Life After People is a television special documentary film that premiered on January 21, 2008 on the History Channel. In the program, scientists and other experts speculate about what the Earth, animal life, and plant life might be like if, suddenly, humanity no longer existed, as well as the effect humanity's disappearance might have on the artificial aspects of civilization. Speculation is based upon documented results of the sudden removal of humans from a geographical area and the possible results that would occur if humanity discontinues its maintenance of buildings and urban infrastructure.
The documentary features the gradual and post-apocalyptic disintegration of urban civilization in a time span of 10,000 years after humanity suddenly vanished. The hypotheses are depicted using CGI dramatizations of the possible fate of iconic structures and landmarks (i.e. the Empire State Building, the Willis Tower, the Space Needle, the Eiffel Tower, the Golden Gate Bridge, and the Hoover Dam).
With an audience of 5.4 million viewers, Life After People was the most watched program ever on the History Channel The program was broadcast in the United Kingdom on Channel 4 on May 26, 2008. The program was broadcast in Australia on Channel Seven on November 27, 2008, edited down to air for 90 minutes, with narration by Australian television presenter Simon Reeve.
The special assumes that humanity disappears suddenly and immediately, but does not speculate as to what would cause such an event. Below is a list of some of the highlighted events that could theoretically take place once humans are gone.
|1 day||Most fossil fuel power stations will shut down, causing cascading black outs worldwide once they run out of fuel. Wind-driven turbines may continue to provide power, but without proper maintenance, their rotors will seize up over time. In the American West, the Hoover Dam's generators are driven by the flow of water from Lake Mead, and the plant could remain operating unattended for months or even years. From space, the glitter of Las Vegas may be the only point of light on the surface of an otherwise dark planet.|
|2 days||Without steady power consumption, most nuclear power plants will shut down and enter an automatic safe mode to avert a possible meltdown. In New York City, water pumps in the subway system pump out 13 million gallons of water a day; once the power fails, the tunnels will fill with water in about 36 hours.|
|10 days||Most food on supermarket shelves and inside home refrigerators has rotted. Pets still trapped inside houses can drink the water leaking from thawed freezers, but a mass die-off of domestic animals begins; those that can escape homes and yards will begin to scavenge for food, but many domestic dog breeds, especially small dogs and those bred for special qualities like stubby legs and short muzzles, will be unable to survive long in the wild. Meanwhile, household pests like rats and mice thrive on the remaining food supplies; once it runs out, they return back to the wild where their populations will quickly diminish as they become food for predators.|
|6 months||Without people to suppress them, wild animals will return to the urban landscape. Small predators such as coyotes and bobcats, which roamed on the outskirts of populated areas, will be the first new residents, followed next by larger species such as cougars, wolves and bears.|
|1 year||Plants have taken over, turning manicured lawns into overgrown fields. Weeds grow in cracks in the roads, eventually forming a layer of nutrient-poor topsoil where clover fields take root. Plants and ivy take root in stone and masonry work, and begin to damage the foundations of buildings. Wild animals will have found shelter in the abandoned cities. At the Hoover Dam, a mollusk called the Quagga mussel begins to clog the pipelines feeding cooling water to the generators and they shut down. As a result, Las Vegas goes dark. Without the generators running, no water passes through Hoover Dam, and eventually the Colorado River will run dry. Meanwhile, the waters rise in Lake Mead and eventually spill over the dam. Sparked by lightning storms, many wild fires will go unchecked without people to fight them. These fires can burn down entire towns and damage cities such as Chicago, San Francisco and Rome. The charred rubble provides the nitrogen that plants need to grow, and plant life consumes the ruins.|
|5 years||Most roadways begin to disappear under a carpet of grass. In London, Buckingham Palace is breached by vines and moss. Red Square in Moscow turns green as it is overtaken by plant life. In New York City, the great lawns of Central Park sprout sapling trees. Before long, it will become a spreading forest. The monuments of Washington D.C. are swallowed by greenery. If they had escaped, it is possible that some zoo animals from exotic areas such as Asia or Africa such as lions, tigers, elephants and rhinos may still survive in the wild if they migrated to the southern climate of the United States.|
|20 years||Here the show examines the ruins of Prypiat, Ukraine, which were abandoned in 1986 after the Chernobyl disaster. They are used as a real-life example of the level of decay that could happen after 20 years of humanity's disappearance. Despite initial high radiation levels that killed the local flora and fauna near the nuclear plant, in 20 years, the plant and animal life has returned to the area, with much of it flourishing significantly without human interference.|
