Climate a factor in Rome's rise and fall -study
By Alister Doyle, Environment Correspondent
OSLO (Reuters) - Climate change seems a factor in the rise and fall of the Roman empire, according to a study of ancient tree growth that urges greater awareness of the risks of global warming in the 21st century.
Good growth by oak and pine trees in central Europe in the past 2,500 years signalled warm and wet summers and coincided with periods of wealth among farming societies, for instance around the height of the Roman empire or in medieval times.
Periods of climate instability overlapped with political turmoil, such as during the decline of the Roman empire, and might even have made Europeans vulnerable to the Black Death or help explain migration to America during the chill 17th century.
Climate shifts that affected farm output were factors in "amplifying political, social and economic crises," Ulf Buentgen, of the Swiss Federal Research Institute for Forest, Snow and Landscape Research, told Reuters. He was lead author of the report in Friday's edition of the journal Science.
The review, by experts in Germany, Austria, the United States and Switzerland, extended study of tree rings 1,000 years beyond previous analyses. Thick rings indicate good growth conditions while narrow ones mean poor.
The study said the evidence, helping back up written records that are sparse in Europe more than 500 years ago, "may challenge recent political and fiscal reluctance" to slow projected climate change in the 21st century.
Modern societies seem less vulnerable but "are certainly not immune" to climate change, especially because migration "will not be an option in an increasingly crowded world," they wrote.
The U.N. panel of climate experts says that greenhouse gases, mainly from burning fossil fuels, will lead to more droughts, floods, heatwaves and rising sea levels that could swamp low-lying island states. Continued...