"What would happen?" "If every human being on earth" "Disappeared?" "[music]" "At some point in the future," "This could be the fate" "Of our planet." "This isn't the story" "Of how we might vanish." "It is the story of what happens" "To the world we leave behind." "The disappearance of humans" "May seem like science fiction," "But eventually," "There will come a day like this;" "A day when people" "No longer walk the earth." "it's no great stretch" "To imagine humans disappearing" "From the face of the earth." "Every generation has its tales" "Of Armageddon or apocalypse." "We're the first generation" "That could," "By deliberate actions," "Cause its own doom." "What will life be like?" "After people?" "We're tantalized by our myths" "About our own destruction," "But also tantalized" "By the notion," ""hey, maybe it's the turn" "Of someone else."" "What will they do?" "If we're gone?" "What will the earth do?" "When I'm gone?" "It's the most natural question" "In the world." "[alarm buzzing]" "Time has run out for man." "Our hold on the planet is over." "Welcome to earth," "Population zero." "Within hours after we're gone," "Lights start going out" "Around the world." "More than 70 percent of power" "In the United States" "Is generated by the burning" "Of fossil fuels." "the plant will only continue" "To produce electricity" "As long as the fuel" "Takes to be consumed." "If there's no one around" "To provide the new fuel" "Into the generating plant," "Then it'll be quite quick" "Before the lights" "Start going out in cities" "All over the world." "Nuclear power plants" "Are unlikely to melt down." "The average reactor" "Holds enough fuel" "To keep running for two years." "But without humans" "Consuming the power" "Generated by the plant," "The reactors will automatically" "Shut down into a safe mode" "In as little as two days." "even wind generation" "Can't last forever." "The turbines require bearings" "And lubrication" "Of those bearings" "In order to keep operating." "If there's no one around" "To maintain the turbines," "The electricity" "Doesn't get produced." "as generating plants go down," "Outages on the power grid" "Contribute to a cascade" "Of failure worldwide." "After a few weeks," "The planet is plunged" "Into a deep darkness." "It has not experienced" "Since humans first huddled" "Around campfires." "Perhaps, the last glow" "Of artificial lights on earth" "Will be seen" "In the American southwest." "Here, the mighty hover dam" "Hydropower plant" "Takes little notice" "Of the absence of humans." "Its source of fuel" "Is virtually limitless." "at hover dam," "Our fuel supply" "Is actually the water" "In the reservoir in Lake Mead" "Behind hover dam," "So as long as there's water" "In the reservoir," "This power plant" "Can keep running." "There's water in the reservoir" "Keeps supplying the water" "To the hydro turbine generators." "These generators" "Are operating automatically" "And that would continue" "As long as all of the systems" "Are functioning normally." "If I and my staff" "Were to leave tonight" "And not come back to hover dam," "Say just in the condition" "Of the plant is in right now," "This would continue operating" "Without us here." "That would still be true" "After about a week," "Several weeks, several months," "Maybe even a couple of years," "Everything would still be" "Running normally." "In a life after people," "It is possible that hover dam" "Would be one" "Of the last power plants" "Still running." "as the power goes out" "Around the world," "Other systems" "Are quickly beginning to fail." "beneath all the major cities," "There's a complex network" "Of underground tunnels," "And these are there" "For drainage purposes" "Or for cabling purposes," "And in the case" "Of the big cities," "For transportation as well." "There are many of those" "Sit below the level" "Of the water table," "And in order to keep them dry," "We have to have" "A system of pumps" "That is switched on" "When necessary" "To drain the tunnels." "deep within new York" "City subways," "More than 700 pumps" "Constantly struggle to keep out" "A flood of ground water," "An average of 13 million gallons" "A day." "now, if all these people" "Were not around," "There will be nobody" "To switch the pumps on." "It's estimated," "That the tunnels will fill" "With water in about 36 hours." "[music] back above ground," "Food is rotting" "On supermarket shelves." "Home refrigerators" "Become nothing more" "Than cabinets for decaying food," "But melt water" "From defrosting freezers" "May provide a temporary lifeline" "For some of the creatures" "We've left behind." "What will be the fate?" "Of our family pets" "Once there are no humans left" "To care for them?" "right from the get-go," "There's going to be a massive" "Die off of dogs." "The instance that humans" "Are gone," "They're not creating the debris" "Or producing the food" "That the dogs are living on." "He can't open cans," "He can't get" "In the refrigerator." "They got to get" "Out of the house." "The family dog" "Has got to get out of the house" "Or he's going to die there." "And once he gets out," "He's got to go" "To some source of food." "The first thing that happens" "Is that they all jump out" "Of the windows" "And they are now out there" "In a new landscape." "And the first to whack at it" "It is that they go back" "To scavenging a whole bunch" "Of dead things out there" "In the world." "there are estimated to be" "Four hundred million dogs" "In the world" "And 300 different breeds." "But very few of them are suited" "To surviving in a life" "After humans." "The smallest dogs" "Probably won't last a week" "Without us." "there's probably no niche" "For the smaller dogs." "Dogs are very competitive" "And when you have wolves," "They displace coyotes," "Coyotes displace foxes," "And we would assume" "That hierarchy would prevail" "Among domestic dogs." "in fact," "Many of the unique features" "That has been bred into dogs" "Over the years" "Will now become major handicaps" "In the fight for survival." "there are dog" "For the really short legs," "I think the dogs" "With the really short faces" "Or long faces, I think," "That they're all doomed." "You know, they're not" "Going to move well," "They're not going to be able" "To search and explore." "I think that the kind of" "The middle of the spectrum," "The kind of average dog," "Have the best chances in this." "I think that they will survive" "In the long haul," "But it's not going to be pretty." "as the surviving dogs" "Struggle to find" "Their new niche," "Household pests" "Are slowly beginning to notice" "Our absence." "Little creatures," "Rats and house mice," "They would seem to be able" "To exist without us" "Are surprisingly quite dependent" "On our food supplies." "rats and mice" "Are usually termed" ""commensally rodents," which means" "That term means literally" "Sharing the table." "They're very dependent" "On people." "And the little house mouse" "And Norway rat" "Are great examples of animals?" "That would do less well" "In the absence of