"Ice cores unambiguously show that temperature can fall while carbon dioxide stays high. "
Does this not show that CO2 is then not a greenhouse gas?
I think it shows that CO2 can be easily out-driven by other things. Water vapor is one such thing. It has a way of producing those things we call clouds.
Does this not show that CO2 is then not a greenhouse gas?
I have maintained (as have others more credentialed in this specialty) that the CO2 is released when the oceans warm up, and is a trailing indicator, not a leading one. The graphs of CO2 and temperature bear this out.
To explain this to my grandchildren, I took two identical bottles of pop, refrigerated one and left the other warm. Upon opening, a greater amount of the CO2 evolves from the warm pop immediately, demonstrating that CO2 is more readily soluable in cold water.
When the oceans warm, CO2 is given off. When a cooling cycle begins, the oceans will take a while to cool to the point that the atmospheric CO2 saturation starts to decline.
When the ocean is cold (from colder climate) the CO2 will take time to come out of solution because it takes time to warm all that water, so the CO2 levels trail the temperature curve.
In my mind, that does not indicate that CO2 forces the climate, but that the climate forces the CO2 levels, which trail the warming and cooling trends.
The process occurred long before humans were burning significant amounts of fossil fuels, so it is likely that even now human contributions are negligible compared to solar influences and catastrophic volcanic activity, which affects how much sunlight reaches the planetary surface.
Certainly, the climate changes, and that is the insidious nature of redefining the terms of debate in midstream. No one denies that climate changes. On the other hand, Anthropogenic Global Warming (what the "Climate Change" people are having cartwheeling fits over) is likely more a matter of cherry picking data (flawed or inadequate data at that), and measurement error (weather stations which have become surrounded by urban growth).
If the data were good and unmolested, and the climate model refined (there would be only one and it would be effective as a predictive tool), the range of outcomes wouldn't vary by nearly 300%.