Guardian: The United Nations Climate Summit in New York last week passed with many promises, but no firm pledges. Most notably, China’s vice-premier Zhang Gaoli promised his country would peak its carbon dioxide emissions “as soon as possible,” and President Obama said that next year he would publish a plan to cut US emissions after 2020. On the fringes, major corporations trading in agricultural commodities grown on former rainforest land joined with governments in signing a declaration promising to halve…