Greenhouse Disaster Symbol

From Viridian Note 00147 (online at http://home.pacific.net.au/~mitch.hub/V-Notes/ViridianNote00147.html but not at time of writing on 2000-04-17):

"This situation requires some very simple stencil, a wordless survival warning like a hobo's sign, that can be quickly chalked or sprayed onto a typical wrecked bridge or drowned beachhouse. This symbol should convey the useful message that this mishap is, in fact, no mishap. It is part-and-parcel of an ongoing Greenhouse crisis.

This simple, multinational symbol should be especially suited for use in the Third World, where literacy rates are low, communication is spotty, infrastructure is limited and disasters are especially spectacular."

Well, here's my entry. When I get a moment, I'll show it in various other styles to get an idea of it's usefulness as a universal sign.