Letters to my Grandchildren by David Suzuki

Author:David Suzuki
Language: eng
Format: epub
Publisher: NewSouth
Published: 2015-04-27T04:00:00+00:00

mammals—5,487

birds—9,990

reptiles—8,734

amphibians—6,515

fish—31,153

In contrast, the number of identified insect species is more than a million.3

Scouring the literature, Wilson calculated that about 1.5 million species have actually been identified—that is, given a name. Being named, however, merely means that someone in a lab has classified or “keyed out” the species in the taxonomic system by following along a series of branches in traits such as kinds of organs, colour, and shape until distinct characteristics of that species have been reached. But that does not indicate that anything is known about that species’ basic biology, like its geographic distribution, its population size, how it interacts with other species, what it eats, how it reproduces, or where it lives. So even though we may have identified close to 2 million species, we know next to nothing about the web of living things on Earth; yet we claim to be able to “manage” forests, air, water, and species like salmon and halibut, grizzlies, wolves, and caribou. It’s absurd.

Of 40,168 known species, scientists in the International Union for Conservation of Nature estimate that extinction threatens one in four mammalian species, one in eight birds, one in three amphibians and conifers, half of all reptiles and insects, and 73 percent of flowering plants. That represents a rate of extinction thought to be a thousand to ten thousand times the normal extinction rate (one species for every million species a year). It would mean that between 2.7 and 270 species disappear every day!

We have entered another major extinction episode, the sixth in the past 439 million years. The first five involved the sudden (in a geological sense) loss of 50 to 95 percent of all species in the fossil record, including the last episode, 65 million years ago, when the dinosaurs disappeared. The current extinction wave differs from the others in that human beings are causing it, not geology—through habitat destruction or degradation, agriculture, overexploitation, and the introduction of invasive species. Species diversity has recovered after past spasms of species loss, but recovery takes about 10 million years. We think of dinosaurs as losers because they suddenly went extinct, but they flourished for more than 150 million years before disappearing. We’ve been around as a species for only 150,000 years!

In October 2014, the World Wildlife Fund released the 2014 Living Planet Report, which concludes that between 1970 and 2010, 52 percent of animals among known vertebrate species had disappeared.4 This is a catastrophic decline in Earth’s richness and tears holes in the web of diversity that keeps the planet habitable for animals like us. Our concern is no longer just about protecting the charismatic or cute and cuddly animals and trees. Although large animals like rhinos, tigers, whales, and pandas are endangered, it is the loss of the collective role that the disappearing plants and animals play within the biosphere that is of greatest concern. Their loss threatens survival of animals at the top of the food chain—animals like us.

What we do or do not do in the coming

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