然而美国却拒绝签署《京都议定书 》 。 由于该协议只呼吁在2012年之前采取有限的举措，所以它对改变地球长期的状况几乎产生不了什么作用。
Yet the United States has refused to sign the Kyoto Protocol, which does little to change the long-term course of events on the planet, since it calls for only small steps up to the year 2012.