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Otterella
08-04-2010, 06:24 PM
For a war-torn Earth to repair itself without people around to keep mucking it up?

Chris P
08-04-2010, 06:44 PM
Depends on what you mean by "repair itself." Do you mean it's pre-war condition? Or its virgin, pre-human state? And in which way? Return of all the animal and plant species? Complete degradation of any pollutants? There are numerous studies of what happens when an area is abandoned, or when it is destroyed, such as Krakatoa island.

In some ways, the earth will never "repair itself." Extinction is forever, and any species lost would of course no longer contribute to the new ecology. Soils that were ruined by irresponsible agriculture will likely never be as productive as they were. The planet has always been changing, and there never really was "a way it used to be"; it's always been on its way to being different. What would happen, in the absence of human input, is that new patterns of species succession and a new ecology would develop. These would be in a relatively stable state but still progressing and changing at a much slower rate.

TWErvin2
08-04-2010, 07:18 PM
For a war-torn Earth to repair itself without people around to keep mucking it up?

Otterella,

There recently was a TV documentary series, Life after People, which speculated on this. It examined how long it would take for human cities and structures to deteriorate and for nature to overtake such cities.

It ran (or is still aired) on the History Channel. It doesn't examine or explore 'why' or 'how' humanity disappeared, just what happens once all people are gone.

It also speculated somewhat about the altered flora and fauna. This series might answer some of your questions, or at least give you some ideas.

Check out the link for more information: Life After People (http://www.history.com/shows/life-after-people) (History Channel Link).

mirandashell
08-05-2010, 12:32 AM
There was also an interesting documentary about what's happening at Chernobyl since the accident.

SF4-EVER
08-05-2010, 01:26 AM
Otterella,

There recently was a TV documentary series, Life after People, which speculated on this. It examined how long it would take for human cities and structures to deteriorate and for nature to overtake such cities.

It ran (or is still aired) on the History Channel. It doesn't examine or explore 'why' or 'how' humanity disappeared, just what happens once all people are gone.

It also speculated somewhat about the altered flora and fauna. This series might answer some of your questions, or at least give you some ideas.

Check out the link for more information: Life After People (http://www.history.com/shows/life-after-people) (History Channel Link).

This sounds very similar to the book The World Without Us (http://www.amazon.com/World-Without-Us-Alan-Weisman/dp/B001C2E0QK/ref=sr_1_1?s=books&ie=UTF8&qid=1280955354&sr=1-1).

Otterella
08-05-2010, 08:04 AM
Yeah, I saw some episodes of that show, but I had some problems with it. It was based on the assumption that humanity was just gone. No war, no disease, no apocalypse, just *poof*. Even if the entire population of Earth left in spaceships, the assumption was they left all their pets and food and stuff behind. It seemed like a totally unrealistic premise. Or rather, totally lacking in any premise at all.

As far as what exactly "repair itself" means, take it as you like. Mostly, how long would it take for a desolate wasteland to support human life again, if humanity was enclosed in a handful of self-sustaining population-controlled cities.

Chris P
08-05-2010, 06:28 PM
As far as what exactly "repair itself" means, take it as you like. Mostly, how long would it take for a desolate wasteland to support human life again, if humanity was enclosed in a handful of self-sustaining population-controlled cities.

My favorite reply: Depends. If the landscape was simply burned and there was no loss of topsoil, then almost immediately; that's how slash-and-burn agriculture works (at least initially). Even from atomic weapons, Hiroshima and Nagasaki were reinhabited almost immediately after the attacks, but of course they had support from outside. If all the topsoil eroded away or was literally burned off (such as what happens in catastrophic forest fires) it would take much longer. You might want to take a look at studies from the Amazon on the progression of rain forest, slash-and-burn, abandonment, and regeneration.

Hallen
08-05-2010, 10:06 PM
Yeah, it totally depends on what the destruction level was and how widespread it was and what type of destruction it was.
It could be anywhere from a 50 years to 50,000 years. In the grand scheme of things, natural processes can work very quickly to "rebuild". If there is something toxic left over, or if the planetary climate is disrupted greatly, or some other form of massive change, then yes, it will take a long time to recover. It will be a blink of an eye in planetary time scales, but it will be a long, long time in human time scales.

Soils that were ruined by irresponsible agriculture will likely never be as productive as they were.
That's not really true. Again, it depends on destruction levels, but soil regenerates itself via new layers of OM and the natural processes that create soil in the first place. It wouldn't take long for soils to regenerate after farming ceased in an area where there were the right conditions for that soil to exist in the first place.