los angeles obama administration evaluate whether international agreement reach early month cut back greenhouse gas use refrigerators air conditioners need approval u.s. senate white house say tuesday nearly 200 countries include unite state china sign deal kigali rwanda would reduce use factory-made hydrofluorocarbon hfc gas white house spokesman josh earnest say unclear whether accord amendment 1987 montreal protocol would need ratify u.s. senate 1987 montreal protocol succeed phase use chlorofluorocarbons cfcs widely use time refrigeration aerosols ongoing analysis agreement determine precisely role congress may play ensure unite state keep commitments make context agreement earnest tell reporters travel president barack obama fundraiser los angeles obama believe agreement would serve national interest unite state help curb impact climate change bolster u.s. company develop alternatives hfcs earnest say note vote agreement would likely take place obama leave office january strong case make senate approve agreement fact approval necessary say white house weigh whether greenhouse gas deal need senate approval