Why is the use of liquid deicers rising?

I would suggest that what’s driving the increasing use of liquids is the increasing pressure to both minimize the costs of deicing, and also the increasing pressure to be good environmental stewards to make sure that we are minimizing our environmental impact.  We do that by minimizing the amount of chemicals that we’re putting out into the environment.  And it turns out that liquids are very useful at doing this.  They enable us to do this primarily through the practices of pre-wetting and through anti-icing.