people." "in the initial weeks" "After people are gone," "They will raid pantries" "In homes, in grocery shelves" "In stores." "After eating through" "These food supplies," "They will struggle to survive" "On things like cardboard, cloth," "Or glue." "I think that if a city" "Was abandoned," "The rats would have to go back" "To earning an honest living." "An honest living" "Means to go back to the wild" "And compete for resources there." "eventually, these rodents" "Will abandon homes" "And buildings," "Which will make them?" "Easy pickings for predators." "Although, rats and mice" "Will mostly likely survive" "In the future," "Their numbers" "Will be greatly diminished." "After six months" "Into a life after people," "Urban areas" "Are already taking a turn" "For the wild." "the predators would return" "Very quickly in the absence" "Of humans" "Because we suppress them," "We create conditions" "That either work against them," "Or we deliberately go out," "And remove and destroy them." "They would come back" "Very quickly." "smaller predators" "Like coyotes and bobcats" "Always survive on the fringe" "Of human populations." "They are the first to colonize" "Our abandoned neighborhoods." "Larger carnivores" "Will have to wait longer" "For the habitat" "To recover enough" "To support their appetites." "But soon enough, they, too," "Will hunt in what" "Were once our backyards." "]" "One year into a life" "After people," "Towns and cities" "Are still recognizable." "But nature" "Is beginning to reclaim" "Her old turf." "one of the first" "Great physical effects" "In the absence of people" "Would be the transition" "Of the impervious surfaces:" "The parking lots, the roads" "Into places that supported" "And then had an abundance" "Of plant life." "any place" "Where you have sunlight" "That's hitting," "You're probably going to get" "Some plant growth." "Little seeds" "Are going to get stuck" "In the cracks and so forth," "And these things" "Are all going to start to creep?" "Plants are wonderful that way." "They can destroy things" "In matters of, you know," "A few years." "without humans" "To remove them," "Weeds like dandelions" "Infiltrate every crack" "In the pavement." "As these weeds die," "Their remnants combine" "With ever-spreading moss" "And lichen" "To create a layer of topsoil." "This sandy soil" "Is poor in nutrients," "So only plants like clover" "That can pull nitrogen" "From the air" "Flourish at first." "Formerly manicured yards" "Morph into fields" "For a white-tailed deer" "Forage for food." "Wild animals have also begun" "To find their way" "Into abandoned cities." "Man's supposed domination" "Over nature" "Has proven to be quite tenuous." "The signs of our vulnerability" "Have always been there." "this is an ailanthus tree." "It seems to enjoy rooting itself" "In very inhospitable locations." "And it likes to attach itself" "To crevices in buildings." "And when it does so," "It causes damage." "The roots expand," "And the expansive forces of that" "Force out mortar" "And stone and cause crumbling" "Of a facade." "If you get a lot of this" "On an entire building facade," "It could cause" "Major, major damage." "as nature battles back," "Even manmade goliaths" "Like hover dam" "Aren't invincible." "To harness the power" "Of this river" "Took 21,000 men and five years" "Of hard labor." "But one year after people," "Its 17 massive and seemingly" "Indestructible generators" "Are about to be brought down" "By an organism" "The size of a human thumbnail." "The lake above the dam" "Is infested" "With an invasive species" "Of mollusk" "Called the "quake mussel."" "This stealthy invader" "From Eastern Europe" "Had no natural predators" "In North America" "Other than the humans tasked" "With scraping it from the grates" "And pipes it colonizes." "the mussels attach themselves" "To the inside wall of pipes" "And they're very prolific." "They colonize" "And rapidly build up" "And can grow" "On top of each other," "And eventually completely block" "The diameter of a pipe." "the small pipes" "That brings cooling water" "To hover dam's generators" "Make perfect homes" "For these creatures." "And with no people around" "To remove them," "They spread like a cancer." "and in fact," "Those mussels could clog up" "The cooling water pipes," "To the point" "Where we couldn't keep" "These generators cool anymore." "And it would cause" "The high temperature alarm" "In the automatic control system." "And that automatic" "Control system" "Would then start" "The shutdown sequence" "Of that generator." "Well, that would happen" "One by one" "For all of the generators" "Of hover dam," "And eventually" "The entire power plant" "Would be shut down." "in lass Vegas," "The last glimmers" "Of manmade light on earth" "Relinquish the night" "To its primeval blackness." "With the generators" "No longer running," "No water at all" "Is passing through hover dam." "And the Colorado River" "Downstream begins to run dry." "On the other side of the dam," "The water has nowhere to go" "And Lake Mead starts to rise." "it would just keep" "Building up in Lake Mead." "And it would eventually" "Gets to the point" "Of spilling over" "Through the spillways" "On either side of the dam." "unchecked," "Nature's most powerful elements" "Reclaim their supremacy" "On earth." "Triggered by lightning strikes," "The wildfires" "Those humans once battled" "So valiantly" "Now rage unchecked." "Cities and neighborhoods" "Full of abandoned buildings," "Wild grasses, and debris" "Is prime fuel for the flames?" "Chicago burns." "San's" "Stately wooden Victorians" "Are now only useful as kindling." "And just as it did" "In the time of the ancients," "Rome is burning again." "As structures" "Burn to the ground," "Charred timbers" "Release nutrients into the soil," "Providing the next wave" "Of plant life," "With the nitrogen" "It needs to grow" "And thrive." "Five years after people," "The roads of the world" "Are disappearing" "Beneath a green map" "That spreads" "Like some relentless monster." "The advance of nature" "Knows no boundaries." "The gates" "Of London's Buckingham palace" "Are easily breached by vines" "And moss." "In Moscow, red square" "Is becoming very green." "in reality," "Nature will reclaim earth" "Very quickly." "These stairs were cleared 18 months ago." "If we came back" "In another 18 months," "We'd have a hard time" "Finding them." "If we came back in five years," "It would be almost impossible" "To find." "man's mastery over nature" "Has always been" "Just an illusion." "When the Cambodian city" "Of Angkor" "And its temple complexes" "Were abandoned in 15th century," "Jungle trees grew" "Indiscriminately" "Over its stone structures." "Entangling them in their roots." "Now, without armies of gardeners" "And repairmen," "Modern cities are laid bare" "To nature's revenge." "In New York's central park," "The great lawns, now untended," "Sprout with saplings." "Five years without humans" "Leaves the park" "Looking more like a forest." "central park will go bananas." "So all of a sudden" "You'll