The ice ages

This is a different kind of work. In 2016 a paper with Michael Palmer appeared in Geoscience Frontiers. It asks why the ice ages last so long, when the wobble of the Earth’s orbit should have warmed the north more often.

The paper describes a feedback. While the northern ice is clean, it reflects the sun and keeps the world cold, and carbon dioxide in the air falls. Near 200 parts per million, forest and grassland die back. The bare soil blows, dust lands on the ice, and the ice darkens. At the next rise in summer sun the dirty ice melts, and an interglacial begins. Carbon dioxide is part of that account. The authors’ argument is that it is not the main control, and that the main feedback is the dust.

Ellis has said that he has not seen a published reply that overturns the paper. That is his assessment, not a statement by the journal. Of the claims gathered on this site, this is the one that went through peer review. The history books did not.