Why Reddit’s Science Forum Banned Climate Deniers


One of Reddit’s most popular sections is /r/science, a forum where even the most curious and uninformed nerd can bulk up on recent, peer-reviewed scientific research. This is possible on /r/science because of its community — more than 4 million people, scientists included, who are more or less genuinely interested in engaging, empirical, and accurate scientific discussion on that material.

But for a long time, that type of discussion — at least surrounding climate change — has been hindered by trolling of the most “rude and uninformed” kind, according to Nathan Allen, a a PhD chemist and /r/science moderator. Which is why the subreddit has since prohibited posts and comments by people who deny the realities of man-made climate change.

“There is a de facto ban of climate denial in /r/science, yes,” Allen told ThinkProgress on Tuesday. “We require submissions to /r/science to be related to recent publications in reputable peer-reviewed journals which effectively excludes any climate denial.”

The news broke on Monday that Reddit’s popular science forum had been enacting the ban when Allen published a post on the popular environmental news site Grist. The announcement sparked outrage on Reddit, which is a website with pages about every topic under the sun. Users post links and text on these pages, which other users vote positively (upvote) or negatively (downvote), so that the most popular posts are at the top of the page.


Allen’s announcement quickly rose to the top of /r/science’s front page. “Candy coated censorship!” one said. “Insecure dictators,” said another.

“Since when is science so concrete that differing opinions are not allowed?” another user complained. “Its actually this sort of behavior that FUELS ‘deniers.’ If man made global warming is so real, why are so many of you NOT willing to discuss it?”

The answer, Allen said, is that the conversation surrounding global warming constantly tends to wade off into a non-scientific, personal debate that is inappropriate for a science discussion forum. “Statements on /r/science must be supported by meaningfully peer-reviewed science,” Allen said.

Where there is no consensus we ask users to support their comments with links to studies and publications. However, the consensus is so overwhelming in the case of climate change that it would effectively be like allowing people to come into a submission on vaccinations and throw around the claim that vaccines cause autism. Our policy limits both deniers and skeptics to the extent that /r/science is for the discussion of current, peer-reviewed research and climate skepticism doesn’t have much to show in that regard.

In his piece on Grist, Allen also noted that, while evolution and vaccines do have their disparagers, “no topic consistently evokes such rude, uninformed, and outspoken opinions as climate change.”

Instead of the reasoned and civil conversations that arise in most threads, when it came to climate change the comment sections became a battleground. Rather than making thoughtful arguments based on peer-reviewed science to refute man-made climate change, contrarians immediately resorted to aggressive behaviors. … After some time interacting with the regular denier posters, it became clear that they could not or would not improve their demeanor. These problematic users were not the common “internet trolls” looking to have a little fun upsetting people. Such users are practically the norm on reddit. These people were true believers, blind to the fact that their arguments were hopelessly flawed, the result of cherry-picked data and conspiratorial thinking. They had no idea that the smart-sounding talking points from their preferred climate blog were, even to a casual climate science observer, plainly wrong. They were completely enamored by the emotionally charged and rhetoric-based arguments of pundits on talk radio and Fox News.

Allen also noted that the ban on climate deniers on the forum has actually been in effect for the last two to three years, and that before his post on Grist, not very many people seemed to have a problem with it. Most of the readers on /r/science will downvote a a submission based on faulty science, he said, so it’s rare to even see one coming up in the subreddit. Indeed, Allen noted, 97 percent of climate scientists agree that man is responsible for our changing climate, which he said should be reflected in scientific discussions.


“As moderators responsible for what millions of people see, we felt that to allow a handful of commenters to so purposefully mislead our audience was simply immoral,” he said. “So if a half-dozen volunteers can keep a page with more than 4 million users from being a microphone for the antiscientific, is it too much to ask for newspapers to police their own editorial pages as proficiently?”