Are you sure? Because my understanding is, in the past what has happened is that some other force causes a bit of warming, and then the oceans heat up, which causes co2 to bubble out, which then causes more warming, which causes more co2 to bubble out, and so on. So co2 is an active part of the picture but it wasn’t the independent variable, so to speak. Whereas now we’re mining fossil carbon and squirting it directly into the atmosphere, which is new.
And climate scientists are very smart and have worked out how much the added co2 amplified the original warming, and have been able to work out how much warming you would get by doubling co2 levels, which appears to be around 3 degrees C.
Hmm, I don’t think you read what I wrote very carefully. I’m making a very specific and rather technical point about the feedback loops in the climate.
Basically the amount of co2 that the ocean can have dissolved in it is a function of temperature and the relative co2 concentration of the air. When the temperature of the water increases it can hold less co2. Just like when soda gets warm and isn’t pressurized, it gets flat.
Some of the recent ones (< 1 million years), co2 seems likely to be a feedback, not a forcing method - but there have been many times in the past where that is not a plausible explanation at all, with levels in the 2000 ppm range.