get trees," "You'll get growth." "All the animals and plants" "That is there now will go up" "In population levels" "And they'll start to spread out" "Into the city." "the story is the same" "In Washington o.k." "The great monuments" "Have been swallowed by greenery." "And on what used to be" "The national mall," "The sounds of the jungle" "Are echoing." "zoo animals" "Are really the great unknown." "Depending on whether or not" "They could escape" "From their confinement," "Then things change dramatically" "Because you might have lions," "You might have tigers;" "Both of which" "Would be perfectly capable" "Of surviving" "In a post-human period." "They'd do better further south" "Than they would do in Washington o.k." "But these are animals" "That is perfectly capable" "Of figuring out how to do it" "And how to survive." "zoo animals" "May be the great unknown" "But there are things" "We can know for sure" "About life 20 years" "After people are gone" "Because there's one spot" "On the globe" "Where it's already happened." "[music] it's 20 years" "Into a life after people." "Without humans" "To apply fresh paint" "And fill in cracks," "Even concrete buildings" "Have already begun to crumble." "Lack of maintenance turns cities" "Into eerie ghost towns." "Animals that have long avoided" "Human population centers" "Now return to make new homes" "Among the decaying walls." "How do we know this?" "Because there's one place" "In the world" "Where it's already happened." "we're standing" "In the central square" "Of prepay, Ukraine," "The city that was once" "The most modern city" "In the former Soviet Union." "For 20 years now," "This city" "Has been sitting abandoned," "And it really gives you" "A picture of what would happen" "If people are removed" "From a place" "Of normal civilization." "evacuated after" "The Chernobyl nuclear disaster," "Prepay went" "From a city of 50,000" "To ghost town overnight." "Dust-covered school rooms remain" "As students left them" "Just over 20 years ago." "Vegetation pries apart masonry" "As it crawls over buildings." "An amusement park" "Scheduled to open" "Four days after the date" "Of the accident" "Remains never used." "The park's ferries wheel" "Accumulates rust" "Rather than riders." "The bumper cars sit in a state" "Of motionless decay." "Prepay has provided an amazing" "And rare opportunity" "To see what happens" "To a manmade city" "When humans disappear." "I can see" "From my Geiger counter" "That it's really quite safe" "To be here," "Radiation levels" "Were not very high." "But you can see" "That we've really hit" "A point of no return" "In recapturing these facilities." "We're in what was" "The cultural center" "Of the city of prepay." "And indeed, this was a place" "Where friends gathered," "Where there would be" "Celebrations," "There would be balls," "There would be music," "There would be dancing," "There would be performing" "On the stage here behind me." "But after 20 years," "The forces of nature" "Have started to decay" "This facility." "this concrete soviet facade" "May look imposing" "But it's no match" "For the frigid Ukrainian winters." "As the temperature drops" "Below freezing," "Water that has accumulated" "In cracks, expands," "Exerting bursting pressure" "That pulls apart" "The masonry." "As vegetation grows unchecked," "The roots spread" "Through foundations and stairs." "These roots suck in moisture" "That makes them expand and grow." "Like miniature hydraulic jacks," "Over time," "They slowly push apart" "The concrete." "this is only 20 years." "Can you imagine?" "What this facility" "Will look like after 200 years?" "after the accident," "Scientists expected the worst" "For the wildlife in the region." "Most of the trees" "In a 1 1/2 square mile area" "Around the nuclear plant" "Were killed off by radiation." "Many animals died." "But incredibly, the effect" "Of the absence of humans" "For 20 years has outweighed" "The initial damage" "Caused by the nuclear nightmare." "this is the red forest," "An area" "That was horribly impacted" "By radioactivity" "Due to the Chernobyl explosion." "And the trees that you see" "Around me were killed" "By the radioactivity." "The original amounts" "Of radioactivity were sufficient" "To kill all of the wildlife" "In the region as well." "But now we see resurgence" "Of the wildlife." "As an example of how wildlife" "Has prospered here," "We see, here, we have an antler" "From a red deer and, obviously," "A fairly large" "And healthy red deer." "Red deer are hardly found" "In any other areas" "In this region" "And the Chernobyl zone" "Is the only place" "That you'll find populations" "Of red deer." "We also find Russian wild boars" "That the populations in the zone" "Are 10 to 15 times higher" "Than they are outside" "Of the zone." "[speaking Russian] we're now at the kindergarten" "Of Karachi village, not far" "From the Chernobyl station." "Children were living here" "While their parents worked." "But after that night" "In April 1986," "They never returned." "We are in what was formerly" "A bedroom in this kindergarten" "Where children used to sleep" "And rest." "Now, there's" "Certain emptiness here." "All these windows are broken." "But the room continues" "To live on." "Birds fly in here" "And sit on these bars." "We even found evidence" "That an owl comes here." "An owl, it regurgitates food," "Fur, bones, and feathers." "Evidently, it likes to sit here" "On this window pane." "So this room continues" "To maintain life." "Even trees which had proven" "Especially vulnerable" "To radioactive fallout." "Are finding new homes" "In the evacuation zone." "I'm sitting" "In the pipit soccer stadium" "Where, 20 years ago," "Hundreds of people would come" "And cheer" "On their favorite team." "You can imagine the laughter" "Of the sounds" "Of the crowds here." "The activity on the field" "Which, 20 years later," "Is barely discernable." "The soccer field now is going" "Through succession" "As you would expect in returning" "To what it was originally" "Hundreds of years ago" "Which was a mixed?" "Deciduous forest." "I grew up in a town" "About like this" "And I used to enjoy" "Riding bumper cars like these" "About a half a world away." "And it seems pretty sad" "When you look now" "And you see what's become" "Of this beautiful city" "Of pipit and that people" "Will never live here again." "But there's another side" "To this story," "A very encouraging side;" "One that says that life" "Is much more resilient" "Than what we thought possible." "That in the absence of man," "That life will continue" "And that life will thrive" "And that the legacy of life" "Will always be here," "Because we are a part of life." "Even if we disappear," "Our legacy of life" "Will continue." "[music]" "Through decaying neighborhoods" "In search of their next meal." "In some of the great cities" "Of the world," "Solid ground is getting harder" "To find." "In the time of humans," "London was protected" "From tidal surges" "By 10 retractable steel gates" "That could be raised" "During storms to seal