President Obama is back in the United States after spending a week in Asia where climate change was almost always at the top of the agenda, and specifically, the United States and China’s joint responsibility for leadership on this important global issue.  As the world’s two largest emitters of greenhouse gas, and two of the world’s largest economies, both leaders acknowledged the important role their countries must play at the upcoming COP-15 meeting in Copenhagen.

U.S. President Barack Obama and Chinese President Hu Jintao reach out to shake hands in Beijing November 17. (AP Images)

The U.S. and China represent two important factions at the negotiating table. As an industrialized country, the U.S. is by far the largest per capita emitter of greenhouse gas in the world; as a developing country, China has a much larger population and a rapidly growing economy that have already made it the largest total emitter, and its emissions will continue to grow. COP-15 negotiations will not produce an agreement without buy-in from both developed and developing countries, and specifically the compliance of the U.S. and China.

With Copenhagen only weeks away, Obama’s visit and a strengthened bilateral U.S.-China understanding could help move the talks forward. In an important sign of cooperation and solidarity, the two countries issued a joint statement emphasizing their commitment to take “significant mitigation actions” and work together to promote a sustainable outcome for the world.

There is still much disagreement over the details of what an enforceable and effective treaty will look like, particularly with regard to specific mitigation and greenhouse gas reduction targets, but the fact that China and the U.S. have publically agreed to the basic principles of what an outcome should be and affirmed their willingness to work together is a step in the right direction.

In his town hall meeting with future Chinese leaders in Shanghai, Obama stated, “Our nations hold something important in common, and that is a belief in the future.” Identifying such common values to address the common problems of our globalized world may be the most important way developed and developing countries can come together on climate change.