| Buy a gasoline car tomorrow. Junk it. Then buy a new electric vehicle and drive it for a decade. You would still do less harm to the climate than if you’d kept driving that gas car for 10 years. That finding, published in the peer-reviewed journal Science in August, reveals a truth that’s blowing up old intuitions about how long to keep our machines: The efficiency of new electric technology is virtually unbeatable. Understanding how this works will help you make the smartest choices about which products to repair or replace — for your wallet and the planet. Elliott Campbell, a professor of environmental studies at the University of California at Santa Cruz, and his colleague Roland Geyer analyzed thousands of data points from the transportation sector to model lifetime vehicle emissions. No matter how they sliced the data, emissions for EVs were lower than for gasoline vehicles — even after junking a brand-new gas vehicle — in 92 percent of the scenarios combining different models, electric grids and battery types. “This is crazy, especially for me, growing up fixing and repairing things,” said Campbell. He once repaired a Volvo station wagon with 300,000 miles on it so he could drive it for a few more years. “The notion that you could take a brand-new, complicated piece of equipment, drive it across the street and scrap it immediately and still be doing something good for the environment — that, to me, is shocking.” The reason is basic physics. Machines demand energy at two stages of their lives: when they’re being manufactured and when they’re being used. Manufacturing appears massive: Mining, refining, factories and transport do take energy. But over time, even the biggest conventional machines (especially those, in fact) consume far more in fuel, and thus generate more emissions, than what’s required to make them. This isn’t just true for cars. Home appliances are the same. Dishwashers, laptops, phones, washing machines and others that demand energy obey the same principle. So I worked with Campbell to answer the question many of you ask me: When should you retire your car or appliance, and when should you keep it alive on duct tape and borrowed time (as I do)? The results were not what I expected. Here’s how to decide when to trash a machine in your life and when to fix it. | 
