Publisher's Synopsis
The calibration of carbon 14 dating by dendrochronology has yielded evidence of an approximate 200-year period in the carbon 14 generation rate in the high atmosphere. Measurements of Beryllium 10 in ice cores have provided additional evidence for this variation in cosmic rays, which must be attributed to changes in the magnetic activity of the sun. Historical observations also show such a modulation of the 11-year sunspot cycle with a similar period. Therefore, the question is whether variations in the total energy output of the sun have had effects on the climate. Such variations are of increasing interest for archaeologists and historians. This new evidence is relevant to interpreting global temperature changes over the past 100 years and to discussions on the greenhouse effect.