 Owners of gas-guzzling cars will have to pay 25 pounds ($50) a day to drive them in central London from October in a push to cut carbon emissions, mayor Ken Livingstone said on Tuesday. Livingstone admitted it would have little immediate impact on emissions but said the lifestyle signal and other moves such as recycling initiatives and new building rules would help cut London's carbon emissions by 60 percent by 2025. "I believe that this ground-breaking initiative will have an impact throughout the world with other cities following suit as they step up their efforts to halt the slide towards catastrophic climate change," he told a news conference. London, which generates 7 percent of Britain's climate-warming carbon emissions, is one of 40 world cities pooling their knowledge to fight climate change. Livingstone said the new scheme would raise 30 million to 50 million pounds ($60 million to $100 million) a year and cover most of the cost of a major cycling initiative he unveiled on Monday that will include a Paris-style roadside bicycle hire scheme in the city centre. Environmentalists welcomed Tuesday's move as a step in the right direction, but said far more was needed. "We now know that we face an emergency situation on planet Earth that requires us to bring down carbon dioxide emissions very quickly indeed," said Friends of the Earth's Tony Juniper. But motoring organisations were not so keen. "We welcome incentives for cleaner, greener cars. However, larger families who do low mileage will be clobbered by this new tax," said Automobile Association president Edmund King. Livingstone, who has made the environment a central plank of his tenure, is facing a tough re-election battle in May. If he loses, his emissions policy is likely to go with him. The 25 pound daily tax on vehicles emitting 225 grams of carbon dioxide per km would apply in the same way as the normal 8 pounds ($16) daily charge does to all but the cleanest cars. "I have every sympathy with a Scottish hill farmer who needs his 4x4 to get around. But there is absolutely no justification for cars producing high amounts of pollution being driven in central London," Livingstone said. 