The report “More losers than winners: investigating Anthropocene defaunation through the diversity of population trends” was published in the online Biological Reviews. It explains that nearly half of the planet’s animal species declining. 

Anthropocene Defaunation is defined as the current age destruction or loss of animal life in a region or habitat.

According to the study, “The global-scale decline of animal biodiversity (‘defaunation’) represents one of the most alarming consequences of human impacts on the planet. “

When evaluating the IUCN Red List of conservation categories assigned to each species, a quarter of the world's animal species are impacted. And are threatened with extinction. Currently, “~1% have been declared extinct.”

“However, extinctions are preceded by progressive population declines through time that leaves demographic ‘footprints’ that can alert us about the trajectories of species towards extinction.” the report claims.

Anthropocene Defaunation

The world we live in is facing a pressing issue – an extinction event, where species are disappearing at an alarming rate. They are being lost faster than they can be replaced. 

This phenomenon is known as a mass extinction event, and it's defined as the loss of 75% of the Earth's species within a relatively short geological period, less than 2.8 million years.

Scientists have been studying this concerning trend and have found that current extinction rates are strikingly higher, between 1000 to 10,000 times higher than the natural "background" extinction rates. This has led some experts to believe that our planet is currently undergoing its sixth mass extinction event.

One of the primary causes of this devastating loss of biodiversity is the destructive impact of human activities. Many species are facing decline due to habitat loss, fragmentation, and degradation caused by human development. 

Pesticides, herbicides, and other chemicals used widely in agriculture have also had negative effects on invasive species. And climate change, which has accelerated beyond control, only makes these issues worse.

Conservation status assessments have traditionally relied on the International Union for Conservation of Nature (IUCN). According to their evaluations of over 150,300 species, 28% of them are considered threatened with extinction, with approximately 1% already declared extinct. 

Extinctions don't just happen suddenly. They are often preceded by gradual population declines that leave "footprints" of impending doom. 

The researchers of a recent study analyzed these population trajectories and discovered that 48% of every species has shrinking populations. And only 3% have increasing populations. Shockingly, they also found that 33% of species labeled as "least concern" by the IUCN are heading toward extinction more slowly.

Certain animal classes are more vulnerable than others. For instance, amphibians are experiencing the most significant population decline of all.

Geographical location also plays a role, with species in tropical regions facing steeper declines compared to those in temperate areas, largely due to their sensitivity to change.

The implications of this extinction crisis go beyond the loss of individual species. Entire ecosystems are at risk of unraveling and collapsing, disrupting ecological functioning and community compositions. 

Causes of extinction 

Human activities are undeniably at the heart of this crisis. With 40% of the Earth's land already altered for food production to sustain the growing population, agriculture alone is responsible for 90% of global deforestation. It consumes a staggering 70% of the planet's freshwater, directly pushing species toward extinction.

Unsustainable food production and consumption contribute significantly to greenhouse gas emissions, causing temperatures to rise and wreaking havoc worldwide. 

The climate crisis leads to severe droughts, more intense storms, and disruptions in food production, making habitats inhospitable for many species. The intertwined relationships between the food system, climate change, and biodiversity loss are putting immense pressure on our planet.

Collective efforts are needed to protect and preserve our planet's biodiversity before it's too late. Our choices today will determine the fate of countless species and the delicate balance of life on Earth.