According to the Starbucks’ impact calculator, by using a reusable travel mug for each of my three cups of coffee every day (stop judging me), I can save 21 trees over the next 50 years. If 10,000 people did the same thing, 343 acres of trees coulc be saved. It could also save millions of cups from ending up in the landfill or worse, on the ground.

The impact calculator is part of Starbucks’ The Big Picture campaign. Starbucks is asking people to switch from paper cups to reusable travel mugs and to pledge to do so. And, if you bring a reusable travel mug to on April 15, Starbucks will fill it for free.

So far, 27,548 people have pledged at the website to switch from paper cups to reusable travel mugs. I switched from paper to reusable years ago. It just makes sense. How about you?

Robin Shreeves ( @rshreeves ) focuses on food from a family perspective from her home base in New Jersey.