The Pocket Environmentalist

17 smartphone apps that help save the planet

5. Green Travel Choice

Here’s to your new carbon diet! The International Ecotourism Society has partnered with Pocketweb and Cleaner Climate to create this GPS-based CO2 tracker for iOS devices. With just a click, the Green Travel Choice map will show you travel options (for nine common modes of transportation) and their expected carbon dioxide emissions.
($1.99; Apple)