Life After People

0:03 what would happen if every human being on the earth were to suddenly vanish at some point in the future this could be the fate of our planet this isn't the story of how mankind might disappear it is the story of what happens to the World We Leave

0:52 Behind the idea of The Disappearance of humans may seem like a science fiction nightmare but if eventually there will come a day when this occurs 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 [Music] what will life be like after people we're

1:38 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 let us imagine that time has run out for

2:23 [Music] mankind our hold over the planet is ended Welcome To Earth population zero within hours of our departure lights start going out around the world More than 70% of power in the United States is generated by the burning of fossil

3:09 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 go into meltdown the average reactor holds enough fuel to keep running for 2 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 2 days even wind generation can't last

3:54 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 cease to produce electricity 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 primitive humans first huddled around campfires perhaps the last glow of artificial light on Earth will be visible in the American

4:42 southwest here the mighty Hoover Dam Hydro power plant takes little notice of the absence of humans its source of fuel is virtually Limitless at Hoover Dam our fuel supply is actually the water in the reservoir in Lake me behind Hoover 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 hydr turbine generators these generators are operating automatically and that would continue as long as all of the systems are functioning

5:27 normally if I and my St St were to leave tonight and not come back to Hoover Dam say just in the condition that 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 Hoover Dam would be one one of the last power plants still running as the lights go out around the world other systems also quickly begin to

6:14 fail beneath all 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 now 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 are switched on when necessary to drain the tunnels deep within New York City Subways more than 700 pumps struggle constantly to keep out a flood of ground water expelling an average of 13 million gallons a day

7:00 now if all these people were not around there would be nobody to switch the pumps on it it's estimated that the tunnels would fill with water in about 36 hours meanwhile above ground food is rotting on Supermarket shelves household refrigerators become mere containers for decaying food but meltwater from defrosting freezers May

7:45 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 [Music] on he can't open cans he can't get in the refrigerator you got to get out of the house the family do has got to get out of the house or he's going to die

8:35 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 whack at it is that they uh they go back to Scavenging a whole bunch of dead things out there in the world world it is estimated that there are 400 million dogs in the world comprising 300 separate breeds but very few of them are particularly well suited to surviving in a life after

9:22 humans the smallest dogs probably won't last a week 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 have been deliberately bred into pet dogs over the years will now become major handicaps in their fight for survival your dogs with a really short legs I think of the dogs with really short faces or long faces uh 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

10:08 middle of the spectrum the kind of average dog has 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 pets struggle to find their new niche in society household pests are slowly beginning to notice our absence those ubiquitous little creatures like rats and house mice would appear well able to thrive without us but are surprisingly quite dependent on our food supplies rats and mice are usually termed commensal rodents which means that term means literally sharing the table they are very dependent on people

10:56 and the little house mouse and the Norway rat great examples of animals that would do less well in the absence of people in the initial weeks after people have gone rodents will raid food Cupboards in houses and the grocery shelves in [Music] shops after consuming these Edibles they will attempt to survive on Commodities like cardboard cloth and glue I think that if a city was abandoned the rats would have to go back to earning an honest living and an honest living means to go back to the Wild and uh and

11:42 compete for resources there eventually the rodents will have to abandon houses and public buildings which will make them easy prey for Predators although rats and mice are most likely to survive into the future their numbers will be greatly diminished after 6 months into a Life After People urban areas are already returning to the wild Predators would return very quickly in the absence of humans because we suppress them we create conditions that either work against them or we we deliberately go

12:28 out and and remove and Destroy them they would come back very quickly smaller Predators like foxes coyotes and bobcats have always survived on the fringes of human populations they are the first to colonize our abandoned towns 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 Sunny patios and neat back Gardens one year into a life without people towns and cities are still recognizable

13:14 but nature is beginning to reclaim them one of the first great physical effects in the absence of people would be the transition of the impervious surfaces the parking lots the grows into places that supported and then had an abundance of plant life any place who you have sunlight that's heading 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 in matters of you know few years [Music]

