By Sasha

To begin his speech on climate change at Georgetown, President Obama evoked the image of earth as seen from space in 1968. “[W]hile the sight of our planet from space might seem routine today, imagine what it looked like to those of us seeing our home, our planet, for the first time.” Imagine what it looks like today—the Alberta tar sands’ vast tailing ponds expanding into the boreal forest, plumes of smoke from brush fires obscuring parts of Australia, algae blooms clogging the rivers, widening deserts, retreating glaciers.

If Obama’s speech made one lasting impression, it was that the US “will reduce its greenhouse-gas pollution to 17 percent below 2005 levels by 2020.” Really, that’s only a 5 percent drop from today. While the reduction in greenhouse-gases in the US will come through a very complex system of tax breaks, emissions caps, techno-fixes, and carbon trading schemes, a…