• Take a gander at these videos of the 12 most thought-provoking green commercials from the past decade. (The polar bear hug is priceless.)

 

• Nature has been inspiring artists for centuries, but some artists take the relationship between art and the environment a step further. Check out the expressive work of these 14 artists with an environmental message to share. (And if the blue wave above reminds of a certain woodcut, you're on the right track.)

 

• Martin Poliakoff is the shaggy-maned professor pictured above — but don't let appearances fool you. This not-so-nutty professor has found an effective way to share chemistry with the masses. 

 

• Is it possible to teach a dog manners? MNN's Morieka Johnson talks to the experts about behaving on walks and how to handle houseguests. (Trust us, dog owners: you'll want to bookmark this one.)

 

• We're still taking our summer tour of parks — don't miss Mount Rushmore or The National Mall in Washington, D.C. Take a look at our list so far and see if we've visited your state. 
 

• Green rooftops save water and energy — plus, they're easy on the eyes. Come with us as we visit 8 exceptional green roofs around the globe. 

 

• Sierra magazine's 2011 Cool Schools list is out, and guess which green school earned top honors?

 

• By mixing the genomes of spiders and humans, researchers say they can create genetically altered human skin that could withstand a bullet fired from a .22-caliber long rifle.

 

• And finally, what better way to end the week than pondering what it would be like to work in a dog-friendly office. Here are 10 companies that encourage employees to bring Fido to the office.

 

Plus: Don't miss the week in photos, including a cosmic gift for Stephen Colbert.