Holocene Climatic Change, 14C Wiggles and Variations in Solar Irradiance
Evidence from the advances and retreats of alpine glaciers during the Holocene suggests that there were at least 14 century-timescale cool periods similar to the recent Little Ice Age. Here, we examine the hypothesis that these cool periods were caused by reductions in solar irradiance. A statistically significant correlation is found between the global glacial advance and retreat chronology of Rothlisberger and variations in atmospheric 14C concentration. A simple energy-balance climate model is used to show that the mean reduction of solar irradiance during times of maximum 14C anomaly like the Maunder Minimum would have to have been between 0.22 and 0.55% to have caused these cool periods. If a similar solar irradiance perturbation began early in the 21st century, the associated climate effects would be noticeable, but still considerably less than those expected to result from future greenhouse gas concentration increases.
Philosophical Transactions of the Royal Society of London Series A
- Pub Date:
- April 1990