14:04 without us to remove them weeds like dandelions infiltrate every crack in the pavement as these weeds die their residues combine with ever spreading moss and lyen to create a thin layer of top soil this sandy soil is poor in nutrients so only plants like Clover that can extract nitrogen from the air flourish initially formally manicured Lawns morph into Fields where white-tailed deer forage wild animals have also begun to find their way into abandoned

14:56 cities man's supposed domination of nature proves to be quite tenuous however the indications of our vulnerability have always been there this is an alanthus tree it seems to enjoy rooting itself in very inhospitable locations and it likes to attach itself to crevices and 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 bounces back even

15:43 man-made goliaths like the Hoover Dam show they aren't Eternal 21,000 men and 5 years of hard labor were necessary to harness the power of the mighty Colorado [Music] River but one year after we disappear it 17 massive and seemingly indestructible generators are about to be brought down by an organism the size of a [Music] thumbnail the lake above the dam is infested with an invasive species of mollusk called the quag muscle this stealthy Invader from Eastern Europe has no natural predators in North America other than the humans tasked with scraping it from the grates and pipes it

16:31 colonizes the muscles 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 [Music] the small pipes that transport cooling water to the Dam's generators make perfect layers for these creatures and with no people around to remove them they can spread like a cancer and in fact those muscles could clog up the cooling water pipes to the point where we couldn't keep these generators cool

17:25 anymore and it would cause a 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 to all of the generators at Hoover Dam and eventually the entire power plant would be shut down in Las Vegas the last glimmers of man-made light on Earth relinquish the night to its primeval Blackness with the generators no longer running no water at all is passing through the Hoover Dam and the Colorado River Downstream of it begins to run

18:13 dry on the Upstream side of the dam the water has nowhere to go and Lake me starts to rise it would just keep building up in Lake me and it would eventually get to the point of spilling over through the spillways on either side of the dam unchecked Nature's most potent elements reclaim their Supremacy on Earth triggered by lightning strikes the wildfires that humans once fought so valiantly now rage unchecked cities towns and Villages choked with abandoned buildings wild

18:59 grasses and dry debris are Tinder for the Flames Chicago Burns San Francisco's elegant Victorian wooden houses 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

19:47 [Music] 5 years after people the roads of the world are disappearing beneath a verdant mat that creeps like some Relentless living carpet the advance of nature knows no bounds the gates of Buckingham Palace are easily breached by Vines and creepers in Moscow Red Square turns green in reality nature will reclaim the Earth very very quickly these stairs were cleared 18 months ago if we came back in another 18

20:35 months we'd have a hard time finding them if we came back in 5 years it would be almost impossible to find man's Mastery over Nature has always been an illusion when the Cambodian city of Anor vat and its Temple complexes were abandoned in the 15th century jungle trees spread indiscriminate Ely over the stone monuments entangling them in their [Music] Roots now without armies of gardeners and workmen modern cities are laid bare to Nature's revenge in New York's Central Park the great Lawns now untended Sprout

21:22 saplings 5 years without humans leaves the park looking more like a forest Central Park will go bananas all of a sudden you'll get trees you'll get growth all the animals and plants that are there now will go up in population levels and they'll start to spread out into the city it is the same in Washington DC the grand monuments have all been swallowed by rampant foliage and on what used to be the American National Mall the cries of the Jungle are beginning to Echo zoo animals are

22:09 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 posthuman period they do better further south than they would do in Washington DC but these are animals that are 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 be sure of about life 20 years after people have disappeared because there's one place on the planet where it's already happened

23:21 it's 20 years into a Life After People without human beings to apply fresh paint and fill in cracks even concrete buildings have begun to fall into disrepair lack of Maintenance turns cities into Eerie skeleton 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

24:08 Square of priot Ukraine a city that was once the most modern city in the former Soviet [Music] 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 [Music] civilization hurridly evacuated after the Chernobyl nuclear disaster Prat went from a city of 50,000 to a ghost town overnight

24:55 [Music] dust covered School rooms remain just as pupils left them over 20 years ago vegetation pries apart the masonry as it crawls through buildings a funfare scheduled to open 4 days after the day of the accident remains [Music]

