“No matter what we call it, poison is still poison, death is still death, and industrial civilization is still causing the greatest mass extinction in the history of the planet,” depicted by Derrick Jensen, an American Eco philosopher and environmentalist.

Mass extinction is the loss of all the species at a large amount within a short time of geological period which existed throughout the globe. 

It refers to the biotic crisis that resulted in the extinction of the species at a glance within a short time interval. The world has already faced the fifth mass extinction.

For the first time before 440 million years ago, a devastating event happened in our mother planet where the fossil records are the witness, turning the Earth’s history.

Before 440 million years ago, the first mass extinction was the Ordovician-Silurian extinction. The second mass extinction known as the Devonian extinction occurred 365 million years ago.

Before 250 million years ago, the third mass extinction named Permian-Triassic extinction occurred. The fourth mass extinction known as the Triassic-Jurassic extinction occurred 210 million years ago. Before 65 million years ago, the fifth mass extinction known as Cretaceous-tertiary death occurred.

It looks pretty shocking that in the last 450 million years ago, the five mass extinction have resulted in a loss of approximately 70% to 95 % of the natural species roaming in their natural habitat.

Sixth Mass Extinction

We are on the way to the sixth mass extinction inferred by the Anthropocene extinction, the dangerous phase of losing the species within a short period. 

Edward O. Wilson, an American biologist, and the nature conservationist, stressed that ‘the extinctions ongoing worldwide promise to be at least as great as the mass extinction that occurred at the end of the age of dinosaurs. 

It has been insisted that the critical causes of the earlier mass extinctions are still unknown. In the present scenario, the population across the globe has been increasing tremendously at an alarming rate. 

The more population resulted in more industrialization and urbanization. Sixth, mass extinction is the ongoing extinction due to anthropogenic-induced human activities.

Due to the accelerated rate of urbanization, forest destruction is very rapid. It has resulted in the wiping of the species within a short time interval. 

Apart from this, our species tends to get lost from the mother planet due to the climate change-induced effects.

The extinction rate in the present context all around the globe is estimated between 100 and 1,00,000 species annually. 

The scientists, too, insist that within 100 years, we would be losing roughly more than half of the remaining species that exist on the mother planet.

Causes of the sixth mass extinction

Scientists have warned that the fundamental cause of the sixth mass extinction is anthropogenic-induced activities. Below are some of the crucial causes of the sixth mass extinction that the globe goes through.

1. Habitat loss and fragmentation

habitat loss of Tasmania signaling 6th mass extinction
Forest activity of Tasmania, Australia| Photo by Matt Palmer

With the high demand of the population to build houses and for agricultural purposes, millions of hectares of forest have been destroyed that harbors a million wildlife species and flora.

Ongoing road and bridge infrastructures inside the forest have also resulted in the wildlife’s habitat loss. Once their habitat is lost and fragmented, it can undoubtedly negatively influence the overall species population.

In the present context, most of our forests have been converted into several forms, such as those intended for agriculture, mining, development infrastructures, and many more. It, too, does hamper biodiversity as a whole.

2. Invasion of alien species

Generally yelling, alien species invasion is inferred as one of the principal causes of mass extinction. 

It has been of international concern throughout the world. The nature of most invasive species is that they reproduce and multiply rapidly and wipe away the native species, thereby invading within a short period. Several examples could support this statement.

For instance: let us consider the case of the brown tree snake. It belongs to the native species of Australia. 

After their transfer to other countries or areas through ships or planes, it initiated invading and wiping the native birds and the mammals in the Pacific islands of Guam as referred to by Guam Island.

The birds and the mammals had been residing and enjoying the natural surroundings of Guam Island. In devoid of the local prey, brown tree snake has caused almost all species to be extinct.

The other example entails the invasion of the forest by invasive species in Nepal inferred as Mikenia micrantha

Inside the Chitwan National Park of Nepal, Mikenia micrantha had invaded almost all the forest cover and affected the habitat of one-horned rhinoceros (Rhinoceros unicornis) as well. 

Since the rhinos rely on forest resources, the invasion would impact their habitat, survival, and development.

3. Over-harvesting

The species’ survival relies upon the forest, grassland, and aquatic resources. The harvesting of the fishes, aromatic and medicinal flora, non-timber forest products (NTFPs) unsustainably threatens the species survival. 

It could lead to the threatened stage and ultimately extinction in the coming days. The rare, endangered, and endemic species population may decline over the over-harvesting and eradicate from the Earth before it strikes with our sight.

4. Human over-population

aerial view of people crossing road on Shibuya, Japan - overpopulation calling out mass extinction
People crossing road on Shibuya Crossing intersection, Japan| Photo by Ryoji Iwata

Human overpopulation has been elevated as a dire global concern that seeks attention to protect our species, and nature aimed to track out the solution regarding the mass extinction.

Human overpopulation increases the chance for the habitat destruction of the species, and such activities could have led the species wiped from their natural environment.

The National Wildlife Federation (NWF) report stresses that approximately 20 species of flora and fauna do get extinct within every hour.

