People sit on a hilltop near a coal-fired power station on the outskirts of Beijing on November 7, 2008. Hundreds of billions more dollars are likely to be needed to reduce greenhouse-gas emissions by a 2030 target, according to UN estimates published on Friday ahead of global talks on climate change.(AFP/File/Frederic J. Brown)AFP - Hundreds of billions more dollars are likely to be needed to reduce greenhouse-gas emissions by a 2030 target, according to UN estimates published on Friday ahead of global talks on climate change.