BiGS Actionable Intelligence:
BOSTON — American companies are forging ahead with investments in climate-related initiatives, from solar projects to low-emissions jet fuel, even as government incentives to do so are under threat, according to research by a team of Harvard Business School professors.
The researchers found that half of U.S. publicly traded firms in climate-relevant industries (49.6%) said they were working on climate solutions of some type in their mandatory annual reports to the Securities and Exchange Commission for 2023. That’s an increase over 2022, when 45% of those companies reported climate-related commitments, and a dramatic rise over 2005, when only 20% of public companies reported such activity.
The research may offer a window on the driving force behind the clean-energy transition in the United States. While the Trump administration has made efforts to weaken federal programs that subsidize climate-related projects, the Harvard research shows that companies themselves have steadily embraced climate solutions and renewable energy. Perhaps more important, many have done so because it benefits their business, as technologies have matured, economies of scale have been built and a supportive policy environment has been implemented.
With that policy support disappearing in the last year, American companies — not the government — may be the primary driver of the U.S. energy transition in the years ahead.
“My view is that companies can be a very powerful source of transition,” said Harvard Professor Shirley Lu, who worked with Professor George Serafeim to conduct the research. “The government always has a role to play, but markets and companies can bring about change simply by searching for good business opportunities, and increasingly that involves innovating and scaling climate solutions.”
The team first released its findings in 2024 and then updated the numbers again in late 2025. As part of the project, they created an algorithm that produces a “climate solution measure,” allowing companies to be ranked and compared according to their climate-related work. The resulting data was used to generate the BiGS Climate Innovators 100 list, which contains companies with more than $1 billion in revenue that are doing the most to engineer climate solutions as identified by the research.
Leading this year’s list was electric vehicle maker Tesla, which climbed from number two on last year’s list. Second was Enphase Energy, which sells solar and battery systems, up from number four last year. SolarEdge Technologies, which sells inverter technology, was number three, moving from number one last year.
While the top of the list is heavy with firms whose core business is climate solutions, many well-known companies from other industries also made the top 100. General Motors (27), Dow Inc. (28), Lear Corp (44), United Airlines (80), Harley-Davidson (84) and Archer-Daniels-Midland (96) are all on the list. So are major energy companies such as Constellation (21), Xcel (24), Dominion (59) and Entergy (61).
The business case for climate work
Researchers studied the annual reports, known as 10-K filings, of 1,918 climate-relevant firms for fiscal 2023, using artificial intelligence tools to determine what portion of the text was devoted to climate investments. Because annual reports are tightly regulated by the SEC, companies cannot inflate their actions or mislead investors, so the information is both reliable and consistent.
Of that group, 952 companies dedicated at least 1% of their 10-K text to climate solutions, up from 879 the previous year. And 435 spent at least 5% of the text discussing green investments, an increase from 392 firms that met that threshold in their 2022 filings.
“Generative AI gives us the ability to move from data to insights about company innovation strategies and investments,” Serafeim said, adding, “Distilling useful information with AI from millions of sentences allows us to research both what drives firms to develop new technologies and … the consequences of those developments."
The projects represent a wide swath of climate-related technologies and approaches. United Airlines, for example, is developing sustainable aviation fuel made from renewable biomass and other waste products, which produces less greenhouse gas emissions than conventional jet fuel. Entergy Corp says it will make 20% of its long-term executive compensation plan dependent on hitting “climate resilience” and “carbon-free generation” goals.
In its 2023 filing to the SEC, General Motors said, “Our vision for the future is a world with zero crashes, zero emissions and zero congestion, which guides our growth-focused strategy to invest in electric vehicles (EVs) and AVs, software-enabled services and subscriptions and new business opportunities.”
While companies feel pressure from stockholders, customers and employees to take environmentally friendly action, experts say many others are finding that it is just good business. The cost of renewable energy, for example, has dropped dramatically. A recent report by the International Renewable Energy Agency found that 91% of new renewable projects are now cheaper than fossil fuel alternatives. Experts say that, under such conditions, it makes sense that companies would gravitate to renewable energy sources.
