• It feels like Armageddon is never that far away.
But what happens to earth when the dominant species is wiped off its face?
Did we make our mark, or are we just another blip in the history of life?
Here’s fifteen things that would happen if humanity went extinct.
15 - , The First Week • The civilisations of the 21st century
run on electricity, and this would cut out within a couple of hours of humanity's departure.
Night-time Earth would go dark and light pollution would disappear completely.
This would immediately change the lives of birds and insects whose flight patterns have
been confused by city lights.
For the first time in over a century, radio signals from the planet would cease and silence
would prevail.
14 - , Domesticated Animals • The first victims would be our beloved
pets.
Cats and dogs trapped at home would die from starvation within ten days.
Of the ones that escape, packs of the tougher, larger breeds would roam cities for years,
but breeds like Chihuahuas and Pugs would die out quickly, as humans bred all survival
ability out long ago.
Animals in battery farms would die too, filling warehouses with millions of tons of dead bodies.
13 - , Man-made Species • Without human intervention, many domesticated
farm animals would die painful deaths, like sheep whose wool we have selectively bred
to grow until it suffocates the animal, and cows whose milk glands would swell up.
Man-made, non-native crops could not survive competition from native species, and other
modified crops would revert to their ancestral form.
Cabbage, broccoli and cauliflower would devolve to one species, and the same would happen
to horses, who would revert to Przewalski's wild horse within centuries.
12 - , Wildlife Recovery • While human-bred animals would die out,
wild species would flourish.
Land animals that suffer hunting would recover, although without conservation, some critically
endangered species like the panda might not make it.
The biggest change would be in the seas.
Populations of fish, sharks, whales and dolphins that have been decimated by overfishing would
recover rapidly within decades, restoring the balance of life to the oceans.
11 - , Nuclear Power Stations • Proving that mankind can still harm the
planet after we're gone, the 450 or so nuclear power stations around the world would cause
lasting damage.
A few hours after power loss, the safety cooling systems would kick in.
After a month, the coolant would have evaporated, leading to meltdowns worse than Fukushima
or Chernobyl.
Clouds of irradiated gases would be released, creating fallout zones that would kill most
local wildlife for a few centuries.
10 - , Chemical Waste • Radiation is not the only mess we'll leave
behind.
Storage containers of harmful chemicals around the world would begin to decay, spilling harmful
substances into the soil that could remain for hundreds of years.
Much of the heavy metals from industry and electronics would enter the soil and be re-purposed,
but some compounds would seep into rivers and lakes, temporarily killing freshwater
life.
9 - , Cities • Even the most advanced and cleanest cities
would quickly fall apart.
After 25 years, 75% of the world's roads and pavements would be cracked and overgrown with
plants.
Over a century, cities in cold climates would crumble as frozen pipes and cracks burst in
the winter, tropical cities would become overgrown as plants force their way into every nook
and cranny and cities in the desert would be overcome by sand erosion.
8 - , New York • Journalist Alan Weisman takes New York
as an example of a city returning to nature.
After a few years, rats and cockroaches die out, deprived of food.
After 20 years, steel structures begin to decay and a visitor might see bears and wolves
roaming Central Park.
After a hundred years, trees have ripped up the surface of the ground and most buildings
have collapsed.
300 years later and almost nothing remains of the Big Apple as we know it.
7 - , Man-made structures • The only structures to last more than
a few hundred years would be stone buildings, just like the pyramids or Acropolis that survive
today.
It's possible that they would survive for many thousands of years, now that acid rain
is a thing of the past.
Glass and concrete buildings would crumble as the steel reinforcements corrode and swell.
Few bridges would survive more than 300 years, without painting or maintenance.
6 - , Machines • Almost all automated systems would fail
within a day or so, as the power grid shuts off.
Some renewable energy plants, like wind turbines would run until their machinery breaks.
After a year, the night skies would light up with a strange shower of falling debris.
There are over 1300 satellites orbiting earth and when they lose their guidance, they will
fall through the atmosphere, burning up like shooting stars.
5 - , Materials • Very few human artefacts would survive
much longer than the collapse of our cities.
Plastic is one of the most durable, with bags lasting 20 years but bottles wouldn't degrade
fully until 500 years after we're gone.
Metal containers like aluminium would be gone in 200 years but it could take as many as
a million years before your glass beer bottle returns to the ground it came from.
4 - , The Next Ice Age • Although current CO2 emissions are pushing
back the world's glaciers, if the climate recovers, many of the world's cities will
be overtaken by the next ice age in over 100,000 years.
The movement of these glaciers will crush and grind the remains of our civilisation,
leaving only a powdered residue of glass and PVC plastics as shameful evidence of our culture.
3 - , The New Rulers of Earth • The most obvious successor to humans as
the most evolved form of intelligent life would seem to be fellow members of the ape
family.
But whatever doomsday scenario wipes out mankind is very likely to kill our simian cousins
as well.
In the new human-free environment, the best traits for dominance may be completely different.
Intelligence is not necessary for survival, but it's possible that another conscious species
could evolve from our reptilian ancestors.
2 - , Human Fossils • Almost everything we know about extinct
species comes from fossil records preserved in rock.
The earliest records of homo sapiens could be up to 300,000 years old.
If people bury themselves in the right places, their traces can last for many eras.
The oldest fossils ever found come from 4.2 billion years ago, so there's a chance that
our bones may be around for quite some time.
1 – The Last Trace of Humanity • When alien archaeologists land on Earth
and search for evidence of our existence, will the find anything after our civilisation
has crumbled?
Well, two things are for certain: Our tv and radio signals will be bouncing around an expanding
universe forever, giving distant planets a taste of MTV.
But the final monument to humankind rests on the moon, in an environment free from bacteria,
moisture and movement, our lunar equipment will survive as a testament
to our ingenuity.