The End of Doom (36 page)

The Climate Change Bottom Line

Despite the current pause in global warming and the real failings in climate computer model projections, the balance of the scientific evidence suggests that man-made climate change could become a significant problem by the end of this century. As we have seen, political progressives and environmentalists like Naomi Klein fervently promote the “climate crisis” as a pretext for radically transforming the world's economy in ways that ratify their own ideological predilections. Thus they advocate the imposition of vast top-down regulatory schemes that ultimately amount to various forms of carbon and energy rationing.

As a response, lots of supporters of free markets and economic growth tend to underplay the science that suggests the possibility that continued unrestrained emissions of greenhouse gases could have really undesirable effects on the planet's climate by the end of the century. Why? Because they have fallen for the false dilemma posed by progressive environmentalists of supposedly having to choose between economic growth and averting the possibility of disruptive climate change. A far better strategy for challenging radical progressive proposals is to advocate policies that further enable market-driven advances in science and technology to cut through the climate/energy conundrum. Among other things, this would include eliminating all energy subsidies, most especially those to fossil fuels.

It is surely the case that if one wants to help future generations deal with climate change, the best policies are those that encourage rapid economic growth. This would endow future generations with the wealth and superior technologies necessary to handle whatever comes at them, including climate change. In other words, in order to truly address the problem of climate change, responsible policymakers should select courses of action that move humanity from a slow-growth trajectory to a high-growth trajectory, especially for the poorest developing countries. Whatever slows down economic growth will also slow down environmental cleanup and renewal.

 

7

Is the Ark Sinking?

WHEN I WAS A BOY, MY FASCINATION WITH
the plight of the whooping cranes was kindled by the book
The Whooping Crane
by National Audubon Society ornithologist Robert P. Allen. Allen was the man who is most responsible for bringing America's tallest bird back from the brink of extinction. The total population in the wild had fallen from an estimated 10,000 before European settlement to just 15 birds by the 1930s. I was so taken by Allen's intrepid and passionate story that during a mid-1960s visit to my Texas grandparents I whined and wheedled my parents into taking me to the San Antonio Zoo to see the two captive whoopers, Rosie and her mate, Crip. Fortunately, I was not viewing the last representatives of a species on its way out, but one on its way back. The good news is that the wild migratory population has recovered to around 280 birds and some 290 others are captive or part of reintroduction efforts. Biologists believe that nurturing the species to 1,000 birds with 250 breeding pairs would pull the whooping cranes safely back from the threshold of extinction.

While the fortunes of the whoopers may be improving, many biologists and conservationists are urgently warning that humanity is on the verge of wiping out hundreds of thousands of other species in this century. “A large fraction of both terrestrial and freshwater species faces increased extinction risk under projected climate change during and beyond the 21st century,” states the 2014 IPCC
Adaptation
report. “Current rates of extinction are about 1000 times the likely background rate of extinction,” starkly asserts a May 2014 review article in
Science
by Duke University biologist Stuart Pimm and his colleagues. “Scientists estimate we're now losing species at 1,000 to 10,000 times the background rate, with literally dozens going extinct every day,” warns the Center for Biological Diversity. The CBD adds, “It could be a scary future indeed, with as many as 30 to 50 percent of all species possibly heading toward extinction by mid-century.” Eminent Harvard University biologist E. O. Wilson agrees. “We're destroying the rest of life in one century. We'll be down to half the species of plants and animals by the end of the century if we keep at this rate.” University of California at Berkeley biologist Anthony Barnosky similarly notes, “It looks like modern extinction rates resemble mass extinction rates.” Assuming that species loss continues unabated, Barnosky adds, “The sixth mass extinction could arrive within as little as three to 22 centuries.”

The Sixth Mass Extinction?

Barnosky is comparing contemporary estimates of species loss to the five prior mass extinctions that occurred during the past 540 million years in which around 75 percent of all then-living species died off each time. The most famous extinction episode—likely triggered by an asteroid crashing into the earth—killed off the dinosaurs 65 million years ago. The asserted cause of the sixth extinction event is human activity, chiefly the result of cutting down forests and warming the planet. About 1.9 million species have so far been described by researchers, whose estimates of the total number of species on the planet range from 3 to 10 million.

Let's assume 5 million species. If Wilson is right that half could be gone by the middle of this century, that implies that species are disappearing at a rate of 71,000 per year, or just under 200 per day. Contrast this implied extinction rate with Pimm and his colleagues, who estimate that the background rate of extinction without human influence is about 0.1 species per million species years. This means that if one followed the fates of 1 million species, one would expect to observe about one species going extinct every 10 years. Their new estimate is 100 species going extinct per million species years. So if the world contains 5,000,000 species, then that suggests that 500 are going extinct every year. Obviously, there is a huge gap between Wilson's off-the-cuff estimate and Pimm's more cautious calculations, but both assessments are troubling.

Earlier Extinction Predictions

However, this is not the first time that biologists have sounded the alarm over purportedly accelerated species extinctions. In 1970, Dr. S. Dillon Ripley, secretary of the Smithsonian Institution, predicted that in twenty-five years, somewhere between 75 and 80 percent of all the species of living animals would be extinct. That is, 75 and 80 percent of all species of animals would be extinct by 1995. Happily, that did not happen. In 1975, Paul Ehrlich and his biologist wife, Anne Ehrlich, predicted that “since more than nine-tenths of the original tropical rainforests will be removed in most areas within the next thirty years or so, it is expected that half of the organisms in these areas will vanish with it.” It's now nearly forty years later and nowhere near 90 percent of the rain forests have been cut and no one thinks that half of the species inhabiting tropical forests have vanished.