off" "The Thames River" "From the North Sea." "Without humans" "To operate the barrier," "London is defenseless." "Another low-lying city," "Amsterdam," "Meets the same watery fate." "In a New York City high rise," "Some windows have already" "Cracked and slipped loose" "From their frames and many more" "Are on the verge of destruction." "After a quarter century" "Of exposure to moisture" "And heat without maintenance," "The normally flexible window" "Sealant has become rigid," "Locking this window" "To its frame." "As the metal frame expands" "And contracts with changes" "In temperature," "It induces stresses" "On the glass." "It cracks and plummets" "To the sidewalk below." "after a few of the windows" "Fall out of a building" "Like this," "Then the wind pressure effect" "Changes dramatically." "As well as external pressure" "Coming on to the building," "You also get suction." "And that aggravates the problem" "So more of the panels" "Are likely to fall out." "through these gaping holes," "The building fills" "With windswept debris." "A summer storm rolls in." "On top of the structure," "The copper-lightning deterrent" "System that once protected" "Thousands of office workers" "Is now corroded and useless." "A lightning bolt turns the tower" "Into a raging inferno." "The gutted building makes" "The perfect home" "For a surprising survivor." "Although pigeons once relied" "On the handouts of humans," "They have done just fine" "In 25 years without us." "pigeons are survivors." "They can live in the wild;" "They do live in the wild still." "And in a period" "Where there were no people" "But there still were edifices" "And artifacts, our buildings," "They would do very well" "Because they would adopt these" "As kind of" "Artificial cliff faces," "Which is what they really are?" "Adapted to." "like the pigeon," "The disappearance of humans" "Forced a change in the habits" "Of the lowly cockroach." "think of the poor cockroach" "After they gorge" "Upon our surplus" "When we're gone," "They'll mourn us." "They'll be sorry." "but the morning won't last" "For long." "While cockroaches thrived" "On our scraps," "They can also eat bookbinding's," "And cardboard," "And any rotting organic matter" "Including dead leaves and roots." "While food isn't a problem," "Roaches also need warmth;" "The kind that humans" "Had always supplied" "Through artificial heat." "Cockroaches started" "As a tropical species" "And some experts say" "They couldn't survive the winter" "In colder cities." "But it's hard to bet" "Against a creature that has seen" "The dinosaurs come and go." "cockroaches are" "Extremely adaptable." "They've been around" "For 300 million years." "If I have to bet," "I'd put my money on them" "Being able to survive" "In one form or another." "the first winter" "After humans did witness" "The die-off of some cockroaches," "But many more moved underground" "To find warmth until" "Milder temperatures returned." "In an abandoned downtown" "Devoid of insecticides," "Overrun by vegetation" "And with a rising water table," "This former pest is now enjoying" "A golden age." "Cockroaches were only a nuisance" "To humans," "But wolves were a terror." "So man hunted them mercilessly." "When the first European settlers" "Arrived in what is now" "The United States," "It's believed nearly half" "A million wolves roamed" "The country side." "By the 20th century," "These predators" "Were nearly extinct" "In the lower 48 states." "Now, with no humans left" "To battle them," "Wolf populations multiply" "By as much six times each year." "Within 25 years" "Of our disappearance," "There could easily be half" "A million of them roaming" "The united states again." "This amazing comeback" "Has been seen" "On a small scale before." "In 1995, biologists released" "A few dozen wolves" "Within the boundaries" "Of yellow stone national park;" "A place" "Where they would be protected" "From persecution by humans." "Within a decade," "A few dozen had multiplied" "Into 1,500" "And the wolves" "Quickly spread out" "From their release point" "To occupy territory" "Throughout the states" "Of Wyoming, Montana, and Idaho." "it would be fast" "If you can start" "With just a few dozen wolves" "And in the course of one decade," "Have a population of 1,500" "And you could have" "A geographic expansion" "Where they filled up a big chunk" "Of a three-state area." "And these are" "Big western states." "Yeah, when the conditions" "Are right," "They can re-colonize" "Pretty rapidly." "Could we see them in Manhattan?" "Or Chicago?" "As soon as the deer get there," "The wolves will be right" "Behind them." "animals haven't" "Just been hunted by humans;" "They've also been hemmed in." "There are roughly three million" "Miles of paved road" "In the united states alone." "And it's no coincidence" "That many of them cut" "Right through the paths" "Animals use to get from place" "To place." "the things that make" "A landscape good" "For animal movement" "Also make it easy to engineer" "A road in that location." "So, we've cut off pretty much" "All major migrations" "In North America." "asphalt and automobiles" "Wreaked particular havoc" "On the grizzly bear." "Their habitat" "Was so carved up by roads" "That they're confined" "To isolated pockets," "Cutting them off" "From food sources" "And potential mates." "In a life after humans," "Roads are no longer barriers" "For the grizzly." "Instead they are pathways;" "Trails that lead them back" "Into the heart" "Of their former range." "forty years after people." "While cities of steel" "And concrete" "Are still standing tall," "The suburbs are under attack." "Roughly 90 percent of all homes" "In the United States" "Have wood frames." "While some have burned," "Others are now being devoured." "Without paint and preservatives," "The lumber of homes" "Is defenseless against termites." "Termites feast on cellulose," "The basic building block" "Of wood." "And their appetites" "Are relentless." "Some colonies can eat" "As much as 1,000 pounds of wood" "Per year." "In this destructive advance," "The termites" "Aren't working alone." "the process we know" "As rotting will occur" "When the wood gets exposed" "To the elements." "And this rotting, actually," "Is a more complicated process." "It's a process by which microbes" "Attack the wood" "And release carbon dioxide" "And methane to the atmosphere." "If humans were to leave," "It'd be a matter of decades" "Before most structures" "That had significant" "Wood components" "Would start to decay." "faced with" "A two pronged attack" "From termites and rot," "The beams that hold up the roof" "Give way." "And the boundary" "Between inside and out," "That had once been so important" "To the humans" "Who called this building home?" "Is forever erased." "other substances" "Like this mortar and rock" "Are going to last longer" "Than several decades," "But they'll still crumble" "After natural, chemical," "And physical weathering" "Processes," "And eventually these walls" "Will fall down as well," "And there'll be no remnants." "now, nature