Settled: Dinosaurs done in by asteroid

• What killed off the dinosaurs?
• Thirty years ago, UC Berkeley geologist Walter Alvarez offered his revolutionary answer to that question and incited one of the liveliest controversies in modern science.
• Now, an international team of scientists says today the issue is settled: Alvarez was right.
• In 1980, Alvarez and his colleagues at Berkeley theorized that a monstrous asteroid 10 miles wide slammed into Mexico’s Yucatan Peninsula about 65 million years ago and dug a crater 60 miles wide and 15 miles deep. The impact sent up a huge cloud of ash, soot, pulverized rock and sulfurous steam that darkened the skies for years like a nuclear winter, dooming more than half the world’s life on land and in the oceans - microorganisms, plants and animals.
• The dinosaurs, those iconic beasts that had ruled the world for 160 million years, also vanished in that long-lasting cataclysm, the Alvarez team maintained.

Now, what will kill off the humans?