Were at the tail end of an ice age.
For most of Earth's history, there were no polar ice caps.
For 400 out of 500 million years the earth was warmer than it is now.
https://www.climate.gov/news-features/climate-qa/whats-hotte...
https://www.climate.gov/sites/default/files/styles/full_widt...
Also for a lot of that time earth was a hellishly hot place with little life.
How? Do you have concrete examples or just fear based conjecture?
Also for a lot of that time earth was a hellishly hot place with little life.