Biological Annihilation

In the last half-billion years, life on Earth has been nearly wiped out not once, not twice, but five times, all for varying reasons. With 66 million years since the last mass extinction occurred, it seems we’re on the edge, or potentially witnessing, the sixth mass extinction on planet earth.

For some context, here’s a quick overview of the “Big 5” extinctions:

1. End of the Ordovician period, 444 million years ago, 86% of species lost.
   • A short and severe ice age caused by exposed silicate rock drawing CO2 out of the atmosphere which lowered the planet’s temperature. This killed off most sea creatures.
2. Late Devonian period, 375 million years ago, 75% of species lost.
   • Land plants evolved during this period, although their roots displaced the ground, releasing new nutrients into the ocean that triggered algae blooms, sucking oxygen out of the water. This suffocated Trilobites, causing most of them to die.
3. End of the Permian period, 251 million years ago, 96% of species lost.
   • To date, this was the worst extinction to occur on earth, nearly ending all life on the planet. The extinction was caused by various combined natural catastrophes; an eruption near Siberia blasted CO2 into the atmosphere; bacteria responded to the eruption by releasing methane, a strong greenhouse gas, into the atmosphere; global temperatures rose quickly; oceans acidified and stagnated, releasing poisonous hydrogen sulfide. As Rolf Schmidt, a Melbourne Museum paleontologist elegantly put it, “it set life back 300 million years”.
4. End of the Triassic period, 200 million years ago, 80% of species lost.
   • No clear cause for this extinction has been found. Up for debate is the possibility of rising sea levels due to a sudden release of CO2
5. End of Cretaceous period, 66 million years ago, 76% of species lost.
   • Ammonites, sea-dwelling creatures, were already under stress from increased volcanic activity and climate change. The defining factor of their destruction was the famous asteroid impact in the Gulf of Mexico that also ended the regime of the dinosaurs.

6th Extinction: Mankind’s Legacy

Mass extinctions typically take thousands of years to play out; it’s not like an alien invasion show or an apocalyptic movie where life is destroyed over the course of a single afternoon. Rome wasn’t built, or destroyed, in a day.

Humans have a bit of a centralized view on the sixth mass extinction. We continue to pose questions around it as, will humans survive? when really, we should be asking, is human activity a cause and/or catalyst for the sixth mass extinction? 

Because the answer is already “yes”.

In this situation, we’re playing the part of the extraterrestrial overlords destroying earth, and other species are the ones at risk. Various studies conducted prove that our impact has increased the overall rate of extinction, through:

• Hunting & overfishing
• Bringing invasive species to foreign areas
• Climate change
• Altering the chemistry of oceans
• Changing the surface of the planet to fit our needs
• Cutting down forests
• Monoculture agriculture

A study published in 2017 by the Proceedings of the National Academy of Sciences of the U.S.A. (PNAS) found that 50% of earth’s wildlife has been wiped out. So, if populations keep reducing by half every 40 years, it doesn’t take much math to realize that earth’s ecology will look extremely different very soon.

So, getting back to the question of whether or not humans will survive the sixth mass extinction: as a species, we’re extremely adaptable, but even if we can survive these ongoing changes, will it be in a world that we want to live in, with a only a small percentage of animals and plant life that had previously existed? Perhaps we’ll be living underground on Mars by then.

“Nature doesn’t need people – people need nature; nature would survive the extinction of the human being and go on just fine, but human culture, human beings, cannot survive without nature.” -Harrison Ford