NEW YORK (AdAge.com) -- Are marketing and media giants ignoring the fact that their primary communications channels are based on environmentally "toxic" pixels? And are some of these companies engaging in "tree washing" or "gray washing" as well as "green washing?" These intriguing issues were at the center of this week's Sustainable Media Climate Symposium in Manhattan. Don Carli, director of the Institute for Sustainable Communication, enlightened many by quantifying how the carbon footprint of electric-powered digital media is nearly as large and environmentally onerous as that of the notorious paper-making industry.