If you know someone who doesn't know about the Tar Sands, this is a good video to send their way.

The Tar Sands, also known as the oil sands, are one of the largest remaining deposits of oil in the world, and efforts to extract the resource from a mix of clay and other materials underneath Canada’s Boreal forest have created the biggest, and by the accounts of numerous scientists and environmental groups, the most environmentally devastating, energy project on earth. For details and background, the Natural Resources Defense Council (NRDC) has compiled an extensive document that challenges many of the claims made by TransCanada and the US State Department about tough regulatory oversight of the project.

Moreover, as my colleague George Zornick makes clear, there are still too many known unknowns about diluted bitumen, the type of oil that would be carried by the Keystone XL pipeline. As he explains, "we don't know exactly what's in it, and the government hasn't fully studied how safe it is to transport."

The State Department's official public comment period on Keystone XL Pipeline is now open — and it's a crucial opportunity to inundate officials there with eloquent letter of opposition. The eco-advocacy group 350.org is collecting comments and will deliver them directly to the State Department.

The Keystone tar sands pipeline will create just a handful of jobs, won’t improve US energy security, and just isn’t worth the potential cost to our health and our climate. Make your voice heard today.