As noted previously, the sun is the single greatest factor affecting Earth’s temperature. During one seventy-five year period, now called the Maunder Minimum (from 1645 to 1715), Sunspot activity virtually ceased and temperatures on Earth fell enough to cause a “Little Ice Age” of severely cold weather across Earth’s northern hemisphere. The winters were so cold that the canals of Holland froze over.
During the 11th and 12th centuries, there was a large warming coincident with enhanced solar activity. The Vikings inhabited Greenland during this period, and they abandoned their settlements when the climate there grew colder.
Other solar minimums:
1. The Oort Minimum (1010-1050)
2. The Wolf Minimum (1280-1340)
3. The Spoerer Minimum (1420-1530)
The sun cycles regularly. The best known solar cycle is the eleven year cycle. Other cycles, some of them hundreds or thousands of years long, have been posited.
Check out <http://www.ucar.edu/news/releases/2006/sunspot.shtml> concerning a computer model of solar activity and note especially: “The scientists have confidence in the forecast because, in a series of test runs, the newly developed model simulated the strength of the past eight solar cycles with more than 98% accuracy.” That is the way to validate a computer model: Feed it historical data and see if it can accurately predict what actually happened later.
And that is the problem I have with current Global Warming computer models. Given historical data, they have incorrectly predicted what then occurred. In some cases, they predicted the opposite of what occurred. So I don’t trust or believe them. Neither should you.
At the power plant (where I used to work), after we computerized our boiler and burner controls, we developed computer models to control each. The key is to identify the predictors of future values for any given variable. Sometimes, the things you think are the key predictors and not in fact as predictive as other factors that do not appear, on the surface, to be important at all. If you ignore these latter variables, your model will be flawed.
And if you construct your model while intentionally ignoring factors which you don’t think are — or don’t want to be — influential, your model will be flawed.
A computer model is only as good as the assumptions made by its authors. I believe that the advocates of Man Made Global Warming are so certain of their Greenhouse Gas Theory that they minimize the influence of solar activity in their models.
There’s no way around it: if the greenhouse gas theory were correct and the climate models were accurate, then the high latitudes would be warming the fastest. But they aren’t. They are barely warming at all on timescales where real climatic variation counts (and by that I mean less than 50 years). Likewise, the models predict greater temperature increases over the oceans than over land (or maybe it’s the other way around; I don’t recall) and the actual increases are just the opposite of predicted. Until they can get such Big Picture items working properly in their models, I’m not about to believe the details.