As the world’s largest emitters gathered in Mexico for the US-led Major Economies Forum, several of my colleagues staged a banner hang to call on the United States to take the lead on climate action. A banner reading "Save the Climate, Act Now!" was unfurled in Cuernavaca City, where the meeting is being held. Leadership is urgently needed to achieve a climate-saving treaty at the UN climate talks in Copenhagen in December and, sadly, that leadership has so far not been provided by the Obama Administration.

We're calling on the Obama Administration to make serious commitments to deep mid-term cuts in greenhouse gas emissions, as well as to provide long-promised funds for developing countries to adapt to climate change, bypass the dirty energy sources of the past where possible, and protect the world's forests. The 16 other major emitters — Australia, Brazil, Canada, China, the European Union, France, Germany, India, Indonesia, Italy, Japan, Mexico, Russia, South Africa, South Korea, and the United Kingdom — must see that the US is serious so they will take the necessary action, too.