Scientific American: Dear EarthTalk: Has China been making any progress reducing its output of global warming gases, and/or in tackling other environmental problems? –Bill W., Saugus, MA Decades of rapid-fire development and lack of government oversight has meant that China now faces some serious environmental challenges. According to research by the Netherlands Environmental Assessment Agency, China surpassed the United States as the world’s leading emitter of greenhouse gases in 2006–and hasn’t …