How clean is natural gas? For President Obama, the answer depends on the broader context in which the question is asked. An economic document released today by the Obama campaign includes a graph charting the growth in "clean energy" over the last eight years, giving gas as much credit as renewable sources like wind and solar or carbon-free nuclear power. The campaign document also reiterates Obama's call for a "clean energy standard" that would require utilities to generate 80 percent of electricity from clean sources by 2035. But the calculations the administration relied on in crafting the CES proposal essentially count gas as only half as clean as renewables or nuclear. Go to story #1