Walking home from class Friday afternoon, I spotted some ghosts on campus. No, we're not haunted by ghosts-of-students-past. Members of the IC Community had gathered together in a "ghost walk," part of an international global campaign against climate change set up by 350.org, a website founded by environmentalist and author Bill McKibben.

The "350 Ghost Walk" is organized around the idea that 350 parts per million CO2 in the atmosphere is the safe limit for humanity. Our current zone of 390ppm is already above that limit, and according to 350.org "unless we are able to rapidly return to 350ppm this century, we risk reaching tipping points and irreversible impacts such as the melting of the greenland ice sheet and major methane releases from increased permafrost melt."

That doesn't sound like much fun to me. But running around dressed up as ghosts (just in time for Halloween!) and trying to change the world? Next time, I'm in.