It doesn't take a lot of googling to find longer periods
. Has it looked different hundreds of thousands of years ago? YES. YES IT HAS. Has it ever changed so rapidly?
Quick question to you (and don't use a search engine to try an answer
... what are the five most common gasses in the atmosphere, and what are their concentrations? Can you answer that? I'll give you N2 and 02, but what about the next three? Be honest with yourself. Did you google it? I've found that most AGW deniers can't even name the first two, which shows a complete lack of ignorance on the subject beyond what they've learned from their filtered media outlets. Without facts, reasoned debate on the subject is impossible. At this point, I'm sure you've used your favorite search engine to look around. Now, what is the most abundant greenhouse gas? What is its concentration in the atmosphere? How much has that increased since the industrial revolution began?