[Human]

Interesting video:

http://permaculturenews.org/2012/11/10/ ... edx-video/

[dinopello]

Can't watch the video now, but I noted the text

Over these centuries there were a few significant dips in average global temperatures, and there is a lot of evidence to show that these cooling periods were caused by rapid regional revegetation in Europe, Eurasia and the Americas. In this case the rapid revegetation was caused, not by the work of such educational institutes as our own, but rather because of a sudden die-off of human population numbers, due to disease.

Reminds me of whoever said "don't worry about saving the Earth, she'll be fine - worry about saving ourselves".

There are many that say humans can't control what happens, and literally I think they are correct. It does make sense to me though that if we want to be so prolific at expanding or even maintaining our numbers we have to pay more attention to our activities and their impact on the Earth. Any attempt by humans to 'manage' large scale things like carbon in the atmosphere will of course be imperfect and I'm sure we'll royally screw up at times with unintended consequences but I guess we need to weigh that against just waiting for nature to care of things her way.

[Narz]

Interesting theory, I've never considered the Black Plague/IceAge link before.

I saw a really sad documentary called "The Charcol People of Brazil" about folks (very poor ones usually) who burn down trees to make charcol which is used in making pig iron. Most of them seem to know what they are doing is wrong (cutting down a 100 year old tree even) but they feel they have no choice. Of course many of them have lots of children but I can't judge them so much for that, their children are probably one of the few comforts they have & maybe they feel since they're lives are pretty meager they can at least have hope for their children.

I hope somehow someway more people can actually make a living via environmental regenerative activities. Part of why I'm not very well off financially myself (besides laziness) is I don't take jobs I feel are going to be destructive.

The key for permaculture is to help those who need it most ultilize it so they don't have to grovel to the world-destroyers for pennies. If I didn't have a kid myself I'd be tempted to go abroad & try to help folks on the edge of empire take the power back (and probably learn a ton myself from them).

[dissident]

At the 10 ppmv level of CO2 change there are many other factors which are more important, so this theory is BS.

1) CO2 is a well mixed gas (pole to pole in a year), so there would not be a regional anomaly sitting over Europe acting to cool it.

2) The Pacific decadal oscillation (PDO) was stalled in a single mode for centuries at a time (http://en.wikipedia.org/wiki/Pacific_de ... scillation). The Atlantic multidecadal oscillation (http://en.wikipedia.org/wiki/Atlantic_m ... scillation) tends to be anti-correlated to the PDO. The Atlantic oscillation is also correlated with regional temperatures. Together, these facts indicate that it was sea surface temperatures that were a significant factor in European "warmings" and "mini ice ages" in the last 1000 years.

2) Aerosols are also a big deal, much more than the tiny CO2 change they talk about. The period in question 1300-1900 AD happens to correspond to the development/industrialization of Europe. Even before the steam engine, there would have been an increase of smoke emissions from population growth. Europe was deforested over this period of time as well. Trees are effective aerosol removers and soil protectors. So as they were cleared the persistence of aerosols in the air increased and there was a new source of aerosol from wind blown dust and soil. That is in addition to the trees being burned to clear land acting as aerosol sources themselves. The increased aerosol burden over Europe would act to produce cooling of surface temperatures by blocking sunlight.