How many species is global warming destroying?

Gregg Easterbrook debunks some recent doomsaying on this topic. You might have noticed a recent study claiming that more than one million species are being endangered by global warming. Easterbrook points out a calmer yet still environmentalist estimate of 12,259 endangered species, and that is from all causes, not just global warming. Easterbrook writes:

…the study in question is dubious because extinctions don’t seem to be happening at anywhere near the rate called for by other assumptions, mainly concerning habitat loss. Species-extinction theories say habitat loss, development, and logging should lead to rapid declines in species. All these factors are at play in the Pacific Northwest of the United States–and no animal species is known to have fallen extinct there in the last couple decades. (Several salmon species and other species of the area are imperiled.) This is significant because the Pacific Northwest is an elaborately studied area; far more is known about it than the tropical regions about which the Thomas study makes vague computer projections. Graduate students comb over the Pacific Northwest, knowing that tenure and academic renown will go to anyone who documents an animal species loss. And average temperatures are rising in the Pacific Northwest. For anything even remotely close to Thomas’s 1.25 million extinctions to be a hard number, we should already be seeing the bow wave in the form of dozens if not hundreds of extinctions in well-studied areas like the Pacific Northwest. Instead we see, um, zero.

Habitat loss and species extinctions are real problems, but let us not politicize science to scare up support for our favorite proposals.

Addendum: See also this trenchant critique from Carl Zimmer defends the study, thanks to Chris Mooney for the link.


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