Reuters: A U.N. climate pact to extend or replace the Kyoto Protocol could be a set of up to three legally binding instruments, not just a single one, Mexico’s climate chief said on Thursday. A U.N. summit in Copenhagen last year failed to produce a legally binding agreement to combat climate change, leaving around 190 nations with no choice but to go back to the negotiating table this year. Luis Alfonso de Alba, Mexico’s special representative for climate change, told Reuters there …