If you’ve searched Google for a sustainability-related question over the last few years—say, “eco-friendly companies” or “how to reduce greenhouse gas emissions”—there’s a good chance you’ve seen an ad from a major oil company at the top of the results.

BP, for example, has spent more than $4 million on Google search ads that tout its “net zero” plans, even as it keeps investing in fossil fuels at a time when studies say new oil and gas fields are incompatible with climate goals. Shell spent $1.2 million on ads that show up when someone searches for net zero, at the same time that nonprofits say it’s not on track to meet global climate goals, and its internal documents have warned employees to talk about net zero as a “collective ambition for the world” rather than a “Shell goal or target.”

It’s not exactly surprising that companies known for decades of greenwashing and disinformation campaigns are still trying to present themselves as sustainable. But a new report argues that Google, the biggest digital ad provider in the world, should not give them such a prominent platform.

“We focused on the degree to which Google is enabling very cynical, very deceptive tactics by big oil companies,” says Imran Ahmed, founder and CEO of The Center for Countering Digital Hate (CCDH), the London-based nonprofit that put out the report. The nonprofit used Semrush, a tool designed for companies to analyze the ad spending of competitors, to look at how five oil companies—British Petroleum (BP), ExxonMobil, Chevron, Shell, and Aramco—used Google search ads between September 2020 and August 2022.

Collectively, the companies are responsible for 14.5% of all carbon emissions in the last 50 years. “These are some of the worst polluting companies in human history,” Ahmed says. Over the past two years, they’ve also spent more than $10 million on ads that the nonprofit calls greenwashing, from Exxon ads touting biofuels that experts say are unlikely to scale up to Chevron ads claiming support for the Paris Agreement despite efforts to weaken it through an industry group. The group estimates that the ads have been viewed more than 58 million times. “Clearly, they’ve been working because they’ve increased their ad spend,” says Ahmed.

One recent survey suggests that 68% of people don’t distinguish ads from other search results, and it’s likely that some of them are misled by oil company messaging. And for those who see the ads and think they’re greenwashing, their presence makes it harder to believe any other claims about progress on climate change. “Every time you inject cynicism into science, you undermine people’s overall confidence in facts and science itself,” Ahmed argues. “This all contributes to the epistemic crisis in our society, which is that people don’t know how to find information they trust.”

Google touts its commitment to sustainability, with a goal to reach net zero across its value chain by 2030, and it was an early convert to renewable energy. In 2021, before a global climate summit, it announced that it would stop running ads that denied climate science, or that were published on climate denying websites. “When we find content that crosses the line from policy debate or a discussion of green initiatives to promoting outright climate change denial, we remove those ads from serving,” says Google communications and public affairs manager Michael Aciman. Still, CCDH quickly identified that some ads banned by the new policy were running anyway (when this was pointed out, Google removed them).

Also, the policy applies only to content that specifically denies that climate change is happening—for example, calling it a hoax or a scam—or that contradicts the scientific consensus on the causes of climate change, as in saying that humans don’t contribute to the problem. Other language from climate deniers isn’t banned, though, even when it seems that it violates the spirit of the policy. The new report highlights ads from one climate denial organization, the Competitive Enterprise Institute, that claim, “fossil fuels make the planet safer” and “climate campaigners hype the risks of global warming.” Under Google’s current policy, those specific claims are allowed.

The report argues that Google should go further and ban greenwashing ads. And it makes the case that this type of ad should be regulated. “The FTC has already come down on greenwashing in the past, and it’s time for them to take digital greenwashing seriously,” Ahmed says. “Because this is the new frontier in how Big Oil seeks to deceive the world.”