Humans are accelerating mass extinction. How far gone is it already?
What is an extinction event?
A mass extinction event occurs when there is a widespread decrease in the biodiversity of the earth in a very short (less than 2.8 million years) amount of time, due to increased extinction of species in our ecosystems. An extinction event usually sees at least 75% of the world’s species going extinct. It occurs when species start going extinct faster than newer ones can evolve. In the history of the earth, there have been 5 mass extinction events, the causes of which are widely debated over, but have always been speculated to be things out of our control – volcanic eruptions, asteroid hits, ice ages, geological changes, etc. We are currently living through another mass extinction event - the Holocene extinction. With the 6th extinction event, however, the cause can be traced back to mainly one factor – humans.
(Also Read: Movies that got disasters wrong)
Are humans driving the 6th extinction event?
Never before has a single species caused such havoc on the natural ecosystems of the earth, that it has led to a new mass extinction event. Humans have been causing disruption on earth since they first evolved. Scientists have theorised that human-driven extinction can be traced back to when prehistoric humans started hunting down mammoths and other animals, which reduced their population. The arrival of humans in an area was marked by megafaunal extinction. They became apex predators, and after the advent of agriculture, started monopolising land. Extinction events are by all means natural, but the Holocene extinction has been greatly exacerbated by human activities. Currently, a quarter of all species are threatened with extinction. In 2018, a study found that since the dawn of human civilization, “83% of wild mammals, 80% of marine mammals and 50% of plants and 15% of fish have vanished.” Today, 41% of all amphibians are considered at risk. A 2020 study found that “human population size and/or specific human activities [have] caused rapidly rising global mammal extinction rates…96% of all mammalian extinctions [can be] attributable to human impacts.”
(Also Read: Covid and Climate: A Tale of Two Crises)
What is the current situation?
More recently, with the emergence of capitalism, we see widespread ecological destruction and exploitation of natural resources. The biggest driver of extinction today is habitat loss, caused by humans. Humans destroy habitats to make way for plantations, pastures, infrastructure, power plants, etc and replace the natural ecosystems for our own gain. The encroachment, contamination, and pollution of both land and oceanic habitats to meet our needs, deforestation and the destruction of wildlife-rich ecosystems to create land for agriculture, forestry, mining, and urbanisation, have disturbed or destroyed more than half of the Earth’s natural habitat. Along with this habitat destruction, overpopulation and overconsumption have led to an increased rate of extinction. Where previously the extinction of an animal may have taken hundreds of years, now it occurs in mere decades. In fact, this is the fastest mass extinction of species the earth has ever seen. If we keep up with this elevated extinction pace, researchers posit that even though this extinction began just 10,000 years ago, it will take only three human lifetimes for the world to completely change beyond recognition.
The extinction of a single animal leads to trophic cascades that completely alter our surroundings. The disappearance of a single species – a bee, or a fish – can have cascading effects on every system it is a part of. Thus, in case the complete destruction of our ecosystems is not incentive enough to radically alter our way of life, our capitalist overlords may be more concerned that mass extinction would destroy civilization as we know it.
(Also Read: Northeast India Floods—the Anthropocene at work)
References
Biodiversity: Which species are most at risk of extinction? (2021, September 10). World Economic Forum.
Dutfield, S., & Magazine, H. I. W. (2021, May 17). The 5 mass extinction events that shaped the history of Earth — and the 6th that’s happening now. Livescience.Com.
Hernandez, D. (2020, June 3). The Earth’s Sixth Mass Extinction Is Accelerating. Popular Mechanics.
Human_Actions_and_the_Sixth_Mass_Extinction Science. (2011).
AAAS.
What is mass extinction and are we facing a sixth one? (2021). Natural History Museum.