I imagine it's fairly obvious that the designs for these stamps and postcards (PHQ cards) were created by children. They were all winners of a television programme called "Blue Peter", very well known to UK viewers. When you look at the ages of the children you are filled with amazement - well I am.
24p: Acid rain, by Christopher Hall (9 years old).
28p: Ozone layer, by Lewis Fowler (6).
33p: Greenhouse Effect, by Sarah Jo Warren (7).
39p: Bird of Hope, by Alice Newton (12).
At that sort of age, I'm not at all sure I had any idea of how to design a stamp, never mind the concept of green issues.
This is a post for Sunday Stamps, now hosted by Violet Sky at "See it on a Postcard!"