I recently read a book called The World Without Us. There was a TV series a couple years ago of the same name, perhaps based on or inspired by this book. Basically, it is about how things would fare if, in one sudden instant, all humans simply died or disappeared in a sort of Rapture or human-specific disease (think biological weapons), or whatever. A thought experiment.
I think I enjoyed the TV show better, because the visuals help, but the book was interesting. Both go into how long buildings (and everything else human-made) would last. Surprisingly not very long for most things. Concrete dissolves in acidic rain, and if there's rebar in it, it goes even faster, since concrete is permeable and when the iron rusts, it expands, crumbling the human-made stone. True stone (granite, marble) lasts millenia, but concrete, steel and glass is cheaper, so our empire's buildings will not inspire people two or three hundred years from now. Besides stainless steel and plastics, very little trace of us will be lasting.
Water turns out to be the major force of destruction. A quote in the book goes, "if you want to tear down a barn, cut an 18 inch hole in the roof and stand back" or something like that. The rot sets in, comes through where roof nails rust, or the plywood glues decay or dissolve, or when the window caulk crumbles, or animals chew holes in. It doesn't take long after that.
There are places in Detroit, abandoned schools, homes, hotels, factories, and so on, where urban explorers like to haunt. I never went myself but I've seen blogs and photos and such about it, plus the afore mentioned TV show which talked about Gary, Indiana, in a similar state of abandonment and decay. Trees growing under broken roofs, pigeon guano and windblown leaves and dirt creating new soils and hastening the rot and rust, root-swell and the freeze-thaw cycle breaking down what was built. Of course, looters, explorers, and vandals hasten this process, but either way it goes quick. There are whole city blocks in Detroit that could be better named prairie than urban. The houses are all gone, burned by vandals or demolished by the city. Feral dogs roam in packs, deer move in, the game-bird population swells during hunting season, there in the new refuge, where the center is hollowing out in this late stage of our modern urban development cycle. Post-worthy all on itself, really.
The thing that really got me thinking, though, was the chapter late in the book about Houston. With all its refineries, chemical plants, and heavy industrialization, and the talk about nuclear plants in general. This is important to consider not merely for the fun of wondering what the world would look like if humans disappeared, how Nature would fare. No, this is important because of what could result from "system disruption." We live in frightening times. Climate is changing, the West is burning, the seas will be rising, cities flooded by the rising tide and destroyed by storms, Peak Oil is here, the Hollow State is here, confidence in the future is looking pretty bad. Who knows what could happen in the next decade or two? The collapse of our modern system is not as far fetched as it was ten, fifteen years ago.
So what about all these highly technical, delicate, and unfathomably dangerous and toxic systems we have. When the power goes out, when the oil and the money stops flowing, who is going to man the power stations, the chemical plant safety systems. It's not terrorism I worry about, and maybe not even World War Three, but systemic failure of these just-so systems and long supply lines is possible and terrifying.
Complex systems WILL fail. I read in the book Deep Survival about this, it's an aspect of Chaos Theory. The example was a pile of sand in a kitchen timer. Flip it over and watch. The sand piles up, up, up. There are little collapses of grains cascading down, but once in a while, the big slip happens, and the whole mound collapses. That may not seem a complex system, but it is, in a way: thousands of irregular-shaped grains piled up randomly and with stress (weight of more sand) being continually added. This model applies to survival disasters, like mountain climbing (all those many factors: snow conditions, sunlight and temperature, the ropes, knots, and anchors, human choice, etc); how much more so must it apply to what goes into creating and maintaining a working nuclear power plant?
I recently saw a show about nuclear weapons, the arms race, and disarmament, and one segment talked about near-accidents. A bomber carrying nukes accidentally drops one in South Carolina, and 14 of 15 redundant safety systems failed. One switch was all that stood between us and a nuclear explosion in a populous region. That was one example in a long list given: nuclear subs sinking with numerous warheads never recovered, false alarms at command posts (on both sides of the Iron Curtain), mid-flight collisions of bombers carrying nukes, the list went on.
And then look at Japan's recent tsunami, and the nuclear disaster. The earth can shift, the weather can turn, and suddenly we're swamped in toxins. I worry every time a hurricane looks like it might hit Houston. And how many chemical and nuclear plants and storage facilities are located in the area of the lower Ohio River and on down the Mississippi? The New Madrid Fault could slip at any time, and who knows what could happen then. Last time it did, in 1812, the Mississippi jumped out of it's bed, flowed backwards for a time, and finally took a new course. Chimneys toppled in Maine, sidewalks cracked in Washington, DC. Back then, the immediate area of the quake was almost unpopulated, save for a few white settlements and of course the Native American villages. Now, we have heavy industry, major cities, and a lot at stake.
So. If humans disappeared, Nature would suffer in the short run. The chemicals and radioactivity would be hard on selected regions for a good while. But left alone, Nature clenses itself rather well. Even if we remained, things could be alright if we'd stop piling on the hurt to the environment and let the healing procede. Truly, the main problem with the human effect on the world is what it does to humans. Yes, extinction is tragic, and the individuals that are dying would surely like to live. But on the whole, the Earth doesn't care, and Nature will fill the niches, or it will have simpler ecosystems. Whether there are lawns, or prairies winking at the sky with a million wildflowers, doesn't matter except in the minds of humans. If things went back to bacterial sludge, so be it. Evolution would start out again, perhaps. And of course, eventually the sun will expand and boil the oceans away and that will be the end of it. Nature, evolution, the Earth, none of them care about any of that. Humans do, or, at least they can.
Environmentalism is about people. Keeping people healthy and well, physically, aesthetically, spiritually, economically, et cetera. Naturally, all is One, so this means that the highest good for humanity is also that for the natural systems; biodiversity is resilience. So it does tie back in to saving the forest for the forest's own sake, because it's sake and ours are the same in the end. But my worry about system disruption in terms of chemical spills and nuclear disasters is more about the horrors it will cause for society, for people. Chernobyl is already basically a nature preserve, though too radioactive for humans thus far.
And that's sort of the point, right? We could be walking into a world-wide Chernobyl. Humans aren't about to be erased from the world, so we need to be asking ourselves, just what kind of future do we want for ourselves? With so much hanging by a thread, we should be acting far more cautiously than we are, with our cavalier attitude, building cities on fault lines, toxic industry in the path of hurricanes and on the shores of rising seas, arming ourselves to the teeth and powering our cities with things we have no way of disposing of safely, simply waiting for some panicking fool in a bunker to push the big red button or for the safety systems to fail. Yeah, Nature will get by, and even some level of society will get by, but is this sort of progress worth the suffering?
Sad thing is, we will do nothing to change. We know we're warming the planet, but nothing is done. There's even a big new coal rush happening in Africa. We know how bad it is, but we keep making it worse. We build one Sword of Damocles after another. Why more people aren't lost in despair is beyond me.