Almost half of the environmental experts on the social media network formerly known as Twitter have abandoned the platform in a trend one study found could damage climate change discourse.
The research, published in the Trends in Ecology and Evolution journal on Wednesday, also found public discussions about the environment, biodiversity and natural disasters on the platform are dwindling faster than other topics due to the expert exodus.
The findings follow a series of major changes at the network now called X, including cuts to staff and content moderation, the removal of user verification, and content limits that experts say have fuelled a wider withdrawal.
The study, conducted at Pomona College in California, looked at a sample of 380,000 "environmentally oriented" Twitter users who posted to the network at least once every 15 days.
The group included ecologists, social scientists, conservationists, policymakers and climate interest groups.
Researchers compared their Twitter use with a group of 458,000 users who posted about politics, starting from October 2022 when entrepreneur Elon Musk bought and took over the network.
After six months, only 52.5 per cent of environmental experts were still actively using the social network, the study found, compared to 79.4 per cent of political posters.
"The rapid decline in active users raises alarm bells and signifies a substantial loss for the conservation community," the study said.
"The exodus of environmental users on Twitter is an existential threat to the primary mode used to disseminate information, mobilise diverse audiences and analyse its data to track contemporary debate and sentiments around... biodiversity loss and climate change."
The report found changes to content moderation on the platform may have contributed to the user decline, as well as increased levels of "hate speech," reduced access to data, and service outages.
Swinburne University senior lecturer Dr Belinda Barnet said the findings were disturbing and revealed the real impact of changes made to the social network, including removing verification for users such as environmental researchers.
"Twitter did play a really important role in public discourse, which is why Musk took it over," she said.
"It gave activists and people who wanted to get a message out a very quick route to the ear of the media and that was a large part of its power."
Dr Barnet said the social network's audience had become "fragmented" as Twitter users tried microblogging competitors to replace it but none offered the same reach.
"I know a lot of people who have moved to Bluesky and Mastodon, even Threads, just to try and find that environment again where they can talk about issues that matter to them," she said.
"But if you haven't got that audience, you've lost the network effect."
