Some days ago I came across an article about how Seoul was able to reduce their CO2 emissions by 10% annually. Of course, it was through a policy which aimed at individual transport. The really unique thing is that the reduction wasn’t made by force or through investing billions into structural measures. A program with certain benefits made it attractive for car drivers to participate voluntarily. The only thing they had to do is to leave their car at home once a week and use public transport to get to work. Even greater is how Seoul monitors this activity: through a sticker. Yes, a sticker saves around 2 million tons of CO2. You don’t believe me?