Agence France-Presse: Brazil said Friday it will offer a "voluntary" cut of 39 percent of greenhouse gas emissions at the UN conference on climate change in Copenhagen next month. The goal, set against Brazil’s forecast level of emissions in 2020, was presented by Environment Minister Carlos Minc and government chief minister Dilma Rousseff at a news conference in Sao Paulo following talks with President Luiz Inacio Lula da Silva. Brazil is considered the fourth-biggest emitter of greenhouse gases …