You are WRONG in EVERY DETAIL of what you state.

1. It IS the CO2.

2. The Earth has been in a slow cooling trend for the last 6,000 years. The Inter-glacial warming period has already "peaked". The planet was about -1.0°C colder in 1810 than it was 6,000ya. By 1950 we had "wiped out" that cooling and started a rapid warming of the planet.

3. There are "cycles" in the planetary climate. The cycle of warming and glaciation is one if them. That's only been active for about 2 million years. However, the ONLY other time it's been this COLD on the planet was 300mya.

4. The CO2 concentration hasn't been above 2,000ppm for the last 500my.

The CO2 concentration has NEVER been anywhere near 9,000ppm. EVER.

In the paleoclimate record it's VERY CLEAR.

420ppm = +4°C of warming from the 280ppm level.

560ppm = +6°C of warming.

+900ppm = +9°C of warming.

+1800ppm = +18°C to +20°C of warming.

We know this with a HIGH degree of certainty because it happened just 55my during the PETM. CO2 levels climbed into the 1700-1800ppm range, the planetary temperature climbed +18°C to +20°C, and alligators and palm trees lived on the shores of an ice free Arctic ocean.

We have the fossils. The evidence is literally written 'in stone".