A new paper by Kelsey et al at Climate of the Past Discussions is attempting to explain the apparent 1470 year periodicity of the Dansgaard–Oeschger and Bond cycles with sunspot cycles, lunar cycles and the anomalistic year.
I predict there are going to be quite a few comments. Eric Wolff has already left one pointing out that the paper’s opening sentence “The existence of a ~1470 year cycle of abrupt climate change is well-established” is not well supported by the recent literature and revisions to the ice-core chronology.
Wolff writes “I leave it to others to assess whether the periodicity in astronomical cycles proposed by the authors could be expected to have any climatic effect, and specifically the one that is observed at D-O timescales.”
Indeed. Certainly the authors don’t address this critical problem in the paper.
The authors seem to be more interested in showing that the cycles they derive from the anomalistic year – “the time Earth’s rotation and revolution (RRA) relative to the perihelion, i.e. the time for perihelion to occur over the same geographic longitude on Earth” – have counterparts in the 14C record. It is not obvious that this is expected.