Trucking Associations v. EPA, 175 F.3d 1027, 1051–53 (D.C. Cir. 1999)).

    As a result of the Congressional directive described above, EPA prepared comprehensive assessments of the health benefits of the Clean Air Act from 1970 to 2020. Those assessments show that the benefits of clean air regulation decisively outweigh costs. EPA’s latest such report, issued in 2011, estimated that clean air rules spanning 1990 to 2020 would result in approximately $1.4 trillion to $35 trillion in health benefits – an amount vastly exceeding the overall compliance costs of $380 billion.  The table below shows estimates health benefits in 2010 and 2020 alone. The data is from EPA’s Progress Cleaning the Air and Improving People’s Health. 

    Compliance  costs are uncertain and frequently overestimated 

    The Trump EPA cites alleged uncertainties as a reason to stop evaluating the health impacts of its attacks on clean air protections. Yet it continues to tout the cost savings to industry from rolling back key protections, even though compliance costs are themselves subject to uncertainty and are frequently overestimated. Since the inception of environmental regulation in the United States, industry has argued that clean air protections will result in economy-crushing burdens. To the contrary, clean air regulation has resulted in enormous economic benefits, in addition to saving lives – and frequently at a much lower cost than originally projected.

    For example, the EPA initially estimated the 1990 Acid Rain Program – a highly successful l Clean Air Act program that dramatically reduced harmful sulfur dioxide pollution from power plants – would cost $6.1 billion annually. Experts later estimated the program cost less than half of the initial estimate, with studies ranging from $1.1 billion to $3 billion.

    EPA also overestimated the annual costs of the 2012 Mercury and Air Toxics Rule for power plants – which successfully reduced mercury from power plants by 86% - by more than $7.2 billion. Instead of $9.6 billion per year estimated by EPA prior to the rule, the cost of the rule ended up being no more than $2.4 billion per year.

    The health benefits of EPA’s clean air standards are significant and measurable. By focusing solely on costs to industry and assigning a zero-value to human health, the Trump administration is arbitrarily attempting to justify deregulation at the expense of human lives.

    This harmful about-face flouts EPA’s mission to protect human health and the environment and ignores decades of science-backed methodologies and longstanding agency and White House guidance.

    Diesel prices are at record highs, squeezing truckers and driving up freight costs nationwide. Prices in parts of California have climbed above $7 a gallon. These escalating costs can force independent drivers off the road and push major carriers to impose fuel surcharges. 

    Fuel is one of the trucking industry’s largest and most volatile costs. When diesel prices spike, margins shrink, small operators get squeezed, and higher costs ripple through the economy.  

    The California Air Resources Board’s next generation of clean truck standards are vital to cutting pollution. They can also help ensure fleets have access to more clean vehicles, reducing their dependence on volatile diesel markets and lower operating costs over time. EDF’s recent comments on CARB’s Drive Forward program lay out how. 

    Cleaner trucks reduce pollution and costs 

    For decades, trucking has depended on diesel no matter the price. Electric trucks offer a more stable and affordable alternative. They replace diesel with electricity, which is often cheaper and more price-stable, while lowering maintenance costs thanks to significantly fewer moving parts and less wear on key components. Over time, these advantages add up. Recent industry analysis shows electric trucks can save fleets tens of thousands of dollars over their lifetime – in some cases exceeding $100,000 per vehicle, especially for high-mileage operations. 

    At a moment of rising and volatile diesel prices, those savings are especially important. The faster California scales cleaner trucks, the faster fleets can reduce their exposure to fuel price spikes – and keep more money in their pockets. 

    Trucks drive outsized diesel pollution 

    Heavy-duty trucks make up just 7% of vehicles on California roads but produce nearly half of on-road nitrogen oxide (NOx) pollution and about 20% of greenhouse gas emissions. This pollution hits hardest in communities near truck routes, warehouses and ports, where families face some of the highest exposure in the country.  

    Smog and soot can harm lung development, worsen asthma and heart disease, and increase premature deaths. Climate pollution fuels extreme heat, drought, and wildfires, already affecting communities across the state. Recent federal rollbacks have made the challenge even harder, eliminating vehicle GHG standards and leaving California with a 175-ton-per-day gap in needed NOx reductions. Reducing tailpipe pollution from heavy-duty vehicles could yield up to $5.6 billion in health and environmental benefits in California alone. 

    Strong standards can drive cleaner, more affordable trucks 

    That’s why strong, next-generation standards are essential. EDF supports CARB’s interest in adopting performance-based NOx and greenhouse gas standards that cut pollution while supporting multiple technology pathways.  

