I started to leave this as a comment over at Borepatch’s place but it just kept growing and growing so I made it a post.
I was at the Natural Science Museum today, and I relearned a few things that I’d forgotten over the years. (And saw a few new things like the amazing giant sloth.)
In the Cambrian period, 500 million or so years ago, CO2 in the air was 20-35 times what it is today. Humans had nothing to do with it.
At the end of the Permian period, there was a mass extinction event. 95% of all life on Earth died. Humans had nothing to do with it.
In the Jurassic period CO2 levels were 4-5 times today’s level. Temperatures averaged 3 degrees Celsius warmer than today. Humans had nothing to do with it.
In the Cretaceous period CO2 was about what it is today. Still no humans.
Another huge extinction event at the end of Cretaceous period. Humans were not involved.
In the Eocene period CO2 was back up to 10 times what it is today. Antarctica was missing its ice cap. Humans had nothing to do with it.
Finally, Humans show up in the Holocene period and immediately start screwing up the weather.
Yes, climate change is real. It’s ALWAYS been happening. And for 99.9998% of the 4.5 billion years the Earth has existed, humans weren’t around to have anything to do with it.