🌋What was the Great Dying?

250 million years ago, our planet experienced its worst-ever mass extinction event.

Experts call it the Permian-Triassic (P-Tr) extinction event, but it’s best known as the “Great Dying.”

As a result of this mass extinction, just 5% of the plant & animal species that lived on Earth during the Permian period survived into the Triassic period.

Here’s what our planet looked like at the time:

This mass extinction event led to the death of:

• Roughly 90% of all aquatic species

• 70% of land species

• The vast majority of insect species

Why does it matter? There are similarities between the global warming seen during the Great Dying and the climate change we’re experiencing today.

Professor Shane Schoepfner explained:

Why did the Great Dying happen?

The P-Tr extinction event occurred over a period of 60,000 years.

It sounds like a long time, but some other mass extinction events lasted millions of years.

(The chart below shows the different mass extinction events and the percentage of known marine animal species destroyed in those events)

It’s clear that major volcanic events played a key role in the Great Dying.

Extraordinarily large volcanos erupted in Siberia in the late Permian period, emitting 1.5 million cubic kilometers of lava from an awesome fissure in the crust.

One scientific paper argues that these volcanic blasts:

Major volcanic eruptions led atmospheric carbon dioxide (CO₂) levels to rise at one of the fastest rates in the geological record.

Global CO₂ levels reached 2,500 ppm, compared to just 280 ppm before the Industrial Revolution and 422 ppm today.

Evidence suggests that high CO₂ levels in the atmosphere caused the Earth's temperature to rise by 14°F.

As a result:

• Ocean temperatures rose rapidly, reaching an average of 104°F.

• Oxygen levels of the Earth’s oceans then fell by 80%.

• High CO₂ levels in the atmosphere also acidified the oceans.

These conditions, over a few thousand years, would kill the vast majority of sea creatures and much of life on Earth.

Some researchers have speculated that an asteroid strike on the Earth could have contributed to the P-Tr extinction, but the scholarly consensus agrees that extreme volcanism was the primary cause.

Scientists agree that an asteroid strike was the cause of the Cretaceous–Paleogene extinction event, which wiped out the dinosaurs. (see below)

Why does the Great Dying matter?

We are currently in an age of global warming and mass extinction.

It’s challenging for us to view events on a planetary timescale, but future generations may look back on this era as the sixth mass extinction.

Human activity & climate change have caused nearly half of the planet's bird species to experience population decline, according to the State of the World's Birds report.

And one in eight bird species is threatened with extinction.

Insects, the most diverse group of organisms on the planet, are also declining at an unprecedented rate.

The global insect population is falling by an estimated 2% per year.

Insects make up around two-thirds of all known animal species on Earth, and they play a huge role in our world by pollinating over 75% of global crops and around 80% of all wild plants.

The authors of a 2019 paper on insect mass extinction even argued:

When 90% of marine species and 70% of land species perished during the Great Dying, it wasn’t just the loss of individual organisms & species — it was the breakdown of entire ecosystems that took millions of years to recover.

It’s important that humanity, which has come to dominate the Earth over thousands of years, remembers that we sit atop increasingly fragile ecosystems.

If they collapse, the consequences will be catastrophic for us, our children, and the other species we share this planet with.

And on that cheery note, here’s a cute owl:

ART OF THE DAY

Little Owl by Albrecht Dürer. 1506.