Climate Feedback (CF) is a web-based content annotation tool that allows qualified scientists to comment on stories online, adding context and noting inaccuracies.

[2][4] In 2016, Climate Feedback raised about $30,000 with Indigogo crowdfunding, which bolstered one of the efforts to conduct fact-checking via web annotation.

Others like PolitiFact have also been experimenting with annotation methods for politicians’ posts on the blogging platform Medium, using a $140,000 grant from the Knight Foundation.

[11] In 2017 Dana Nuccitelli, in a Guardian article on the role of denialist blogs in undermining public acceptance of anthropogenic global warming, described Climate Feedback as "a highly respected and influential resource.

"[12] The website has identified errors in content published by outlets, such as Fox News, The Wall Street Journal, The Mail on Sunday and New York magazine.