The end of the Bronze Age at WUWT (not really!)

In a bit of a change from the norm of late at WUWT, Anthony Watts decides to copy and paste a press release about the end of the Bronze Age. No "claim" headline. Just a straight up press release (archived here).  I think he screwed up the title of his article talking about the "collapse of the Bronze Age", when he should have referred to the "collapse of the population", but other than that he made no comment. He hasn't done that in a while - posted a straight article without any dog-whistles. But don't get excited. I don't think it means that WUWT is about to convert to a science blog (or emerge from its metaphorical Bronze Age).

The paper talks about a population collapse toward the end of the Bronze Age, occurring around 800 BC. (Don't ask me, I'm not an historian - but that's what the paper says.) Apparently it was "widely thought" that it was climate change that caused the population to decline. Not so, say Professor Ian Armit and the other the authors of this new paper. The population started declining before the European climate became colder and wetter.

Here are some Wikipedia entries of relevance - the timeline of the Bronze Age in Europe; with more detail here; and the Iron Age which followed; with another article on the Iron Age in Europe - and a timeline.

You can read about the paper here at ScienceDaily.com. If you've a subscription, you can read the paper itself at PNAS. It looks as if it would make an interesting read. What the work of the research team showed was:

...that human activity starts to decline after 900BC, and falls rapidly after 800BC, indicating a population collapse. But the climate records show that colder, wetter conditions didn't occur until around two generations later.

The "two generations later" was around 750 BC. The press release goes on to describe the findings in more detail:

Fluctuations in levels of human activity through time are reflected by the numbers of radiocarbon dates for a given period. The team used new statistical techniques to analyse more than 2000 radiocarbon dates, taken from hundreds of archaeological sites in Ireland, to pinpoint the precise dates that Europe's Bronze Age population collapse occurred.

The team then analysed past climate records from peat bogs in Ireland and compared the archaeological data to these climate records to see if the dates tallied. That information was then compared with evidence of climate change across NW Europe between 1200 and 500 BC.

"Our evidence shows definitively that the population decline in this period cannot have been caused by climate change," says Ian Armit, Professor of Archaeology at the University of Bradford, and lead author of the study.

Graeme Swindles, Associate Professor of Earth System Dynamics at the University of Leeds, added, "We found clear evidence for a rapid change in climate to much wetter conditions, which we were able to precisely pinpoint to 750BC using statistical methods."

According to Professor Armit, social and economic stress is more likely to be the cause of the sudden and widespread fall in numbers. Communities producing bronze needed to trade over very large distances to obtain copper and tin. Control of these networks enabled the growth of complex, hierarchical societies dominated by a warrior elite. As iron production took over, these networks collapsed, leading to widespread conflict and social collapse. It may be these unstable social conditions, rather than climate change, that led to the population collapse at the end of the Bronze Age.

According to Katharina Becker, Lecturer in the Department of Archaeology at UCC, the Late Bronze Age is usually seen as a time of plenty, in contrast to an impoverished Early Iron Age. "Our results show that the rich Bronze Age artefact record does not provide the full picture and that crisis began earlier than previously thought," she says.

"Although climate change was not directly responsible for the collapse it is likely that the poor climatic conditions would have affected farming," adds Professor Armit. "This would have been particularly difficult for vulnerable communities, preventing population recovery for several centuries." 

There you have it. Another bit of knowledge to add to what you know (or don't know, or replace what you thought you knew) and raising probably as many questions as it answers. Don't look to me for any of the questions or answers though. What I know about the Bronze Age and the Iron Age wouldn't cover a postage stamp :)

From the WUWT comments

It looks as if some of the people at WUWT are even more ignorant than I am on the subject, if that's possible. At least, I think I understand what the research found and what it was about.

 There were quite a few people who got in a bit of a tizz over what was meant by "two generations". The paper itself suggests a time period of around 50 years or so, from 800 BC when things really started to go pear-shaped, to 750 BC when the regional climate changed.

Charles Nelson decided that two generations is 70 to 80 years:

November 17, 2014 at 8:16 pm
Two generations…so what are we talking here…seventy/ eighty years?
Wow they are so wonderfully precise with their measurements!

Alan Robertson  disagreed with Charles Nelson and wrote:

November 17, 2014 at 8:57 pm
A generation is a lot closer to 20 yrs 

Dudley Horscroft figures this research lends support to the unorthodox writings of Velikovsky :)

November 17, 2014 at 9:34 pm (extract only)
“We found clear evidence for a rapid change in climate to much wetter conditions, which we were able to precisely pinpoint to 750BC using statistical methods.”

This date is remarkably close to the dating of an earth mini-catastrophe as postulated by Immanuel Velikovsky. He dates this as -747 = 748 BC. (Being a very devout, perhaps even orthodox Jew, he refused to use AD or BC in his dating.) ...

You can read more of the comments here, if you're interested.

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Ian Armit, Graeme T. Swindles, Katharina Becker, Gill Plunkett, and Maarten Blaauw. "Rapid climate change did not cause population collapse at the end of the European Bronze Age." PNAS, November 17, 2014 DOI: 10.1073/pnas.1408028111