cologne donald trump would highly unlikely able renegotiate global accord climate change elect u.s. president u.n. climate chief say wednesday would require agreement 195 countries trump presumptive republican presidential nominee tell reuters early month big fan climate accord would seek renegotiate elements deal know donald trump relish make dramatic statements many issue surprise highly unlikely would possible christiana figueres executive secretary unite nations framework convention climate change tell journalists carbon expo event cologne accord strike paris last december saw countries agree cut greenhouse gas emissions 2020 aim limit rise global average temperature less degrees celsius agreement adopt 195 countries would require 195 countries agree new negotiation say add current u.s. administration strong supporter deal benefit country many accord backers say u.s. interest limit greenhouse gas emissions partly cut use fossil fuel would also mean less air pollution big cause disease trump say past believe global warm concept invent china hurt competitiveness u.s. business paris agreement formally enter force 55 nations represent least 55 percent world greenhouse gas emissions ratify china unite state represent 38 percent say join year figueres say happen agreement could come force early 2017. would even hard u.s. pull rule state nation want leave wait four years date agreement entry force length u.s. presidential term trump unlikely able renegotiate climate deal u.n. climate chief