Anti-climate groups are using Facebook to sow doubt and confusion around climate science, a new report showed. A set of ads falsely denying climate change or the need to take action were viewed by at least eight million people on the first half of the year.

In September, Facebook launched a Climate Science Information Center and said to be committed to “tackling climate misinformation” through its fact-checking program. But this doesn’t seem to be enough.

Influence Map, an independent think tank that provides data and analysis on how business and finance are affecting the climate crisis, identified 51 climate disinformation ads, paid by conservative groups.

The social media network uses some fact-checkers to ban false advertising but this isn’t meant to “interfere with individual expression, opinions and debate,” and it’s not clear if Facebook is deploying sufficient manpower for this. Facebook’s is likely to allow some forms of climate disinformation to be exempt from fact-checking, the report argued. Of the 51 ads identified, only one was taken down.

Massachusetts senator Elizabeth Warren said in a statement: “The devastating report reveals how Facebook lets climate deniers spread dangerous junk to millions of people. We have repeatedly asked Facebook to close the loopholes that allow misinformation to run rampant on its platform. Facebook must be held accountable.”

The money came conservative groups

According to Facebook’s Ad Library, there are currently 250,000 Facebook pages in the US that use paid-for-ads to promote political messages. Using a list of 95 advertisers known to have promoted climate disinformation, InfluenceMap identified 51 climate disinformation ads in the US across a six-month period starting in January. The organization then looked to see where the money was coming from.

The ads were paid by conservative groups with opaque funding. These include non-profits such as Prager U, The Mackinac Center for Public Policy, Texas Public Policy Foundation and the Competitive Enterprise Institute, among others. Collectively, the groups identified in the report as using Facebook advertising to spread climate disinformation have a total revenue of $68 million per year.

The most common strategy by them is to attack the credibility of climate science and climate science communicators, frequently targeting the United Nation’s Intergovernmental Panel on Climate Change (IPCC). Arguments used include denying there’s a widespread consensus on climate change and suggesting there’s a high level of uncertainty.

The report showed the ads were heavily distributed in rural US states and to males over the age of 55. Regarding the geographic spread, the largest intensity of impressions per person was found in Texas and Wyoming.

Additionally, the climate disinformation ads were more distributed to males than to females across all age groups. Dylan Tanner, of InfluenceMap concludedt:

“[Climate disinformation adverts] will be of concern to advertisers like Unilever and others who are clearly concerned about climate, both from the viewpoint of the company’s risk and also being on the same platform as these ads.”