Swapping stuff, from clothes to tools to garden tomatoes, reduces the energy consumption that goes into developing and purchasing more stuff, says Debra Berliner, the climate action coordinator for Berkeley Ecology Center in Berkeley, Calif. Swapping also diverts waste from landfills, helping to create a more sustainable economy.

Arrange and attend neighborhood swap meets. It will cost you time: 10 to 12 hours to organize the swap. But purging your house of unwanted and unneeded stuff—and getting a great hammer free—is priceless.