Roman rise and fall 'recorded in trees'

[Demeter]

http://www.bbc.co.uk/news/science-environment-12186245

An extensive study of tree growth rings says there could be a link between the rise and fall of past civilisations and sudden shifts in Europe's climate. A team of researchers based their findings on data from 9,000 wooden artifacts from the past 2,500 years. They found that periods of warm, wet summers coincided with prosperity, while political turmoil occurred during times of climate instability.

The findings have been published online by the journal Science.

"Looking back on 2,500 years, there are examples where climate change impacted human history," co-author Ulf Buntgen, a paleoclimatologist at the Swiss Federal Research Institute for Forest, Snow and Landscape, told the Science website. "Archaeologists have developed oak ring width chronologies from Central Europe that cover nearly the entire Holocene and have used them for the purpose of dating artefacts, historical buildings, antique artwork and furniture," they wrote. "Chronologies of living and relict oaks may reflect distinct patterns of summer precipitation and drought." Once they had developed a chronology stretching back over the past 2,500 years, they identified a link with prosperity levels in past societies, such as the Roman Empire.

"Wet and warm summers occurred during periods of Roman and medieval prosperity. Increased climate variability from 250-600 AD coincided with the demise of the western Roman empire and the turmoil of the migration period," the team reported. "Distinct drying in the 3rd Century paralleled a period of serious crisis in the western Roman empire marked by barbarian invasion, political turmoil and economic dislocation in several provinces of Gaul."

Dr Buntgen explained: "We were aware of these super-big data sets, and we brought them together and analyzed them in a new way to get the climate signal.
If you have enough wood, the dating is secure. You just need a lot of material and a lot of rings."

[InvisibleTouch]

1. Very interesting.

Climate instability would limit crop growth, so less food = more desperate people = social and political turmoil. Makes sense.

[Hydra]

2. Mother nature always wins

But someone is always trying to beat the system...

[CrispyQ]

3. We won't have that problem - we cut them all down.

One of my fave bumper stickers:

Urban Sprawl - Cut all the trees down & name streets after them

[Uncle Joe]

4. I also believe that modern warfare adversely affects climate change.

I saw a graph of global temperatures; over the past 100 years or so floating around here somewhere and there was a major spike in temperatures during WWII.

Thanks for the thread, Demeter.

[Demeter]

5. Always a Pleasure, Uncle Joe

Delighted when something I post catches your eye.

Those firestorm bombings and the devastation would be sure to affect the climate regionally....thinking of Dresden, Hiroshima and Nagasaki in particular.

[Uncle Joe]

7. Yes with all the fires and bombings, I imagine the amount of carbon burned and released

into the atmosphere was greatly increased over that of peacetime Earth.

Peace to you, Demeter,:hi:

[bhikkhu]

6. This points out the high sensitivity of climate to CO2 levels

...if it is correct. If human impacts on CO2 levels through the cutting down and burning of forests, and clearing of forested land for cultivation, were sufficient to cause climate changes back then, we are definitely in for it now.

However, as good as the correlation is, and as likely as the interpretation is, I still wouldn't walk to have to argue it as "proven fact" to a skeptic.