Sierra Club Recalls Web-based Density Calculator

"In mid-June, the Sierra Club's Web site proclaimed that 500 households per acre is efficient urban density (that's three times the density of Manhattan's most concentrated census tracts). Two days later, it lowered its estimate to 100 households per acre (still as dense as teeming neighborhoods in San Francisco) while stipulating 10 households per acre for "suburban efficient" (three or four times more crowded than most suburban developments.) ... Shortly after the first major overhaul of its position, the Sierra Club decided to distance itself from its own work, adding a disclaimer that the group does not endorse a "specific density level." ... And finally, the Sierra Club reconsidered again and simply stripped the density figures from its Web site. When I tried Friday to visit the same link, the material was gone. In its place was a message that said 'Our Environmental Impacts Calculator is currently under construction -- please check back later.'"