will act quickly" "To swallow up these ruins." "This crumbling house" "In Baltimore's druid hill park" "Was once home to the caretaker?" "Of the city zoo." "it looks like this building" "Has been abandoned" "For more than a hundred years." "But in reality," "People have been living here" "Up till 40 years ago." "It's amazing how quickly" "The vegetation has reclaimed" "The area." "The vines have started to climb" "Up the walls." "The trees are growing" "Into the structure," "And they're both physically" "Pulling the structure apart," "And chemically dissolving it." "structures built entirely" "Of stone or masonry" "Will far outlive" "Anything made of wood." "Exactly how fast" "They will crumble depends" "On their environment." "the coast of Maine, really," "Isn't very kind to buildings." "Structures out here" "Don't so much decay" "When you live them alone;" "They melt." "these structures" "On black island, Maine" "Used to be part" "Of granite quarry whose stone" "Was used to build and decorate" "Cities like Boston, New York," "And Philadelphia." "It was abandoned around 1920." "here, the buildings" "Have all vanished" "Within the space" "Of 80 and 90 years." "There's almost nothing left." "in the right conditions" "And with human maintenance," "Stone construction can last" "For thousands of years." "In some places in Europe," "Ancient roman aqueducts" "Are still in use." "But without maintenance," "Stone can fall victim" "To a very stealthy enemy." "one of the great enemies" "Of stone are actually salts" "And salt crystals." "Even thousands of years ago," "People notice the effect" "That salts had on deteriorating" "The ancient pyramids." "there are many ways" "Salts infiltrate stone buildings" "And monuments:" "Polluted air, seawater," "And even bird droppings." "soluble salts dissolve" "In water," "And as the water evaporates," "It will rise up inside" "Of porous building materials;" "Things like brick and stone" "And even concrete." "And what happen are the salts" "Will continue to grow" "Inside the pores of the stone" "Until they come up" "Against the side of the wall," "And they'll actually push" "The stone apart." "what we're seeing" "In this time-lapse video" "Really shows the rapid decay" "Of the stone in response" "To this deterioration by salts." "In this experiment," "It took about three weeks to go" "From this piece of stone" "To this piece of stone," "Which is completely deteriorated?" "By sodium sulfate" "Crystallization." "three weeks in this" "Accelerated aging chamber" "Are equivalent to a few years" "In the harshest of environments," "Or a few decades in a more" "Benign desert climate." "if we could see" "Microscopically what's going on?" "Inside the pyramids," "This is what" "Would be taking place." "You can actually see the salts" "Deteriorate the stone." "although not immune to decay," "The pyramids have survived" "For nearly 5,000 years" "Because of their sheer volume" "And their hot," "Dry desert environment." "Too massive to be destroyed" "By either man or nature," "The pyramids of Giza" "Were the only one" "Of the seven wonders" "Of the ancient world to survive" "Into the modern era." "Many ancient monuments" "Have survived only" "Because of human maintenance" "Throughout the centuries." "The sphinx was uncovered" "And restored for the first time" "Back in 1400 back." "Modern experts who have studied" "The sphinx, predict" "That without human intervention," "Deterioration from salts" "And wind erosion could render it" "A pile of dust" "Within 500 to 1,000 years." "The largest concrete structures" "Like hover dam, will last" "Even longer than that." "Hover is so thick" "That over 70 years" "After it was constructed" "The concrete deep inside" "Was still curing." "But of the 15 tallest dams" "In the United States," "Only 10 are concrete." "The others are made of compacted" "Rock or earth," "Like northern California's" "Trinity dam." "If there were humans around," "This leak in the dam would get" "An emergency fix." "But those days are long gone." "some of these dams" "Are absolutely enormous." "And if they fail," "As they will in time," "Then the surge of water" "That falls in behind them" "And cascades" "Down a valley below" "Would have a huge force," "Big enough to sweep away" "Everything on its path." "fifty years after humans," "The strain of neglect" "Is beginning to show" "On even the best design" "Of manmade structures." "everything that man designs" "Carries within it, the seeds" "Of its own destruction;" "That includes bridges" "And buildings." "The Brooklyn Bridge," "One of the most famous bridges" "In the world for over 125 years." "The reason" "Those bridges last so long" "Is because engineers" "Look after them." "They inspect them regularly," "They maintain them," "They paint them," "They replace pieces that need" "To be replaced." "Without people," "Without engineers," "The deterioration process" "Will accelerate dramatically." "the most vulnerable parts" "Of a suspension bridge" "Are the steel vertical hanger" "Cables." "these have been tested" "In the laboratory," "Unfortunately not on the bridge," "But what you see" "Is a classic kind of a failure?" "That occurs in these wires." "These are the individual wires," "All right?" "That's an individual wire." "That probably has" "A tensile strength" "That's maybe 200,000 pounds" "Per square inch." "That's a very high strength" "Steel." "as strong as they are," "These cables have a fatal flaw:" "It's the stuff they're made of." "steel is a mineral" "That comes from the earth" "That's mostly iron," "So it's probably 95, 98 percent iron." "exposed to moisture" "In the environment," "Iron will start to revert" "Back to the minerals" "It came from." "Ashes to ashes, dust to dust." "it's going to go back home." "It came from the earth" "As iron oxide of some form," "And it's going to go back." "this is the process we know" "As corrosion," "And you see it wherever steel" "Is exposed to moisture." "the enemy of steel" "Is corrosion." "The problem" "Is keeping the water out." "Part of that is maintenance." "If you don't maintain them," "You will get corrosion." "completed in 1883," "The Brooklyn bridge cost" "$15 million to build." "Over the last two decades," "$3 billion have been spent" "Maintaining it" "And the other bridges" "Over the east river." "In the time of humans," "The Brooklyn Bridge" "Was continually maintained" "And fully repainted," "Roughly, every dozen years." "While across the country" "In San Francisco," "The golden gate bridge" "Was protected at all times" "By a vigilant brigade" "Of 17 iron workers" "And 38 painters." "what do they do all the time?" "They will tell you, "We paint" "This bridge continuously."" "What happens when that stops?" "I can tell you what happens" "When that stops." "The cables begin to rust," "The paint peels off," "The wires begin to break," "And they'll come to a point" "When the bridge" "Is going to come down." "seventy-five years" "After people." "Most of the 600 million cars" "That once traveled the roads" "Of the world" "Are now just