Who can doubt the virtue of the climate change protesters who clog our streets in the noble name of saving the planet?

We older people are stealing the future of the idealistic young and now they are angry. Who can blame them?

Me, actually.

Firstly, I don't like it when people decide to disrupt my life to try to make me do something. It's not democratic. It's a form of bullying.

And, secondly, it won't work.

If you put pressure on people - particularly if you do it sanctimoniously, flaunting your holier-than-thou virtue - some people will push back and take the opposite view. We're a bolshie people who won't be pushed about.

One activist in Victoria said protesters must "get right up in people's grills". In my view, a sure fire way of putting people off a cause is to "get right up their grills!"

My gripe is not about the cause itself. I am sure that climate change is (literally) the burning issue of our time. The science is robust. Nobody but a fool or a knave holds much doubt that human beings burning coal, oil and gas are causing climate change.

The science about what causes global warming seems to me to be beyond doubt but that doesn't mean the method of heading it off is.

But the protesters portray the issue in simple terms: either you agree with them that global warming is a catastrophe racing towards us all or you are some sort of bone-headed neanderthal. They seem to me to be nice middle class people who sneer at the legitimate concerns of unfashionable "ordinary people" who have to count the cents each week.

Some activists have called for net-zero carbon emissions by 2030 which would imply the closure of all 20 or so power stations in the next 11 years. On the latest figures, 35,638 people work in coal mines. They have a right to a say, too.

The choices are not what is called in the posher jargon "binary" - it's not a simple choice: are you against climate change or are you for it.

What is the trade-off between sacrificing prosperity now to ensure a cleaner future? What mechanisms should we use - low emission nuclear power, taxing the output of carbon dioxide, government investment in research into cleaner technologies?

To simply shout without addressing the economic impact (even as the cost of generating from the sun and wind falls) is to dodge an issue.

St Greta Thunberg may have the time and the money (though presumably not her own money) to sail across the Atlantic to scowl at world leaders who don't want to shut down the economy this very day but they have the weight of people's prosperity on their shoulders.

And in the Western democracies, politicians are voted in. People choose. Remember the last election which the chatterati billed as being about climate change where the young would vote for their future against the selfish oldies who had stolen it.

The Coalition won.

And all those quiet reprobates who happened to vote the wrong way have rights, too, like the right to go about their business without their way being blocked.

And the right to be sceptical about St Greta, the crusader who is, remember, just a 16-year-old girl. Nice she may be. Bright for her age, no doubt - but still only a sweet-faced, telegenic teenager. She has no scientific or economic expertise.

I don't trust cults. In cults, all doubt becomes apostasy. Questioning is not allowed. You are for the cult or you are cast into outer darkness. The high priests pronounce their truth - follow or be banished.

There is, too, a puritanical tinge to the climate activists, a sense that they don't quite like prosperity. They mistrust economic growth - and economic growth, I should remind you, is what pays for better hospitals and smaller class sizes as well as those guilty luxuries like a flight to a distant holiday.

Some of the activists give the impression that they really want us all trudging around in misery. We must cycle everywhere and stop eating meat. Just put on another layer of clothes in winter. And whatever you do, never, ever go in an airplane. Never.

They have a touch of "millenarianism" - the belief that the end of the world is nigh, echoing the English economist, Thomas Malthus, who 200 years ago foretold plagues and disasters as population growth overwhelmed the planet.

He was wrong. Technology came to the rescue. Today's scientific cavalry may or may not ride in to prevent even more global warming but I put more trust in smart scientists, particularly in Germany, Denmark, China and, yes, Australia, than I do in children bunking off school to make a gesture.

The indications are that progress involves governments and companies working together - governments funding research and underwriting ventures and providing stable rules so investors invest.

Protesters can push governments - but I am wary of virtue signalling. Wearing a badge - or lying down and playing dead on a street - may make people feel better about themselves but they won't win the bulk of the people over. Getting up people's grills is not the way to persuade them that something really needs to be done.

There is a danger in gestures. It's called "moral credentialing" where people feel unconsciously that a good deed justifies a bad deed. Because you're on the side of the angels, the global guzzling flight to Europe is permissible. Signal your virtue and then roar off in the Lexus.

Canberra is a car city like no other I've known. Only Detroit rivals it. I wonder how many of the protesters go home in a car. I wonder how many concerned politicians and public servants take the bus to Sydney rather than the plane. After all, both take the same time, city centre to city centre.

By the way, I haven't stolen anybody's future. I have paid a lot of taxes to educate the children who now lecture me.

I walk to work. I wonder if they walk to school.

I wonder how many of their parents are as familiar with the bus station as they are with the airport.