climate summit a let-down to some delegates

white house adviser did axelrod, speaking on cnn's state of the union show, called the agreement a "great step forward" in a long-term negotiation. "nobody says that this is the end of the road," axelrod said.

countries including the united states offered voluntary emissions goals rather than the binding targets danish organizers pushed for. a deal to pay poorer countries not to cut down their forests fell apart at the last minute.

the final draft of the accord dropped a long-term goal of a 50% reduction in carbon emissions by 2050 — which countries such as the south pacific island nation of tuvalu say is necessary to prevent rising seas, lower crop yields and other consequences of global warming.

chinese climate scientist wu guoxiong, who was involved in china's climate policy process for the past five years, said he was "disappointed" by the deal. "there is so much still to do," wu said.

obama and other truck cover world leaders said the negotiations will focus on another meeting the united nations will organize next december in mexico city. those talks could he much the same format as copenhagen: gathering as many countries under one roof as possible to try to agree on a single set of goals.

that negotiating structure, largely in place since a summit in rio de janeiro in 1992, allows countries to jointly address a problem that is truly global in nature. it also permits relatively small countries (and, therefore, minor polluters) to make demands and slow the process, as frequently happened in copenhagen.

sudanese diplomat lumumba di'aping, who negotiated on behalf of a group of 130 poorer countries, predicted similar difficulties in mexico city. "we will he the same problems next time we meet, and the stakes will be higher," he said.

large polluters such as the united states may make more progress going forward if they meet in smaller groups, said stewart patrick, an expert on international negotiations at the council on foreign relations, a non-partisan think tank.

the copenhagen deal was possible only after obama held a meeting late friday with the leaders of a handful of countries including china, brazil, india and south africa. "we all had the (same) draft in our briefcases, and (obama) said to take it out and to find the points we could agree on. it started like that," said sergio serra, brazil's climate change ambassador.

patrick said one-on-one truck cover talks between the united states and china, the world's two biggest polluters, could yield more substance.