Sure, up to a point.Actually Frankfoot, a smart person questions government and scientists who claim to know everything (not that I'm a truther btw, lets get that straight)
I'll question some medical treatments but I'm also not going to refuse blood transfusions, vaccines or antibiotics for an infection.
Climate change research is like that, its got the backing of 97% of climatologists the world over, the backing of almost every legit scientific organization and the backing of very conservative industries like the insurance industry. And the ones who are pushing the contrary position are all tied back to those who financially stand to lose the most, the fossil fuel industries.
As for claiming that the IPCC 'claim to know all', all you have to do is read the reports to understand that they are very clear about what they know and what they don't. They give uncertainty percentages, ranges of outcomes and references to all the research and data.