Is it because my birthday falls in World Environment Day?
I don't know honestly, I have a special likening for Environment.
So, I believe that I should contribute towards saving (or not destructing, at least!) the environment.
I cam across an interesting web page http://www.coolkidsforacoolclimate.com which runs a cool kid project - Kids take initiative in planting Trees (of course, plants!).
I found a Tree Calculator, how many trees you should plant to soak up the carbon dioxide produced by your journey (by car / bus)!