Despite recently showing signs of a policy u-turn, the US has up to now refused to make a binding commitment to reducing CO2 emissions.

But three grassroots initiatives in California, one of the largest states in the Union, are tackling climate change head on.

In Sebastopol, north of San Francisco, the ‘Solar Sebastopol’ initiative has been established to install one megawatt of solar power production across the town – and, at the same time, the city council aims to reduce total emissions by 42% over 10 years, which is the most ambitious target in the US.

“Our community is very tuned in, very well informed on climate change, and wants to take action,” said Mayor Sam Pierce. “So, as a result, the policy-makers are very aggressive, and find ways to satisfy that demand in the public.”

In Berkeley, ‘Biofuel Oasis’ is a female-run biofuel station serving local residents who want alternatives to oil. Six partners share evening shifts to convert fuel from waste cooking oil provided by local restaurants, selling the juice at a little above the price of diesel.

And ‘Cool Schools’ in Sonoma County, which is in northern California, is using education to reduce CO2 emissions in schools by 25% below 1990 levels by 2015.

“It’s young people that have to take on the burden of this issue,” said Jessica Kellett, co-ordinator of the Sonoma Climate Protection Campaign’s ‘Cool Schools’ programme. “We need to have young people be leaders today – not just to be educated but to understand how to start engaging with elected officials, with their parents, because we need to be taking action now.”