The saddest truth is that animals are disappearing faster than researchers can record all the extinctions we are causing, so we can only roughly estimate the horrific scale. But their numbers could be in the hundreds of thousands.

How many animal species have been wiped out by humans so far?

Let’s start with confirmed extinctions. According to the Red Book of the International Union for Conservation of Nature (IUCN), Since the beginning of the modern era in 1500, 777 animal species have become extinctSome of these extinctions may have been caused by natural processes, but the truth is that humans certainly had a hand in at least most of them, especially considering how much we’ve impacted nature in the last 500 years.

But humans actually began contributing to species extinction thousands of years ago, long before 1500. There were no scientists to study the process back then, so no one was aware of it. There is a lot of uncertainty about today’s extinction rates, so it’s best to focus on the last 500 years.

The IUCN estimates that only 5% of known species in the world are at risk of extinction, so there are many more extinctions that have not been recorded. A 2022 study published in the journal Biological Reviews shows that: Between 150,000 and 260,000 of all known species may have become extinct since 1500..

To calculate this figure, the team took a random sample of 200 land snails and used previous scientific research and expert advice to determine how many of them had gone extinct. They then calculated how many species would become extinct if all known species went extinct at the same rate over 500 years.

The extinction rate they calculated was 150–260 extinctions per million species years (E/MSY); in other words, 150-260 extinctions per year for every million species on EarthThe scientists also analyzed extinction estimates for other wildlife groups, including amphibians and birds. Estimates ranged from 10 to 243 E/MSY, but there was a middle ground.

They tend to cluster around 100 [E/MSY]. I think this is a more reasonable value, not too conservative but not too exaggerated either.
– says Robert Covey, professor at the University of Hawaii, lead author of the study.

Applying 100 E/MSY to the Covey method shows that: Of the approximately 2 million known species, 100,000 have become extinct in the last 500 years.But this doesn’t take into account the unknown animal species that exist, and we are discovering more and more new animals every day.

Unknown species

A 2011 study published in the journal PLOS Biology estimated that there are around 7.7 million animal species, so it’s understandable how many we have yet to discover and what their current status is. If we take that number and assume 100 E/MSY in 500 years (subtracting the 3,850 animals that would naturally die out in 500 years at a background extinction rate of 1 E/MSY), The final estimate of human-caused animal extinctions is 381,150 species.

But all of this is only a very rough estimate and should be taken with a certain degree of skepticism.

Current extinction rates

John Alroy, an associate professor in the Department of Biological Sciences at Macquarie University in Australia, works on measuring diversity and extinction. Current extinction rates are nearly impossible to calculate.

We have to be very careful when we try to calculate a number based on the existing literature. I don’t think we have very accurate data on current extinction rates.
Alroy says.

According to the scientist, to understand the overall rate of extinction, researchers first need to know how many species exist. Not only is much of the world’s wildlife unknown to science, it is also concentrated in less-studied areas such as the tropics. To make matters worse, insects have more species than other animal groups, but we know very little about them compared to larger animal groups such as mammals and birds. They are small, often very fast, and therefore harder to study and detect.

Whatever the exact figure, Alroy stresses: Humans are accelerating the rate of extinctionIt was noted that the number of endangered species is much higher than the 777 species included in the IUCN Red List. Moreover, all estimates have one thing in common: they significantly exceed the natural background indicator, and therefore this indicates an undeniable harmful impact of humans on nature.