Ancient Fires Drove Sabertooth Cats and Other Large Mammals Extinct, Study Suggests

Wildfires are getting worse. Parts of the United States, scientists say, are experiencing wildfires three times as often — and four times as big — as they were 20 years ago. This summer alone, smoke from Canadian blazes turned North American skies an unearthly orange, “fire whirls” were seen in the Mojave Desert and raging …