CNN: The world's population is aging at the very time that immediate action on climate change has become crucially important. And we ignore the shared link between these two global patterns at our own risk. Consider: The number of people 60 and older on Earth has doubled since 1980, and is forecast to reach 2 billion by 2050 -- jumping from 11% to 22% of the total population during the first half of this century, according to the World Health Organization. In the U.S. alone, adults 60 and older made...