Scientists warn: We are on the cusp of an accelerating second wave of mammalian extinction

A new study indicates that the emergence of humans on the horizon represents more of an existential threat to "innocent" animals than the massive environmental disruptions caused by past climate change so far.

On September 4, the journal Science Advances published a study stating that the extinctions of mammals dating back to 126,000 years ago had more to do with the negative effects of humanity than any previous climate factors.

Even worse, according to the report on the study on the Science Alert website, calculations indicate that this deadly byproduct of human existence is accelerating at a rate unprecedented in prehistoric times, as the mortality of mammalian species reaches faster rates the closer we get to 22nd century.

Computer simulation predicts

"Based on current trends, we expect in the near future an increase in the rate of an unprecedented scale," explains the research team, led by the first author and computational biologist Tobias Andermann from the University of Gothenburg, Sweden, in a new research paper.

Using Bayesian modeling, a type of computer modeling to measure probabilities, the researchers sought to make a statistical assessment of whether the extinctions of mammalian species over the past 126,000 years - since the beginning of the Late Ice Age - were likely attributable to human or climatic factors.

In this time frame, at least 351 mammal species have become extinct, although around 80 of these species have already become extinct in the last half millennium or so, since the year 1500.

Based on the new calculations, the team says current rates of extinction today are about 1,700 times higher than they were at the beginning of the Late Ice Age.

At the new rate we see today, researchers say we can expect to see the known number of 351 extinctions since then repeated in just 810 years - while it took 126,000 years the first time.

Current rates of extinction today are about 1,700 times higher than at the beginning of the Late Ice Age (Flickr / Wikipedia)

Humans or others

If we look back all that time, the data indicates that the largest hypothetical cause of past extinctions is the human species, as human population density is related to mammalian extinction patterns with an accuracy of 96%, while human land occupation is explained by extinction with an accuracy of 97.1%.

"On the other hand, the authors write," climate predictions lead to very low accuracy values, such as global temperature with an accuracy of 63.6%. The rate of temperature change with an accuracy of 60.2%. "

In fact, the authors say, the causes of extinction are more complex and are not expected to depend entirely on a single variable.

However, "our results show that population growth and associated processes have had a strong influence on mammalian extinction, while global climate patterns leave no statistically detectable impact on the extinction record."

The team admits that trying to intensify complex biological phenomena, such as extinctions, down to one clear factor, is a color of oversimplification, but they nevertheless concluded that human influence has great predictive power when trying to attribute causation.

The researchers believe that a number of human factors could be involved, including intense hunting pressure, land use, ecosystem modifications, and other "human cascading impacts on the natural world."

Causes of extinction are more complex and not expected to be completely dependent on one variable (Aaron Logan - Wikipedia)

Anxiety begins now

Even more disturbing when researchers modeled what the future might look like: predicted the extinction of as many as 558 new species by the end of this century, at which point the rate of extinction could be up to 30,000 times faster than it was at the start of the Ice Age. Late.

"By the year 2100, we expect all regions of the world to have entered a second wave of extinctions," the researchers wrote, noting that in some parts of the world, the transition has already become apparent.

They also said, "We found that Australia and the Caribbean in particular have already entered a second wave of extinction today based on the extinctions that occurred during the past decades."

This demonstrates - the researchers say - that although our expected future rates and associated losses in biodiversity are shockingly high, they fall in a realistic scale "where we can actually see these future scenarios unfold in parts of the world."

Due to the very abstract nature of this simulation, it cannot be expected that all of these predictions will come true.

These are, after all, just estimates based on mathematical calculations.

The rate of future extinctions is 30,000 times faster than it was at the beginning of the Late Ice Age (J. Nielsen - Wikipedia)

But whatever it is, these horrific numbers are a crystal ball, we should not delay in acting on what we can see inside it - the researchers say - to prevent this reality from emerging further.

"We can save hundreds of species from extinction with more targeted and effective conservation strategies," Anderman returns. "But in order to achieve this, we need to increase our collective awareness of the looming escalation of the biodiversity crisis, and take action to combat this global emergency. The time is urgent." .