They are periodic and can be loosely predicted. There are cycles within cyclesso that within a 90 year major cooling cycle you will have a lesser 45 year warming cycle and a lesser 45 year warming cycle, but the overall trend is still one of cooling. I wish we had graphics herepicture two circles, touching so that they look like a plump figure 8 on its side. One represents 90 years of coolong, the other 90 years of warming. Within each is another figure 8 representing 45 year cycles. Within those are figure 8s of roughly 11 year cycles.
"I saw this diagram in a popular magazine back in 1985 0r '86written by a scientistI have been unable to find it again, but I sure remember it."
There is abundant data showing these cycles are tied to the sun's cyclic activity and sun spots. The sun is the planet's major source of energy.Because 45 and 11 year cycles fall within normal human lifespans, many people notice temperature patterns when they stop to think about themlike the ten years in the late 60s-early 70s when Ann Arbor, MI had little or no snow (it sure ended when we moved there and had to buy a snowblower for our tractor.) Farmers and ranchers are particularly sensitive to these patterns as they have to plan ahead. Honest scientific research and data gathering has documented these cycles into prehistoric times.
We find it reprehensible that James Hansen at NASA turns a blind eye to this truth along with many other scientists. There is no way human activity caused past climate cycles and this can be extrapolated into the future. It is Anthropomorphic Climate Change that is the lie. The more honest truth is that human activity can and does cause messes in the form of regional pollution and combustible garbage, easily recognized, well-documented and fixable.
This Anthropomorphic Climate Change scam is keeping folks from buckling down in cleaning up our regional nests and preparing for some real weather challenges, which may or may not occur exactly as partisan experts predict. Scientists of this order have left their original calling in becoming the henchmen of government ideologues. Sadly, these environmental hijinx are happening in conjunction with the US and global economies being destroyed by greedy governments preparing to cash in on new industries they have incentivized.