DBS: His term may be winding down, but President Obama is determined to continue hammering away at the effects of climate change. In a new video address, the president previewed his latest efforts to address what he called "one of the most urgent challenges of our time," noting that despite national -- and international -- movement on climate change, "there's still so much more to do." "We're not done yet. In the weeks and months ahead, we'll release a second round of fuel efficiency standards for heavy-duty...