California's Governor Jerry Brown has signed into law a bill requiring his state to produce half its electricity from renewable sources by 2030. The bill also requires a doubling of energy efficiency in buildings by 2030.

The move is a key example of growing regional climate leadership ahead of the universal climate change agreement in Paris at the end of the year.

Earlier this year, the Governor issued an executive order to reduce greenhouse gas emissions in California 40 percent below 1990 levels by 2030 - the most ambitious target in North America and consistent with California's existing commitment to reduce emissions 80 percent under 1990 levels by 2050.

To that end, California has spearheaded a global pact amongst cities, states and countries - called the Under 2 MOU - to limit the increase in global average temperature to below 2 degrees Celsius - the internationally agreed defence line against the worst impacts of climate change.

To date, a total of 42 jurisdictions representing 19 countries and five continents have signed or endorsed the Under 2 MOU, collectively representing more than $13.1 trillion in GDP and 463 million people.

If the signatories represented a single country, it would be the second largest economy in the world behind only the United States.

Read the press release by the Office of the Governor of California

See examples of subnational climate action on the Lima-Paris Action Agenda (LPAA) website.

Image: Office of the Governor of California