[Harmless Teddy Bear]

A greenhouse gas that has become the bane of modern society

A bane? Don't you mean a blessing?

No carbon dioxide = no plants.

No plants = no animals.

No plants + no animals = NO LIFE.

[geopyg]

I'm surprised they don't mention it in this article, but I believe some of the oldest fossils (bacteria) can be found in some of the Canadian shield precambrian rock and date to almost 3.5 billion years ago.