San Diego leaders are eying a massive “green growth” initiative that includes bustling new train stations and high-speed rail to usher in a boom in dense housing construction from Chula Vista to downtown San Diego and beyond. This urban strategy is being sold as a win for the economy as well as the environment — in theory, encouraging hundreds of thousands of residents in coming decades to swap fossil-fuel-burning car trips for walking, biking and riding transit. “This is an opportunity for job creation,” San Diego Mayor Todd Gloria told the Union-Tribune editorial board in January. “It’s an opportunity for meeting our climate goals.”