The 2009 Farmer’s Almanac predicts global cooling over the next 50 years based on lack of sun spots and, well, common sense.  If you haven’t heard of sun spots, they are caused by magnetic activity in the sun that leads to hotter surface temperatures and a warmer Earth.  Odd that an immense ball of fire in the sky might have something to with our termperatures, but there you go.  The last time the sun spots stopped was also the last time we had a “mini ice age” from, I dunno, 1750 to 1825 or something.  Anyway, historical records. There are few if any historical records, however, showing that cow farts and gasoline engines cause global warming.