The following is a list of ways to celebrate Earth Day:

1. Plant some trees
2. Go for a hike in the Great Outdoors
3. Swim in the ocean to appreciate the miracle of salt water
4. Get a free Chipotle burrito

It's clear which of these HuffPost Food is most interested in doing. (A hint: It's not one, two or three.)

Luckily for us, Chipotle is commemorating Earth Day, which falls on April 22nd, with a special free burrito promotion. Of course, there's a catch.

To qualify for a free meal, you have to have purchased a limited edition reusable lunch bag from Chipotle. They're made of old Chipotle billboards, so each one is apparently unique. To be honest, they aren't attractive, but the recycled element is nice. And when you consider the fact that a Chipotle burrito with guacamole can run upwards of $11, the lunch bag's $18 price tag sounds almost like a bargain.

Of course, ocean-swimming and outdoor-hiking don't cost a cent, so if you have to pick just one of the four, those start to seem more appealing. Then again, hiking into the wilderness can make you very hungry -- in which case it wouldn't hurt to have a 1000-calorie burrito waiting stashed in your reusable lunch bag made from recycled materials.

Read more http://www.huffingtonpost.com/2012/03/27/chipotle-earth-day_n_1383613.html