I had a great time at the APS March meeting in Portland this past week, but I was struck by a bit of irony. Several of the talks had to do with energy technology and sustainability, and yet the whole idea of having thousands of physicists travel in planes to a remote conference seems at odds with this goal. Given the advent of high speed internet, Skype, etc., the technology certainly exists to have speakers present their talks as a live streaming video in the same way that Ignite and TED do. In addition to being more environmentally friendly, it would be more cost effective since APS wouldn’t have to rent a huge conference center and members wouldn’t have to pay for hotels and airfare. For just the flights, how much of a carbon footprint did the APS meeting create?1
In the meeting program, there are about 10 talks listed per page for about 600 pages. Most speakers only gave one talk, meaning there are about 6000 people at the conference, and that doesn’t even include all the organizers, staff, sales people, and other physicists who did not present a talk. Some attendees live in Portland and don’t have to have to fly, while others flew half way across the globe. A quick scan of the participants reveals that many live in the U.S., so as a rough estimate of the average travel distance, I’ll assume the average flight was from Omaha, NE to Portland, OR. Since physicists don’t generally like to waste money, I’ll assume most got a cheaper flight with one layover. According to one carbon footprint calculator, this contributes about 1,962 lbs of CO2 per attendee. From this, we can estimate the total carbon footprint to be roughly 12 million lbs of CO2. It would be much more efficient—and probably cheaper—to supply every physicist with a video camera and have the talks streaming over the web.
 Other people have considered this problem before. If you’re interested, you can find a good discussion here.