Earth is enduring the sixth mass species extinction which is plunging the planet into 'global crisis', scientists have warned.

Scientists warn humanity's voracious consumption and wanton destruction is to blame for the event, which is the first major extinction since the dinosaurs.

Two species of vertebrate, animals with a backbone, have gone extinct every year, on average, for the past century.

Currently around 41 per cent of amphibian species and more than a quarter of mammals are threatened with extinction.

Starting Saturday, a comprehensive, global appraisal of the damage, and what can be done to reverse it, will be conducted in Colombia.

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There are an estimated 8.7 million plant and animal species on our planet and about 86 percent of land species and 91 percent of sea species remain undiscovered. Of the ones we do know, 1,204 mammal, 1,469 bird, 1,215 reptile, 2,100 amphibian, and 2,386 fish species are considered threatened

Two species of vertebrate, animals with a backbone, have gone extinct every year, on average, for the past century. Hotter temperatures and less rainfall will have a dire impact on numbers of African elephants (pictured, stock image)

There are an estimated 8.7 million plant and animal species on our planet and about 86 percent of land species and 91 percent of sea species remain undiscovered.

Of the ones we do know, 1,204 mammal, 1,469 bird, 1,215 reptile, 2,100 amphibian, and 2,386 fish species are considered threatened.

Also threatened are 1,414 insect, 2,187 mollusc, 732 crustacean, 237 coral, 12,505 plant, 33 mushroom, and six brown algae species.

'The science is clear: biodiversity is in crisis globally,' WWF director general Marco Lambertini told AFP ahead of a crucial meeting of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES).

'We depend on biodiversity for the food we eat, the water we drink, the clean air we breathe, the stability of weather patterns, and yet our actions are pushing nature's ability to sustain us to the brink.'

Worryingly, the decline seems to be getting faster.

The global populations of 3,706 monitored vertebrate species - fish, birds, mammals, amphibians, and reptiles - declined by nearly 60 per cent from 1970 to 2012.

Climate change threatens the breeding patterns of marine turtles (pictured, stock image). More than 25,000 species of 91,523 assessed for the 2017 'Red List' update were classified as 'threatened'

WHAT IS THE STATE OF THE EARTH'S SPECIES? - Two species of vertebrate, animals with a backbone, have gone extinct every year, on average, for the past century. - Currently around 41 per cent of amphibian species and more than a quarter of mammals are threatened with extinction. - There are an estimated 8.7 million plant and animal species on our planet and about 86 percent of land species and 91 percent of sea species remain undiscovered. - Of the ones we do know, 1,204 mammal, 1,469 bird, 1,215 reptile, 2,100 amphibian, and 2,386 fish species are considered threatened. - Also threatened are 1,414 insect, 2,187 mollusc, 732 crustacean, 237 coral, 12,505 plant, 33 mushroom, and six brown algae species. - The global populations of 3,706 monitored vertebrate species - fish, birds, mammals, amphibians, and reptiles - declined by nearly 60 per cent from 1970 to 2012. - More than 25,000 species of 91,523 assessed for the 2017 'Red List' update were classified as 'threatened'. - Of these, 5,583 were 'critically' endangered, 8,455 'endangered', and 11,783 'vulnerable'. Advertisement

More than 25,000 species of 91,523 assessed for the 2017 'Red List' update were classified as 'threatened'.

Of these, 5,583 were 'critically' endangered, 8,455 'endangered', and 11,783 'vulnerable'.

African elephant numbers dropped to 415,000 in 2016, down about 111,000 over 10 years.

Compiled over the last three years, the reports will provide the most up-to-date picture of the health of the world's plants, animals and soil.

The diagnosis will be unveiled in two parts at the summit in Colombia's second-largest city, Medellin.

First, on March 23, the IPBES will simultaneously release separate assessments for the four regions into which it has divided the world - the Americas, Africa, Asia-Pacific, and Europe and Central Asia.

Maps showing extinction hotspots around the world and areas expecting most land clearance in the decades to come, further putting animal species in danger

Percentage of local population extinction in 177 species of mammals in the continents of the world, where dark areas show areas of high rates of extinction

WHEN WERE EARTH'S 'BIG FIVE' EXTINCTION EVENTS? Traditionally, scientists have referred to the 'Big Five' mass extinctions, including perhaps the most famous mass extinction triggered by a meteorite impact that brought about the end of the dinosaurs 66 million years ago. But the other major mass extinctions were caused by phenomena originating entirely on Earth, and while they are less well known, we may learn something from exploring them that could shed light on our current environmental crises. The Late Ordovician : This ancient crisis around 445m years ago saw two major waves of extinction, both caused by climate change associated with the advance and retreat of ice sheets in the southern hemisphere. This makes it the only major extinction to be linked to global cooling. The Late Devonian : This period is now regarded as a number of 'pulses' of extinction spread over 20m years, beginning 380m years ago. This extinction has been linked to major climate change, possibly caused by an eruption of the volcanic Viluy Traps area in modern-day Siberia. A major eruption might have caused rapid fluctations in sea levels and reduced oxygen levels in the oceans. The Middle Permian : Scientists have recently discovered another event 262m years ago that rivals the 'Big Five' in size. This event coincided with the Emeishan eruption in what's now China, and is known to have caused simultaneous extinctions in the tropics and higher latitudes. The Late Permian : The Late Permian mass extinction around 252m years ago dwarfs all the other events, with about 96% of species becoming extinct. The extinction was triggered by a vast eruption of the Siberian Traps, a gigantic and prolonged volcanic event that covered much of modern day Siberia, which led to a cascade of environmental effects. The Late Triassic : The Late Triassic event, 201m years ago, shares a number of similarities with the Late Permian event. It was caused by another large-scale eruption, this time of the Central Atlantic Magmatic Province, which heralded the splitting of the supercontinent Pangaea and the initial opening of what would later become the Atlantic Ocean. Advertisement

The reports are not prescriptive, but 'we hope that this will help inform policy decisions to stem the loss of biodiversity and the fundamental services it provides us with,' chief scientist Tom Brooks of the International Union for the Conservation of Nature told AFP.

Annual economic losses as a result of deforestation and forest degradation alone may be as high as $4.5 trillion (3.6 trillion euros, £3.2 trillion).

A conference of the UN's Convention on Biological Diversity (CBD) agreed in Nagoya, Japan in 2010 on a 20-point plan to turn back biodiversity loss by 2020.

The plan's so-called 'Aichi Biodiversity Targets' include halving the rate of habitat loss, expanding water and land areas under conservation, preventing the extinction of species on the threatened list, and restoring at least 15 percent of degraded ecosystems.

A map showing the dramatic decline in the range of African lion populations. Orange shows the historic range of lions, while brown shows where they currently roam