Friday, January 25, 2008

Anthropocene Age

It is been proposed by a group of British geologists that the Holocene Age is over and that the new era should be named the Anthropocene Age to reflect the clear commencement of human induced geological change. The idea appears compelling although the fact is that human activity has modified the geological record since the onset of the Holocene which began with the Pleistocene nonconformity.

In fact our incredibly stable climate that has permitted the global rise of humanity as an organizing agent is unique to the Holocene and ended the million year northern ice age brought on be the closing of Panama. The key feature of this era has been the stable temperature range that has fluctuated only over a one degree range. Prior to that the global temperature galloped back and forth over a range of several degrees.

I have already explained now this major break came about in my item tittled the 'Pleistocene Nonconformity'.

The fact is that man's role has been paramount throughout the Holocene. The major change that has occurred in the past 200 years is that we have mastered the art of extracting geological carbon and burning it. I expect this to continue until it is all consumed, even if conservation drags the process out for a thousand years.

Since all this carbon has already overloaded the capacity of the biosphere to absorb it, as can be reasonably expected, we are now preparing to remove this carbon back into a sequestration protocol. Otherwise we are returning to the Carboniferous Age, when the globe early on was covered in huge accumulations of plant material.

It is here with the onset of terra preta sequestration in the soils that a true geological break will take place. Soils are like living organisms that live in the air soil contact and will actually migrate with any slow change of the surface. Otherwise all the sediments on earth would contain long sequences of buried carbon bearing soils. This is simply not true. In fact the main source of coal appears to be buried peat bogs were oxygen was quickly cut off. Which tells us that in a normal aerated soil that deeper plant carbon is recycled back to the surface by various mechanisms.

On the other hand terra preta soils will have a pure carbon component that will resist ever been easily broken down. That means that over thousands of years, that accumulating soils will begin to leave behind soils that are carbon rich yet already outside the growing zone. This will be a unique signature that will certainly be apparent in the geological record.

Since I anticipate that atmospheric water harvesting will soon open all temperate climes to plant husbandry of some sort, even if it is a Douglas fir on top of Ayer's rock, this means that a global geological event is really in the offing that will be more dramatic than almost any other major event. We can also expect this process to be sustained for as long as mankind occupies this planet, a time period surely as long and sustained as the reign of the dinosaurs. At the same time, the incipient soils will be built and nurtured with terra preta providing the signature.

Compared to that type of epoch, the ten thousand years of the Holocene is merely a prelude.

It may seem to some that this is all a bit optimistic, yet all the tools for a totally sustainable globe have already been described. Even some of the lesser perceived difficulties on the way to pure sustainability are resolvable.

I particularly point out that terra preta in will very likely allow the total recycling of the nutrient load eliminating dependence on chemical fertilizers. At the very least, it should reduce out consumption by an order of magnitude or two. In fact the fertilizer free exploitation of established terra preta soils for decades say exactly that.

It is easy now to imagine a human future in which mankind has small special purpose urban ares and is mostly living in small agrocomplexes, each in harmony with its square mile of farm and woodland. Such could readily support global populations vastly larger than the present.






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