Natural climate change

This post is to help differentiate between natural and man-made climate. In modern day climate, the main factor is sunspot cycles. The more sunspots, the warmer the weather as cloud-forming cosmic rays are diverted away from earth during higher sunspot activity.

However, back through the medium term (last million years) cycles of ice ages and interglacials which are determined by three factors summed up under the term “milankovitch cycles“. Adding all these cycles together shows when we had ice ages and interglacials in the past (see bottom waveform in the graph below).

Prior to that we need to look at Paleoclimatology back to over 4 billion years ago when there was almost no life on earth to get the long term picture. A good guide is available from the IPPC web site.

Tags: Climate, natural