What Would the World Be Like If Humans Disappeared?
This scenario seems impossible, but in the last hundred years our species has faced numerous events that could have resulted in the disappearance of people, from the Spanish flu of 1918 to the Cold War (which was very close to cause a nuclear conflagration). Also, if certain diseases like Ebola or AIDS would develop the ability to be transmitted by air the consequences would be dramatic for humanity. Annually, the Bulletin of the Atomic Scientists unveils the Apocalypse Clock which estimates how close we are to a cataclysmic event.
What would happen to our planet if all humans disappeared one day? Journalist Alan Weisman explores this scenario in the book "The World Without Us" by analyzing how the Earth would change if it would not be inhabited by homo sapiens.
Weisman shows that the end could come as a result of our own hubris : Central American Mayan civilization disappeared in the eighth century after 1,600 years of existence, " destroyed by its own greed ." An expert quoted by Weisman notes that "the balance between ecology and society is very fragile , and disruption of this balance can bring the end ."
" To understand how the world would look without people we need to discover how the world looked before there were people - and the picture varies from continent to continent. Also , we must take into account that the Earth's surface is two-thirds covered by water. How would oceans look like without us? To get all the answers, I talked to paleontologists , engineers , biologists , mining, marine biologists , astrophysicists and even with Buddhist monks , among many others. "said Weisman.
Also , to understand the changes that would take place on Earth , Weisman visited places like the Białowieża Forest , one of the last remnants of a huge virgin forest that once stretched across Europe ,the Chernobyl area and many other sites in Micronesia , Africa , the Amazon , the Arctic and Guatemala.
All these efforts have enabled the author to understand what will happen on Earth if humanity would vanish. " I wanted to write a book with the clear intention that it should not be apocalyptic . Apocalypse means destruction and end of the world , "says Weisman . I wrote a book where people are already gone and we see how nature would do without us . I wrote this book not because I want people disappear, but I temporarily removed them from the landscape to show how nature would be able to heal without us , then we can understand how we can return to this landscape in balance with all the other elements "says the author .
What would happen to our homes?
Shortly after people disappear, nature will start to regain supremacy on the planet. One of the first places where this will occur will be the houses where we used to live.
Architect Chris Riddle cites a popular saying among American farmers that highlights the power of nature : "If you want to destroy a barn , just cut a 45 centimeter hole in the roof and then do nothing."
No matter how well we seal our homes , nature always manages to get inside them , if only by mold or insects. However, they are not the most powerful weapon of nature. This quality belongs to the same substance without which life is not possible: water.
After people disappear , water will be the first weapon that will penetrate our former home. Wooden elements of the roof will be among the first affected , allowing water to enter the house . If your home is in an area with cold winters , the water in the pipes will cause them to break. If your home is equipped with a basement or a cellar , it will fill itself with soil and plants. PVC pipes will turn yellow in sun-exposed areas , in time they would dissolve . The only elements that remain unchanged are tiles and floor tiles, but in time they will be buried under a carpet of leaves. In a temperate zone , houses will be fenced by new forests in about 500 years.
What would happen to the cities?
Like the houses in which we live , the cities are in a constant struggle with nature and depend on human activity to resist. New York , for example , requires a continuous underground pumping system . If the pumps are stopped , in 30 minutes the water will reach a high enough level to not allow the subway to move . In 36 hours , the tunnels would fill and within days the streets would begin to break down under the action of water . In about 20 years, the steel pillars that support many streets in New York would break, and these streets would become veritable rivers.
Long before this happens the asphalt covering the roads will be destroyed. Every year in March, temperatures drop and raise above the threshold of 0 degrees about 30 times . Every time this happens , the melting and refreezing of water causes cracks in concrete and asphalt. When the snow melts , water gets into these cracks and the repeating phenomenon amplifies them.
As the asphalt cracks, weeds enter the newly created space and extend it. They will be followed by trees , and in five years their roots will deteriorate even more sidewalks and streets. As the ground hidden under the asphalt will become exposed to the sun and rain, other species will begin to appear.
