Updated: Mar 11, 2019
A biological annihilation. That's what we are doing to our fellow Earth inhabitants. Extinction has already happened to so many species and the threat of extinction hangs over so many more. And its all our fault.
A couple of years ago, a study came out that came with some of the most dire warnings of the state of our biodiversity that I had ever read. The study was global evaluation of the ranges and populations of thousands of species, conducted by Paul Erlich, one of the founders of conservation biology who is very outspoken on the issue of human overpopulation, and Gerardo Ceballos from the National Autonomous University of Mexico, among others.
What they found was not good news. The Earth has entered an era of mass extinction, with the extinction rate much higher than what is natural, and the threat of extinction hanging over so many of the species we share our planet with. Instead of looking at extinctions, this study looked at how many species have dwindling populations and ranges. What the authors had to say about their results was intense.
Here is just a few of the quotes from the authors that accompanied the release of the study:
“This is the case of a biological annihilation occurring globally.”
“The massive loss of populations and species reflects our lack of empathy to all the wild species that have been our companions since our origins. It is a prelude to the disappearance of many more species and the decline of natural systems that make civilisation possible.”
“Sadly, our descendants will also have to do without the aesthetic pleasures and sources of imagination provided by our only known living counterparts in the universe.”
“We’re toxifying the entire planet.”
“A massive erosion of the greatest biological diversity in the history of the Earth.”
“A frightening assault on the foundations of human civilisation.”
“We emphasise that the sixth mass extinction is already here and the window for effective action is very short, probably two or three decades at most. All signs point to ever more powerful assaults on biodiversity in the next two decades, painting a dismal picture of the future of life, including human life.”
“The resulting biological annihilation obviously will have serious ecological, economic and social consequences. Humanity will eventually pay a very high price for the decimation of the only assemblage of life that we know of in the universe.”
They didn’t mince their words when it came to explaining the cause too: “human overpopulation and continued population growth, and overconsumption, especially by the rich.”
When questioned about their use of such alarming language, not usually found in a scientific paper, they said it was what a situation that is so alarming requires: “It wouldn’t be ethical right now not to speak in this strong language to call attention to the severity of the problem.”
So what did they find in their study? They found that more than 30% of all vertebrates are declining in population size and range. Range maps of 27,600 species of birds, amphibians, mammals and reptiles showed that as much as 50% of the number of individual animals that we once shared Earth with have disappeared completely, as have billions of animal populations.
Analysis was also conducted of population losses between 1900 and 2015 in a sample of 177 well-studied mammal species. Of the 177, all have lost 30% or more of their geographic range. More than 40% of them have lost 80% of their ranges. This is the result of factors such as pollution, habitat degradation and climate change.
Particularly affected are the mammals of south and southeast Asia, where all the large-bodied mammals analysed have lost more than 80% of their geographic ranges. However, so many parts of the world are seeing species declines. In most parts, mammals are losing 70% of their populations because of habitat loss alone. Some species the authors comment on specifically are cheetahs (declined by 7,000 individuals), Borneo and Sumatran orangutans (with less than 5,000 individuals remaining), pangolins (populations have been “decimated” due to the illegal wildlife trade), African lions (populations declined by 43% since 1993), and giraffes (which now number less than 100,000).
The authors suggest that previous estimates of global extinction rates are too low because they have focused on the complete extinction of a species. Yet it is important to identify where entire populations have disappeared, or populations which have declining numbers, because it means that extinction is more imminent. Population extinctions are a “prelude to species extinctions.”
The overall scope of population losses means that we cannot wait to address the damage we are causing to our biodiversity. We are being called on to do something now, to curb overpopulation and overconsumption, and move away from the “fiction that perpetual growth can occur on a finite planet.” Intensive, local conservation efforts are urgent, as is the global effort to prevent climate change from getting even more serious.
Extinctions of local populations cause cascading effects that ripple throughout the ecosystem, and the smaller populations left behind are even more vulnerable. We must heed the strong warnings the scientists are giving us – animal populations are plummeting and the consequences are serious. We are the cause, it’s up to us to do something about it.