After eight months of intensive data collection, researchers from across the country came to a startling conclusion: The earth is currently going through the sixth mass extinction. Their findings were published last month in the popular magazine Science Advances and included the work of Paul Ehrlich, Stanford’s Bing Professor of Population Studies and senior fellow at the Woods Institute for the Environment.

“It is now unambiguous that we are going into a sixth mass extinction,” Ehrlich said.

The history of earth has been rich with life, but since the earliest life forms first appeared on this planet approximately 3.5 billion years ago, there have been five catastrophic events that have wiped out virtually all life on earth at any given time. These events are called mass extinctions.

The researchers fear that in just two generations, 75 percent of the species we know today could be extinct. This is a predicted catastrophe similar in scale to the Paleogene extinction that led to the extinction of most dinosaurs.

“The critical issue is that mass extinction is characterized by much more than rapid rates because there is always a background rate, which is around 500 species a year,” Ehrlich said.

In order to get the most conservative estimate possible, researchers brought the current estimated extinction rate and the average past extinction rate as close to each other as possible. For determining the current extinction rate, the researchers only focused on analyzing the extinctions of already-known species rather than estimating numbers for unknown species as well.

“We would have ended up with a much more rapid rate if we also included all of the species we think are undergoing extinction as well,” Ehrlich said. “The conclusion drawn by other scientists who have studied the same issue is not as conservative. In all likelihood, our estimate is far too conservative.”

Despite the researchers’ concerns that their calculations underestimate the severity of the crisis, they still found that the current species extinction rate is around 100 times greater than it has been in the past.

 

Human impact

In addition, the scientists also explained that the reasons behind the sixth mass extinction are undoubtedly human-centered.

“Virtually everything we do takes resources away from other organisms,” Ehrlich said. “The basic reason is because people are just consuming too much.”

According to Ehrlich, humans are also at risk for extinction in the current period of rapid extinction.

“Agriculture is an industry that is heavily dependant on other organisms,” Ehrlich said. “But at the same time, the toxic chemicals we are spreading pole-to-pole are killing the organisms we depend on.”

In Ehrlich’s research, he also explained that the worsening of environmental conditions is a key threat to humanity’s survival. He cited examples such as the human population’s susceptibility to infectious diseases and the depletion of groundwater in many agricultural areas. The latter of the two is especially relevant right now in California, which has been in a period of drought for the past three years.

However, Elrich also mentioned several solutions that would slow the current pace of species extinction. Among them are reducing consumption by the rich and humanely reducing human population size by giving more people access to contraception and instituting a national birth policy.

“The basic problem is that in the U.S. there are way too many people who want to consume at a high level,” he said. “We are the most destructive nation because we have a huge population of super consumers.”

Ehrlich believes that hope for the future lies in the fact that the scientific community knows what we need to do. The problem, however, seems to be a mixture of ignorance and unwillingness to take necessary action.

“It is all going the wrong way because people want to consume more and keep the human population growing above all else,” Ehrlich said. “There are few politicians who actually say that we need sustainable growth. It is rare that population issues are ever even discussed in the U.S. like they are in places like Australia. Doing things we need to do is tough. We need mobilization on a great scale.”

Ehrlich also believes in the possibility of such a collective effort.

“Society has changed rapidly in the past in times of peril in the past, like after Pearl Harbor,” he said.

 

Student reactions

Charlie Jiang ’16, a member of the student-led organization Fossil Free Stanford, spoke about how he strives to educate more people about the effects of fossil fuel consumption on the environment due to climate change.

“Because environmental problems affect people of poverty in undeveloped countries the most, we often do not see the impact,” Jiang said. “But we do in fact see it a little bit because of the current drought.”

However, some of Ehrlich’s propositions have been met with skepticism.

Holly Grench ’16, an American studies major with a focus on nature and the environment in American culture, has strong reservations towards putting mandatory limits on births and believes that such policies could lead to human rights abuses.

“Having a limit on the amount of children a certain person can have just seems like it would lead to bad outcomes,” she said. “It also seems difficult to enforce.”

Grench does, however, agree that a major social shift is necessary to ameliorate the effects of the coming crisis.

“Knowledge alone is not sufficient enough to change behavior,” Grench said. “Strong social pressure is needed to change social values, which then in turn influence action.”

“There needs to be a major shift rather than a superficial shift,” she added. “It’s not just people buying eco-friendly products. There has to be an overarching shift in culture.”

 

Contact Pranav Jandhyala at pranavjandhyala1 ‘at’ gmail.com.