Brendan I. Koerner answers a Wired reader’s question about whether it’s greener to purchase an item online or drive to a nearby mall:
Buying a product online involves a data transfer of about 1 to 2 MB, which means that your ecommerce experience uses around 0.002 kWh [kilowatt-hours of electricity]. If you translate that figure into carbon emissions, you’re doing as much planetary damage as driving less than 25 feet in an average car—a tiny fraction of the few miles you log on your journey to and from the mall.
True, any product bought online has to be delivered to your home. But since delivery vans serve scores of customers on each route, they’re much more efficient than private cars. Even if you string together a bunch of errands while at the mall, you’ll have a tough time closing the emissions gap per item between yourself and UPS.
But online shopping won’t magically save your children from an overheated, dystopian future. You are, after all, still accumulating manufactured goods that spewed forth from distant, coal-reliant factories. You know that iPhone 5 you just can’t live without? Seventy-six percent of its lifetime greenhouse-gas emissions stem from production, versus just 4 percent from transport. Which means that buying one is pretty much the same thing as pushing a polar bear off his ice floe.
The Dish 