Led by paleoclimatologist Ulf Büntgen, researchers at Switzerland's Federal Research Institute for Forest, Snow and Landscape studied over 9,000 samples of tree ring data to create a 2,500-year history of European climate fluctuations.

Comparing these to major historical events, the scientists determined a link between climate and society. They found, for instance, that the abundant crops nourished by wet and warm summers helped support prosperity during Roman and later in European Medieval times, and that the fall of the Western Roman Empire occurred during a period of drought and increased climate variability, which would have adversely affected food supplies.

In another example, combined cold and wetter summers around 1300 coincided with plague and famine that led to the loss of nearly half of Europe's population within the next 50 years. The researchers concluded that climate change events which positively or negatively affected agricultural production amplified political, social and economic situations in the past, and may have implications for our modern era.

Dr. Büntgen and colleagues at the Swiss Federal Institute for Forest, Snow and Landscape, we appreciate your comprehensive analysis that shows the connection between physical and social events. May such revealing comparisons remind us to strive ever more urgently for lives of balance and harmony with nature. As during an October 2009 videoconference in Indonesia, Supreme Master Ching Hai has often discussed the importance of the moral aspect that determines a civilization's sustainability.

http://news.sciencemag.org/sciencenow/2011/01/fall-of-rome-recorded-in-trees.html?rss=1 , http://voices.washingtonpost.com/postpartisan/2011/01/does_climate_change_explain_th.html, http://www.swissinfo.ch/eng/science_technology
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