Q: I try hard to make environmentally conscious choices. As a vegetarian who avoids leather, I usually buy inexpensive boots made of synthetic materials. But they soon start to look terrible and fall apart, so I throw them away. I dread the thought of hurting animals in the name of fashion, but I wonder if a one-time purchase of quality leather boots that last longer is better for the environment than buying synthetic ones and sending the beat-up pairs to landfills. What's better for my carbon footprint, leather or artificial? 

—Kristin in Palmyra, New Jersey 

A: A pair of leather boots affects the climate about three times as much as its plastic or pleather cousins. However, since the emissions associated with a leather pair are about equal to those from burning a gallon of gasoline, you might stomp a bigger carbon footprint just by driving to a shoe store to replace those plastic alternatives. So I don't think you need to fret over leather's carbon footprint. 

A far greater concern is the plight of livestock, as animal welfare groups often remind us. PETA says, "With every pair of leather shoes that you buy, you sentence an animal to a lifetime of suffering." But millions of animals are sentenced long before their skin is turned into shoes. In the United States, hides account for only about 3 percent of the market value of hogs and cattle, which are mainly raised for their meat. 

Another consideration for leather, as with so many other products, is where it's produced: often poor countries with far less stringent environmental and animal-protection rules. More than 60 percent of the world's cowhide and leather comes from developing countries. The proportion of sheepskin is even higher.