In 1979, Oxford University biologist Norman Myers stated in his book
The Sinking Ark
that 40,000 species per year were going extinct and that 1 million species would be gone by the year 2000. Myers suggested that the world could “lose one-quarter of all species by the year 2000.” At a 1979 symposium at Brigham Young University, Thomas Lovejoy, who is the former president of the H. John Heinz III Center for Science, Economics, and the Environment, announced that he had made “an estimate of extinctions that will take place between now and the end of the century. Attempting to be conservative wherever possible, I still came up with a reduction of global diversity between one-seventh and one-fifth.” Lovejoy drew up the first projections of global extinction rates for the
Global 2000 Report to the President
in 1980. If Lovejoy had been right, between 15 and 20 percent of all species alive in 1980 would be extinct right now. No one believes that extinctions of this magnitude have occurred over the last three decades.

What did happen? As of 2013, the International Union for the Conservation of Nature (IUCN) lists 709 known species as having gone extinct since 1500. A study published in
Science
in July 2014 reported that among terrestrial vertebrates, 322 species have become extinct since 1500.
That being noted, the IUCN Red List records 6,451 species as endangered and 4,286 as critically endangered. Species are considered to be endangered if, among other findings, they number fewer than 2,500 mature individuals, their habitat encompasses fewer than 5,000 square kilometers, and/or their population size has been reduced by more than 70 percent over the last ten years or three generations, whichever is the longer. They are deemed critically endangered if they number fewer than 250 mature individuals, their range is less than 100 square kilometers, and/or their population has been reduced by more than 90 percent over the last ten years or three generations, whichever is longer.

In September 2014, the World Wildlife Fund published its
Living Planet Index 2014
report, which alarmingly calculates that the Earth is home to about half the number of vertebrates (mammals, birds, reptiles, amphibians, fish) that it hosted in 1970. Let's be clear: The report is
not
saying that half of vertebrate species have gone extinct, but that the overall number of wild vertebrates have declined by half. The trend is calculated using a complicated system for weighting the declines in various vertebrate species populations. The report also finds that 37 percent of the population declines result from direct exploitation (for example, overfishing and hunting); 31.4 and 13.4 percent are from habitat degradation and destruction (for example, cutting down tropical forests).

In an effort to deal with the threat of species extinction, in 1973 the United States adopted the Endangered Species Act, with the goal being to prevent the extermination of native species. The United States is home to approximately 200,000 species. In 2014, there were 1,529 domestic and 625 foreign species listed as either endangered or threatened under the Endangered Species Act.

A 2004 report by the Center for Biological Diversity lists 108 species as having gone extinct since the adoption of the Endangered Species Act. The researchers found that while 23 species became extinct after they were placed on the endangered species list, 85 species that died off never made it onto the list. The CBD list of US extinctions underlines the reality that most extinctions occur on oceanic islands—for example, Hawaii, Guam, and Puerto Rico—and in freshwater streams. The relatively small size and isolation of islands and freshwater streams render their endemic species especially vulnerable to being wiped out. In addition, lots of island species have lost their wariness of predators and consequently are devastated when mainland carnivores and omnivores such as rats and pigs are introduced. As a result, most of the species listed as going extinct in the CBD report were island endemics or denizens of freshwater streams (mostly mollusks). Interestingly, the 2004 CBD report lists the giant Palouse earthworm as having been extinct since 1978. The good news is that it was rediscovered in 2008 and was found to be so abundant that the US Fish and Wildlife Service declined in 2011 to list it as endangered.

Still, humanity is quite capable of wiping out species. Just as the last ice age was ending, our hunter-gatherer ancestors spread across the world, killing off megafaunal populations already stressed by climate change. Some 178 mammal species weighing more than a hundred pounds disappeared, drastically reducing the total mammalian biomass of the planet. For example, after humans arrived in North America, more than thirty different groups of large mammals, including horses, camels, mammoths, and mastodons, disappeared. In South America, 100 percent of mammals weighing more than a ton, including ground sloths, armadillo-like glyptodonts and rhinoceros-like toxodons, and 80 percent of those weighing more than a hundred pounds went extinct. Total mammalian biomass did not recover until just before the Industrial Revolution, when the post-ice-age losses were finally offset by the collective weight of the populations of humans and our domesticated animals. A 2013 study estimates that Polynesian wayfarers caused the extinction of 1,300 species of birds as they colonized the isolated islands of the Pacific Ocean. The arrival of Europeans killed off an additional 40 Pacific island bird species.

As we've seen from the IUCN list, biologists are not actually counting the number of species that are going extinct. As the example of the giant Palouse earthworm shows, it is really difficult to be sure when the last individuals of a species die off. So how do biologists come up with their shocking estimates of the number of species that they believe are likely to go extinct before the end of this century?

Calculating Extinctions

For the most part, the dire extinction estimates cited earlier are based on computer model calculations using the species-area-curve relationship derived from the theory of island biogeography. In the 1960s, Harvard University biologists E. O. Wilson and Robert MacArthur devised that theory, which basically predicts that the bigger the island, the more species it can support. This relationship is captured in the species-area curve. As Wilson explained it, in general if an ecosystem is reduced by 90 percent, the number of different species it can sustain is cut by 50 percent. For example, the Ehrlichs simplistically extrapolated from this crude species-area-curve relationship to make their wrong prediction back in 1975 that half of all tropical species would be extinct by 2000.

More recent research is questioning the calculations made on the basis of the species-area-curve relationship. For example, in a 2011 article in
Nature,
“Species-Area Relationships Always Overestimate Extinction Rates from Habitat Loss,” researchers concluded that “extinctions caused by habitat loss require greater loss of habitat than previously thought” and that reliance on the species-area curve overestimates species loss by as much as 160 percent.