Earth’s sixth mass extinction has begun according to scientists

It is no secret that extinctions have been happening at an alarming rate in recent decades with human involvement and climate change blamed for creating habitats unsuitable for many species of wildlife.

Even more worrying is the findings of a major study by the International Union for Conservation of Nature (IUCN) Red List of Threatened Species and BirdLife International which found that the earth may be on the brink of a mass extinction event.

Worldwide it is thought that more than 500 species of land animal are close to extinction and could be lost within the next 20 years. The report was published in the scientific journal Proceedings of the National Academy of Sciences, and studied 29,000 species of land vertebrate. They estimated that the number of extinctions expected in the next two decades would likely take thousands of years if not for the negative impact of humanity.

In other news:

What is a mass extinction?

Scientists estimate that 99% of all living organisms that have ever lived on earth are now extinct. The planet’s natural ecosystem is constantly evolving and as the environment changes certain older species will begin to fade away.

However there are some points in the earth’s history when the gradual evolution has become more of a sudden revolution and a majority of the planet’s living species are wiped out in a relatively short space of time. In the last 500 million years, there have been five occasions when 75-90% of all species have gone extinct, in what is called a mass extinction.

It should be remembered that the ‘short period of time’ is described in geological terms, dating back across the vast period of time since the start of life on earth. With this in mind, Earth.org explains that a mass extinction event can take anything up to 2.8 million years.

Why should we be worried about a mass extinction?

There have been at least five other instance of mass extinctions so the threat of a sixth may not seem too distressing. However scientists estimate that this one could occur in a timeframe unlike many of the previous mass extinctions. Rather than taking millions of years, we are seeing sweeping changes during the course of a single human lifetime.

Data collected as part of the IUCN’s report shows that 77 of the species who are most in danger have lost 94% of their populations in the last century. More than 400 species of vertebrate became extinct in the last 100 years, a figure that would take around 10,000 years to reach in the normal course of evolution.

This all points to a series of extinctions in the near future, which could have a catastrophic resultant effect on the natural ecosystem. The IUCN’s analysis shows that 388 species of land vertebrates had populations of less than 5,000, and that 84% are primarily found in regions where other species have a population of less than 1,000.

Experts warn that ‘extinction breeds extinction’, as species reliant on lifeforms that become extinct also suffering as a consequence.