25:42 pristine the amusement Park's big wheel accumulates rust rather than Riders [Music] the dodam cars sit motionless Prat has provided us with an extraordinary and rare opportunity to see what happens to a city when humans leave it suddenly I can see from my gager counter that it's really quite safe to be here radiation levels are not very

26:29 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 Pria 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 behind me but after 20 years the forces of nature have started to Decay this facility this Soviet concrete facade looks imposing but it's no match for the

27:14 unforgiving Ukrainian winter as the temperature drops below freezing water that has accumulated in cracks expands exerting bursting pressure that splits the concrete as vegetation grows unchecked the roots spread through foundations and stairwells these roots suck in moisture that makes them expand and grow like miniature hydraulic jacks over time they slowly push the walls apart this is only 20 years can you imagine what this facility will look like after 200 years

28:03 after the accident scientists expected the worst for the Flora and FAA of the region most of the trees within a 1 and A2 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 uh by radioactivity due to the Chernobyl explosion and the trees that you see around me were were killed by the

28:48 radioactivity the original amounts of radioactivity were sufficient to kill all of the wildlife in the region as well but now we see a Resurgence of the wildlife as an example of how Wildlife has prospered here uh uh we see here we have a 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 uh populations of breed deer we also find Russian wild boar that

29:35 the populations in the zone are 10 to 15 times higher than they are outside of the Zone we are now at the kindergarten of carpet Village not far from the Chernobyl station children were living here while they parents worked but after that night in April 1986 they never returned we are in what was formally a bedroom in this kindergarten where children used to sleep and rest now there is a certain emptiness here all these windows are broken but their room continues to live

30:22 on birds fly in here and sit on these bars we even found evidence that that an owl comes here an owl that 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 shown themselves as especially vulnerable to radioactive fallout are finding new homes in the evacuation zone I'm sitting in the priviate soccer

31:09 stadium where 20 years ago hundreds of people would come and cheer on their favorite [Applause] team you can imagine the laughter the sounds of the crowds here the activity on the field which 20 years later is barely discernible the soccer field now is going through succession as you would expect and returning to what it was originally hundreds of years ago which was a mixed deciduous [Music] forest I grew up in a town about like

31:57 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 cot and that people will never live here again but there's another side to the 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

32:44 if we disappear our Legacy of life will continue [Music] it's 25 years into a Life After People out in the countryside nature is beginning to erase all evidence of man in the suburbs packs of feral dogs roam through deric neighborhoods in search of their next meal [Music] in some of the great cities of the world

33:30 Solid Ground is getting harder to find in the time of humans London was protected from tidal surges by the temp's barrier 10 retractable steel Gates that could be raised during storms to seal the River from the North Sea without technicians to operate the barrier London is defenseless another low-lying city Amsterdam suffers the same watery [Music]

34:18 fate in a New York City high-rise block some windows have already cracked and slipped loose from their frames and many more are on the verge of destu ruction after a quarter Century of exposure to moisture and heat without any 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 which cracks and plummets to the pavement below after a few of the windows fall out of a building like this then the wind pressure effect changes dramatically as

35:05 well as external pressure coming onto a building you also get suction and that aggravates the problem so more of the panels are likely to fall out through the gaping holes the building fills up with Windswept debris a summer storm rolls in on the top of the structure the copper lightning rods that once protected thousands of office workers from strikes is now corroded and useless a lightning bolt turns the tower into a pillar of Fire

36:03 the gutted building makes the perfect home for an unlikely Survivor although pigeons once relied on the rubbish produced in abundance by human beings they have done surprisingly well in 25 years without us pigeons are survivors they can live in the wild they do live in the wild still and 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

36:48 the humble and despised 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 mourning won't last long while cockroaches thrived on our food scraps they can also eat book bindings and cardboard and any rotting organic matter including Dead Leaves and Roots food isn't a problem but cockroaches also need warmth the kind that we had always supplied through artificial Heat cockroaches started as a tropical species and some experts say they

