Earth is Never in Equilibrium

[Guest guest]

Earth has had ice ages and warmer periods when alligators were found in Spitzbergen. Ice ages have occurred in a 100,000-year cycle for the last 700,000 years, and there have been previous interglacials that appear to have been warmer than the present despite lower carbon-dioxide levels. More recently, we have had the medieval warm period and the little ice age. During the latter, alpine glaciers advanced to the chagrin of overrun villages. Since the beginning of the 19th century, these glaciers have been retreating. Frankly, we don’t fully understand either the advance or the retreat, and, indeed, some alpine glaciers are advancing againhttp://just-me-in-t.blogspot.com/2010/04/earth-is-never-in-equilibrium.html