Here's how I determine if I'm listening to an fossil fuel industry paid liar. First look at his/her background. Is he/she a climate scientist or experienced in a related discipline? If not, forget it, stop listening. Second, does he/she spend a lot of time trying to discredit particular climate scientists, organizations, studies, or activists. This is a judgement call, but if the answer is yes, it's a red flag. Third, does he/she discuss the mountain of empirical evidence that supports the assessment that climate change is an existential threat to all life on Earth. If not, he/she either doesn't know the subject or is deliberately trying to hide or distort the facts.
Some YouTube channels are spreading disinformation and propaganda. I include GWPF, Tony Heller, Sky News Australia, Heartland Institute, Independent Institute, Friends of Science, among many others, in this group, and some of them are in the pockets of the fossil fuel interests. Link: https://www.ucsusa.org/our-work/global-warming/solutions/global-warming-solutions-fight-misinformation