Colouring in the climate

If you were to ask a classroom full of children to draw a picture for an environmental cause of any kind – whether it’s climate change or pollution or even littering – many of them will draw something that includes a blue globe with green continents on it. Or some green blobs roughly approximating the continents.

I was thinking about this the other day because if you look at actual satellite pictures, the continents are not all green. Some parts of the world are sandy-coloured, some parts are wh...