In praise of scepticism
The word "sceptic" is in danger of becoming a term of abuse. A "climate sceptic" is used to mean someone who rejects the evidence of global warming. But scepticism is actually a healthy instinct and should be celebrated.
We are lucky here in Britain to be home to the most august scientific institution in the world, the Royal Society. It celebrates its 350th anniversary next year. Its motto is "nullius in verba" which means "take nobody's word for it" - which is pretty much a charter for scepticism.
It is a fitting motto, because healthy scepticism is the foundation of good science.
The urge to question accepted truths, to doubt received wisdom, to investigate things for yourself, is the basis of scientific enquiry.
So let's not damn people for being sceptical of the climate science... unless, that is, they don't make the effort to make a reasonable examination of the evidence.
The opinion polls suggest that almost half the people in Britain are not persuaded that man is causing global warming.
So Newsnight decided to do a little (and very unscientific) experiment of our own.
We challenged two leading British scientists to try to prove the science of global warming to a group of people whose views very loosely reflect national opinions.
And, as if that wasn't tough enough we asked them to do it in my kitchen.
Can they do it? Well, you can see for yourself.
Obviously, we had to radically cut down the scientists' presentation to squeeze it into the tight TV time constraints but if you want to dig a bit deeper into the science of global warming the best place to go is the Intergovernmental Panel on Climate Change.
The Science Museum's site is more accessible to non-scientists, or you might try the Meteorological Office's site which has a section on climate change science. There's also loads of stuff here on the BBC site.
Get stuck in!
I'm happy to celebrate the instinct to question authority because scepticism is also the basis of journalistic enquiry.
Right from the get-go, the idea of the Ethical Man series was that it should be a sceptical inquiry into what ordinary people can do to reduce their impact on the environment.
But not everyone is comfortable with scepticism.
A couple of days after my blog on cars was published, I was shocked to find an e-mail from an environmentalist who said it should never have been posted. He made no effort whatsoever to refute my claims, his argument was simply that it undermined the debate to publish such heresy.
That instinct to suppress evidence that challenges preconceptions is very dangerous. Any hint that the climate change science is anything other than transparent will - understandably - encourage people to be even more sceptical.
If it looks like that's what people are trying to do, the scientific community should be very clear in its condemnation - as Sir David King, a former chief scientific adviser to the government, was in my kitchen.
Because, if our "experiment" says anything it says that people are hungry to understand the science of global warming and that when the evidence is explained clearly, lots of people find it very persuasive.
So let's celebrate scepticism and follow the Royal Society's injunction to interrogate accepted wisdom. But let's do it with an open mind and on the basis of a reasoned examination of the evidence.
That's how scientific hypotheses get proved and - yes - disproved. And wouldn't it be great if someone proved the science of global warming was wrong?