In 2011, people in the United States watched about 20.4 billion hours’ worth of movies and TV episodes online or on DVD, with an estimated 13% of that total being streamed over the Internet. The carbon footprint for that viewing—including emissions produced due to online viewing and those generated during the manufacturing, packaging, and shipping of disks, either directly to consumers or to stores where they’re sold or rented—was about 10.5 million metric tons, a new study suggests. (One of the largest contributors to that carbon footprint was vehicle emissions generated by consumers on shopping trips either to buy a DVD or to rent and then return it.) But a complete shift to video streaming, which generates about 400 grams of carbon dioxide for each hour of movie or television content viewed online, would cut those total emissions to about 8.6 million metric tons, researchers report online today in Environmental Research Letters. That’s the same benefit that would be achieved by cutting off power to almost 200,000 households. Which, to be honest, would make it a bit harder to stream those movies.