Comment Seems counter-intuitive (Score 1) 26
LED lights are extremely directional, to the point it can be difficult getting them to diffuse like an incandescent bulb. Most streetlights (and now, lights in sports stadiums, parking lots and the like) are extremely directional, pointing straight down and having abrupt drop-off in illumination around the periphery. In fact, in my town, streetlights that are being replaced with LED are not as good because they don't cover as large of an area or fade out on the edges in a more natural way. They almost look light spotlights shining straight down - objects are either in the light or not at all.
So I guess the light pollution from LEDs is due to light reflecting off the ground? I'm just surprised LEDs haven't decreased light pollution because of how directional they are. They should definitely be decreasing light pollution outside of the visible spectrum, because that was always an issue with the various kinds of lights used in the past for lighting large outdoor areas. A big part of their inefficiency was generating unwanted infrared or ultraviolet as a by-product.