The last big ice age ended about 11,000 years ago, and not a moment too soon — it made a lot more of the world livable, at least for humans.
But exactly what caused the big thaw isn't clear, and new research suggests that a wobble in the Earth kicked off a complicated process that changed the whole planet.
Ice tells the history of the Earth's climate: Air bubbles in ice reveal what the atmosphere was like and what the temperature was. And scientists can read this ice, even if it's been buried for thousands of years.
For many, the only way they learn a tornado is approaching are sirens. In the spring and summer, tornado sirens go off a lot more when twisters roar across Alabama, which has been hit by 900 since 2000, accounting for a quarter of all U.S. tornado deaths.
"I am still surprised that so many people rely on just one source of getting warned, and that has to change," said Jim Stefkovich, meteorologist in charge of the Birmingham office of the National Weather Service.
In White River Junction, a melange of fascinating businesses face challenges recovering from Irene...but not nearly so great as the obstacles facing residents of West Hartford, many of whom lost their homes to the raging White River.
Just over the border from New Hampshire in Vermont, the Upper Valley town of Hartford was ravaged by flash floods from Hurricane Irene.
Business owners and residents in the villages of White River Junction and West Hartford who have lost everything are doing what they can to dig out from the mud and debris.