The Global Warming Survival Guide

Oversize houses aren't just architecturally offensive; they also generally require more energy to heat and cool than smaller ones, even with efficient appliances. And in the U.S., big houses are becoming the norm, even though a relatively inefficient small house consumes less energy than a greener large house and uses fewer building materials, which expand the carbon footprint. A typical new single-family home in the U.S. is nearly 2,500 square feet today, up from about 1,000 square feet in 1950, even as the average household has shrunk from 3.4 to 2.6 people.

If you really want to live small, visit Jay Shafer. The former art professor dwells alone in a home fit for a hobbit, 100 sq. ft. in northern California that he designed and built himself in 1999. Shafer now runs Tumbleweed Tiny House and sells custom designs for miniature dwellings that range from 70 sq. ft. to 350 sq. ft. He made his move because he felt guilty about the size of his residential carbon footprint, and now prefers life tiny and tidy. "If I throw my jeans down on the floor, I can't get across the room."

This is an extended version of the article that originally appeared in TIME Magazine.