The Icecap Riddle

"Climate scientists believe that if the North Pole icecap melted as a result of human-caused global warming, global sea levels would rise—true or false?"

SPOILER ALERT. You'll want to answer this question before reading on.

Today's New York Times reports that 2016's Presidential contenders are further apart than they've ever been on the issue of climate change. That can't surprise many people, but it's worth pointing out how new this difference is. As recently as 2008 candidates of both major...