1. The Medieval Climate Anomaly and the Little Ice Age

2. The Medieval Climate Anomaly

3. The Vikings Explore… Colonised Iceland between 870-930AD Farms prosperous in medieval times were engulfed by glaciers by 1700 Erik the Red, Thorvaldsson reached Greenland about 985AD The settlers experienced above average temperatures for the first crucial years Eastern Settlement on the south coast, abandoned by 1500 Western settlement near current Nuuk, abandoned around 1350. Sea-ice and snow probably played a role.

4. The Vikings Explore… Leif Eriksson, Erik the Red’s son, arrived in North America in 1000AD. He establishd Vínland (wineland), Helluland (slab land), Skaeling land (wretch land) and Markland (forest land). Travel between Greenland and North America would only have been possible for 2 months of the year. In years of heavy sea-ice, travel would have been perilous. Conflicts with indigenous people probably led to the abandonment of the American settlements after a few years.

5. The Little Ice Age – When was it? Three particularly cold intervals: one beginning about 1650, another about 1770, and the last in 1850, each separated by intervals of slight warming May have been independent events at different places at different times Peak cooling in Europe was in the 17 th Century Peak cooling in N. America was in 19 th Century

6. The Little Ice Age – Where was it?

7. The Little Ice Age - Volcanoes Volcanic forcing of climate over the past 1500 years: An improved ice core- based index for climate models 2008, Chaochao Gao, Alan Robock, and Caspar Ammann

8. The Little Ice Age – The Sun

10. The Little Ice Age – Conclusions Changes in the Sun and volcanic activity, coupled with changes in the North Atlantic Oscillation (the pressure difference between Iceland and the Azores), the ocean circulation in the North Atlantic, the north Atlantic storm track and feedbacks involving the quantity of polar ice and the natural release of greenhouse gases combined to give the Little Ice Age, at least in Europe and at best in the northern Hemisphere.