“Low odds, in the long run, can still be deadly.”
The title is the line of the book The Sixth Extinction (chapter 9) where Kolbert provides the example of a pair of birds on an island to demonstrate “relaxation,” the ecological term used to describe a delay of extinction that sometimes happens for smaller populations; however, extinction is often still imminent. This has implications not just for small populations but for isolated ones, such as those increasingly found on islands. In presenting these cases, Kolbert emphasizes the randomness of life, which increases the probability of catastrophe over time.
The planet has survived five mass extinctions, but it’s the sixth that we should be worried about.
Elizabeth Kolbert’s wonderful book The Sixth Extinction: An Unnatural History outlines the human impact on the globe by following researchers who are studying not only the past but today’s resources and species currently at risk, from the oceans to the rainforests.
“What this history reveals, in its ups and downs,” Kolbert writes, “is that life is extremely resilient but not infinitely so.”
In the first half of the book, Kolbert covers species that are already gone — the mastodon, the great auk — and while this is fascinating reading, what’s even more compelling is the second half, which deals with the current crises facing the planet.
As Kolbert writes, “If extinction is a morbid topic, mass extinction is, well, massively so…I try to convey both sides: the excitement of what’s being learned as well as the horror of it.”
Initial theories of evolution favored the gradual change of living things adapting to their environment favoring survival of the fittest.
The idea of catastrophic mass dyings was resisted until evidence gradually began to mount and it is only in our lifetimes, for example, that the total annihilation of Dinosaurs by a meteor strike was finally accepted with great resistance by the scientific community.
What has emerged from these studies is a picture of extreme geological events making life on Earth suddenly difficult for a large number of life forms — sometimes in a very short time span.
A lot of this is geological sleuthing. Whole groups of creatures suddenly vanish from the geological strata. What happened? Sometimes it was continents crashing together and altering global weather patterns, other times it may have been massive volcanic eruptions spewing gasses into the atmosphere and killing off life in the oceans.
Once she introduces us to the idea of cataclysmic environmental change, Kolbert shows how it relates to our own epoch which some geologists want to rename the Anthropocene (age of man).
Humans are burning fossil fuel stored away in rocks over 100s of billions of years and, in the process, changing the composition of the atmosphere back to what it was before prehistoric forests sucked the carbon out of the air.
As we do this our climate returns to prehistoric conditions. Few currently living things are adapted to such a climate.
But as the book makes clear, there is more at work than climate change. Humans have unleashed a whole host of drastic changes that by themselves and, in interaction with each other, make it difficult for current plants and animals to adapt quickly enough to avoid going extinct.
Some of these include the acidification of the oceans as CO2 mixes with seawater, the conversation of large areas of the land surface to human uses, the destruction of forests, and the moving plants, animals, and their diseases across oceans where they can wipe out the native species that encounter them.
Kolbert goes everywhere. She hunts frogs with a flashlight in the jungle of Panama, dives on the Great Barrier Reef, observes experimental forest fragments in the Amazon, walks on dead bat carcasses in an abandoned mine in upstate New York, and watches a Rhino being inseminated at the Cincinnati Zoo.
All the while she meets local scientists and conservationists at work. This makes for lively reading for people who may find a discussion of science to be off-putting.
But she lays out the relevant concepts clearly enough. We are an ingenious species that has managed to invade all corners of the planet in a period of 10s or 1000s of years.
On the way we gradually killed off most of the large animals that had not evolved to be wary of us.
We created agriculture and modified a large part of the vegetation covering the earth’s surface.
We created the industrial revolution and began to alter the composition of the atmosphere and the acidity of the oceans.
We moved organisms across oceans where they reduced the native species. In fact, we even killed off or out-competed our near relatives, the Neanderthals, but not before mating with them.
She suggests we are a restless, “Faustian” species out to change everything in our path without always realizing we are doing it. At the end of the book, she tries to add an upbeat note that we are also very caring about other species and what we are doing and that we can still do things that may help the situation. I expect future books may have more upbeat stories about how people are trying to address the problem.
As for the human effect of these activities, I became impressed by using a couple of factors. She discussed one test where scientists off the coast of Italy are reading sea existence near ocean vents in which herbal CO2 is bubbling into the water. Where the extent of acidity reaches what it may be in the international’s oceans through 100 AD, at that location she describes: “…the underwater equivalent of a vacant lot” (web page 122). In different phrases, if we stay on our contemporary route as far as climate trade, we are searching at a wipeout of existence inside the ocean by the cease of the century, or as a minimum this is how I interpret it. The ocean is chargeable for producing now not just fish but a massive part of the oxygen we breathe — about 1/2. How will this extinction have an effect on our delivery of oxygen?
I was also struck by a description of what happened to the inhabitants of “Biosphere 2”, the experimental, closed ecosystem created decades ago in Arizona. Four bouts entered that sealed environment for two years to live in a simulation of the planet’s ecosystems. It had farmlands, a rainforest, and its own mini ocean with a coral reef. Toward the end of their stay, the inhabitants didn’t have enough food or oxygen to breathe. Is this just a coincidence? What happened to Biosphere 2 is not identical to what is happening to Biosphere 1, but we are also experimenting with what happens when you put 7–9 billion human beings and their pollution-spewing industries into an enclosed bottle.
Also, She observes that one of the reasons for the success of our species, unlike other primates, is our capacity to cooperate. That, along with our ability to create and use symbols such as language rather than our use of tools, which are used by other species, is probably at the root of the Sixth Extinction.
