An appeal to authority is not always logical, and in this case it's very logical. If you're a scientist you should know that you're not really qualified to disagree with another scientist in a field that you're not active in. It's not your job. You couldn't possibly know as much as they do, or have the kind of context that they have. You're ignorant compared to them, scientist or not.
Actually, I am. I am a PhD geologist who is qualified to teach every climatology class there is. All the way up to graduate level.
A PhD climatologist on the other hand, can't even handle 4th year geology classes. Optical crystalography, minerology, all of those classes are beyond a climatologist.
So, yes. I AM qualified to have an opinion on what they claim.