U.N. talks of tough global climate targets, vague on national action

COPENHAGEN (Reuters) - A draft U.N. guide for slowing climate change says world greenhouse gas emissions may have to fall to a net zero this century but is vague about what each nation should do now.

About 500 delegates, including scientists and government experts, are meeting in Copenhagen to edit the report, which is meant to guide policymakers in setting national goals for a global climate deal at a U.N. summit in Paris in late 2015.