|25 years||Concrete structures begin to crack and crumble, pried apart by freeze and thaw cycles, as well as invading vegetation. Without people to maintain levees, low lying cities such as Amsterdam and London will have flooded. As their metal frames corrode from rust, windows crack and fall from buildings, exposing the interiors to the elements. Birds can now take up residence inside these structures. The copper lightning rods on top of skyscrapers will have corroded, and a lightning strike could turn a building into a towering inferno. In cities, gutted buildings provide pigeons a new home. Cockroaches still survive after people, now thriving on rotting paper and cardboard. With no humans to control their numbers, the wolf population has exploded, and they follow the deer herds into formerly populated areas. Without road traffic, most wild life migration routes are restored and predators such as bears expand their feeding grounds.|
|40 years||Small wood structures, such as houses, crumble away as they are attacked by mold and termite infestations. Although they can stand for years, stone and masonry deteriorates quickly when exposed to salts, such as from bird droppings or exposure to seawater. With no one left to repair them, minor leaks in earthen dams, such as the Trinity Dam in California, will get worse and eventually cause them to break.|
|50 years||Without vigilant maintenance, the steel cables of the Brooklyn Bridge in New York City and the Golden Gate Bridge in San Francisco have been weakened by corrosion and the structures threaten to collapse.|
|75 years||By now, most of the roughly 600 million automobiles in the world, even in the most forgiving of environments, will have rusted away to barely recognizable skeletal heaps. The tires will have deflated within a few years after people, but the synthetic rubber and plastic components will last for centuries.|
|100 years||The Brooklyn Bridge and the Golden Gate Bridge finally collapse when their rusted cables snap and can no longer support the weight of the road deck. Within a controlled environment of a preservation vault, materials such as paper and film can last 200 to 300 years, but once exposed to moisture and unregulated temperatures, they will have deteriorated away in half the time. In a humid environment, most books will have been eaten away by mold. Digital media such as CDs and DVDs will take longer to degrade, but ironically, they will not last nearly as long as the information once recorded by primitive cultures on clay tablets.|
|150 years||In major cities, the support columns of flooded subway tunnels fail, causing cave-ins and collapsing sections of the streets above. Vines have climbed up and into the gutted buildings where pools of water collect. Plants now grow throughout the floors, forming vertical ecosystems. Birds, rodents and snakes have moved in, followed by the descendants of house cats who find all they need to survive in one place. After generations of breeding with wolves, domestic dogs have returned to their pack hunting nature. Without the interference of man, the oceans recover from pollution and populations of sea life will have exploded. Seagulls, once dependent on human refuse for survival, would have a large die off decades ago, but the birds make a comeback once the fish populations return.|
|200 years||In the midst of the "Era of Collapses", many of man's greatest structures, such as the Eiffel Tower in Paris, the Tower Bridge in London and the Space Needle in Seattle, will have fallen. Once their iron structures succumb to corrosion, a strong wind would be enough to cause them to collapse. An example given in the show is the collapse of the neglected Kinzua Railway Viaduct in Pennsylvania in 2003. The collapse of the Willis Tower (formerly known as the Sears Tower) in Chicago and the Empire State Building in New York City will soon follow.|
|500 years||By now, most reinforced concrete structures will crumble away once the iron rebar supports inside them succumb to moisture and the expansion of rust bursts them apart. Without humans to maintain them, it is believed that long standing ancient structures, like the Sphinx at Giza, will have eroded away within 500 to 1000 years.|
|1,000 years||Nature has re-established itself and nearly all evidence of modern civilization will have vanished. Most modern cities would be collapsed and become barely recognizable husks overgrown by a jungle of trees, waters, flowers and vegetation. New York City may look as it did when it was first explored by Henry Hudson in 1609.|
|10,000 years||By now, little evidence is left of mankind. Even our radio and television signals that were beamed into space, and once thought to traverse for hundreds of light years, will have faded to unrecognizable static at close to two light years and not even reach our closest stellar neighbor, Alpha Centauri. The Great Wall of China in Beijing will have aged like a mountain as it decays very slowly over the centuries. The Pyramids of Giza remains, but will have stood long enough to be swallowed up by the Sahara Desert's sands. Hoover Dam remains to be the last of the great collapses. Mount Rushmore in Rapid City will be one of the last symbols of man. Carved from granite, it will remain visible for millennia, possibly to be viewed by man's replacements, which may be chimpanzees if they evolve to take up the mantle of civilization.|