rusted remnants" "Of the human past." "abandoned cars will behave" "Differently depending" "On the environment" "That they're in." "A car left in the Mojave Desert," "For example," "Is going to last a long time." "A car abandoned" "In my native Scotland" "Is going to have" "A very different fate." "Any cars" "In a coastal environment" "With salt in the atmosphere," "They might not last" "More than 20, 30 years." "tires deflate" "Within a few years," "Although the rubber" "And synthetics they're made of" "Will remain intact" "For centuries." "Paint deteriorates quickly." "And once it flakes away," "Rust corrodes the car's body" "At a rate of 5,000ths" "Of an inch per year." "Seventy-five years after humans," "Most cars," "Even in the most forgiving" "Of environments," "Will be reduced to skeletons." "After a century, the family car" "Is a barely recognizable heap" "Of metal." "It's now 100 years into a life" "After people." "The Brooklyn Bridge," "Which had stood?" "For over 125 years with people," "Can't survive even a century" "Without them." "As the cables fail," "The deck and railings begin" "To warp and sway." "The deck pulls free," "And the roadway spills" "Into the east river." "as an engineer," "It's very sad to contemplate" "That this beautiful iconic" "Structure has got an end" "To its life." "But without maintenance," "An end to its life" "It certainly has." "how exactly do bridges fail?" "Once corrosion starts," "The wires begin to crack." "and the wire" "Doesn't have to have" "A very big crack" "Before it breaks." "Maybe a third" "Of the way through." "You may wonder what happens" "When they fail." "How do they fail?" "Do they just break?" "And what do they do?" "And the answer" "Is they tend to shred and fail," "With individual strands" "Starting to fail" "And then, kind of, cascading," "And a whole series of wires" "Then begin to break." "a suspension bridge" "Like the golden gate can survive" "The weakening of one" "Of its vertical cables." "But once two or three" "Start to go," "The whole bridge is in jeopardy." "Twisted steel crashes" "Into the waters below." "it's going to be gone." "Two hundred years?" "I doubt it will last 200 years." "The bridge is going to be" "In the drink." "[music] if some" "Of our largest structures" "Have already failed" "After 100 years," "Can there be any hope" "That our civilization" "Will leave a permanent mark" "After we're gone?" "What will remain of the records?" "Of our history and culture" "A hundred years after people?" "our vaults contain" "Our most precious materials," "And their biggest enemies" "Are temperature and humidity." "As long" "As their long-term storage" "Is kept at these" "Very controlled settings," "We feel assured" "That the materials" "Will be lasting a long time." "stored" "Under ideal conditions," "Paper and film both have" "An estimated shelf life" "Of 200 to 300 years." "But expose them to the rigors" "Of an uncontrolled environment" "And that lifespan is cut" "At least in half." "if all the power went off," "Probably within a week," "We'd see very big spikes" "In the temperature and humidity." "in this hostile environment," "Cellulose acetate," "The most common material" "Used for films and photographs" "Throughout the 20th century" "Begins to bubble and warp." "All of that culture and history," "From the landings on d-day" "To Hollywood films" "And even your cherished" "Home movies and photographs," "Won't last a century" "Without the care of humans." "so, those precious images," "Given time," "Are going to end up like this." "All of these are examples" "Of various stages in the decay" "Of cellulose acetate-based film" "Exposed to very high amounts" "Of humidity." "Essentially," "These materials are finished." "in libraries," "The great repositories" "Of our collective knowledge," "The damage comes" "From microscopic invaders." "Although we can't see them," "Mold spores" "Are on all the surfaces" "Around us, lying dormant," "Biding their time" "For the right conditions" "To strike." "High humidity" "Creates the right conditions." "and so," "The situation is set up" "For the mold to really boom." "some books and documents" "Will avoid this fate." "The Dead Sea scrolls" "Survived 2,000 years in caves" "In the Judean desert," "Owing their longevity" "To the arid climate" "And lack of damaging sunlight." "But these are rare exceptions." "so without" "Human intervention," "A book like this might last," "At best, another hundred years." "[music] even our digital media" "Won't last forever." "Estimates for the lifespan" "Of cads and DVDs range" "From a few decades" "To a few centuries" "Under ideal conditions." "we know" "About the ancient Egyptians" "Because what they left behind" "Was engraved in stones." "[music]" "Our form of capturing knowledge," "Information, our history," "Our advancement is typically" "Either in a computerized form," "In a cod, or in a printed paper" "Like this." "What we have here is something" "That will degrade over time." "It will not last" "For thousands of years" "Like what" "The ancient Egyptians" "Left behind." "it seems pretty ironic" "That with all of our advances," "We still have not come up" "With anything as durable" "As clay tablets and stone tools." "[music] 150 years after humans," "The subways" "That had started to flood" "In the first 36 hours" "Are now flowing" "Subterranean streams." "The beams and archways" "That holds up the roofs" "Of these tunnels" "Are on the verge of collapse." "now, these tunnels" "Are not far below street level." "These columns are supporting" "Not just the roof of the tunnel," "But the street above." "And in time that these tunnels" "Are inundated," "Flooded with water," "Corrosion will start" "To take hold and we'll start" "To see collapses." "the tunnels echo" "With the sound" "Of cracking steel and cement" "As the streets above" "Are sucked into the underground." "[music]" "Above ground, life in the city" "Is once again bustling." "Vines have grown up the sides" "Of abandoned skyscrapers," "Adapting to feed off rainwater" "That pools in crevices" "And on ledges." "these vines all start up." "And the vines" "Have little branches." "It'd be nice" "If they produce a fruit" "Or something that was edible." "You got to have a plant" "With some fruit or, you know," "Some source of energy" "For animals." "And then you would get" "This vertical ecosystem" "Out there, and you would get" "Birds nesting in there." "You get things" "Hunting in through there." "You could have snakes there." "You could have" "All kinds of things." "as insects" "And smaller animals" "Get established," "Cats move in." "and there's some" "Interesting examples of that" "Around the world." "If you go to the coliseum" "You just look in it" "It's just loaded with cats." "And the old tombs" "And old catacombs and so on" "Get loaded with cats" "That uses this as a living space" "From which, then," "They radiate out during the day." "these felines" "Are the descendants" "Of our former house cats." "Immediately after people" "Were gone, they replaced" "Their