California’s Governor Arnold Schwarzenegger has certainly got the bit between his teeth. He has just signed a new law that sets targets to reduce the state’s greenhouse gas emissions by 25% by 2020 – the first US state to set such an ambitious target.

Although details on how the emission cuts will be achieved are yet to be worked out, it seems inevitable that businesses will face tougher emissions limits. Critics of the move argue that firms may just relocate out of the state.

The new Californian law has been backed by UK Prime Minister Tony Blair, who said. “This will echo right around the rest of the world,” said Mr Blair. Arnie obviously agrees.  “We begin a bold new era of environmental protection here in California that will change the course of history,” he said. “Also our federal government will follow us. Trust me.”