Reuters: New York City’s plan to turn its entire fleet of yellow cabs green by 2012 was halted on Friday by a federal judge who ruled that regulation of fuel emissions standards falls under federal, not city, authority. The plan, which had been promoted as an environmental model for other large cities, called for every new taxi to have a minimum standard of at least 30 miles per gallon, a target now met by hybrid and clean diesel cars. U.S. District Judge Paul Crotty found that the …