    California’s leadership is especially important now. As federal protections weaken, CARB has a vital opportunity to adopt more protective standards that cut pollution and expand the availability of clean and affordable trucking solutions. That includes protective greenhouse gas standards that give manufacturers flexibility to cut emissions across their fleets, including by deploying more zero-emission vehicles. 

    To deliver real-world pollution reductions, CARB should also strengthen how emissions are measured and controlled. That includes updating vehicle testing to better reflect real driving conditions, adopting standards for trailers to improve efficiency and addressing pollution beyond the tailpipe, including from brake and tire wear.  

    Getting cleaner trucks on the road faster 

    Standards alone are not enough. To deliver meaningful results, clean trucks must be deployed across the fleet – especially in communities most burdened by pollution. EDF supports pairing supply-side standards with targeted demand-side policies that ensure adoption keeps pace. That includes prioritizing high-impact fleets like drayage trucks near ports while supporting cleaner solutions across the entire heavy-duty fleet.  

    At the same time, CARB should unlock pathways that reward fleets and manufacturers for taking early action, such as deploying zero-emission trucks or ultra-low NOx engines ahead of schedule. These actions deliver immediate benefits: lower fuel costs, cleaner air and faster market momentum.  

    Align state policies  

    Drive Forward will be most effective when paired with complimentary state policies – from charging infrastructure deployment and clean vehicle procurement to voluntary programs like Clean Fleet Connect. Coordinated implementation can reduce friction and accelerate adoption. 

    Incentives remain important, especially for early-stage markets. But they work best when paired with strong, durable standards that provide certainty and direction.  

    A chance to lead and lower costs 

    California already leads the nation on clean vehicles and it can continue to raise the bar. At a time of rising diesel prices and federal efforts to weaken and eliminate pollution safeguards, the state can lower costs for truckers, reduce harmful pollution and strengthen economic stability. 

    That’s what a strong Drive Forward program can deliver and exactly the kind of leadership that is important to protect Californians. 

    California is building a vital corporate climate disclosure program that will foster greater transparency and economic resilience. The decisions made now will determine how clearly investors, companies and the public can understand where greenhouse gas emissions occur, how risks and opportunities are evolving and where solutions can scale.

    In comments recently submitted to the California Air Resources Board regarding its March 2026 workshop, Environmental Defense Fund offered views on these important issues. The goal is simple: deliver disclosures that are consistent, credible and useful for real-world decisions. CARB is accepting further input on its workshop concepts through June 1, with rulemaking to follow.

    Evidence shows that standardized climate disclosure creates real economic value. It helps investors better understand risk and make more informed decisions, which in turn protects workers’ and retirees’ savings. Stronger disclosures can also lower companies’ cost of capital by reducing uncertainty and improving transparency, while helping businesses identify opportunities to cut costs and emissions.

    Align with established practices to reduce cost and improve usability

    The good news is that California is not starting from scratch. Many companies already report greenhouse gas emissions using widely accepted frameworks. For example, nearly 90% of S&P 500 companies report Scope 1 and 2 emissions data, with nearly 70% already reporting Scope 3 as well.

    Maximizing alignment with the GHG Protocol and the International Sustainability Standards Board disclosure standards will reduce duplication, lower costs and make disclosures more comparable across markets and interoperable across reporting systems. It will also allow companies to use the same disclosures globally, improving consistency for investors while minimizing unnecessary reporting burden.

    State law already points in this direction. California’s corporate GHG reporting statute (SB 253) requires companies to measure and report emissions in conformance with the GHG Protocol, reinforcing alignment with established standards. The focus now is on rigorous yet practical implementation, ensuring companies build on existing systems to deliver valuable information without adding unnecessary complexity.

    Pair flexibility with transparency to protect data integrity

    CARB has proposed a workable on-ramp that allows companies to make good-faith efforts in early years while building toward stronger reporting over time. That flexibility is important, but it must be paired with transparency on methods and inputs to protect the integrity of the data and ensure disclosures remain useful for investors and the public.

    Companies should clearly disclose how they measure or estimate emissions and explain any changes from year to year. When methods shift, they should disclose and, if relevant, quantify the impact of those changes so investors and other stakeholders can still track progress. For significant updates, companies should recalculate base-year emissions and report results using both old and new methods during a transition period. CARB should also allow companies flexibility in selecting among established approaches to setting organizational boundaries but should require parent companies and subsidiaries to use consistent approaches.

