A personal CO2 calculator called Commute Greener! hit the app store day. Volvo Group, which developed the online site and smartphone app (downloadable for $3.99) had initially tested a prototype internally and showed that employees reduced their CO2 emissions from commuting by 30% on average. Commute Greener! entices with a one-two punch of personal-data diving and competition. After calculating your baseline commute, you can set weekly reduction targets, track your cumulative damage, and compare your data with other users.
Kerstin Hanson developed a "CO2 pedometer" application for cell phones, which measures commuters' carbon emissions. Inspired by the data, Hanson's test group altered its behavior and reduced its carbon footprint by 30%.