Typhoon Haiyan

The deadly typhoon that swept through the Philippines was one of the strongest ever recorded. But storms nearly this powerful are actually common in the eastern Pacific. Typhoon Haiyan's devastation can be chalked up to a series of bad coincidences. Typhoons — known in our part of the world as hurricanes — gain their strength by drawing heat out of the ocean. Tropical oceans are especially warm, which is why the biggest storms, Category 4 and Category 5, emerge there. These storms also intensify when there's cool air over that hot ocean. "The Pacific at this time of year is very ripe and juicy for big typhoons," says Kerry Emanuel, a climate scientist at the Massachusetts Institute of Technology. "Once or twice a year we get a Category 5 typhoon out there."

How Can Cities Reduce the “Heat Island” They Create?

More than 20,000 high-temperature records have been broken so far this year in the United States. And the heat is especially bad in cities, which are heating up about twice as fast as the rest of the planet. High temperatures increase the risk of everything from asthma to allergies, and can even be deadly. But a researcher in Atlanta also sees this urban heat wave as an opportunity to do something about our warming planet. The story starts at Ebenezer Baptist Church, arguably the most famous place in Atlanta; it was Martin Luther King Jr.'s church and the heart of the civil rights movement.

Greenland’s Ice Melting Overestimated

A new study has some reassuring news about how fast Greenland's glaciers are melting away. Greenland's glaciers hold enough water to raise sea level by 20 feet, and they are melting as the planet warms, so there's a lot at stake. A few years ago, the Jakobshavn glacier in Greenland really caught people's attention. In short order, this slow-moving stream of ice suddenly doubled its speed. It started dumping a whole lot more ice into the Atlantic. Other glaciers also sped up. "Some people feared if they could double their speed over two or three years, they could keep doubling and doubling and doubling and reach very fast speeds," says Ian Joughin of the University of Washington's Polar Ice Center.