The United Nations Environment Programme (UNEP) welcomed last night the decision of the United States and China to cooperate in the fight against climate change through the phasing-out of a group of synthetic chemicals nominated by the United Nations Environment. Presidents Barack Obama and Xi Jinping declared during their talks in California recently that they will be targeting hydrofluorocarbons (HFCs) that contribute to so-called \"greenhouse gases\" as used in refrigerators, air-conditioners and other industrial equipment. According to the White House, a global phase down of HFCs could potentially reduce 90 gigatons of CO2 equivalent by 2050, equal to roughly two years worth of current global greenhouse gas emissions. In remarks made in reaction to the agreement, Achim Steiner, Executive Director of the United Nations Environment Programme, noted that the declaration from the leaders of China and the United States may be an indication of a new chapter in international cooperation on climate change.