There would be more trees everywhere

Green fluorescent protein! GFP! My favorite thing in the world!

That tree just has a light behind it.

I wonder how that will affect the animals that feed on those trees

There is a bus in Paris lit with bioluminesence

Street lights are on poles for one reason. This is how you get ants. Flying ants. And raccoons. And bums under trees. Or is it cold light? I remember pressing light-bug's butt on my face and it was warm. And you can't turn them off.