“The existing case for green investment remains,” said Lily Hsueh, author of Corporations at Climate Crossroads and a professor at Arizona State University. “Companies definitely are helping to drive the train.”
The role of the Inflation Reduction Act
Lu and Serafeim uncovered a spike in corporate activity on climate projects after the enactment of the Inflation Reduction Act in 2022. The law, regarded as the biggest and most sweeping climate-related policy in U.S. history, included $369 billion in spending and tax credits to boost climate and green energy investment, ranging from money for solar farms and renewable-energy battery storage to consumer tax credits for buying electric vehicles. All told, the 10-year measure was projected to reduce carbon emissions by 40% by 2030.
While the bill was passed without a single Republican vote, GOP-led congressional districts have been the primarily beneficiaries. Nearly 60% of announced projects, representing 85% of investments and 68% of the jobs, went to districts represented by Republican lawmakers, as of the law's two-year anniversary, according to an analysis by E2, a nonpartisan business group that promotes policies that are both pro-environment and pro-business.
Backers of the Inflation Reduction Act hoped that would help build bipartisan support for the law and thwart any efforts to weaken it. However, President Trump, who has expressed a desire to remove the law, has canceled or paused many projects through executive orders, federal agency mandates and legislation known as the One Big Beautiful Bill Act. For example, a $7 billion residential solar program and funding for electric vehicle charging infrastructure has been halted. Some funding stops have been challenged in court, with mixed results.
Experts say it is too soon to determine whether the threats to IRA funding for climate projects will slow or reverse the commitments companies have made to green projects because the Harvard research predates administration efforts to weaken the law. The researchers examined SEC reports for 2023 that were filed in 2024. The Trump administration’s efforts took place in 2025.
While the researchers did examine corporate investment in climate solutions separately for companies operating in red and blue states, they found only limited differences. Investments by companies in red states were lower than in blue states, but that gap disappeared when researchers looked only at lower-cost climate solutions, Lu said.
“We did not see major trends when we examined the data state-by-state through a political prism,” Lu said. “Most companies are making the low-cost climate solution investments based on business needs and acting in their own best interests. Generally speaking, that appears to be happening in both red states and blue states.”
U.S. companies have momentum
As America struggles with energy politics, the international community remains on a path toward sustainable policies, according to experts at the 2026 World Economic Forum in Davos, Switzerland.
“The trend of renewable energy is eating fossil fuels for lunch,” Andrew Forrest, executive chairman and founder of the Australian mining company Fortesque, said at the annual economic forum, underscoring the lower cost of renewables.
In the United States, experts say that companies continue to march toward an energy transition in part because of basic momentum. Though the Inflation Reduction Act funding is imperiled and other environmental regulations are being rolled back, experts say it’s not easy for companies to simply abandon projects they have already started.
“In general, corporation planning cycles are longer than election cycles,” said sustainable investor Patrick McVeigh. His firm, Reynders, McVeigh Capital Management, has about $4.2 billion in assets under management, all dedicated to sustainable investments. “I think once companies have permits in place ... it's hard for them to change. And I think companies get benefits from it. Companies see that it's helpful to them.”
Of course, not all companies are moving forward. The U.S. retreat on government spending and incentives does imperil the development of newer climate-related technologies, such as advanced geothermal energy and sustainable aviation fuels, said Peter Davidson, CEO of Aligned Climate Capital, an investment firm focused on the energy transition, and former head of the U.S. Department of Energy's loan programs office.
Because those technologies are still in earlier stages and expensive to develop, businesses sometimes need help. Davidson says U.S. companies may no longer get that support, giving companies in other counties an advantage.
“The world of innovation doesn't stop,” he said. "Unfortunately, it has moved dramatically toward China. They've made really strategic decisions toward a clean energy future.”
In the meantime, experts say U.S. companies are driving green investment, despite uncertainty over government financial support.
“It's challenging, especially with the pullback,” said Amy Duffuor, co-founder and general partner at Azolla Ventures, a venture capital firm that focuses on climate tech start-ups. “But corporations are leaning into it … [they] are going to have the long view.”
Harvard Research Associate Rhea Manoharan created the graphics for this report