We can’t prove that Christy knows what he says is wrong, but it is definitely noteworthy how many wrong things he says. Also, they’re not mere disagreements. Many of the things he says are claims about data, models, trends, and so on. Claims which can be checked factually by clicking on the responses to each individual claim or statement.
Completely irrelevant when the articles they write cite papers from the peer reviewed literature. It’s why the website is endorsed by many scientists with relevant qualifications:
Edit: Oh and on a related note, seems like ExxonMobil’s own scientists disagree with John Christy: