The World Without Us (2007) outlines the fictional scenario where, all of a sudden, the whole of mankind disappears. With humanity missing, the process by which nature claims back what was once hers is described. Although most of the footprints left by humanity would be gone after a relatively short period, some would remain. Among these remnants would be some of the many toxic substances released by mankind, meaning that, even after we’ve gone, the damaging effects of human civilization would linger.
Before the evolution of human beings, nature did a great job recycling every substance that ever appeared on earth. Yet humanity invented a substance that broke this cycle, something that cannot ever be recycled by nature – plastic.
Plastic is impervious to nature because it doesn’t biodegrade. Other substances can be broken down by microorganisms over time, but not plastic. This means that it will last forever, even after humanity has gone.
But if humanity were to disappear what would happen to all the billions of pieces of plastic we have created?
Rain and the oceans have the power to erode rocks and they will do the same to plastic. Over time, plastic pieces will become smaller and smaller as they are bashed by the forces of nature. And yet these tiny pieces will still not biodegrade.
Experiments have shown the durability of even the tiniest fragments of plastic. Scientists fed plastic fibers and particles to bottom-feeding lugworms that usually live on organic sediments. Although the worms ingested the pieces, they passed through the creatures’ digestive tracts harmlessly.
So over the centuries plastic pieces will continue to get smaller and smaller, until, according to the marine biologist Richard Thompson, they will become so small that even zooplankton will swallow them.
As plastic continues to disassemble in this way, it will spread into areas untouched by human habitation. The smaller the pieces of plastic, the easier it is for them to be transported by wind and water. This means that in the future, plastic will even reach the places that we currently cannot.
The amount of plastic produced by humanity is massive. For example, in India alone there are 5,000 factories that solely produce plastic bags. As each piece of plastic will never biodegrade, these bags will be around forever. And as the substance has only been around for 60 years we do not know if it will have any other long-term effects on the ecosystem.