The only reason to make the absurd statement that human activity has no effect on Earths climate is to entertain yourself.
It is pretty self evident that deforestation, i.e. albedo changes (thermal reflectivity), atmospheric gas changes, etc. all impact climate.
At #66 & #72 points were presented regarding human impact and the utility of applying what is known & can be proven.
Cretaceous CO2 levels were nearly 1000 PPM. Presently they are about 410 PPM, up in about 150 years from a relatively steady state 270 or so of the last 1000 or more years. The Cretaceous world was ice free, and forests extended to the poles. There was less available dry land. From #66, the implications of that are grim for people. A smart guy would try to get ahead of that end
if he could. Maybe yes, maybe no, but without trying the end result is predictable.
Earths climate also has solar, geologic and probably interstellar components. The ones we can affect through our actions are land albedo and CO2 from our activities. A survivable
environment is another thing we can affect, which is related to but not exactly the same as climate.
"Why are you talking about conspiracies? There is no conspiracy, it's a collective delusion."Really? This from a guy constantly banging on about "Greta" and her "Swedish Overlords" and their dark designs for us? We have real world issues that are not going to be resolved by ignoring them and doing nothing. That's not entirely true though, as doing nothing is also a choice. If you are "all good" with the probable outcome of inaction, you're already there.
https://en.wikipedia.org/wiki/CretaceousThe Cretaceous ( /krɪˈteɪ.ʃəs/, krih-TAY-shəs)[1] is a geological period that lasted from about 145 to 66 million years ago (mya). It is the third and final period of the Mesozoic Era, as well as the longest. At nearly 80 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin creta, 'chalk', which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation Kreide. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth by the end of the Cretaceous, co-incident with the decline and extinction of previously widespread gymnosperm groups.