I realise that George Monbiot is discussing climate change, but...

I find a lot of the topics I discuss here can have comments made along the lines of

There is one question that no one who denies manmade climate change wants to answer: what would it take to persuade you? In most cases the answer seems to be nothing. No level of evidence can shake the growing belief that climate science is a giant conspiracy codded up by boffins and governments to tax and control us. The new study by the Met Office, which paints an even grimmer picture than the Intergovernmental Panel on Climate Change, will do nothing to change this view...

Perhaps we have to accept that there is no simple solution to public disbelief in science. The battle over climate change suggests that the more clearly you spell the problem out, the more you turn people away. If they don’t want to know, nothing and no one will reach them. There goes my life’s work.

George Monbiot, The Unpersuadables

It is amazing how people will see what they want to see and remain fixed in their beliefs.

Or as George also says:

Tell people something they know already and they will thank you for it.
Tell them something new and they will hate you for it.