    Emissions factors are another component of the reporting methodology where flexibility is appropriate, but transparency is needed to contextualize the data. Methane from oil and gas operations is a clear example, where a growing body of peer-reviewed research shows that real-world emissions are often 1.5 to 2 times higher than conventional estimates based on standard emissions factors.

    California should require companies to provide information about emissions factors used, encourage companies to use the most accurate emissions factors possible – such as measurement-based, basin-specific emissions data where available for oil and gas methane – and continue updating the set of permissible emissions factors over time.

    Require Scope 3 reporting that reflects the full picture

    Scope 3 emissions – indirect emissions associated with upstream and downstream activities in a company’s value chain – account for 70-90% of total emissions in many sectors. Scope 3 data is therefore essential for investors trying to understand transition risk exposure and for companies working to manage it.

    CARB has outlined three potential paths for Scope 3 reporting, which is required to begin in 2027 under SB 253:

    EDF supports Option 1 because it delivers what markets actually need, and what many companies are already set to provide under other reporting regimes: a view of the most relevant emissions and risks for each reporting company across sectors. Requiring full value chain reporting from the start (with justified exclusions) will produce more useful data, strengthen reporting capabilities and better align with how many companies already report.

    Keep costs in perspective and focus on value

    California’s disclosure program is positioned to deliver substantial economic benefits at a reasonable cost. Disclosure does require investment, especially in early years, but the evidence shows these costs are manageable and even tend to decline over time as systems mature and processes become more efficient.

    For the companies California’s program covers – those making $1 billion or more per year – the estimated compliance costs amount to at most .02% of annual revenue. And for many companies already reporting GHG emissions voluntarily or under other programs, incremental costs will be far lower than for setting up an entirely new reporting system.

    A durable standard that supports better-informed decisions

    California has a chance to establish a durable standard that works for reporting companies and end-users of data alike. That means aligning with global frameworks, requiring transparency, improving accuracy over time and ensuring disclosures reflect the full picture of emissions.

    When data on climate risk and opportunity is clearer, more comparable and more actionable, investors, consumers and the public can make better-informed decisions. That helps protect both our environment and our financial security.

    The Trump EPA recently made the deeply damaging decision to repeal the Endangerment Finding — the foundational scientific determination that climate change harms public health and welfare. To justify that decision, it relied on new and deeply flawed analysis that the American public never got a fair chance to examine.  

    Environmental Defense Fund led a group of 16 environmental and public health groups in filing a petition that calls on EPA to reopen its decision and let people comment on the new material. This is a core rule of fair decision-making, and it is especially important now, as the Trump administration races ahead to abandon scientific consensus and repeal a decade-and-a-half of protective standards.  

    The Endangerment Finding supports commonsense safeguards to cut pollution, protect health, and save money 

    The Endangerment Finding is EPA’s bedrock protection against the climate pollution that endangers people’s health and well-being. It’s also the legal basis for limits on climate pollution from cars and trucks. The Trump EPA’s
    repeal attempts to remove this bedrock finding along with all federal limits on vehicle climate pollution.  

    EDF, along with hundreds of thousands of concerned stakeholders — individuals, business representatives, state and local officials, and public health and medical associations — filed public comments opposing this unlawful rollback, and we have done extensive analysis that shows the enormous stakes for Americans.  

    Repealing these climate protections could: 

    All those damages are on top of $1.4 trillion in additional fuel costs — a cost estimate that was based on cheaper gas prices, predating the current high prices at the pump.  

    (See EDF’s new interactive maps for more about how climate change is already raising costs for families and how the administration’s attack on the Endangerment Finding will make that worse.)

    Totally new and flawed analysis  

    The Clean Air Act requires EPA to disclose the factual basis and methodology for a proposed rule so the public has a real chance to respond. However, EPA is attempting to repeal these foundational protections based on totally new and flawed analysis that did not exist at the time of the public comment period — so no member of the public could ever critique it.   

    The biggest problem involves EPA’s new so-called “futility” analysis, which claims that the agency can’t regulate climate pollution from cars and trucks because their impacts on health and welfare are so small as to be meaningless. This is particularly cynical given that the U.S. transportation sector is the largest source of climate pollution in the U.S. and one of the largest sources in the world. 

    In its earlier proposal for the repeal, EPA leaned heavily on a draft Climate Working Group report to justify this conclusion — a report written by a small group of handpicked climate skeptics that was inconsistent with overwhelming scientific evidence. Following a lawsuit brought by EDF and the Union of Concerned Scientists, a federal court found that draft was secretly created in violation of federal sunshine laws.  