Habitat loss is high because of human overpopulation. Most troublingly, the situation may arise so that our children of future generations might not see the bird and the mammal species.

5. Pollution

Using chemical fertilizers and pesticides does have detrimental effects on the species survival. 

Once the chemicals are swept away into the aquatic resources such as lakes and rivers, it hampers the fish and other marine species. Besides this, the heat and the noise released from the urban area could harm the organisms.

Ironically, due to the excessive use of the pesticides such as DDT (Dichloro Diphenyl Trichloro Ethane) induced by humans, there have been resulted in bird’s song silencing. 

The research published from the Netherlands supports its findings that it has hurt the bees and other pollinators.

6. Climate change

Climate change has always been of global concern and a dire issue. Due to the tremendous increase in population in recent years, fossil fuels are very rapid and standard. 

Additionally, the emission of greenhouse gas has to be raised. It enhances the increment in the Earth temperatures, thereby causing global warming, ultimately resulting in ocean acidification and rising sea levels.

Fundamentally, the aquatic species are in massive trouble since they rely on water to sustain their daily livelihood. 

It could threaten the species highly and result in a brick of extinction once they cannot adapt to the outcomes resulting from the anthropogenic alteration in the climatic system.

Effects of the sixth mass extinction

1. Large mammals and other species Extinct

large elephant marching
Large elephant marching| Photo by Lucas Metz

The large populations of the mammals such as wolves and lions are in the phase of declination, representing the sixth mass extinction. 

The researchers have alerted that the sixth mass extinction could possess a massive loss of species and the maximum habitat. 

There is the declination of the frog species due to human-induced activities such as disease and climate change. 

As it is the most complex mass extinction in history, it is believed that it could create a devastating catastrophe in the coming days no matter how the species sustain in their habitat. The lost salmons are a very vital part of an ecosystem.

It has been recorded that the lost salmon of Northern California, without a doubt, is facing a sharp decline in their population number. 

It’s unfortunate to reveal that California and Oregon were compelled to stop the salmon fishing season in 2008 and 2009.

Due to the anthropogenic caused activities, the sixth mass extinction induced the loss of species massively, thereby making the ecosystem issues more complex ahead.

2. Ecosystem functions and services

Scientists and wildlife biologists revealed that there are 550 species whole populations remained below 1000, and roughly half of these species possess less than 250 populations remaining in number.

The globe has been already shrinkage with the advancement in technology. Upon the massive declination of the species accelerated, the ecosystem services would be affected at maximum.

For instance: The bison of North America can be taken into account. It had supplied meat and robes to the native Americans and Europeans in the past. 

Only 325 populations were left behind by 1844 as a cause of the transformation of the original land into agricultural purposes and overharvesting to gain meat and skins.

After the gradual declination of the species, prairies were hugely affected. Once the bison gets wiped out, there is no control of the grassland and the prey. 

The tourism industry gets down if the number of tourists who visit the national parks and the forests is low. 

It directly affects the balance of the natural ecosystem. It may hamper the food chain and the food web since there remains fluctuation in the predator and the prey populations.

3. Genetic variability

It causes variation in the genetic characteristics of the organism and due to the fragmented forest into smaller patches. 

It hampers the species reproduction and the voice system, thereby creating the genetic make-up of an organism.

It has gradually led the species to extinction. The carrying capacity of the species in the forest is reduced, causing declination of the species in large numbers.

4. The rise in the infectious disease

a new visualization of the COVID-19 virus
A new visualization of COVID 19 virus| Photo by Fusion Medical animation

Healthy biodiversity is foremost when it comes in the name of species conservation. Upon the infectious disease rising tremendously, the biodiversity disappearance specific led by the sixth mass extinctions.

Once the pathogen transmissions grow higher, the species cannot sustain healthily in their natural environment. 

During the shrinking of the local biodiversity, scientists have alerted several diseases, including lime, hantavirus, and West Nile virus.

Additionally, the illegal bushmeat trade could transmit diseases from animals to humans inferred by zoonotic diseases.

Conclusion

Organisms wish to sustain in that environment where the natural water flows in their way, the vast canopy-covered forest, free of diseases, stable climatic conditions, and many more.

The continuous wiping away of the flora and fauna species could undoubtedly lead the organisms on the extinction verge. 

Aimed to conserve and protect our pride, the species biodiversity, it seems imperative to launch out the activities to assure that it could cover the species and the associated biodiversity for a prolonged period.

Are we the next? What are the chances of human beings in the line of 6th mass extinction? If you have such queries check out our article in are humans next Dinosaurs in line for extinction.

(Last Updated on March 24, 2022 by Sadrish Dabadi)

Kalpana Ghimire holds a post-graduate degree in Environmental Science from Nepal. She possesses numerous research experiences working in water pollution, community forestry, environment conservation status, and wildlife ecology. She was an internee in the Department of Environment (EIA monitoring and auditing section) under the Government of Nepal. Kalpana Ghimire is an avid traveler, an enthusiastic wildlife researcher, and has a huge passion for working in the environment sector. She loves far traveling to the natural areas, conducting field wildlife research and reading the novels.