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How did changes in carbon dioxide and methane concentrations reinforce glacial and interglacial climate change?

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Quaternary paleogeography — Quaternary Distribution of landmasses, mountainous regions, shallow seas, and deep ocean basins during the Quaternary Period. Included in the paleogeographic reconstruction are the locations of the interval's subduction zones.

During the Quaternary period, fluctuations in atmospheric carbon dioxide and methane concentrations acted as critical feedback mechanisms that reinforced glacial and interglacial climate cycles initiated by orbital variations.12

While orbital forcing serves as the primary "pacemaker" for these cycles, the resulting changes in solar radiation are insufficient on their own to explain the magnitude of observed climate shifts. Greenhouse gas concentrations, which are recorded in ice core bubbles, were found to be lower during cold glacial periods and higher during warm interglacial periods.324

These variations reinforced the climate system through the greenhouse effect:
* During glacial transitions: A reduction in greenhouse gas concentrations amplified the cooling already underway, helping to sustain lower global temperatures.12
* During interglacial transitions: An increase in these gases amplified warming, facilitating the shift toward warmer conditions.12

Understanding these dynamics remains a major focus of research, as they involve a complex interplay between ocean chemistry, atmospheric circulation, and the ecology of terrestrial and marine organisms.12