If people who use fabric shopping bags end up buying plastic trash liners, are they still helping the environment?Kira Freed, Tucson, AZ Turns out, the environment comes out ahead in this scenario. “Research in Australia has estimated that even if consumers do have to purchase bin liners, the reduction in the number of single-use plastic shopping bags consumed will far outweigh the increase in the number of bin liners purchased,” Helen Lewis, an adjunct professor with the Centre for Design at Australia’s RMIT University, wrote in an email. Lewis has worked for more than 20 years on reducing the environmental impacts of production and consumption.Plastic shopping bags have become ubiquitous because they’re strong, cheap, and impervious. The downside is that they’re often used only once, aren’t recycled, and are harmful to wildlife. “There have been several instances where a whale has washed up on the beach, and when they do a necropsy, they find more than one plastic...