NAGOYA — The success or failure of U.N. conferences often hinges on whether delegates come to agreement after days or months — in some cases years — of intense haggling over a few numbers.

But at the COP10 talks in Nagoya, the numbers debate is of secondary importance to more basic issues that have no real quantitative solutions.

The 1997 Kyoto Protocol conference and the 2009 Copenhagen Accord conference went into overtime, with delegates, and in the case of Copenhagen, world leaders, meeting behind closed doors and arguing heatedly over by what percent the world should reduce its greenhouse gas emissions, by when it should reduce them, and how much money developing nations should receive to meet their own reduction goals.