In case you don't know, today is Earth Day. (Please go stick a sapling in the ground, or whatever.) And more than any other day, really, today is San Francisco's day to bask in its green, self-righteous, CO2-reducing glory. Or is it? LA Times scribe Margot Roosevelt threw down the gauntlet today when she asked, which city is greener? According to Nancy Sutley, Los Angeles' deputy mayor for energy and environment, we just don't......