California approves first US carbon-trading scheme

California has become the first US state to approve a carbon-trading plan aimed at cutting greenhouse emissions. State regulators passed a "cap-and-trade" framework, which allows companies to buy and sell permits, thereby providing an incentive to emit fewer gases. State officials hope the scheme will be copied across the US, but opponents warn it may harm California's growth and lead to higher electricity prices. The scheme means that from 2012 California will allocate licences to pollute and create a market where they can be traded.