In a way the same exchange continues today over climate change. This debate is just one of the examples of the ongoing contest of ideas between right and left, between sectoral and social interests. And you'd have to say that despite all the scientific evidence to the contrary the deniers have hardly been routed. Yes, there's much more awareness of climate change and moves to soften the impacts. But as happens so often in the debate about the environment - emissions being the latest example - business often sets the agenda and corporate media follow. So the debates over these critical issues tend to be dominated by industries concerned about their balance sheets. Never mind the fact that we'd like to breathe clean air, that we desperate want our grandchildren to inherit a sustainable Earth.

Just in case you meet a denier here's a book - just one of the many to recommend. It has lots of pictures and none of that pointy headed, wet scientific stuff. It's called Earth - then and now. Potent visual evidence of our changing world. Written by Fred Pearce, Environment consultant for the New Scientist, it’s a before and after book which shows how locations all over the world have been transformed by rising sea levels, retreating glaciers, vanishing lakes and urbanisation. It's not all gloom and doom. It also demonstrates how mankind can dramatically improve our environment. But only when we leave our baggage behind.

Paul Smith