When Lewis and Clark explored North America 200 years ago, they noted, with amazement, the wildlife they saw during their travels as being diverse and vast.
Little did they know, thousands of years prior, giant armadillo the size of a Volkswagen Beetle, an American lion twice the size of today’s African lion, and a sabre tooth bear that weighed 2,600 pounds, roamed the earth.
Lewis and Clark experienced an impoverished nature without realizing it. In its time, the earth has undergone five major extinctions and scientists believe the sixth is now ongoing.
Robin Smith, a Paonia resident who has worked as a high school biology teacher and spent summers working as a Park Ranger for the National Park Service, will present May 23 at the Basalt Library on “The Sixth Extinction.” It’s considered the sixth because there have been five before and the sixth is underway. That means it is likely that 50 percent of the earth’s species will go extinct unless humans intervene and do something quickly.
“The extinctions are related,” Smith said recently in an interview. “Most people, when they think of an extinction crisis, tend to think this is something that happened in the last hundred years or so. In my presentation I try to get across that that’s not the case.
“The sixth extinction probably began 45,000 years ago. As human beings migrated out of Africa and began to expand throughout the world, pretty much most places we migrated to, we’ve left a trail of extinction. The (United Nations) just put out a global assessment on biodiversity and they said it best. We’re putting our own lives at risk by eroding the foundations of our economy, our health, our food, our quality of life. I have to say, for me more personally, Pope Francis has written that humans should not be the cause of the extinction of any species.”
While the cause of the sixth extinction seems to be climate change, as it has been for some extinctions in the past, humans are heavy handed in it. Human beings use 72 percent of the ice-free land surface for their homes, agriculture, producing oil and gas to fuel cars and heat houses. There’s very little place for plants and animals to survive.
“What I can tell you, though, is that loss of habitat doesn’t really give us the answer because then the question is what causes loss of habitat?” Smith said. “That gets to the real cause of the sixth extinction and what’s really the purpose of my presentation. I want to make sure people understand that human population growth and overconsumption of resources result in an extinction crisis that affects all life on earth. Each of us needs to be part of the solution.”
Although extinction is part of the natural process, scientists try to determine how severe the impact is through fossil records. When looking at past fossil records, one to five species become extinct per year under natural circumstances. But since humans have arrived on the scene, it appears we are losing close to a thousand species per year. In Smith’s view, there is a solution.
“We need to encourage people to have small families. If each of us voluntarily chooses to have one or two children, the world’s population will not continue to grow. Right now we’re adding 216,000 people to the world’s population every day. That translates to 79 million people per year. That’s the number of people in a country about the size of Germany. We’re adding the population of Germany to the world every year.”
There’s also the matter of reducing our carbon footprint by cutting down on meat and dairy consumption, basing our consumption of resources more on needs rather than wants, and purchasing an electric car if possible. Smith also mentions striking a balance between the amount of land humans choose to protect versus develop.
“In the U.S. in the lower 48 states we only set aside 5 percent of our land for protection. Costa Rica set aside 25 percent. New Zealand leads the world by setting 30 percent of their land aside for parks and protection. Five percent is insufficient. It means 95 percent of our country is available for residential, agricultural and resource development.
“We need to strike a balance between protection and development. Ninety-five percent being open and 5 percent being protected—we haven’t struck a balance. With an overgrowing population, it’s becoming increasingly harder to strike because more people want more resources to consume and to get those, we need to go into our natural areas to extract what we need, which results in loss of habitat,” according to Smith.
Five prior mass extinctions
The larger the animal is, the less likely it’s going to survive human presence as humans expand throughout the world. Large animals, those over 2,000 pounds, are less likely to survive in the wild in the future. It’s believed most predators over 100 pounds—called megafauna—are the first to go extinct. Then, scientists say, only 50 percent of remaining animals, meaning not megafauna, will likely go extinct because 50 percent of plants will also go extinct.
Of the five previous mass extinctions, the most memorable one for humans today was the extinction of the dinosaurs. After that mass extinction, over a million years of evolution created a new diversity of plants and animals to replace those previously in existence. If humans were to wait tens of millions of years, the earth will be re-populated with new plants and animals, but that won’t help those of us alive today.
One previous event called the Triassic extinction, 201 million years ago, was believed to be caused by global warming in which the climate increased by nine degrees Fahrenheit and resulted in 76 percent of all the species on earth going extinct. Many scientists are predicting the planet will heat by this amount at the end of the century.
“I want people to understand the landscape up until very recently was very different than it is today and humans were most likely the cause of the loss,” Smith said.
About his May 23 talk, he said: “I would like people to walk away knowing that it’s each of our responsibility in the process of the extinction, and what I mean by that is be responsible by being part of the solution. I want people to walk away with the feeling that they have within their control to take their own personal actions to do what they can to help stop the sixth extinction by having a small family and reducing their consumption.”
As long as most species are still alive, they still exist, and as long as they exist, there’s still hope.
For more information about Smith’s May 23 presentation at the Basalt Regional Library, which begins at 5:30 p.m., visit basaltlibrary.org/events-calendar.html.