Our picks for the week of April 4-10: 

• This week, it's age before beauty. Behold, the world's oldest trees!

• Jeff Koons has joined an elite club of artists. He follows in the footsteps of Andy Warhol to paint the next BMW art car. (And if you haven't seen this racy art form, it's worth a click.)

• From nature to art to innovation. Here are 11 clean tech innovations you should know about.

• MNN travels far and wide to bring you cool, eco-friendly destinations. This week, we visit Montreal — a foodie paradise that's easy to navigate.

• Ken Edelstein returns with the Planet Pundit column, taking a critical look at Obama's offshore drilling decision and questioning if the president is learning from his political mistakes or repeating them.

• Plastic or paper? Car wash or driveway? The greenest spot to wash your car is something every environmentalist should consider.

• Now here's a simple decision: 5 ways to save $450 around the house.

• And let's bring some good green ideas to school, too: 5 ways to green your child's classroom.

• Jayma May of Glee fame carries a purse made from can tabs. Catch up on this and other green gossip from the week.

• Finally, to top off your week, consider these 10 environmentally aware superheroes. The power is yours!

PLUS: Don't miss this week's photo gallery. You've seen the sweet face of a baby Coquerel's sifaka (picture above), but don't miss the rest of the gallery, including historic floods and a surfing photo that will make you want to catch a wave.

MNN week in review: BMW's latest art car and great clean tech innovations
Catch up on the environmental headlines from the Mother Nature Network for the week of April 4-10.