The Climate Crisis is a Scam - Professor Ian Plimer

https://www.youtube.com/watch?v=8kNvSu93P9Q&t=1153s

This guy says many of the same things I’ve been saying, such as pointing out how changes in the Earth’s orbit can cause ice ages.  He talks about the massive CO2 decline over Earth's history and how it got dangerously low 20,000 years ago, where if it had been any lower, all terrestrial plant life would have died.

However, he denies any relationship between man-made emissions and rising temperatures.

The average global atmospheric temperature has risen by about 1 to 1.1 degrees since 1880. Some of the temperature records are controversial because the government has adjusted past measurements, claiming that earlier methods were not consistent with modern ones. Nevertheless, we know that temperatures have increased, albeit rather slowly.

It seems very likely that man-made emissions have been at least partially responsible for this increase. However, we also came out of the Little Ice Age around 1850, so there was already an upward trend.

The temperature and CO₂ data suggest that the rate of change is gradual and that temperature sensitivity to CO₂ is relatively low. I have no reason to believe that we are in a climate crisis, at least not in the near future.

Reportedly, out of the 100+ models that the IPCC uses, the only model that accurately predicts actual climate is the less extreme Russian model.  However,  the IPCC likes to average all the models, including the more extreme ones.  They make their predictions with huge error bars, indicating a wide range of possible outcomes, because they really don't know.  However, the focus tends to be on the more extreme predictions.

Almost all of the disagreement is about the degree of positive feedback, also known as Climate Sensitivity.  Although this seems mild now, I can't rule out some significant effect in the future.  However, if there were, we would have plenty of warning.  These changes happen very slowly.

All of the really bad scenarios would require us to raise the temperature by 4 to 5 degrees.   We just aren't getting there very fast, and we are running out of fossil fuels.