After several years pipes would explode. As components shrink and grow in size, the water has more and more spaces in which to penetrate , increasingly deteriorating building elements. The steel inside the concrete would begin to rust , causing new cracks in the building.
In about two decades, lightning rods will rust and fall to the ground and lightning will be the perfect opportunity to start a fire, taking advantage of accumulated dead branches on the ground and flammable materials left behind by people. Fires will ignite gas pipes , causing explosions that in return will destroy windows and other elements that protect buildings from rain and snow. In a short time, large amounts of precipitation will penetrate into the building wrecking it even more.
Creatures that depend on people to live will not survive for long after we disappear. Beetles, apparently invincible, will die shortly after our disappearance, as they will not benefit from heated buildings during the winter. Also, the rats will die either of starvation or by being hunted by birds that will occupy our buildings.
The ruins of the major financial institutions will remain intact and the money will be safe inside the vaults, even if they mold and become useless. On the other hand, works of art from museums deposits will not last. As buildings yield to water, it reaches to fill the basements of museums and opera houses storerooms will fall prey to mold, bacteria and insect larvae. The only art that will remain intact will be the ceramic. Also bronze statues will suffer corrosion, but their shape remains intact.
What are we leaving behind?
After 15-20,000 years we will not see too many traces of humans or human activity. Glaciers would have deleted much of our architecture. It is possible, however, to leave some traces in desert areas where glaciers can’t reach. "
However, future scientists will be able to identify signs of our presence, no matter how much time passed from the moment we disappeared. The ceramic elements will last longer, with brass and plastic. The four presidents carved on Mount Rushmore - George Washington, Thomas Jefferson, Theodore Roosevelt and Abraham Lincoln - will endure for at least 7 million years from now.
Natural ecosystems will regenerate shortly after the disappearance of people. This is shown by some experiments carried unintentionally by people in the last century. Looking at Varosha, Cyprus, an abandoned area after the civil war of 1974 and at the demilitarized zone between South Korea and North Korea. In both places people have not carried out activities in recent decades, and today they are genuine natural reservations.
Further evidence on the ability of nature to recover is provided by Johnston atoll in the Pacific Ocean. The U.S. Army detonated there 12 thermonuclear warheads, and in the Cold War they used this site to incinerate various chemical weapons, including sarin gas, Agent Orange or dioxin. However, recently conducted diving expeditions in this region shows that it is not an "aquatic desert." They saw a relatively healthy coral and lots of fish. Moreover, in recent years seals were observed near the atoll. Near Chernobyl researchers observed a similar phenomenon: a year after the disaster in 1986, the swallows have returned to the region, and now near Pripyat the forests are inhabited by wild boar, deer and wolves. Research studies have shown that rodents live less than in other regions, but they compensate by maturing faster and producing offspring earlier, so the total population was not affected. Ordinary human activity is more devastating to biodiversity than the most severe nuclear accident.
Music is the human creation that has the potential to live even after our planet will be destroyed. The Voyager space probes, launched in 1977, carry on board a golden disc that contains whale and bird sounds, along with 26 musical pieces. This includes both works by Beethoven, Mozart and Stravinsky, as well as music from Guan Pinghu (a famous Chinese virtuoso that plays a traditional stringed instrument called the guqin) or Kesarbai Kerkar (an Indian classical music singer).
Although the Voyager probes will be destroyed in their long journey through space, mankind will forever leave its mark in the Universe, an element of our existence that persists even after the Earth will be swallowed by the Sun: radio waves. Four years after being emitted from a TV studio in Hollywood, sounds and images from the “I Love Lucy” series already passed Proxima Centauri, the nearest star to our solar system. In 2005, the airwaves were already 50 light years away from Earth. Since the Milky Way is approximately 100,000 light years in diameter and 1,000 light years thick, and our solar system is around half the galaxy, this suggests that around 2450 the radio waves will exit our galaxy, penetrating the intergalactic space.
Radio waves, like light, continue to expand. They will continue to travel through the universe long after the Voyager probes will be gone, carrying with them a small piece of human existence. Anyone waiting at the border of time will have a noisy moment. Maybe they won’t understand Lucy but they will hear us laughing.