CO2 emissions and pollution are just two of the accusatory fingers pointed at the world's favorite form of transport: the car.
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While car ownership rises steadily in Europe and America, it's set to soar elsewhere.
In China last year, there were 22 million privately owned cars. That figure is set to climb to 55 million by 2010, says China's National Development and Reform Commission, and could explode to 140 million by 2020. Environmental campaigners say the world's atmosphere can't take that kind of CO2 increase, which comes both from more cars on the roads and from manufacturing processes.