Hows this for a scenario! http://www.dailymail.co.uk/pages/live/articles/news/news.html?in_article_id=468267&in_page_id=1770 How the world would thrive without mankind By MICHAEL HANLON Last updated at 22:56pm on 13th July 2007 Six-and-half billion - and rising. That is how many humans crowd our Planet Earth. And there is no doubt that we are wreaking terrible damage on our world. So much so that scientists talk about the "Anthropocene" - the destructive Era Of Man. Our gases are polluting the atmosphere and warming the skies. Our chemicals taint the seas and the rivers; our farms and cities gobble up the landscape, pushing flora and fauna aside like sand before a bulldozer. Our green-and-blue world is still beautiful, but it is far from pristine. Our mark is everywhere. The world according to Alan Weisman But just imagine what would happen if we were all to disappear, each and every one of us, tomorrow. That's right - think what would take place if every single man, woman and child were to vanish off the face of the Earth in an instant. That is the bizarre premise of a new book which speculates what would happen in the days, months, years and millennia ahead if homo sapiens - surely the most extraordinary species ever to have evolved - were suddenly to be swept away. The author, Alan Weisman, of Arizona University, does not speculate on the cause of the disappearance; this is immaterial, as this is not a book about the end of the world but about an imagined beginning - the beginning of The World Without Us, the title of his book. The results of this huge thought-experiment are both fascinating and surprising. Fascinating for what they tell us about the impermanence of the works of man, and surprising for the simple reason that it soon becomes clear that our world would carry on regardless, indifferent to our demise. In fact, the first things to happen after the disappearance of humanity would be very dramatic - and destructive. Within a week, the emergency fuel supply to the diesel generators that circulate cooling water around the world's 441 operating nuclear reactors would run out. After that, one by one, the reactors would overheat, burn, melt and in some cases explode. Several hundred Chernobyl disasters would play out, simultaneously, across the deserted world. Huge quantities of radioactive material would be released into the air, rivers and oceans. What effect this would have on animal and plant life is unknown. But much to everyone's surprise, the flora and fauna around the Chernobyl disaster site has thrived. The ecologist James Lovelock, a pro-nuclear Green, argues that wildlife, by and large, does not notice radiation. Certainly, from then on, planet Earth would probably give a sigh of relief at our passing, as a spectacular environmental recovery would begin to take place. Quickly, the oceans would cleanse themselves; similarly the air, the streams and the rivers. In a remarkably short time, Mother Nature would reassert herself over her old dominions. In the new, human-free world, a few species would do badly - the rats, cockroaches and starlings that cling to our coat-tails would suffer. So would cows, sheep and other farm animals. The human head-louse would become extinct within a year, and HIV would vanish. In Africa, an orgy of feasting would take place as an exploding lion and leopard population guzzled its way through the continent's millions of cattle, no longer protected by the herdsmen's spears and guns. Most wild species would thrive. By 2100, the half-a-million surviving African elephants would have multiplied to their pre-colonial population of ten million or so. Africa's plains and forests would quickly fill with the great menagerie of game that once foraged and migrated unhindered across the continent. The jungles would start to regrow. In the countryside, an even more rapid transformation would take place in the decades following our demise. Britain's mechanised farmlands - in truth, no more "natural" than London's Piccadilly Circus - would see the rapid growth of fescues and lupins, tangled swathes of grass and wild mustard. Within years, oak shoots would sprout from the former fields of wheat, barley and rye. After a couple of centuries, Britain would revert to a pre-medieval knot of forest and undergrowth, its ancient patchwork of fields and hedgerows gone for ever. Exotic species - wolves, wild boar and perhaps some African game species - might even make it through the Channel Tunnel to recolonise our island. That is what would happen to the natural world - but what about the works of man? The big cities would crumble with remarkable ease. London or New York, like all large towns near the sea, would start to rot from their foundations up, as underground tunnels and conduits that carried trains and cables, roadways and sewage, started to fill up with water within days. The pumps that keep them dry would have simply ceased to operate. Indeed, the recent floods in northern England showed just how much damage can be caused when human defences fail. Without people to patch them up, and the rumble of traffic continually to keep them at bay, weeds would win their long battle with the asphalt. Within a few weeks, grass shoots would begin to shatter every road surface in the world. Within 15 years, the M1 would look like one of those roads built in Africa in the 1960s and never since maintained. Within a decade, the combined onslaught of weeds, waterlogging from blocked drains and the freeze-thaw action of water seeping into cracks would combine to turn the foundations of the urban world to rubble. Many buildings would start to fall apart within 20 years. Walls would groan and creak, roof tiles lift, joints between walls and roofs separate. Without central heating, with gutters permanently clogged and no maintenance, most of Britain's homes would be in ruins by 2040. America's cities, with their generally harsher climates, would fall apart even sooner. Some of the first buildings that would decay are, paradoxically, some of the newest. The shoddily built box-homes that have sprung up across Britain in the post-war era, the badly-made tower blocks and the cheap conversions, would collapse like houses of cards. Large, well-designed modern buildings with steel-framed constructions might survive for centuries, however, as would some of the thick-walled buildings of the Georgian era and before. Of course, some constructions would last a very long time. Massively over-engineered, the Forth Rail Bridge could stand for hundreds of years. And one structure which, interestingly, would survive far longer than you might think would be the Channel Tunnel. Dr Weisman points out that it wouldn't flood because it is built deep under the seabed, in a single geological layer. That is why it might