Where did the little ice age go?
Studies of the ice cores drilled in the Greenland glacier suggest a pattern of cold spells based on the superposition of two cycles: 80 years and 180 years. The causes of this complex pattern is not known (but there is some C-14 evidence that the 180 cycle may be due to changes in the sun). At any rate this pattern fits all the cold spells since 1200 A.D.–except that we should now be in a cold period that should have started about 1950 and continue until about 2000 A.D. These results were published in the 1970’s. The cycles are associated with Willy Dansgaard, and are discussed in the chapter on the history of climate in the text book GEOLOGY TODAY from CRM. See Figure 1 for the past record of warm and cold spells since 1200 AD, and the predicted “little Ice Age of 1970-2000 AD. At about the same time, the proponents of the greenhouse effect were predicting a global warming, but they did not consider the natural climate cycle. Since neither the predicted warming nor the predicted cold
