The conference…comes as leading Western powers struggle to recover from one of the worst economic downturns in memory. The event also comes hot on the heels of other global environmental gatherings that have fallen short of hopes, leading to summit fatigue and diminished expectations. Some news coverage has already depicted the meeting as a failure, in part because some prominent world leaders won't attend and in part because there isn't a clear agenda to frame the discussion. But supporters...believe that the summits can succeed...Rio...may not produce major new treaties, the boosters say, but they can still raise awareness about pressing environmental problems and their possible solutions, and build political will for future action. And even if some national governments won't make environmental pledges, the meetings can lead to commitments from local governments and businesses.