It’s International Polar Bear Day, a day of action by Polar Bears International to encourage reducing our carbon footprints. And polar bears, after all, are in serious danger of extinction due to global warming.

Polar Bears International encourages self-challenges today viaThe Thermostat Challenge by adjusting your thermostat a few degrees; installing a programmable thermostat to save energy; and making a video of your actions at home and share on the organization’s My Planet, My Part page. The challenge launches PBI’s Save Our Sea Ice campaign, to reduce carbon emissions that negatively affect sea ice creatures, like the polar bear.

In honor of this day, and spread awareness of the polar bear”s plight and natural history, Mountaineers Books is offering a pretty ridiculous sale on any titles involving polar bears. The sale goes on until March 3.