Netherlands: Smoking Air Show Postcard with an Environment Friendly Stamp

Another lovely official Postcrossing postcard is coming your way today!

This colourful postcard showing the view of an Airplane Show was sent to me by josephine in 2012. Somehow I love flying aircrafts and this one is pretty amazing.

The stamp used on the postcard was issued in 2011 by Nederland Postal services as a part of Environment Series. The phrase written on the stamp, inside a green tree seems to say "denk groen voor een groene wereld" or something like that. Google Search suggests that it is a Dutch phrase for "Think Green for a Green World". 

I hope a native Dutch reader could improve our exploration.

I wonder what good are these flying/ Smoking aircrafts doing to make the World greener. The stamps and the postcard seem to be an interesting combination. 

What do you say?