prove to be a vital conduit for the recolonisation of Britain by dozens of animal species long banished by man. Meanwhile, as the buildings crumbled and decayed, what about the other works of man? Our world is still very much the Iron Age, but iron - and its modern incarnation, steel - is the most transient of materials: strong but powerless against corrosion. "Don't be fooled," says David Olsen, an American materials scientist, "by massive steel buildings, steamrollers, tanks, railway tracks... sculptures made of bronze (an extraordinarily resilient alloy) will outlast the lot". Again, we are faced with the paradox that some of the oldest artefacts on Earth might outlast the newest. Within a century or two, nearly all automobiles would have rusted away. Within a millennium - without maintenance and painting - the steel fabric of our civilisation would have crumbled. But bronze sculptures from the ancient world - as well as more modern bronze artworks - might last millions of years. Indeed, by AD10,000,000, the world would still be littered with hundreds of semi-oxidised bronze artefacts - sculptures and statues, reliefs and delicate instruments. Add to that billions of copper-alloy coins, which might survive just as long. Humans might vanish at the height of the steel age, but it is to the Bronze Age that the Earth would return. We live in the steel age, but we might also be said to live in the plastic age. Depressingly, it may be the plastic bag that proves to be one of mankind's most persistent legacies. The billions of bags blowing across the Earth like tumbleweed would continue to blow. Come back in ten thousand years, and most of them will still be there. So would some other surprising things. Most people think that paper is automatically biodegradable, but it is not. In the absence of air and water, it can last for millennia - that is why we can read 3,000-year-old Egyptian scrolls. Some of our books, printed on good-quality paper, may be readable for 10,000 years if they are buried in landfill sites. So what would the world be like in, say, 100,000 years' time? Billions of bits of metal - aluminium, stainless steel, titanium and bronze - would litter the forests and savannas. Some of these bits would still be recognisable - as nuts and bolts, tools and decoration, possibly even the skeletons of aircraft. A few buildings might survive this long - the Pyramids and Stonehenge could soldier on, maybe some of the huge concrete casings around nuclear reactors. And the world would probably still be littered with plastic bags. And then? Nobody knows. Nature abhors a vacuum, and Alan Weisman speculates that another species could quickly evolve to occupy the niche vacated by homo sapiens. His favourite candidate is the baboon - they are less bright perhaps than chimps, but there are many more of them (meaning a far bigger, and healthier, gene pool), and baboons are very adaptable. "Has their cranial capacity lain suppressed because we got the jump on them, being first out of the trees?" Weisman asks. With humans gone, baboons could become the next dominant super-primate. We can only speculate what would happen if they did. What would happen in 250,000 years, say, when a curious, intelligent simian dug up a wheel, or a plastic bag, or a computer disc? Weisman speculates that "their intellectual development might be kicked abruptly into a higher intellectual plane by the discovery of ready-made tools". Even as ghosts, we would continue to shape the future. But not for ever - not on Earth, anyway. Eventually, even the baboons or whatever else took over would be doomed. For there are forces beyond any conceivable control that will shape the long-term future of the Earth - a future about which scientists are now as certain as they are vague about next month's weather. Our sun is now a middle-aged star; in a few hundred millions of years, it will change noticeably, growing hotter and brighter as it gobbles its dwindling fuel supply at an accelerating rate. By AD1billion, natural solar warming will wipe out nearly all species on Earth. By then, perhaps only a few insects and plants will survive, as the oceans start to evaporate. Evolution on Earth will grind to a halt as the planet starts to boil. In a few hundred more millions of years, Earth will be a sterile, hellish, lifeless desert with an atmosphere of super-heated steam. Any visiting aliens would then be hard-pressed to find any traces that humans, or even intelligent monkeys, once lived here. Of our civilisation, nothing will remain - except perhaps a few unusual metal structures buried in the rocks, maybe one or two piles of suspicious rubble where some of the largest monuments stood. Maybe even some plastic bags. The aliens would probably conclude that nothing interesting had ever lived here. But they would be wrong, and if they knew where to look, they could discover that even now, even with the sun dying, billions of years hence, there will still be evidence of homo sapiens. On the moon, a couple of tons of assorted metalware, three electric moonbuggies, six American flags and thousands of footprints will - in the absence of rain and air - survive until the dying days of the solar system. Similar human-made ironmongery litters the surfaces of Mars, Venus and Saturn's moon Titan. And in deep space, a quartet of probes - the Nasa Voyagers and Pioneers, launched in the 1970s - will continue their long, silent journey through the galaxy. Unless they collide with a star or planet (unlikely) or are grabbed by a passing alien (even less likely), they will sail on for aeons: the last concrete vestiges of man and his works for millions upon millions of years. But even these little robots may not be man's last gasp. As the Voyagers and Pioneers erode away to stardust, billions of years hence, there will still be a relic of mankind. This is the shell of radio waves - bearing sound and television images, military radio traffic and, latterly, the internet - that has been expanding out into the cosmos at the speed of light for the past 100 years since Marconi's first transmissions. There is no reason to suppose that our radio and TV signals will not continue to do so for eternity. They will weaken with time and distance but, theoretically at least, they could be picked up at colossal distances. It is easy to conclude that the world without us would be a cleaner, better place. Yet without humans, something would be lost. We are the only species to have evolved that can contemplate not only our own existence, but also the grandeur and beauty of our planet and its other inhabitants as well. We may be making a terrible mess in places - but without us, the world would surely be a duller place. â€¢ The World Without Us by Alan Weisman is published by Virgin Books at Â£12.99.