Administrator of United Nation Development Programme Kemal Dervis speaks after presented to Brazil's President Luiz Inacio Lula da Silva the Human Development report during a ceremony at Planalto Palace in Brasilia, November 27, 2007. Unless the international community agrees to cut carbon emissions by half over the next generation, climate change is likely to cause large-scale human and economic setbacks and irreversible ecological catastrophes, a United Nations report says on Tuesday. REUTERS/Jamil Bittar (BRAZIL)