17 signs we're in the middle of a 6th mass extinction

dead fish

The planet appears to be undergoing a sixth mass extinction: the sixth time in the history of life on Earth that global fauna has experienced a major collapse in numbers.
Historically, mass extinctions have been caused by catastrophic events like asteroid collisions. This time, human activities are to blame.
A new report from the United Nations found that up to 1 million species are threatened with extinction.
The primary culprits are deforestation, mining, and carbon dioxide-emissions, which cause the planet to heat up.
As a result, frogs and insects are dying off at record rates, animal species are experiencing "biological annihilation," and invasive aliens are driving native species to extinction.

The phrase "mass extinction" typically conjures images of the asteroid crash that led to the twilight of the dinosaurs.

Upon impact, that 6-mile-wide space rock caused a tsunami in the Atlantic Ocean, along with earthquakes and landslides up and down what is now the Americas. A heat pulse baked the Earth, and the Tyrannosaurus rex and its compatriots died out, along with 75% of the planet's species.

Although it may not be obvious, another devastating mass extinction event is taking place today — the sixth of its kind in Earth's history. The trend is hitting global fauna on multiple fronts, as hotter oceans, deforestation, and climate change drive animal populations to drop in unprecedented numbers.

These alarming extinction trends are driven by one key factor: humans. According to a 2014 study, current extinction rates are 1,000 times higher than they would be if humans weren't around. A summary of a United Nations report released Monday put it another way: "Human actions threaten more species with global extinction now than ever before," the authors wrote.

That report, which assesses the state of our planet's biodiversity, found that up to 1 million plant and animals species face extinction, many within decades, due to human activity.

Other recent research has led to similar conclusions: A 2017 study found that animal species around the world are experiencing a "biological annihilation" and that our current "mass extinction episode has proceeded further than most assume."

Here are 17 signs that the planet is in the midst of a sixth mass extinction, and why people are primarily to blame.

Insects are dying off at record rates. Roughly 40% of the world's insect species are in decline, according to one study.

A 2019 study found that the total mass of all insects on the planets is decreasing by 2.5% per year.

If that trend continues unabated, the Earth may not have any insects at all by 2119.

"In 10 years you will have a quarter less, in 50 years only half left, and in 100 years you will have none," Francisco Sánchez-Bayo, a coauthor of the study, told The Guardian.

That's a major problem because insects like bees, hoverflies, and other pollinators perform a crucial role in fruit, vegetable, and nut production. Plus, bugs are food sources for many bird, fish, and mammal species — some of which humans rely on for food.

Another recent study, published in the journal Nature Communications, reported that one-third of 353 wild bee and hoverfly species in the UK experienced declines between 1980 and 2013.

The study authors noted that the geographic ranges of bee and hoverfly species declined by 25% — that's a net loss of about 11 species per square kilometer, primarily due to a reduction in the pollinators' habitats.

The recent UN report calculated that projected declines in the number of of wild bees and other pollinators puts up to $577 billion in annual crop production at risk.

Insects aren't the only creatures taking a severe hit. In the past 50 years, more than 500 amphibian species have declined worldwide — 90 of them going extinct — thanks to a deadly fungal disease called chytridiomycosis that corrodes frog flesh.

A recent study in the journal Science recounts the spread of chytridiomycosis, or chytrid fungus, and how quickly it has wreaked havoc on frog, toad, and salamander species around the world.

Humans have enabled the fungal disease to spread further than it otherwise could have, in large part because of the global wildlife trade.

According to the study authors, amphibian deaths associated with chytrid fungus represent the greatest recorded loss of biodiversity attributable to any one disease.

Another study published in the journal Current Biology noted that amphibians overall — not just frogs — are among the most highly threatened groups of animals, with at least 2,000 species estimated to be in danger of extinction.

See the rest of the story at Business Insider