U.S. President Barack Obama, left, and Chinese President Xi Jinping drink a toast at a lunch banquet in the Great Hall of the People in Beijing Wednesday, Nov. 12, 2014. Obama is on a state visit after attending the Asia-Pacific Economic Cooperation (APEC) summit. (AP)

Last week, we explored the potential policy implications behind a landmark Intergovernmental Panel on Climate Change report with a panel of experts. This week, with news from President Barack Obama’s visit to Asia on an unprecedented agreement for climate change reduction between the leaders of both the United States and China, one guest, Constantine Samaras of Carnegie Mellon University, offered his take on the new deal.

Last week the UN’s Intergovernmental Panel on Climate Change issued its latest report and Summary Presentation, and the language is clear: the choices we make in the near-term will lead to different climate outcomes. The impacts from climate change are already underway, and a path without substantial greenhouse gas reduction efforts will lead to a “very high risk of severe, widespread and irreversible” global impacts by the end of the century. Yet the report also offered hope and outlined ambitious, but doable, steps to dramatically reducing global greenhouse gas emissions by the middle of century. Later last week, Eileen Claussen, Anthony Leiserowitz, Andrew Revkin and I joined On Point’s Jane Clayson to discuss climate solutions and how to achieve the reductions necessary.

We need big improvements in energy efficiency, a sustained effort to transition to a very low-carbon electricity sector, innovation across the transportation, industrial and agricultural sectors, market-based policy measures, and a serious commitment to low-carbon energy research, development, demonstration and deployment. But since greenhouse gases emitted locally have impacts globally, cooperation from China is another critical piece in any climate change plan.

China is now the world’s largest greenhouse gas emitter, the U.S. is the second largest, and together they comprise more than one-third of global greenhouse gas emissions. For a long time, China and the U.S. have used each other as an excuse for inaction, adopting a ‘You First’ stance on climate change. That ended today, with the White House releasing the details of a U.S.-China joint announcement on climate change and clean energy cooperation. The U.S. intends to step up efforts for greenhouse gas mitigation, with a goal to reduce its emissions by 26-28% by 2025. China now plans for its emissions to peak by 2030 or earlier, and to scale up low-carbon energy sources to be 20% of their consumption in 2030. Building this amount of low-carbon energy in China by 2030 would be a giant undertaking, but with large potential benefits. These are all important emissions reductions commitments from the two countries that are critical to any global climate change solution. Yet these commitments alone are unlikely to get us where we need to be.

While much of the initial coverage of this announcement has focused on the emissions reductions goals, an equally if not more important part is the rest of the U.S.-China climate deal. The two countries have agreed to renewed and expanded efforts on joint clean energy R&D, and will develop advances in building efficiency, clean vehicles, capturing greenhouse gas emissions from fossil power plants, and understanding how energy and water are inextricably linked in a world with climate change. China and the U.S. have also agreed to advancing major carbon capture and sequestration as well as clean energy demonstration projects, cooperating on phasing down hydroflurocarbons (HFCs) toward climate friendly refrigerants, launching a climate-smart cities initiative, and promoting trade in green goods. As we all discussed on the show last week, limiting the risks of climate change requires a scaled-up effort across the policy, political, governance, technology, and behavioral domains. Because some efforts won’t work out in the time we have, we need continued progress on many fronts to address the very real risks of climate change. Today’s U.S.-China deal is the next step in that path.

Constantine Samaras is an Assistant Professor of Civil and Environmental Engineering at Carnegie Mellon University. His work analyzes the transition pathways to a low-carbon energy system.