37:34 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 had to bed I'd put my money on them being able to survive in one form or another the first winter after humans did witness the death of some cockroaches but many more moved underground to find warmth until milder weather returned in an abandoned Town Center devoid of insecticides overrun by vegetation and with a rising water table this former pest is now enjoying a new

38:22 golden age cockroaches posed a threat to hygiene for 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 that nearly half a million wolves roam the land by the 20th century these Predators were almost extinct in the lower 48 states now with no humans left to kill them wolf populations multiply by as

39:08 much as six times each year within 20 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 already in 1995 biologists released a few dozen wolves within the boundaries of Yellowstone National Park a place where they would be protected from persecution by men within a decade the few dozen had multiplied into

39:54 1500 and the Wolves quickly spread out from their releas point to occupy territory throughout the states of Wyoming Montana and Idaho it'll be fast and if you can start with just a few dozen wolves in the course of one decade have a population of 1500 and you can have a geographic expansion where they filled up big chunk of a three-state area and these are Big Western States yeah when the conditions are right they can recolonize pretty rapidly could we see them in Manhattan or Chicago as soon as the deer get there the Wolves will be right behind [Music]

40:41 them animals haven't only been hunted by men they've also been confined by them there are over 3 million miles of paved Road in the United States alone and it's no coincidence that many of them cut through the paths animals use in order to get from place to place the things that make a landscape good for animal movement also make it easy to engineer a road into that location so we've cut off pretty much all major migrations in North America asphalt and car cars waked

41:28 particular havoc on the habits of the grizzly bear their habitat was carved up so comprehensively by Road networks that the Bears became confined to isolated pockets of land thus cutting them off from food sources and potential [Music] mates in a life after humans roads are no longer barriers instead they are Pathways trails that lead the Grizzlies back into the peace and plenty of their former [Music]

42:15 hotlands 40 years after people while cities of Steel and concrete are still Standing Tall the suburbs are under attack approximately 90% of all houses in the United States are Timber framed while some have burned others are now being literally devoured without paint and preservatives the Timbers are defenseless against Termites Termites beast on cellulose the basic element of wood and their appetites are insatiable some colonies

43:03 can eat as much as ,000 pound of wood per year in this annihilating Advance the termites aren't working alone the process we know is riding 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 would be a matter of decades before most structures that had significant wood components would start to Decay faced with the two-pronged attack from termites and rot the beams that hold up the roof give way and the distinction between inside and out that

43:49 had once been so important to the humans who called this building a home is forever erased other substances like this mortar and rock are going to last longer than several decades but they'll still crumble uh through 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 the home of the caretaker of the city's Zoo it looks like this building has been abandoned for more than 100 years but in reality people have been living here up

44:34 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 brick stone or masonry will far outlive anything made of wood exactly how fast they will Decay depends on their surroundings the coast of Maine really isn't very kind to buildings structures out here don't so much Decay when you leave them alone they melt these structures on Black Island Maine used to be part of a Granite

45:20 Quarry the stone of which was used to build and embellish cities like Boston New York and Philadelphia it was abandoned about 1920 here the buildings have all vanished within the space of 80 or 90 years there's almost nothing left in the right conditions and with regular maintenance stone structures can endure for thousands of years in some places in Europe Roman aqueducts are still in daily use but without constant repair Stone can fall victim to a very stealthy enemy one of the great enemies of stone is actually salts and salt crystals even

46:06 thousands of years ago people noticed the effect that salts had on deteriorating the ancient pyramids there are many ways in which salts infiltrate Stone buildings and monuments polluted air sea waterer and even bird droppings soluble salts dissolve in water and as the water evaporates it will rise up inside of uh porous building materials things like brick and stone and even concrete and what happens is the salts will continue to grow inside the pores of the stone until they come up against this the side of the wall and they'll actually push the stone apart what we're seeing in this timelapse video really shows the rapid decay of the stone in response to this

46:52 deteriation by salts in this experiment it took about 3 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 could actually see the salts deteriorate the stone although not immune to Decay the pyramids have survived for nearly 5,000

