This is a pretty common propaganda pattern. Pointing to a massive group of people, throwing them all together under one label (in this case, 'climate deniers',

This is a pretty common propaganda pattern. Pointing to a massive group of people, throwing them all together under one label (in this case, 'climate deniers', in other cases 'vaccine deniers', etc.) even though the people in the group have a massive range in their opinions and beliefs, and then point out some small subset of the group that are the craziest/weirdest/most "wrong" members in the group, and straw manning them as representative of the entire group.