A compelling and layman's read
Those elements included the reduction of Antarctic sea ice and polar sheets, the release of methane trapped on the ocean floor and Amazon rainforest dieback.
They are the big three. less ice means less solar reflected away, huge methane also exists in Siberia, a lot of it is in tundra that is barely below freezing, and the Amazon is a large releaser of O and a soak for CO2.
This represents the first half of a Bell Curve