47:38 years because of their sheer volume and the 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 modern times [Music] many ancient monuments have survived only because of regular maintenance through the centuries the Sphinx was uncovered and restored for the first time in 1400 BC contemporary experts who have studied the Sphinx predict that without human intervention deterioration caused by salts and wind erosion could render it a pile of dust within 500 to 1,000 years

48:31 the largest concrete structures like the Hoover Dam will last longer than that it is so thick that 70 years after it was constructed the concrete deep inside was still curing but of the 15 highest dams in the United States only 10 are made of concrete the others are made of compacted rock or earth like Northern California's Trinity Dam if there were engineers around this leak in the dam would receive emergency repair work but those days are over some of

49:18 these Earth dams are absolutely enormous if they fail as they will in time then the surge of water that falls in behind him and Cascades down the valley below we would have a huge force and big enough to sweep away everything in its path 50 years after humans the strain of neglect is beginning to show on even the best designed of man-made structures [Music]

50:04 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 [Music] years the reason that 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 elements of a suspension bridge are the steel vertical hanger cables these have been tested in the

50:51 laboratory fortunately not in the bridge but 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 um that probably has a tensil strength that's maybe 200,000 lb per square in that's a very high strength steel as strong as they are these cables have a fatal weakness it's the very stuff they're made of Ste our mineral that comes from the earth that's mostly iron so it's probably 95 98% iron exposed to moisture in the environment iron will start to revert back to the minerals it came from ashes

51:36 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 cost5 million to build over the last two decades $3 billion have been spent maintaining it and the other bridges over New York's East River

52:27 in the time of humans the Brooklyn Bridge was continually maintained and completely repainted roughly every 12 years while Across America in San Francisco the Golden Gate Bridge was protected at all times by a Vigilant Brigade of 17 iron workers and 38 [Music] 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 stopped the cables begin to rust the paint peels off the wires begin to break and they'll come to a point where the bridge is going to come

53:15 down 75 years after people most of the 600 million cars that once traveled the roads of the world are now completely corroded remnants of the human past abandoned cars will behave differently depending on the environment that they're in 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

54:01 they're made of will remain intact for centuries paint deteriorates quickly and once it flakes away rust consumes the car's body at a rate of 5,000 of an inch each [Music] year 75 years after humans most cars even in the most forgiving of environments will be reduced to skeletons after a cent the family car is a barely recognizable heap of rusty metal it's now 100 years into a Life

54:47 After People the Brooklyn Bridge which had stood for over 125 years with humans to repair it can't survive even a century without them as the cables fail and the deck and railings begin to warp and [Music] 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

55:32 got an end to its life but without maintenance an end to its life it certainly has how exactly do Bridges fail once corrosion sets in 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 or what do they do and the answer is they tend to shred and 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

56:20 or three start to go the whole bridge is in jeopardy Twisted steel crashes into the water below it's going to be gone 200 years I doubt it will last 200 years the bridge it's going to be in the drink if some of our largest structures have already failed after a 100 years can there be any hope that our civilization will leave a permanent Mark after we've gone what will remain of the records of our history and culture 100 years after people our vaults contain our most

57:06 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 in ideal conditions paper and film both have an estimated shelf life of 2 to 300 years but expose them to the rigors of an uncontrolled environment and that lifespan is cut by half at least if all the power went

57:52 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 the manufacturer of films and photographs in the 20th century begins to bubble and warp all that culture and history from the D-Day Landings to the great artworks of the cinema and even our cherished snaps and home movies won't last even a century without the care of human curators so the precious images given time are going to end up like this all of these are examples of

58:38 various stages in the decay of cellulose acetate based films exposed to very high amounts of humidity essentially these materials are finished in libraries the Great repositories of our Collective knowledge the damage originates from microscopic Invaders although we can't see them mold spores are on all the surfaces around us lying dormant Bing their time for the right conditions to [Music] strike high humidity creates the right

59:24 conditions and so the situation is set up for the mold to really [Music] Bloom 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 aridity of the climate and the absence of damaging sunlight but these are rare exceptions so without human intervention A Book Like This Might last at best another hundred

