News bites: Climate threats to polar bears, mining Arizona, and more

NBC News reports that climate change is threatening polar bears.

Reuters reports that mining giant Rio Tinto is seeking approval for a big copper mine in Arizona.

The Interior Department hit Black Elk Energy with citations – a precursor to penalties – over last year’s fatal explosion on an offshore oil platform, The Houston Chronicle reports.

Politico’s magazine has an interview with former Energy Secretary Steven Chu.

Bloomberg talks with Sen. Sheldon Whitehouse (D-R.I.) about his work on climate change.