Is it really "green"

So, we are told to use fluorescent lights in place of incandescent lights in our homes. It's more energy efficient, it will save us money in the long run. It's better for the environment.

But is it really?

A normal incandescent light is made of glass, metal, and a carbon filament.

A fluorescent light is made of glass, metal, and mercury lines the inside wall of the glass tube (it's how it works).

When either light burns out (and yes my fluorescent lights have burned out in less than 3 years), we throw them away to be taken to a land fill. Where, undoubtedly, both are broken. Thus, mercury is now in the ground at the landfill in greater quantities than it was prior to this light.

Hmmm...is it really "better for the environment?"

Now, a fluorescent light does supposedly last longer (just not some of mine I guess), so less bulbs than incandescent lights would be in the landfill. The amount of mercury needed per bulb is not a huge amount. Glass thermometers with mercury have been throw away in landfills before I'm sure. Possibly they contain more mercury. A fluorescent light uses quite a bit less energy (about a 1/4 of the incandescent light), so does the energy requirement savings offset the mercury?

*just a sample of a recent discussion between Dh and I one Saturday night*