A Sixth Mass Extinction?

The world today has been losing more and more species due to habitat and climate changes. In effect, this means we are in the middle of a sixth “mass extinction” event of life on Earth, according to several studies that were published in Thursday’s journal, Science.

The Holocene extinction is a name proposed to describe this event, which is occurring during the present Holocene epoch that began around 10,000 BCE. This extinction seems to be in large part due to human activities.

According to The Associated Press, species of plants and animals are dying out 1,000 times faster than they did before humans were around. That’s a rather compelling argument for what could be causing the problem.

One study says that since about 1500 AD, more than 320 terrestrial vertebrates have become extinct. Others studies appear to have confirmed these findings.

“We are on the verge of the sixth extinction,” says Duke University’s Stuart Pimm, a biologist working with Brazilian ecologist Clinton Jenkins on one of the studies. “Whether we avoid it or not will depend on our actions.”

Rodolfo Dirzo, lead researcher from Stanford University, said, “While previous extinctions have been driven by natural planetary transformations or catastrophic asteroid strikes, the current die-off can be associated to human activity, leading to an era of ‘Anthropocene defaunation. Where human density is high, you get high rates of defaunation, high incidence of rodents and thus high levels of pathogens, which increases the risks of disease transmission.”

Sixteen to 33 percent of all vertebrates are estimated to be globally threatened or endangered at this time. This includes the larger “megafauna” like elephants, rhinos, polar bears, and others. This trend of losing larger animals fastest has occurred during other extinction events.

Over the past 35, years human populations have doubled, and in that same period the number of invertebrate animals — beetles, butterflies, spiders, and worms — has decreased by 45 percent. The loss of habitat and global climate changes seemingly brought on by the humans seems to have affected them as well.

“Immediately reducing rates of habitat change and overexploitation would help, but these approaches need to be tailored to individual regions and situations,” Dirzo said. “We tend to think about extinction as loss of a species from the face of Earth, but there is a loss of critical ecosystem functioning in which animals play a central role that we need to pay attention to as well.”

Concerns over the possibility of a sixth extinction have been around for years, but it just doesn’t seem to be sinking in where most humans are concerned. But, if we don’t begin to think about the survival of our fellow creatures and take steps to correct what we’ve done to the environment and to its life, there may be a heavy price to pay.