1:00:13 years even our digital media won't last forever estimates for the lifespan of CDs and DVDs range from a few decades to a few centuries under ID storage conditions we know about the ancient Egyptians because what they left behind was engraved in Stones our form of capturing knowledge information our history our advancement is typically either in a computerized form in a CD 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

1:01:01 all of our advances we still have not come up with anything as durable as clay tablets and stone tools 150 years after humans the underground passages that had started to flood in the first 36 hours are now fast flowing Subterranean streams the beams and archways that hold 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

1:01:49 if these tunnels are inundated and flooded with water corrosion will start to take hold and we'll start to see collapses the tunnels Echo to the sounds of cracking steel and cement as the streets above are sucked into the [Music] void above ground life in the city is once again bustling with life [Music] creepers have grown up the sides of abandoned skyscrapers adapting to feed off rainwater that collects in crevasses and on

1:02:34 [Music] Ledges these Vines all start up and the vines have little branches it'd be nice if they produced for fruit or something that was edible we got to have a plant with some fruit or you know some some sauce of energy for for animals and then you would get this vertical ecosystem system 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 become established in these vertical ecosystems the cats creep [Music]

1:03:21 in there's some interesting examples of that around the world if you go to the Coliseum you're just look and it's just loaded with cats and old tombs and old catacombs and so on get loaded with cats that use this as a living space of which then they radiate out uh during the day these felines are the descendants of our former moggies immediately after people were gone they replaced their human supplied pet food with field mice and small birds hunting out in the open was hard work but here the pickings are easy now they live their whole lives

1:04:06 high above the city streets finding all they need to survive without ever having to touch the ground they are the monarchs of the new high altitude food chain enjoying elevated views of a bizarrely altered landscape [Music] I could picture New York City with all the buildings covered with vines you know Hawks sailing around it would be lovely it would be absolutely lovely for cats life in this new environment could eventually lead to some strange

1:04:53 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 uh imaginative responses to this unusual environment while some cats have made a Great Leap Forward many dogs have reverted to the ways of their canine ancestors some that have interbred with Wolves now prowl in packs to stalk larger

1:05:43 prey I think our dogs as Placid as they may seem when they're in our homes lying on the living room floor still possess the instinct to survive enough that they would be able to do whatever it took in bringing down prey in order to [Music] live 150 years after humans disappear from the planet the oceans are positively teeming with life Marine creatures have welcomed The Disappearance of mankind [Music]

1:06:31 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 as men were no longer fishing and polluting the Sea The Path was cleared for this as ising recovery it has happened before during the second world war Allied fishing trollers avoided the North Atlantic and the fish population soared and here the basic biology of these kinds of animals is working in our favor because animals like the Sunfish

1:07:17 can produce millions of Offspring in a year much more than a 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 depredations of modern man the oceans were capable of sustaining phenomenal amounts and varieties of life forms 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

1:08:03 the Earth then that's the kind of ocean it could be seagulls are also flourishing but it has been a treacherous time for them the abundance of food supplied by 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 G's 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'd had to feed for themselves sudden they

1:08:49 had all this 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 decline in numbers the remaining gulls took advantage of the recovering Oceans Where plentiful raw fish erased any memories of the convenience food feasts they used to enjoy courtesy of us 200 years after people from New York to Chicago Seattle and Paris our Iron and Steel icons are finally on the verge of

1:09:37 collapse although it has outlived the great suspension bridges the Eiffel Tower is not Invincible in the time of humans its iron superstructure had to be painted every s years to protect it from corrosion comparable in both age and structure the Eiffel tower has a lot in common with the 300t high Kinzua Railway viaduct in Pennsylvania with a bridge that was RW 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 at the corrosion the connection points freeze up they are not allowed to

1:10:22 move and here are some pieces from that itic 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 imposed by high winds eventually in this strong Windstorm it literally fell over section by section piece by piece it fell over into the valley where had spanned the valley for over a 100 years just not maintain you can think of many structures that are coming from that same area like the Eiffel Tower it's iconic structure that doesn't Shield it

1:11:09 from the fact that's 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 [Music] the period between 1 and 300 years after people will most likely be the era of the great collapses worldwide

