California has been ravaged by wildfires for thousands of years; they're an essential part of the natural ecosystem. But the fires that burned hundreds of square miles between Oct. 20 and Nov. 6 — at the disaster's peak, 18 separate fires were burning, the worst of them in San Diego County — killing 10 people and forcing at least half a million more from their homes, weren't entirely natural. At least one, the Santiago Canyon blaze, was deliberately set, while two others — the Witch and Rice Canyon fires — were caused by downed power lines that ignited surrounding brush. Whether that brush should have been more thoroughly cleared, and whether people should be permitted to build homes in remote, fire-prone areas, are now matters of active debate, to say nothing of lawsuits.
Yangtze River Dolphin Extinction
The Chinese called it baiji and "goddess of the Yangtze," and it was the only surviving member of a family of species that split off from saltwater whales and dolphins between 20 million and 40 million years ago. But now, according to a survey released in August, this rare freshwater mammal is almost certainly extinct — the first aquatic vertebrate species to disappear from the Earth in 50 years, and the first large mammal to fall victim to human impact. The multiple pressures: noisy boat collisions and dam construction that may have imperiled the sonar-driven animals, and overfishing — not for the dolphins themselves, but for river fish — with such indiscriminate techniques as netting, dynamite and powerful electric shocks. The disappearance of a top-level predator like the baiji — an indicator species that signals the health of its ecosystem — portends trouble for the Yangtze River and for the 400 hundred million people who depend on it.
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