Interesting new science coming out about how the 20, 40 and 100 thousand year Milankovich cycles have been forcing climate change:
‘Today Earth is affected by fluctuations called the Milankovich cycles. There are three different Milankovich cycles, and they occur each 20,000, 40,000 and 100,000 years. Over the last one million years these cycles have caused ice ages every 100,000 years, and right now we are in the middle of a warming period that has so far lasted 11,000 years.
“Earth’s climate history is complex. With this research we can show that cycles like the Milankovich cycles were at play 1.4 billion years ago – a period, we know only very little about”, says Donald Canfield, adding:
“This research will also help us understand how Milankovitch cyclicity ultimately controls climate change on Earth.”
In the new scientific paper in the journal PNAS, the researchers report both geochemical and sedimentological evidence for repeated, short-term climate fluctuations 1.4 billion years ago. For example the fossilized sediments show how layers of organic material differed over time, indicating cycle changes in wind patterns, rain fall and ocean circulations.’