File photo of over-water photovoltaic power panels in East China's Jiangsu.

US President Barack Obama and Chinese President Xi Jinping have just issued a joint statement on climate change that sets out a common vision for the Paris climate agreement to be concluded this December, and which strengthens their respective national climate policies.

China announced that it would launch a national emissions-trading system in 2017 and develop a "green dispatch" system that prioritizes power generation from renewable sources. This follows the recent finalization of the US Clean Power Plan.

China also agreed to contribute $3.1 billion to a bilateral fund to help developing countries fight climate change, consistent with the previously pledged $3 billion for the Green Climate Fund from the US.

The two countries also committed to synchronize the introduction of new heavy-duty vehicle fuel-efficiency standards in 2016, with plans to implement them in 2019. And they will scale up efforts to control emissions of super-warming hydrofluorocarbons.

To strengthen climate action, global corporations depend on strong, harmonized policy signals in the countries where they have operations and supply chains, and this joint announcement by the leaders of the world's two biggest economies sends precisely the signals business needs to act on climate.

This announcement is the latest example of strong cooperation between the US and China on climate change. Last November, the two presidents announced new climate targets for both countries, which have since been submitted for inclusion in the Paris climate agreement. China committed to peaking its carbon-dioxide emissions around 2030 and to increasing the share of energy produced from non-fossil fuels to around 20 percent by 2030.

To achieve this, China will need to install as much renewable energy capacity as the entire US electricity system currently offers. For its part, the US committed to reducing emissions by 26 to 28 percent below 2005 levels by 2025, doubling the pace of reductions currently underway.

The launch of the US-China Climate Change Working Group in April 2013 has led to bilateral cooperation in eight areas, including vehicle-emissions standards, smart grids, energy efficiency, carbon capture and storage, and more.

Earlier this month, the two countries held the first US-China Climate-Smart/Low-Carbon Cities Summit in Los Angeles, where Chinese cities pledged to peak their carbon emissions faster than the national target. Beijing, Guangzhou, and Zhejiang committed to do this by 2020, and Shanghai and Shenzhen pledged to do so by 2022. On the other side of the Pacific, US cities and states have committed to reducing emissions by 80 or more by 2050.

With clear cooperation among national, regional, and local governments in the US and China, now is the time for business to ramp up its climate partnerships.