EDIT: I want to add that man made climate change needs to be addressed and the defendant is objectively opposing this. That said, the great HL Menchin once said “The trouble with fighting for human freedom is that one spends most of one’s time defending scoundrels.”

Concluding that scientific research is fraudulent because you have you own reasons to believe its conclusions are false can’t be defamation without compromising free scientific inquiry. Even if your reason for concluding its fraudulent is because you believe in a flat Earth, courts are not the venue to resolve questions of scientific debate. That is a can of worms that should never be opened lest we find ourselves in a new Lysenkoism.