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Early anthropocene climate change

post #1 of 8
Thread Starter 

i have had an idea since i learned about interglacials at school that there was something funny about this one. the strangely flat top, where all the previous ones peak sharply then sawtooth down back into the next glacial period.

reading some anthropological workgave me an idea of the vast scale of deforestation by mesolithic peoples onwards.

'the bog people' for starters, the amount of wood that went into the early lake settlements, and the trackways, was staggering, and that was a fraction of what was burned and cleared in europe post 10000 BC.

 


recently i found this is a genuine scientific theory, the early anthropocene hypothesis.

en.wikipedia.org/wiki/Early_anthropocene

(is it ok to use wiki on here?)


this morning i found this latest article on it;
Did Early Global Warming Divert A New Glacial Age?

www.sciencedaily.com/releases/2008/12/081217190433.htm

 

 

 

post #2 of 8

Sure you can link any other sites.  And by the way, rather than pasting the URL into your post, you can just highlight words and use the linking tool to turn them into links.  It looks like a planet with a chain link in the upper right message window.

 

This theory really intrigues me. The same thought had occurred to me (about the unusually stable interglacial), but I thought we were just lucky to somehow be in an extensively stable interglacial cycle.

It's tough to believe that such a small anthropogenic effect could cause such a significant climate change as to extend an interglacial cycle. If it's true, it really gives you a sense as to how much climate change our modern emissions could cause.

The other key part about this study is that again it shows that according the planet's natural cycles, we should be in a cooling phase right now, not a rapid warming phase.  So once again that invalidates the argument that the current warming is just a natural cycle.

 

Very interesting.  I'll have to read up on this theory some more later.


Edited by dana1981 - Thu, 18 Dec 2008 20:29:20 UTC
post #3 of 8

It's an interesting theory, though I think it would be taken more seriously if it also had some estimate of CO2/CH4 concentrations at the time.

 

...but then again even if there was an increase in CO2, couldn't it just be the result of warming brought on by the milankovich cycle that brought on the holocene optimum in 7000 BC?

 

It just doesn't seem like a world population of 20,000 could cut down enough trees to stave off an ice age, especially considering that European deforestation was "miniscule" until about 1000 BC. (From this book)

 

post #4 of 8
Thread Starter 

i would have thought a bit more than miniscule, but maybe i'm being euro-centric. thinking of eire in particular, there is a folk tale that tells of 'all the men of ireland poured all the wood of the land into the bog' to make a bridal path (which is still there, a huge wooden trackway across the centre of the island) i'll look for the reference. and there are no trees harldy there now, thats for sure, and havnt been for centuries, thats why they burn peat.

but there's australia, there is some evidence that the early aborigenes burned it into a different state over the first few thousand years they were there, from mainly wooded and thick scrub to a mosaic of open grass and scrub with woodland.

and china, the rice paddies, and the rise of herding instead of hunter/gathering all across the asian and russian steppes.


Edited by gerda - Fri, 19 Dec 2008 00:21:41 GMT
post #5 of 8

Here's another article on pre-historic anthropogenic climate modification:

 

http://www.theatlantic.com/doc/200203/mann

 

 


Edited by gcnp58 - Fri, 19 Dec 2008 19:31:14 GMT
post #6 of 8
Thread Starter 

fascinating gc. the idea of waves of disease spreading out from the settlers, devastating the population right across the land, awful.

the built up islands and quays in the amazon very interesting too, there was a section on the florida keys in my old 'bog people' book (not online unfortunately), they built the land up too, and had long quays and harbours made of big shells and wood.

 

i read this recently that ties in to the plagues idea;

New World Post-pandemic Reforestation Helped Start Little Ice Age, Say Scientists

ScienceDaily (Dec. 19, 2008)

 

 

oh, and you can make a live link by using the little world with chain link icon above the reply box.

 

i found the original article that re-aroused my interest in this subject of early a.c.c.;

The ice age that never was

New Scientist 03 September 2008 by Hazel Muir

 


Edited by gerda - Fri, 19 Dec 2008 17:37:27 GMT
post #7 of 8

It's probably not coincidental that the rise in methane also occured about the same time cattle were domesticated

 

Small changes in forcing can produce large changes in climate, that's a fact.  What I find amusing is that skeptics will constantly claim small changes in solar output are critical in climate yet deny the huge forcing from anthropogenic CO2 will have any effect. 

 

I filed the Atlantic article and the one you cite under "plausible theory but would get you taken apart intellectually by a climate scientist if you claimed were absolutely true." 

 

:-)

 

post #8 of 8
Thread Starter 
Quote:
Originally Posted by gcnp58:

I filed the Atlantic article and the one you cite under "plausible theory but would get you taken apart intellectually by a climate scientist if you claimed were absolutely true." 

 

:-) 

 

i file stuff like that in 'anthropology' which is 80% guesswork anyway. in between carbon dating and folk tales. its a sliding scale of confidence, but doesnt mean there is not some value in the lower end, any more than in the physicists though-experiments. theoretical earth science?

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