The Little Ice Age-1300 to 1850
Posted by Don in Hollister on November 19, 2005 at 19:18:43:

Hi All. The Little Ice Age may be a little off topic in regards to earthquakes, but might not be in regards to volcanoes. I know one thing for sure. It may have started a lot earlier then I thought and lasted a lot longer then I thought. I know I would have loved to have seen people walking across New York Harbor from Manhattan to Staten Island when it froze. It would have been even funnier to see Eskimos paddling their kayaks onto the shores of Scotland. Have to wonder though if that really did happen. Take Care…Don in creepy town

“Scientists have identified two causes of the Little Ice Age from outside the ocean/atmosphere/land systems: decreased solar activity and increased volcanic activity. Research is ongoing on more ambiguous influences such as internal variability of the climate system, and anthropogenic influence (Ruddiman). Some have also speculated that depopulation of Europe during the Black Death and the resulting decrease in agricultural output may have prolonged the Little Ice Age.”

“One of the difficulties in identifying the causes of the Little Ice Age is the lack of consensus on what constitutes "normal" climate. While some scholars regard the LIA as an unusual period caused by a combination of global and regional changes, other scientists see glaciations as the norm for the Earth and the Medieval Warm Period (as well as the Holocene interglacial period) as the anomalies requiring explanation (Fagan).”

“Solar activity”

“Solar activity events recorded in radiocarbon. During the period 1645–1715, right in the middle of the Little Ice Age, solar activity as seen in sunspots was extremely low, with some years having no sunspots at all. This period of low sunspot activity is known as the Maunder Minimum. The precise link between low sunspot activity and cooling temperatures has not been established. But the coincidence of the Maunder Minimum with the deepest trough of the Little Ice Age is suggestive of such a connection [17]. Other indicators of low solar activity during this period are levels of carbon-14 and beryllium-10 [18].”

“Volcanic activity”

“Throughout the Little Ice Age, the world also experienced heightened volcanic activity. When a volcano erupts, its ash reaches high into the atmosphere and can spread to cover the whole earth. This ash cloud blocks out some of the incoming solar radiation, leading to worldwide cooling that can last up to two years after an eruption. Also emitted by eruptions is sulfur in the form of SO2 gas. When this gas reaches the stratosphere, it turns into sulfuric acid particles, which reflect the sun's rays, further reducing the amount of radiation reaching the earth's surface. The 1815 eruption of Tambora in Indonesia blanketed the atmosphere with ash; the following year, 1816, came to be known as the Year Without A Summer, when frost and snow were reported in June and July in both New England and Northern Europe.”

http://www.discover.com/web-exclusives-archive/a-new-ice-age-day-after-tomorrow/

http://en.wikipedia.org/wiki/Little_Ice_Age