Green in other ways, too
It has never failed to amaze me that the holding of traffic, particularly in town scenarios, has a particularly detrimental effect.
Most combustion engined vehicles are at their most polluting, and fuel consuming whilst the engine is running but the vehicle is at rest.
Having lived abroad in Germany, Netherlands and France, I can confirm that the 'flashing amber' crossings present very few issues: just a case of using the rules of the road in that locale. Germany, in particular, would 'reward' careful driving by giving a driver a green light, largely through each junction, if they drive at or slightly below the speed limit - Very efficient and effective.