Heat Flux From Below Melts Ice Sheets, drives Temperatures & CO2 Variations.
It has long been established in the peer-reviewed scientific literature that naturally-driven fluctuations in the Earth’s surface temperature preceded the rise and fall of carbon dioxide (CO2) concentrations for at least the last 800,000 years.
As oceans warm, they release more of their vast stores of CO2; as oceans cool, they retain more CO2. During cold glacial periods, when ice sheets covered much of the Earth, atmospheric CO2 concentrations only hovered around 200 parts per million (ppm). After surface temperatures naturally warmed up by multiple degrees C during interglacials, it took at least several hundred years before atmospheric CO2 concentrations began rising in response to the temperature rise.
This lag supports the conclusion that glacial-to-interglacial variations in CO2 concentrations may be driven by temperature changes, as the temperature change occurred well before the CO2 change did.