Here's a question, if there was a positive feedback loop back then, why did it ever stop?
We've been through this before. There are both positive and negative feedbacks. And forcings--the events that throw climate out of its stability--don't last forever. Volcanic activity eventually stops, so less new CO2 or methane gets put into the air. The oceans (yes, phytoplanton as well as other chemical and biological factors), new plant and tree life, the soil--these things absorb CO2 over time. Long periods of time. We aren't Venus, which is so hot that water exists only as vapor, not as liquid. There are also plate movements and ocean currents, which can either cool off or warm up the planet depending on what is happening at any given time.
You seem to want to pretend that just because CO2 isn't the only factor influencing climate, or just because climate has changed due to non-anthropogenic factors in the past, then the CO2 we are adding to the atmosphere must not be the primary forcing right now. That isn't to say it is the only factor. But it is the new factor that is driving the current change. |
