In the last 30 years Lake Superior, one of the largest deepest and coldest fresh water lakes in the world, has warmed nearly six degrees Fahrenheit. The increased temperature is a boon to some fish species, such as the highly prized walleye, but warmer water also boosts numbers of invasive species like the sea lamprey. Host Steve Curwood hears more from Jim Kitchell from the University of Wisconsin.

Mining giant Anglo American has pulled out of a partnership to develop the massive Pebble Mine in Southeast Alaska. Conservation groups are pleased, as the mine would stand at the headwaters of the most productive salmon run in the country. But the mine could produce some $300 billion worth of minerals, so Mike Mason, news director at KDLG in Bristol Bay, Alaska tells host Steve Curwood the proposal may not be dead.

Scientists at the University of Hawaii have figured out a way to pinpoint when weather extremes at a given location will move outside the range of anything we’ve known in modern times. Geographer Abby Frazier, a co-author on the paper in Nature, tells host Steve Curwood it’s going to be sooner then we might think.

Alan Weisman’s bestselling book The World Without Us imagined our world if humans suddenly vanished from the planet. Weisman’s new book, Countdown, looks at an opposite reality; the earth with potentially far too many of us. Host Steve Curwood discusses the new book and the hot-button issue of reducing population with Alan Weisman.

Adapting to a future of rising temperatures will be especially hard for people who work outdoors during the summer. Courtney Flatt of the public media's EarthFix, reports that Washington state now requires employers to take the heat into account in order to provide safe working conditions.

There are many ways to make your home more energy efficient. In Massachusetts a partnership of northeastern utility companies aims to guide residents through these choices by providing free advice on cheapest ways to save energy. As part of our ongoing Power Shift series, reporter Poncie Rutsch followed a home energy auditor to see how the program works.