I don't have the background to properly evaluate either the site or the rebuttal. My only feeling is that the rebuttal makes a good general point about "bullshit asymmetry" and cherry-picking statistics.
Oh, the site is definitely cherry picking and I wouldn't take any one chart or data point as meaningful.
It's just that there are a lot things that point to a turning point since 1970. It's like looking at something like obesity. It's tied to heart disease, cancer, ED, million other things. Any one of those things could maybe be explained away but if you look at the aggregate and how many things there are I think its okay to say "obesity likely has health effects".
Why is the rebuttal 'naive' but the site not?