CNN: A new U.S. call for curbing greenhouse gas emissions shook up climate talks Thursday in Paris among the world’s biggest polluters. U.N. climate chief Yvo de Boer said Bush’s speech became a central topic Thursday in climate talks. While some welcomed President Bush’s gesture, others called it too little, too late. Bush said Wednesday that the United States must stop the growth in its emissions of greenhouse gases by 2025, acknowledging the need to head off serious …