Local governments key to relationship with US

Agreements with states such as California would help nations meet their climate goals

For Orville Schell, a top China hand in the United States, the climate agreement struck by President Xi Jinping and US President Barack Obama in Beijing in November was "historic", but he said enlisting sub-national level support is critical to implement the deal.

Under the agreement, the US intends to reduce its emissions by 26 to 28 percent below its 2005 level by 2025, while China intends to achieve a peak of CO2 emissions and increase the share of non-fossil fuels in primary energy consumption to about 20 percent by 2030.