Top level talks between China and the US head into their second day, after opening on how and when to wind back both countries’ towering economic stimulus packages, replacing them with measures to promote steady long-term growth.But they are also talking about North Korea and climate change. President Barack Obama said the relationship between the two countries will shape the 21st century. “The current crisis has made it clear that the choices made within our borders reverberate across the global economy,” he said, “and this is true not just in New York and Seattle, but Shanghai and Shenzhen as well. That is why we must remain committed to strong bilateral and multilateral coordination.” While US Treasury Secretary Timothy Geithner urged China to boost its domestic consumption, Obama was challenging Beijing’s record on human rights. Dick Rosecrance from Harvard University said: “I think what’s happening now is greater realism on the part of the State Department and the President, to move toward accepting liberalisation in China that is somewhat short of complete democratisation.” Between them, the United States and China are the world’s two biggest producers of greenhouse gases. Obama said they will have to work together to bring about a world response to climate change at December’s global warming summit in Copenhagen.