Climate summit sheds light on collaboration

With a long, successful partnership on clean energy, China and California will highlight their leadership role in fighting climate change this week.

From Wednesday to Friday, California Governor Jerry Brown will host more than 4,000 international delegates at the Global Climate Action Summit in San Francisco to "Take Ambition to the Next Level".

Featuring 25 breakout sessions, more than 325 affiliate events and more than 500 major climate commitments, the summit will celebrate the achievements of states, regions, cities, companies and citizens and call for national governments to raise their ambitions for climate action by 2020.