POZNAN - The current economic crisis cast a pall over climate change talks held this month in Poland. While negotiators hoped for concrete progress towards an international climate agreement, the world's two largest polluters were distracted - the US with preventing a collapse of the financial system in the midst of a presidential transition, China with a slowdown in domestic investment and weakening foreign demand for its manufactured goods. With American home values and retirement savings falling and Chinese unemployment numbers rising, observers worry that neither America nor China will have much appetite to cut emissions.