By: Mark Leon Goldberg on September 22, 2009 Chinese president Hu Jintao delivered what is arguably the most important speech of the day. Hu endorsed the rubric that countries have “common, but differentiated responsibilities” to combat climate change and laid out specific policies that China is willing to undertake at home to combat climate change. I’ll post a link to the text of the speech when it is available, but Hu said that China would enforce a carbon-emissions cap on a “per unit of GDP basis” by 2020. He also pledged that China would incease its carbon sink by increasing forrest cover. I’ll post a link to the text when it is available, but suffice it to say, China just positioned itself to play a fairly significant leadership role ahead of the climate change summit in Copenhagen in December. If President Hu Jintao’s speech at the UN today is any indication of what to expect from China at the General Assembly, Security Council and at the G-20 in Pittsburgh, this week may very well mark a turning point in Beijing’s embrace of global governance structures.