Environmentalist Hyperbole

My school-age son asserted that 17 species were going extinct per hour, claiming it was true because he read it in a magazine. He has a lot to learn; unless it is in The American Spectator, I'm as cautious with media reporting as when a cold caller announces I've won a sweepstakes. I found the number unbelievable and was sure it was debunked in "The Skeptical Environmentalist" among other places. Sure enough, it is false:

In 1990, the World Conservation Union commissioned a report to investigate rates of extinction, the findings of which can be seen in Tropical Deforestation and Species Extinction by T Whitmore and A Sayers. The report found that the recorded rates for extinction remain 'very small', believing it to be about 2300 species, or 0.8 percent, per decade. Bjørn Lomborg, after studying a number of reports and extinction estimates - including the UN Global Diversity Report - reckons an extinction rate for all species of about 0.7 percent per 50 years is pretty accurate.

But wait, the environmentalists say Lomborg is wrong and it's higher:"Estimates for current species extinction rates range from 100 to 10,000 times that, but most hover close to 1,000 times prehuman levels (0.1 percent per year)." Yet when you peel the data back you find numbers consistent with Lomborg's estimates, for example - "anywhere from one to several bird species go extinct annually ... 0.01-0.03 percent of living bird species are extinguished per year." Even the 'pro-environmentalist' numbers show that the "17 per hour" extinction claims are off by a factor of 100 or 1,000.

Greenpeace founder Patrick Moore questions the extinction numbers that are based on models not measurements:

This gives rise to the obvious concern that if the trees are cut down the habitats or homes will be lost and the species that live in them will die. Indeed, in 1996 the World Wildlife Fund, at a media conference in Geneva, announced that 50,000 species are going extinct each year due to human activity. And the main cause of these 50,000 extinctions, they said, is commercial logging. The story was carried around the world by Associated Press and other media and hundreds of millions of people came to believe that forestry is the main cause of species extinction.

During the past three years I have asked the World Wildlife Fund on many occasions to please provide me with a list of some of the species that have supposedly become extinct due to logging. They have not offered up a single example as evidence. In fact, to the best of our scientific knowledge, no species has become extinct in North America due to forestry.

Where are these 50,000 species that are said to be going extinct each year? They are in a computer model in Edward O. Wilson's laboratory at Harvard University. They are electrons on a hard drive, they have no Latin names, and they are in no way related to any direct field observations in any forest.

Why is such hyperbole tolerated in environmental reporting, and how is it that the loud proponents of such hyperbole claim the mantle of "science"?
Even some environmentalists ask of their own movement's irrationality, "How Sick is That?"