High-end hand-me-downs (the smart set calls them vintage) are more ecologically sound than new clothes. Why? Buying a shirt the second time around means you avoid consuming all the energy used in producing and shipping a new one and, therefore, the carbon emissions associated with it. Every item of clothing you own has an impact on the environment. Some synthetic textiles are made with petroleum products. Cotton accounts for less than 3% of farmed land globally but consumes about a quarter of the pesticides. One quick way to change your duds: invite friends over for a closet swap, to which everyone brings a few items they want to trade. It's easy on the environment—and your pocketbook.