Opponents of high-speed rail contend that it's a boondoggle because of its $68 billion pricetag. But a recent UC Berkeley study provides evidence that a California bullet train might be a good investment, particularly when it comes to reducing greenhouse gases and fighting climate change. The study, published recently in the journal Environmental Research Letters, was the result of two years of research by UC Berkeley civil and environmental engineering professor Arpad Horvath and Mikhail Chester, professor at Arizona State University's School of Sustainable Engineering and The Built Environment. The study analyzed the environmental sustainability of a high-speed rail network...