While you're right, there aren't any ice melts that are good for the environment, sand isn't the best option either. It's harsh on storm drain systems causing expensive damage to the lines. As for what will melt ice and isn't harsh on plants... phosphorous is one of the best options, but again, there are draw back. While it melts the snow and keeps your plants beautiful, it's not something that we want to have excessive supplies of in our water supply. There really is no happy medium. Also, calcium chloride melts at a colder temperatures than sodium chloride which is the biggest difference when they refer to not using salt, which means much less damage to our concrete during freeze thaw cycles.
BTW, good call on the CMA... I wasn't aware of its use but after reading a little about it, it is a good option with the exception of the cost. Granted, it would require increased erosion control during its use but it is a viable option. I would be interested to see the full impacts on cities that currently use CMA.