It is important that such themes are discussed in schools - after all, the politicians of tomorrow are formed in today's classrooms. Yet there is a possible downside to dwelling on these ideas in primary classrooms.
Children often respond enthusiastically; they are in the process of working out concepts of morality and justice, often through their own experiences.
This can be a difficult task, and children tend to make it easier by classifying issues in black and white terms. Just as they get emotionally involved with making sure that things are fair in school life, so they can become passionate about ideas in the real world that they perceive as "the right thing to do". Most teachers use their skills to help them understand that issues outside school are often more complex, and encourage them to see the grey areas as well.
But for some children, the emotional response created by discussions such as these can have a darker side. I remember one Year 5 child - I will call him Tom - who developed an obsession with the dangers facing the world.
Although I would hesitate to draw a causal relationship, this began shortly after a literacy lesson using text focusing on the rainforests, which led to a discussion on conservation. Every few days, Tom would tell me about his fears. He was worried there would be a nuclear war, frightened of the possibility of global warming and rising sea levels. He even said that he had been waking up at night disturbed by these thoughts.
My feeling was that he was really worried by events in his own life: the absence of his alcoholic father and anxieties around the arrival of a new baby. He wasn't really worried about the end of the planet, he was scared about the impending breakdown of his family life. Sadly, he became more and more depressed, gradually turning in on himself and each day becoming a little bit more unreachable. Tom's reaction was perhaps unusual, but not wholly uncommon.
I don't know if my class discussion really did serve as a trigger or whether this was something that Tom would have latched on to in any event.
Of course conservation and sustainability issues should be included in the curriculum, but it is worth bearing in mind the emotional reactions that can occur. Children can use issues in the adult world as a way of expressing anxieties about what really matters to them, their family and school. With careful handling these discussions can be an entry point into general considerations of feelings and how we deal with them. Perhaps if I had been more attuned to this possibility with Tom's class it might have helped him recognise where his anxieties really lay.
Joseph Mintz is a senior lecturer in education at London South Bank University