Thinking About Mass Extinction

Lessons in sharing are some of the earliest and most important during early childhood development. From the very first moments we are able to understand, we are taught to share our toys, our food, our time, and our attention with people; we are encouraged to remain cognizant of others’ physical and emotional needs and treat others the way we would like to be treated.

That sentiment doesn’t exactly translate when it comes to how we treat our environment and the other species within it. Human beings have inflicted enormous change on the planet, from its atmosphere to its vast oceans. The changes have been so drastic, in fact, that many scientists believe the Earth is currently experiencing a mass extinction–the sixth in its history. And while that may not seem so bad on the surface, it could abhorrently detriment our own species in the end.

One such scientist is Anthony D. Barnosky, executive director of the Jasper Ridge Biological Preserve at Stanford University. He’s written extensively on the topic of mass extinction, from scholarly articles to books, including “Dodging Extinction: Power, Food, Money, and the Future of Life on Earth.” Barnosky sat down with BTRtoday to discuss the severity of extinction rates, the potential consequences, and why the issue is so easily overlooked.

BTRtoday (BTR): You’ve written extensively about extinction, from your books to scholarly articles and more. Can you talk about the current rate of extinction and why it’s so concerning?

Anthony D. Barnosky (AB): Well basically, the current rate of extinction is really, really fast. When I say fast, I mean it hasn’t been this fast since the dinosaurs went extinct. What that means is that if we don’t slow it down dramatically, and soon, we are headed for a mass extinction on the planet equivalent to the kind of thing that happened when the dinosaurs died out.

BTR: Based on your research, can you tell us the reasons why the current extinction rates are so high?

AB: The reason that extinction rates are so high now boils down to a very clear cause, and that’s humans. Us. We are changing the planet so fast, in so many ways, that other species just cannot keep up with us.

BTR: You’ve written that Earth is undergoing its sixth mass extinction. What did the others look like?

AB: Mass extinctions are very rare in the history of the planet—they’ve happened only five times in the last half billion years. What makes a mass extinction is about three quarters of the familiar species at that particular time relatively suddenly going extinct. So that’s the sort of thing we’re looking at today.

When that happens, you can imagine that you look out your window and see that three out of the four species that are supposed to be there are not. That’s a tremendous loss of biodiversity, a very depauperate world, and it takes literally millions of years to recover from an event like that.

BTR: What are some of the biodiversity benefits we can expect to lose due to this mass extinction over the next few generations?

AB: If we lose biodiversity, it’s more than just losing species to look at. Other species on the planet are actually our life support system. High biodiversity is necessary for such basic things as clean air, clean water. Water filtration systems for Manhattan, for example, are based on the rain falling out of the sky and percolating through soils in the Catskills.

There are actually some very important life support systems that other species provide to us. Things like productive soils depend on high biodiversity. Climate change is a big issue these days—high biodiversity sequesters carbon out of the atmosphere. That’s why it would be such a dramatic thing if we happened to lose the rainforest, that would really exacerbate global climate change. Other species give us medicines that we rely on very heavily. For example, some of the most widely used high blood pressure medications actually were discovered from prospecting for species in rainforests.

And then things that we would never really expect, surprises that lead to major breakthroughs. Nowadays we just take it for granted that we can do sophisticated genetic analyses, everything from solving crimes to tailor-making cancer treatments based on the genetic peculiarities of a particular person. The reason we can do that is because of an obscure bacteria that was discovered in the hot springs at Yellowstone National Park that had been preserved, and it turns out that bacteria allows us to produce the chemical reactions needed for all sorts of DNA analyses.

BTR: What are the major differences and similarities between this mass extinction and the previous five?

AB: The main difference with this mass extinction is that it’s one species causing it. But what’s kind of the same, and the way we’re causing the extinction, it’s the same effect that’s caused previous mass extinctions. That is dramatically changing the chemistry of the atmosphere and the Earth’s oceans. Today we’re doing that. In the past, it was things like giant volcano eruptions in Siberia or an asteroid hitting the Earth. So now you can look at us as equivalent to an asteroid or equivalent to literally tens of thousands of square miles of volcanic eruption.

BTR: What are some of the things average people can do to help quell mass extinction?

AB: As far as what the average person can do to mitigate the main causes—energy production/power, food, and money—each one of those causes is the accumulation of what each of us does. For example, in the category of power or energy production, the big issue is climate change. We are changing the climate too fast and going to a climate condition that other species have never seen in their evolutionary history. So, anything an individual does to slow climate change is dramatically important. Walk rather than drive when you can. If you have the means, make your home more energy efficient. Drive fuel-efficient cars, or ideally electric.

One of the most absolutely important things people can do these days is vote for people who are going to take the climate crisis seriously in order to actually solve this problem. It has to be both a top-down and bottom-up approach. So keeping on top of what the legislators we put in office are doing in this respect, and letting them know how important it is to stop climate change is a really important thing to be doing nowadays.

BTR: There’s a lot going on in the world today that holds people’s attention, but the issue of mass extinction is decades old. Why do you think this topic flies so easily under the radar?

AB: I think disconnection from nature is a very big part of the problem. We’re becoming more and more of an urban and suburban society worldwide. We’re disconnected from our life support systems, which are the natural world. Let me just give you one example of things we don’t think about. There’s a very real possibility that by the year 2070 there will be little, if any, coral reefs on the planet. Those of us sitting in big cities in America say, “oh my gosh, no coral reefs, no snorkeling.” Well, it’s a lot more than that—coral reefs support 25 percent of the species in the ocean, 10 percent of the world’s fisheries, and those fisheries feed hundreds of millions of people who rely on them for their main source of protein, mostly in poor and developing countries. You take away that source of protein, all of the sudden you have hungry people, societal unrest, migration. That’s just one way in which these systems are connected in ways we don’t think about them.