Sol Boutet asked for more info in his letter of Jan. 2 regarding rising snowlines, etc.
The best info I have read concerning this is in a book “Heaven and Earth,” by Iam Plimer, professor emeritus of earth sciences at the University of Melbourne and professor of geology at the University of Adelaide.
Also, Scientific American (Aug. 23, 2012) notes that May 2013 could be the peak of the 11-year solar activity cycle. Based upon historical evidence, NOAA scientists concluded that during times of increased solar activity, global warming occurs. Note: The 11-year cycle is approximate. There was a 70-year cycle (1645-1715) when there were almost no sunspots observed and the earth cooled 1.5 degrees Celsius and the corresponding “Little Ice Age” occurred.