In the lead up to COP 21, another historic agreement has been made between the United States and China, bolstering hopes that substantive commitments can be achieved in Paris this December. In today’s anouncement, China has agreed to cap some emissions, put a price on carbon and contribute US$3.1 billion to financing decarbonisation in poor nations. As the largest contributor to global emissions, China’s leadership on this file is key to curbing emissions world-wide and today’s agreement demonstrates capacity to achieve commitments made by the two countries last November.