I don't believe that moderating away content and discussion of climate denial would actually result in climate change deniers changing their views. They'd simple disengage with the social networks that institute such moderation and instead seek out alternative mediums. They are plenty of other venues online and offline for climate change denying and other questionable content.

This could even create a business opportunity for new social networks with different moderation policies. That could backfire and create even stronger echo chambers. Imagine a social network that prohibits content in support of prochoice for abortion. The site administrators could simply argue that the issue has been settled and prolife is the only moral stance.