Welcome back, Mike.
He's locked on the assumption that carbon caused the warming, which is not a totally unreasonable assumption, but it ignores the very real possibility that warming ocean waters hold far less C02. Had warming come from another source, more solar activity, etc, the warming ocean waters would have emitted tons of C02.
I appreciate the interesting/entertaining video.
Sounds convincing and authoritative but he's missing some key points.
It was this warm 1,000 years ago during the Medieval Warm Period, 2,000 years ago during the Roman Warm Period and just over 3,000 years ago during the Minoan Warm Period and much warmer than this during the Holocene which was 9,000 to 5,000 years ago.
The funniest/ironic thing about the Holocene climate optimum is that it was much warmer than this.................and that's why they use the word optimum.
Much less warming than that today is being described as catastrophic warming.............instead of the reality of it being beneficial warming.
During past warmings, the global temperature went up BEFORE the CO2 went up, based on almost every study. This suggests natural warming, possibly from the sun and outgassing of CO2 from the warming oceans into the atmosphere, which increased atmospheric CO2.............as Tim suggested.
There is alot that we don't know of course.
The oceans have much more CO2 dissolved in them than is in the atmosphere. Outgassing of CO2 from the oceans recently is an underappreciated source in our atmosphere.