Christian Science Monitor: The world's second largest emitter has made big promises to trim output of the planet-warming gases that scientists say raise global average temperatures. The question is whether or not the US can actually follow through on its ambitious climate targets. A study released Wednesday says it can, but success is by no means guaranteed. Without relying on nonexistent technologies or new federal laws, the US could meet or even exceed its climate targets at little or no cost to the economy, according...