How can these softer & thicker Seventh Generation wipes be better for the environment?

While the Free & Clear Baby Wipe is thicker and softer, they use 70% less plastic compared to the material used in the Original Free & Clear Baby Wipe. The Original Free & Clear Baby Wipe material is 100% viscose (polymerized plastic) and the Free & Clear Baby Wipe material is 70% plant material and 30% plastic.