1:11:57 in Seattle the iconic Space Needle was designed to sway 1 in for every 10 mph of wind but with its steel weakened by corrosion it takes little more than a strong Breeze for the emblem of the 1962 World's Fair to plummet from the skyline when humans disappeared sea levels were already rising alarmingly in Manhattan over the centuries saturated soil around the

1:12:42 Empire State building's foundation piles 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 but once it does start to Incline gravitational force will cause the top of the building to collapse downwards on top of itself the first 500 years after human beings has been an era of decay and

1:13:31 destruction our concrete structures have lasted longest the ancient Romans invented the first form of concrete and some of their buildings remained intact for over 2,000 years but modern concrete isn't nearly as durable as the Roman variety it has a higher water content and is more Loosely packed which results in more air pockets and cracks and modern concrete buildings hide another fatal floor below the surface of reinforced concrete structures there is a a mesh of Steel reinforcing bars uh they don't corrode because the concrete maintains an alkaline environment around them now when that alkalinity breaks down as it

1:14:17 will in time then the steel will start to corrode as the steel rebar rusts it expands to three times its original volume creating outward pressure that causes the concrete to fracture in very broad terms after 50 years would start to see surface cracking on concrete after a 100 Years pling of the concrete surface after maybe 500 years most reinforced concrete structures will be gone we look at these images of our fallen [Music] civilization it helps us to identify

1:15:03 with the past with the Greeks and the Romans with the crumbled mudbrick cities of UR each of us knows that our bodies are going to fall apart why not our cities too a thousand years ago 6 and a half billion people called this planet home by the early 21st century more than half of those people lived in cities now their cities are unrecognizable after maybe a thousand years or so the scene behind me would be

1:15:50 very very different there' 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 humans can be best imagined by looking into the past this is manetta Street in grenwich 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 manetta Brooks there were more than 40 streams on Manhattan Island all flowing down and carrying the rain

1:16:36 water 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 start to crumble up they start to break apart trees will come back vegetation would come back and eventually the hydrological cycle would reestablish itself and who knows maybe manetta Street might once again become manetta Brook with the help of old maps and computer modeling scientists at the manah project are rediscovering what Manhattan Island looked like when the Explorer Henry Hudson first sailed around its Shores in

1:17:23 1609 here we are in Hoy Square the administrative Center of New York City and the location of the famous Courthouse you can see on TV this place hasn't always had such colossal buildings and Stony streets Once Upon a Time 400 years ago the kle 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 it 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 tble 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

1:18:10 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 in New York the transformation is most shocking in Time Square as the once Beating Heart of the City is silenced by Nature's onslaught

1:19:23 it's 10,000 years after people could it be possible after only 10 Millennia that humankind has vanished Without a Trace scientists once predicted that our history and culture would live on through our radio and television broadcasts which travel through the universe toward the infinite perhaps to be tuned into to 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

1:20:10 the universe here we are and this is our culture unfortunately recent calculations by of all people the seti search re terrestrial intelligence group has shown that all of this dissipates within one or two light years into noise if this is true our signals won't even reach the closest Heavenly Body beyond the Sun so what will remain 10,000 years after we go to tell the story of the once great civilizations that Ruled the Earth

1:20:56 iron corrodes concrete crumbles wood and paper Decay nevertheless some of what we built on Earth Remains the most colossal examples 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 intact by the desert sand the Hoover Dam designed to be as tough as the canion walls around it is

1:21:42 one of the last man-made structures Still Standing but now thousands of years into 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 Mount Rushmore carved out of solid granite in an ecolog ically stable place the only

1:22:27 enemy it has is wind driven pellets of rain I think that Mount Rushmore may be around a 100,000 years possibly 200 possibly even in time to be looked at In Awe by the earliest of our [Music] Replacements and who or what might those Replacements be 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

1:23:12 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 and a half billion years of existence were condensed into 24 hours the passage of 10,000 years would

1:23:57 be represented by a fraction of a second according to this analogy Mankind's time on the planet so far would be about half a minute so like an abandoned Village on a global scale the Earth will move on without us there was life before people and there will be Life After People

1:24:53 B for