If you were to search on YouTube for terms like "global warming", you may be directed to videos that deny climate change.
That's according to a new report from the campaign group, Avaaz.
Their investigation found that millions of users are being recommended climate-denying videos through YouTube's algorithm.
Some of these videos also feature paid adverts from green companies such as Greenpeace.
A number of environmental groups have since called on YouTube to stop promoting "dangerous climate misinformation".
"We are talking about millions of people being convinced and being sent down the rabbit hole of climate-denying misinformation," said Fadi Quran, Campaign Director at Avaaz.
Climate change science denied in 1 out of 6 videos
Avaaz's report found that around 16% of the top 100 related videos for the search term “global warming” on YouTube contained misinformation.
The top 10 of these related videos had an average of more than 1 million views.
The report examined videos that appeared on YouTube's suggestions bar and recommended lists on mobile and desktops and found similar results for other search terms related to climate.
8% of the videos recommended to users who searched for "climate change" contained climate-denying content, while this number rose to 21% for "climate manipulation".
The content of these videos was found to range from scientists describing climate change as a "hoax", to videos claiming that there was no evidence that carbon dioxide (CO2) emissions contributed to global warming.
Avaaz says YouTube’s promoted videos, through the recommendation algorithms, account for 70% of the total time users spend on the platform.
More than 100 brands were also found to have adverts running on videos containing climate misinformation, including Samsung, Decathlon and Carrefour.
Under YouTube's advertising business model, 55% of the advertising revenue from these adverts goes directly to the creator of this misinformation.
Algorithms are "redefining how we see the world"
"This is not about free speech, this is about the free advertising YouTube is giving to factually inaccurate videos that risk confusing people about one of the biggest crises of our time," said Julie Deruy, Senior Campaigner at Avaaz.
Avaaz's report called on YouTube to detox their algorithm to remove videos containing misinformation and disinformation from its recommended lists.
"YouTube's algorithm learns about users - what they watch and what gets them hooked - and it then presents and pushes them to them to keep them on the platform," Quran told Euronews.
"The company's executives could make a decision right now to change how the algorithm is designed to send people towards healthy, authoritative and objective content," Quran added.
"These algorithms are redefining how we see the world ... it cannot distinguish between good content and bad content, fact-based content, misinformation, and that can be abused by malicious actors".
Avaaz also urged the social media giant to alter its demonetisation policy to include climate misinformation and work with independent fact-checkers to verify videos and inform users.
Does false information violate YouTube's policies?
In 2015, YouTube launched a campaign, #OursToLose, to “help change the way people discuss climate change".
In 2019, the company also published a whitepaper on disinformation, saying it had “introduced a higher bar for videos that are promoted through the YouTube homepage or that are surfaced to users through the “watch next” recommendations.”
However YouTube's community guidelines say that false information does not violate their policy unless "it crosses the line into hate speech, harassment, inciting violence or scams".
The company says that they have reduced the spread of borderline violative content, including climate misinformation, by 70% since 2019.
A YouTube spokesperson told Euronews that their "recommendations systems are not designed to filter or demote videos or channels based on specific perspectives".
"We’ve also significantly invested in reducing recommendations of borderline content and harmful misinformation, and raising up authoritative voices on YouTube."
The social media giant said they prioritise "authoritative voices" on content prone to misinformation, such as climate change and are expanding these efforts "to more topics and countries".
Avaaz's report also urged brands to establish ethical ad placement requirements and the YouTube spokesperson said they have "strict ad policies that govern where ads are allowed to appear and we give advertisers tools to opt-out of content that doesn’t align with their brand".
YouTube has previously introduced strict policies against anti-vaccination videos which they said were a "violation of YouTube's policy regarding dangerous or pernicious acts".
But Avaaz says their findings indicate that YouTube's algorithms "continue to misinform users in harmful ways".
"We are hopeful that YouTube is seriously considering our recommendations," Fadi Quran told Euronews.
"Social media platforms are allowing disinformation, outrage to spread more and more, which is harming the political debate across the world".
"All platforms need to act, not only to stop disinformation but to redesign their algorithms to serve humanity and not downgrade humanity".