California

New research reveals success of air quality rules

Cap-and-trade scheme to "fill the vacuum created by the failure of Congress to pass any kind of climate or energy legislation"

Western states are considering entering the North East Regional Greenhouse Gas Initiative

"Oil companies flexed their muscles and we flexed back and won"

Regional carbon trading scheme on track to launch in 2012

High-profile taxi trial will see four battery-switching stations installed in the Bay Area

California governor fights hard to protect his green legacy, taking on oil executives who aim to annul law via Proposition 23

US will get there first with 1GW plant, but South Africa's plan for a 5GW solar park threaten to put everyone in the shade

But mid-term polls suggest wider US climate change policy could be scuppered by Republican victory

Shareholder groups accuse oil giants of using company money for "overt political purposes"