An illustration of four stacked blocks against a background of the world map. Read one way the blocks spell out "fact", read the other, they spell "fake".

Fossil fuel companies have known about climate change since 1966 and have been buying TV, radio and newspaper ads to make sure you don't. The lies about climate change have gone digital.

Half of people in the US get their news from social media, according to a survey. The social networks are full of lies. According to a new report by Friends of the Earth, the efforts of social media companies to combat false information on climate change are insufficient. The report ranked the platforms from best to worst.

The author of the report said that researchers, advocates, and lawmakers are powerless to judge whether these companies are acting responsible in building and regulating their own platforms. She said that these social media leaders are leaving the public in the dark.

Five big social media companies were ranked by researchers on how transparent they are in addressing fake news about climate change on their platforms. They found that although some platforms are better than others, all five of the companies had major gaps in their transparency surrounding climate disinformation and their strategies for enforcing policies against it.

It is almost impossible to adequately address climate misinformation without transparency on how much it is on these platforms.

Responding to the report, a spokesman for the company said that they will have more to share in the coming months on related efforts.

The company works with fact-checkers to limit the spread of climate misinformation. The climate misinformation reporting panel is used by a mix of machine learning and human review to evaluate posts. The search and recommendation systems on YouTube promote authoritative sources on climate change.

Facebook did not speak on the record.

Think tanks were involved in climate change misinformation in the 1980s. These groups funded by Big Oil started and spread many of the most common myths about climate change, like the belief scientists are exaggerating its consequences or that rising temps are unrelated to the burning of fossil fuels. Superspreader accounts are no longer pumping out false information.

Samuel Woolley, a computational propaganda researcher at the University of Texas, said in a phone call that social media is a crucial factor for the spread of climate change denial, climate skepticism and climate misinformation. He wasn't involved in the report. The science on climate change is very clear, and it seems to take back a backseat, which is really worrying.

To arrive at their rankings, the researchers devised 27 yes-or-no questions assessing the different social media companies, and looked through all of the publicly available community guidelines, terms of service, press releases, and self-assessments from each company regarding misinformation. They asked if the platform was clear about the process by which dis/misinformation was verified.

In addition to the findings of harmfully opaque policies and enforcement, the report also noted fun tidbits, such as the fact that neither Youtube nor Twitter prohibit disinformation from being directly recommended to users. Even though all of the social media companies publish quarterly or biannual assessments of misinformation on their platforms, none of them specifically address climate disinformation in their own reports.

The researchers found that even though the social networks have misinformation policies, they don't necessarily enforce them against advertisers. It's not clear how repeat misinformation violations are categorized or enforced.

The report pointed out one positive, that both Youtube andPinterest have publicly available policies that are focused on reducing climate change misinformation, and both companies consulted climate change experts to develop those policies.

It is time for social media platforms to change their ways, or for the law to make them. Lawmakers need to mandate transparency and accountability if they win.

Frank Kelly, a researcher at the University of Cambridge who led a report about online scientific misinformation in the Royal Society, agreed that the rise of disinformation extends beyond just the social media sites themselves. In a video call. He said that policy makers, tech companies, and even the scientific community share responsibility.

The Digital Services Oversight and Safety Act was introduced in the US House of Representatives in February.

Woolley, the University of Texas researcher and author of a book on the subject of online propaganda, said that more still needs to be done. He thinks social media companies will have to go back to the drawing board to address climate misinformation.

Woolley said that they have to think about the systems, the recommendation and algorithmic systems that underlie their platforms.