    In its final rule, EPA said it was no longer relying on that report. Instead it switched to a completely new and different technical approach — modeling claiming to show how U.S. vehicle carbon dioxide emissions impact global temperature and sea level rise. That analysis was never put before the public for comment, and it’s wrong — slanted in countless ways that make the impacts look artificially small.  

    For instance, EPA begins its modeling in 2027, after more than fifteen years of greenhouse gas protections have already reduced pollution and delivered cleaner technology into the vehicle market. It’s like examining a patient after medicine has lowered a fever and saying the medicine must have been pointless because the temperature is lower now. EPA’s choice of starting point takes credit for years of pollution protections and then uses that already-improved baseline to claim the pollution protections do not matter. 

    EPA also chooses to focus on only two climate indicators — global average temperature and global sea level rise. EPA itself admits these numbers “are not themselves the adverse impacts on health and welfare.” They are middle steps, not the final harm people actually experience.  

    EPA then takes its artificially small temperature and sea level impacts and just divides them in half to make them look even smaller. EPA admits that its method “pairs some analytic tools not intended for this purpose with other tools in the literature” and “cannot be assumed to translate with precision directly to specific adverse health or welfare impacts.” In other words, EPA admits it used a method not intended for this purpose and the results do not represent what the agency claims.

    EPA goes on to compare its slanted calculations of temperature and sea level impacts to three yardsticks  against  which it claims climate pollution does not measure up:  

    According to EPA, if its modeled temperature and sea level changes fall below these yardsticks, then they’re so small as to be meaningless. But these are the wrong yardsticks — and the wrong conclusions. 

    To begin with, the agency uses measurability and variability even though those metrics do not speak to the impacts that result from reducing climate pollution from cars and trucks. For example, say the average global temperature in 2030 is 60 degrees plus or minus two degrees, for a temperature band of 58-to-62 degrees. If we reduce temperatures by one degree, that would reduce the average temperature to 59 degrees, and the entire temperature band to 57-to-61 degrees. The whole world would be one degree cooler, a meaningful change.  

    In addition, EPA doesn’t explain how it derived its measurability and variability figures. In one case, it doesn’t reveal the figure at all. The government websites EPA cites do not contain the agency’s numbers, and in trying to reconstruct EPA’s work we found numerus math errors which, when corrected, produce figures as much as 85% lower. This is an especially serious problem when those flawed numbers are so central to EPA’s conclusions in the final rule. 

    When we apply more rigorous methods to estimate both the impacts and the thresholds for measurability and variability, we find that the impacts far exceed these thresholds. Our modeling shows that U.S. cars and trucks produce so much climate pollution that they could

    cause sea level rise almost 36 times the size of measurement uncertainty. They could also cause temperature impacts 24times the size of measurement uncertainty and almost 14 times the size of variability (all through 2200).  

    EPA’s one percent threshold is even more revealing. EPA suggests that if an impact is around one percent of total projected global warming or sea level rise it is too small to count. The agency tries to justify this based on a string of court cases, only one of which talks about a one percent threshold but does so in an entirely different context. But context matters. One percent of a problem as vast as climate change is not a rounding error — it translates into real illnesses, real deaths, real dollars.  

    Overwhelming scientific evidence supports the imperative for climate action and highlights that every single ton of climate pollution matters for protecting human health and welfare. In this case, when we assess the climate pollution harms from U.S. cars and trucks through 2200, they range up to $52.5 trillion in damages – almost twice the Gross Domestic Product (GDP) of the entire American economy in 2024.  

    Another major problem is EPA’s decision to treat public health benefits from reducing deadly soot and smog as worth zero dollars. For decades, the agency has assigned dollar values to the health benefits of reducing these pollutants that worsen asthma, trigger heart and lung disease, and cause premature deaths. These monetized benefits are supported by robust scientific assessments developed across decades of empirical research and countless studies. EPA offers no new science to support its deeply damaging conclusion to assign no value to the tremendous health benefits of reducing soot and smog pollution.  

    EPA is trying to support its sweeping rollback of climate and public health protections with deeply flawed analysis, without giving the public a chance to vet the agency’s work. Our petition argues that the agency must follow the law by allowing the public to see and respond to EPA’s choices before EPA locks them into place.  

    Read more:  

    Petition  
    Accompanying technical appendices 
    Erratum 
    Press release 

    You can also read more about the lawsuit challenging EPA’s repeal of its Endangerment Finding. This petition for administrative reconsideration is separate from and in addition to that lawsuit.