252 million years ago, in modern day Siberia,
a string of volcanic eruptions pierced the Earth’s crust with pillars of magma. Greenhouse gases bellowed into the atmosphere. Life was pushed to the brink, and the Earth’s
ecosystem nearly collapsed. Over millions of years, the Permian Extinction
eradicated nearly every species on Earth, but a greater disaster may be waiting in the
wings. Could another extinction event exterminate
life on Earth? The Earth was created 4.5 billion years ago. 500 million to one billion years later, life
emerged at the bottom of the ocean, where single-celled organisms flourished around
hydrothermal vents. Since the genesis of life, an estimated five
billion species have evolved on our planet; however, 99% of those species are now extinct. In order to survive the planet’s changing
conditions, species evolve to adapt to unexpected and radical shifts in their environments,
which creates competition for food, water, and territory. Species that rise above their competition—the
so-called fittest, according to Charles Darwin’s Theory of Natural Selection—dominate the
changing world. Struggling species, on the other hand, dwindle
and, eventually, disappear. Balanced by natural selection, animal and
plant populations have fluctuated wildly over geological time. From the 90-foot apatosaurus to the giant
ground sloth, a diverse range of creatures have prospered, and perished, on our planet. Gradual extinction, in other words, is a natural
step in the evolution of life; but no amount of genetic adaptation could prepare living
organisms for the catastrophic events to come. In the last 500 million years, five mass extinctions,
known as the Big Five, have nearly annihilated life on Earth. To qualify as a mass extinction, an event
must eradicate at least half of the species on our planet, resulting in a significant
elevation of the extinction rate. When the environment changes naturally—even
massively—extinction, adaptation, and speciation follow. Though natural disasters have rocked our terrestrial
planet, life on Earth has survived, evolved, and flourished for billions of years. In the last two centuries, the drivers of
the natural world have changed. No longer is the environment governed exclusively
by the laws of nature. Humans, the most dominant species to walk
the Earth, have transformed environments around the world, subverting billions of years of
meticulous evolution. Could humans bring about a Sixth Mass Extinction,
the first since the dawn of man? According to the National Academy of Sciences,
the Sixth Mass Extinction has already begun. It started in the middle of the 20th century,
during a period called the Great Acceleration. During the Great Acceleration, human civilization
experienced significant growth, resulting in a step-increase in anthropogenic damage
to the Earth. Rapid technological advancements, soaring
demands for natural resources, and the growing production of pollutants have exponentially
increased our footprint on the natural world. Few hazards have left a more significant impact
than the release of carbon dioxide into the atmosphere. Since the Industrial Revolution, humans have
produced and released CO2 at a rate 100 times faster than any period in the last 420,000
years. The astronomical increase in the production
of CO2 has destabilized the delicate balance of our global ecosystem. To date, greenhouse gases have warmed the
planet by almost 1-degree Celsius. A single degree change in the Earth’s global
temperature affects the entire natural world. Oceans, for example, have absorbed 90% of
the excess heat created by man-made CO2. The rise of ocean temperatures has damaged
and destroyed rich aquatic ecosystems like coral reefs, which could disappear as early
as 2050. Since the Great Acceleration, humans have
made little effort to curb our overwhelming production of greenhouse gases. In 2018, humans released an estimated 40 billion
tons of CO2 into the atmosphere. This byproduct of human industry has negatively
impacted the Earth’s climate, pushing vital ecosystems to and beyond their tipping points. Now, natural wonders like the Amazon rainforest,
one of the most diverse ecosystems in the world, are inching closer to endangerment
and collapse. The effects of human development extend far
beyond the Earth’s climate and atmosphere. Decades of pollution, deforestation, and consumption
have triggered a deadly cascade on par with the most destructive disasters in history. Already, the sixth mass extinction event has
affected 75% of terrestrial habitats and 66% of marine habitats. We’ve interrupted food chains. We’ve changed weather patterns. We’ve disrupted ocean currents. And now, we’re losing species at an alarming
rate. Approximately 200 species of vertebrates have
gone extinct in the last 100 years. That’s about 2 species per year. If we compare the current rate of extinction
to the background or “normal” rate of extinction, the same 200 vertebrates would
have taken approximately 10,000 years to die out through natural selection. In other words, human interaction has accelerated
the extinction rate by over 100 times—a rate comparable to the Big Five. Even low-risk species, including common populations
spread throughout the world, are struggling. A 2017 study examined a sample of 27,600 vertebrate
species. They discovered that 40% of those populations,
ranging from low risk to endangered species, are declining at a dangerous rate. With so many populations dying and declining,
our planet faces a massive deterioration of global biodiversity. The impending domino effect will further deplete
and destroy worldwide ecosystems. Can we save the Earth from ourselves? How long do we have left to preserve our planet? The Sixth Mass Extinction event is well underway. The world’s glaciers are melting. Ecosystems are crumbling. Access to fresh water is rapidly declining,
and humans are creating more toxic waste than ever. Humans have severely disrupted the natural
world, and the current landscape foreshadows a greater extinction event to come. While humans have driven this planet into
the ground, we can still return the natural world to its former glory. Humans can slow the loss of species. We can reduce the destruction and pollution
of our environment. We can revitalize a planet that once contained
the greatest biodiversity in history. On the other hand, if the future contains
more of the present, humans may damage the environment beyond repair. The future of the planet is in our hands. If we can’t save the Earth, no one else
will.
