Why do people think Co2 causes global warming?

If Co2 causes global warming why didn't it do it decades ago? It's clear that Co2 doesn't cause global warming.
I think the answer is clear. Global Warming was noticed in the 80's which was the same time the gay "rights" movement came into being. It's obvious that God is causing global warming because we are embracing sin! In the Bible it says that during the end times, natural disasters will be common such as extreme heat! It's obvious the Bible is talking about global warming! This is a part of the end times people! Better accept Jesus or face eternal damnation.