Two articles in this Friday’s issue of Earth Current report on new findings about the impact of climate change on human society.
The first study drew new conclusions about why and when our human ancestors moved out of Africa. “Up till now we thought of cultural developments leading to the opportunity of people to move out of Africa,” said study co-author Hans-Peter Uerpmann. “Now we see, I think, that it was the environment that was the key to this.” The study notes that climate change about 130,000 years ago would have made travel out of Africa via the Arabian Peninsula easier by lowering sea levels and creating lakes and rivers in the Arabian Peninsula. These new findings were spurred by the recent discovery of several 120,000-year-old tools with distinctly African design at site in the United Arab Emirates.
Humans Left Africa Earlier, During Ice Age Heat Wave. National Geographic News, Jan. 27, 2011.
The second article, published in the journal Science, explores how climate changes in Europe in the past 2,500 years can be linked to major social upheavals. For example, the summers at the times when both the Roman Empire and the Middle Ages were at their zenith were relatively warm and climate was stable. The decline of the Roman Empire coincided with a period of colder and more variable climate. “The cultural revival of the early Middle Ages occurred as both temperatures and rainfall began to increase with the dawn of the 7th century. It is also possible that climatic factors may have contributed towards the spread and virulence of the Black Death after 1347.”
Climatic Fluctuations in Last 2,500 Years Linked to Social Upheavals. Science Daily, Jan. 27, 2011.