Former President Carter announces opposition to pipeline

摘要

Jimmy Carter became the first former president to officially join the ranks of Keystone XLrnopponents yesterday, publishing an open letter to President Obama and Secretary of StaternJohn Kerry.rnThe letter by Carter and other Nobel laureates, published as an ad in Politico, cautioned thernadministration officials that they "stand on the brink of making a choice that will define yourrnlegacy on one of the greatest challenges humanity has ever faced - climate change."