The initial UN special session on climate change, which took place on Tuesday, primarily focused on urging wealthy nations to take the lead in reducing greenhouse gases. British economist Nicholas Stern emphasized the importance of both rich and developing countries participating in a global agreement to address human-induced emissions. Stern suggested that the global target for reducing greenhouse gases, particularly carbon dioxide, should be a 50 percent reduction by 2050. He also argued that wealthier nations, due to their historical contributions to pollution and greater access to resources, should aim for even larger reductions, around 75 percent. Stern, a former head of the British government's economic service and current professor at the London School of Economics, suggests that responsibility for reducing emissions may also include financing cuts in other countries. British Prime Minister Gordon Brown echoed similar sentiments at the United Nations, emphasizing that the impacts of climate change will disproportionately affect the poorest nations despite them contributing the least to the problem. Sunita Narain, director of India's Center for Science and Environment, criticizes the lack of significant emissions reductions by industrialized countries and calls for more concrete action on climate change rather than just rhetoric from political leaders. At a climate meeting at the United Nations, environmental scientist John Holdren from Harvard University stated that global climate change is responsible for extreme weather events such as droughts, floods, and more intense storms, which cannot be attributed to natural climate variability. The United States, a major emitter of greenhouse gases, did not make a statement during the meeting and has been resistant to setting firm targets for reducing emissions, citing concerns about the impact on the economy. Instead, the US has advocated for voluntary rather than mandatory emissions cuts. President George W. Bush, along with other leaders of the Group of Eight, agreed in June to make significant reductions in emissions and to negotiate a new global climate agreement to replace the Kyoto Protocol after 2012. The two-day climate meeting, the first of its kind in terms of content and format, will conclude on Wednesday. The event is carbon-neutral, as any emissions produced by air travel and the UN Headquarters building in New York are balanced out by supporting a biomass fuel project in Kenya.