Paint

Alyse Nelson says that when it comes to placemaking, sometimes all you need is some brightly-colored paint.

Two artists have teamed with a favela in Rio de Janeiro to use bright colors to re-frame the slum as a more vibrant area.

Though funding is usually the limiting factor in road projects, the current shortage of a chemical is creating a sharp undersupply of the paint used to paint road lines.

Fighting global warming could be as simple as a paint job -- a global, sun-reflecting, white-wash paint job, according to scientist Hashem Akbari.