human-supplied diets" "With field mice and small birds." "Hunting out in the open" "Was hard work." "But up here," "The pickings are easy." "Now, they live" "Their whole lives" "High above the city," "Finding all that they need" "To survive without ever having" "To touch the ground." "They are the kings" "Of the new high altitude" "Food chain," "With million-dollar views" "Of a bizarrely" "Altered cityscape." "I could picture new York city" "With all the buildings" "Covered with vines, you know?" "Hawks sailing around." "It'd be lovely." "It would be absolutely lovely." "[music] for cats," "Life in this new environment" "Could eventually lead" "To some strange adaptations." "I suppose, if you wanted" "To be really imaginative" "About it, you could say that," "Eventually, they could be" "Like flying squirrels and so on." "They could glide from places." "The possibility is always there" "For some imaginative responses" "To this unusual environment." "while some cats" "Have made a great leap forward," "Many dogs have reverted" "To the ways of their ancestors." "Some that have interbred" "With wolves now fall in packs" "To bring down larger prey." "[music]" "I think our dogs," "As placid as they may seem" "When they're in our homes" "Lying on the living room floor," "Still posses the instinct" "To survive," "Enough that they would be able" "To do whatever it took" "In bringing down prey" "In order to live." "[music] 150 years after people," "The oceans are teeming" "With life." "The creatures of the sea" "Have welcomed" "The disappearance of mankind." "historically," "We've treated the oceans" "In two strange ways" "At the same time:" "A pantry and a toilet." "And over time," "Our ability to damage the ocean" "Has grown and grown and grown." "with humans no longer fishing" "And polluting the sea," "The path was cleared" "For this astonishing recovery." "It has happened before." "During World War II," "Allied fishing trawlers" "Avoided the north Atlantic," "And populations of fish there" "Skyrocketed." "in here, the basic biology" "Of these kinds of animals" "Is working in our favor" "Because animals" "Like this sunfish" "Can produce millions" "Of offspring in a year," "Much more" "Than an equivalent-sized" "Terrestrial animal like a cow." "And because of that" "Prodigious potential" "To reproduce," "The oceans could come back" "Pretty quickly" "If the human population" "Were suddenly to disappear." "research has shown" "That in the 18th century," "Before the havoc" "Caused by humans," "The oceans were capable" "Of sustaining" "Massive amounts of life." "so many whales" "That they stink up the air;" "So many tunas" "That they froth the ocean;" "So many turtles" "That you could walk" "Across the sea on their backs." "So, if people were to vanish" "Off the face of the earth," "Then that's the kind of ocean" "It could be." "[music] seagulls are also" "Flourishing, but it has been" "A treacherous flight." "The abundance of food" "From humans" "Had allowed gull populations" "To explode beyond what nature" "Could normally support." "we humans" "Are pretty messy species." "And for a very long time," "We had open landfill dumps" "Where, as far" "As we were concerned," "All the stuff" "That wasn't fit to eat" "Was just thrown out." "But from the gulls'" "Point of view," "This was an amazing" "Free lunch counter." "So, you had a lot of birds" "That probably" "Wouldn't have made it through" "Their first winter" "If they've had to feed" "For themselves." "Suddenly, they had" "All these free food" "Available to them." "An immediate consequence" "Of a world without people" "Would be some very hungry gulls" "Who would be very voraciously?" "Looking for other things to eat." "after an initial die-off," "The remaining gulls" "Took advantage" "Of the recovering oceans," "Where plentiful schools of fish" "Erased any memories" "Of the human-manufactured feasts" "They used to enjoy." "Two hundred years after people," "From New York to Chicago," "Seattle and Paris," "Our iron and steel icons" "Are on the verge of collapse." "While it has outlived" "Our great suspension bridges," "The Eiffel tower" "Is not invincible." "In the time of humans," "Its iron superstructure" "Was painted" "Once every seven years" "To protect it from corrosion." "In both age and structure," "The Eiffel tower" "Has a lot in common" "With the 300-foot high" "Kinsman railroad viaduct" "In Pennsylvania." "was a bridge" "That was wrought iron" "Originally." "It was reconstructed" "About the turn of the century" "In steel." "And what happens here of course" "Is that unless it's maintained," "Corrosion occurs." "And what happens" "With the corrosion?" "The connection points freeze up." "They are not allowed to move." "And here are some pieces" "From that viaduct." "You can see" "That there's corrosion" "All over the place." "That's no longer steel." "a structure" "With frozen connection points" "Can't absorb the stress" "Of high winds." "eventually," "In this strong wind storm," "It literally fell over." "Section by section," "Piece by piece," "It fell over into the valley" "Where it had spanned the valley" "For over a hundred years." "Just not maintained." "You can think of many structures" "That is coming" "From that same era" "Like the Eiffel tower," "Its iconic structure." "That doesn't shield it" "From the fact that's it" "In a corrosive environment." "And so in time" "If you do not do anything" "For that structure," "It will fail." "And it will come down." "the time between one" "And 300 years after people" "Will likely be the era?" "Of the great collapses" "Worldwide." "In Seattle," "The iconic space needle" "Was designed to sway" "One inch for every 10 miles" "Per hour of wind," "But with its steel" "Weakened by corrosion," "It takes little more" "Than a strong breeze" "For the symbol" "Of the 1962 world's fair" "To crash down from the skyline." "When humans disappeared," "Sea levels were already" "On the rise." "In Manhattan," "Over the centuries," "Saturated soil" "Around the empire state" "Building's foundation pilings" "Have allowed the building" "To lean." "once a building strays" "From the vertical," "Then gravity forces" "Are also acting" "Against the structure," "Increasing the stresses" "At the base of the building," "Now we're unlikely to see" "A skyscraper fall" "Like a tree in the forest." "Once it does start to incline," "Gravitational force will cause" "The top of the building" "To collapse downward" "On top of itself." "decay has also overtaken" "The city of Chicago," "The birthplace" "Of the skyscraper." "The sears tower," "The tallest man-made structure" "In North America," "Has reached" "The end of its reign." "The first 500 years" "After people has been an era" "Of decay and destruction." "Our concrete structures" "Have lasted the longest." "The ancient Romans" "Invented the first form" "Of concrete." "And some of their structures" "Remained intact" "For over 2,000 years." "But modern concrete" "Isn't nearly as durable." "It has higher water content" "And is more loosely packed," "Which leads