The Supreme Court is once again weighing legal challenges with potential ramifications for the global fight against climate change.

The nation’s top court heard first arguments last week in  two cases that legal scholars say could redefine the internet and free speech as we know it. The cases stem from a pair of laws Republicans in Texas and Florida passed in 2021. Both laws, which were written in reaction to social media companies banning former President Donald Trump from their platforms, attempt to restrict how the companies moderate content on their websites.

Specifically, the laws prohibit the platforms from banning users based on their political viewpoints and require the companies to provide an individual explanation to any user who has their content removed or altered. Florida lawmakers also passed legislation that prevents social media platforms from rapidly changing their terms of service agreements, threatening them with large financial penalties for doing so.

Trade groups that represent the social media companies say that both laws infringe on First Amendment rights, which broadly prevent the U.S. government from restricting speech but don’t pertain to private companies. In fact, landmark First Amendment cases have explicitly allowed privately owned companies to choose not to publish certain content—the government can’t censor citizens, but it also can’t dictate what they say when they do speak. The laws’ supporters, conversely, argue that the social media companies are today’s modern public squares and have been discriminating against conservative viewpoints through bans and content removal.

While it’s clear the outcomes of the cases could have major implications for social media companies and free speech in general, disinformation experts say the rulings could also affect the fight to slow climate change.

That’s because should the Supreme Court uphold the state laws, it would make it far more difficult for social media companies to curb the circulation of disinformation on their platforms, including false and misleading content about climate change, said Michael Khoo, a climate disinformation researcher and member of the Climate Action Against Disinformation Coalition.

“I think there’s a lot at stake for climate disinformation and disinformation of all kinds,” Khoo told Inside Climate News. “The vast majority of Americans believe in climate change and they want their online discussions to reflect that.”

The online world is flush with conspiracy theories and misleading facts about climate change. Watchdog groups track thousands of social media posts every year that claim anything from climate change being a total hoax that’s perpetuated by the global elite to global warming being real but only caused by natural factors like the sun, not human activity.

Disinformation experts say that the prevalence of such claims, which far outpace the spread of accurate information online, is contributing to a highly polarized political landscape that makes it far more difficult for nations to take adequate steps to address climate change.

A report released last summer by the Climate Action Against Disinformation Coalition found that social media companies, despite explicit pledges to curb misinformation on their platforms, have largely failed to stop the increasing spread of false claims about climate change online. YouTube, Meta and TikTok have all made commitments to address climate misinformation on their platforms.

Other reports found that right-wing politicians often use culture-war rhetoric when talking about global warming and that social media platforms tend to see a spike in climate disinformation campaigns—which seek to intentionally deceive their audience—during major weather events or global climate conferences such as COP. 

Climate action has become an especially polarizing topic in the United States, in large part because of the amplification of misinformation by Donald Trump, including during his presidency. A study published last month in the peer-reviewed journal Scientific Reports found that between 2017 and 2019 Trump was the most influential spreader of climate misinformation on Twitter—now called X. He was followed by conservative media outlets like Fox News and right-wing activists, according to the study, which also estimated that 15 percent of Americans don’t believe in climate change at all.

Last week, as the Supreme Court weighed oral arguments from the attorneys representing Florida and Texas, most of the justices appeared skeptical that the two laws didn’t violate the First Amendment. Chief Justice John Roberts noted that because the companies are not bound by free speech rights, “they can discriminate against particular groups that they don’t like.”

But some justices also expressed concern that blocking the laws in their entirety might go too far, appearing to suggest that the way social media companies have practiced “content moderation” has ultimately resulted in the silencing of certain viewpoints.

“Is it anything more than a euphemism for censorship?” Justice Samuel Alito asked.