Global Warming aka Climate Change Extremes

I almost forgot to apply one of my favorite understanding techniques to Global Warming aka Climate Change... Extremes:

What if we could some how stop putting CO2 into the air and removed every bit we have added in the last 116 years would temperatures and sea levels return to what they were in 1800?

Conversely, what would happen if some how we could return to the atmosphere all the the CO2 that was sequestered in coal and oil? Would the predictions of a world meltdown be correct?

Before the Carboniferous Period (about 359 to 299 million years ago) this CO2 was in the atmosphere and the fossil record shows the planet wasn't a run away green house like that of Venus but humid, lush and green. There were even periods of glaciation during this time and vast polar ice caps. How is that possible?

As I've stated in past posts, I'm a global warming aka climate change agnostic who is passionate about clean air, water and land and I'm very concerned that many scientists, politicians, environmentalists and the media are focused on the 1 in 10,000 atmospheric CO2 increase and not pollution that adversely impacts millions of lives.

Furthermore, the alarmist clearly don't understand that if we burned all the worlds coal the atmosphere would return to what it was 359 million years ago which was obviously very livable and if the fossil record is to be believed very lush, green and productive.

It's interesting to note that during the last half of the Carboniferous Period significant ice cap formations covered the poles even though atmospheric concentrations of carbon dioxide (CO2) were approximately 1500 ppm.