to more?" "Air pockets and cracks." "Modern concrete structures" "Have another fatal flaw." "below the surface" "Of reinforced" "Concrete structures," "There is a mesh" "Of steel reinforcing bars" "And they don't corrode" "Because the concrete maintains" "An alkaline environment" "Around them." "Now, when that alkalinity" "Breaks down," "As it will in time," "Then the steel" "Will start to corrode." "as the steel rebar rusts," "It expands to three times" "Its original volume" "Creating an outward pressure" "That causes the concrete" "To crumble." "in very broad terms," "After 50 years" "We'd start to see" "Surface cracking on concrete." "After a hundred years," "Flaking of the concrete surface." "After maybe 500 years," "Most reinforced" "Concrete structures" "Will be gone." "we look at these images" "Of our fallen civilization," "It helps us to identify" "With the past," "With the Greeks and the Romans," "With the crumbled" "Mud brick cities of urn." "Each of us knows" "That our bodies" "Are going to fall apart;" "Why not our cities too?" "a thousand years ago, 6 1/2 billion people" "Called this planet home." "At the early 21st century," "More than half of them" "Lived in cities." "Now those cities" "Are unrecognizable." "after maybe a thousand years" "Or so, the scene behind me" "Would be very, very different." "There'll be very little evidence" "Of buildings," "Very little evidence" "Of the activities of man." "What we would see" "Would be a jungle of vegetation." "the future of cities" "In a life after people" "Can be best imagined" "By looking to the past." "this is minute street" "In Greenwich Village." "Most new Yorkers might come here" "And wonder why it curves" "Like this." "It curves" "Because once upon a time" "There was a stream here," "And then a brook." "There were more than 40 streams" "On Manhattan island." "All flowing down" "And carrying the rainwater" "Down to the sea." "So what happens today?" "The rain falls, the snow melts," "But it flows" "Right along the street" "And down into that storm drain" "There." "If there weren't people here" "Anymore, there'll be no one here" "To maintain the sidewalks" "And maintain the streets." "They'd start to crumble up." "They'd start to break apart." "Trees would come back," "Vegetation would come back," "And eventually" "The hydrological cycle" "Would reestablish itself." "And who knows," "Maybe Minute Street" "Might once again" "Become minute brook." "using historic maps" "And computer modeling," "Scientists" "With the Manhattan project" "Are rediscovering" "What Manhattan Island" "Looked like when explorer" "Henry Hudson first sailed" "Around its shores in 1609." "here we are in Foley square," "The administrative center" "Of New York City" "And location to the famous" "Courthouses you see on TV." "This place hasn't always had" "Such colossal buildings" "And stony streets." "Once upon a time, 400 years ago," "The collect pond was here," "The freshwater source" "For New York City." "Right behind me," "There was a stream that drained" "Down to the Hudson River shore," "Another stream" "To the east river." "And there was" "This beautiful pond" "That was nestled" "In an amphitheater of hills." "So what would happen?" "If all the people" "Were to disappear?" "The buildings," "They would tumble down." "The soil would start to reform." "Trees would start to grow" "Out of them." "They would become the new hills," "The new amphitheater" "Around this place." "Nature would reestablish itself" "And slowly bring this place" "Back into the green heart" "Of what it means to be here" "On planet earth." "new York city," "Like the rest of the planet," "Has changed radically." "The transformation" "Is most shocking in Times Square?" "As the once beating" "Heart of the city is silenced" "By nature's onslaught." "It's 10,000 years after people." "Could it be possible?" "After only 10 millennia" "That humanity has vanished" "Without a trace?" "Human scientists once predicted" "That our history and culture" "Would live on through our radio" "And television broadcasts," "Which carry on?" "Through the universe" "Toward the infinite," "Perhaps to be tuned in" "By an intelligent species" "On a distant planet." "some people think" "That there's an expanding shell" "Of radio and television" "From earth, expanding outward" "Alerting the universe," ""here we are" "And this is our culture."" "Unfortunately," "Recent calculations" "By of all people, the seta," "Search for extraterrestrial" "Intelligence group," "Has shown that all" "Of this dissipates" "Within one and two light-years" "Into noise." "if this is true," "Our signals won't even make it" "Out to the newest star" "Beyond the sun." "So what will remain 10,000 years?" "After people to tell the story" "Of the once great civilizations" "That walked the earth?" "Iron corrodes," "Concrete crumbles," "Wood and paper decay." "Still, some of what man" "Built on earth remains." "The most colossal" "Of our stone structures" "Like the Great Wall of China" "Have aged like mountains," "Subject to erosion," "But at such slow time scales," "They will still be recognizable" "In some form for eons." "The great pyramid at Giza" "Is so massive that it lasts" "Long enough to be swallowed up" "By the desert sands." "The hover dam" "Built to be as tough" "As the canyon walls around it" "Is one of the last?" "Man-made structures" "Still standing." "But now thousands of years" "In the future," "Earth is about to be visited" "By the last" "Of the great collapses." "it's the environment" "That eventually wins." "Earthquakes, sandstorms, rain." "But there are a few exceptions." "I would have to say" "That mounts Rushmore," "Carved out of solid granite" "In an ecologically stable place," "The only enemy it has" "Are wind-driven pellets of rain?" "I think that mount Rushmore" "May be around" "A hundred thousand years," "Possibly 200." "Possibly even in time" "To be looked at in awe" "By the earliest" "Of our replacements." "and who or what might" "Those replacements are?" "Perhaps chimpanzees" "Might somehow make the leap." "but we have to consider this:" "Some scientists believe" "That it's easy for nature" "To bring animals" "Up to a clever level" "Where they might use tools," "They might become masters" "Of their environment." "But the leap to being able" "To stare at the sky" "And imagine a cosmos," "To be able" "To contemplate yourself," "To be able to contemplate" "Your own role in the earth," "This may be a leap" "That was a sheer accident" "For humanity." "In which case," "You're not talking" "About a complete recovery." "You're talking about a planet" "That may continue," "But nobody to talk about it," "Nobody to think about it." "if earth's 4 1/2 billion years of existence" "Were condensed into 24 hours," "The passage of 10,000 years" "Would be a fraction of a second." "Man's time on the planet so far" "Would be" "About half a minute long." "So, like an abandoned village" "On a global scale," "The earth will move on" "Without us." "There was life before people." "There will be life after people."