At https://chaamjamal.wordpress.com/2018/06/29/a-theory-of-ice-age-cycles/ … an intriguing blog post by Chaam Jamal concerning some ideas by Gerald Marsh, a retired laboratory physicist who challenged mainstream views that ice age cycles were initiated by Milankovitch orbital cycles – and driven by the Arrhenius effect on carbon dioxide (co2). One can instantly see a problem – is the Arrhenius effect real (a hypothesis that has been subsumed into the mainstream narrative). The Arrhenius hypothesis goes back to 1896 (and before that we had Tyndal in 1861). The idea that carbon dioxide controls climate has been popular at times – and fell out of favour at other times. Nowadays it is closely bound up with the global warming mantra but also it is now wel known that water vapour is the principle greenhouse gas with carbon dioxide playing a secondary role. Climate models, in contrast, still use carbon dioxide as the principle variable and water vapour is treated as a feedback mechanism. The assumption has always been that temperatures during the interglacial episodes were dependent on co2 concentrations. The current situation, high co2 levels without a definable rise in temperatures, s not consistent with this assumption (and so on). Well worth a read.
The article continues with evidence contrary to mainstream climate models and of course Gerald Marsh has a preferred explanationfor the initiation of the ice ages – increased levels of cosmic radiation (and the production of clouds). It is doubtful if his ideas will receive traction amongst mainstream – who do the soft shoe shuffle and do not poke their heads above the parapet. The option of catastrophism is once again ignored. Milankovitch had it right in that orbital change can create a shift in the ice sheets. The big question might be said to be was that gradual (as embedded in the uniformitarian mind set) or was it sudden (as in a change at the axis of rotation). In a catastrophist scenario there is no requirement to adher to a 100,000 year cycle, or even cycles of lesser duration. The arguments of Gerald Marsh may in effect be whistling in the wind.