"Starting an eco-friendly lifestyle is like anything, going to the gym, changing your eating habits, etc.," Cahill says. "We've found that in order to keep a sustainable life, you have to make one swap at a time and find what works for you. It can be overwhelming going zero to a 100."
To help you get started, or provide some more ideas if you're already trying to live sustainably, we rounded up 21 swaps to make (with some help from Cahill and Dahan).