Use of wind power is on the rise, Sawyer said, as governments all over the world consider how to generate more electricity and emit fewer of the greenhouse gases thought to be warming the planet.
"Creativity is critically important for sustainable business," said Robert Epstein, "in part because sustainability is a goal that has a deadline." Read more.
There's a longstanding mystery about the craters on Venus. There aren't enough of them. Could active volcanoes be wiping them from the planet's surface?
"When we think of climate change impacts, we talk about are drought, floods, storms, sea level rise, and melting glaciers... all those things have to do with water."