Environment News Service: The vice presidential candidates, Democratic Senator Joe Biden and Republican Alaska Governor Sarah Palin, held their only debate of the election campaign at Washington University in St. Louis, Missouri on Thursday night. Gwen Ifill of PBS was the debate moderator. Among many other topics, the candidates differed on how they would deal with energy and climate change if elected on November 4. A poll taken continuously as the debate was taking place, shows that of 1,195 …