I've been in demonstrations and situations penned up by the police and subject to their intimidation and I know that it's frustrating, an abuse of power and that it just rubs your nose in the rhetoric about there being a right to protest, about our policing and legal system being based on justice.

But I also think that shaking fists at capitalism and smashing the windows of banks is not going to achieve anything at all. Absolutely nothing.

Yes, it ventilates and expresses very angry feelings.....it tells bankers and governments how much they are hated. But so what? They will survive hatred because they have extremely well equipped police forces who enjoy an opportunity to push people, club them, pepper spray them and use CS gas. Being hated is something that has never bothered people in power, it makes them feel even more self important, even more powerful. There is nothing that so much pleases a power junky than to impose their will on the seething rage of others and make them submit. Since it is their power that matters most of all to our betters this power is felt to be at its greatest when they can regard themselves as imposing it on those of us who are their inferiors.

This kind of politics is rather like expecting anything positive to come from writing to my Member of Parliament. It may give expression and ventilate a feeling of repeated outrage but it yields absolutely no return at all. It is futile.

If you are going to have mass action you must have millions of people behind you - and if you want millions of people behind you then you must have a tangible workable alternative that is already in existence, at least in embryo, that they want to defend and fight for. Today's anti capitalist demonstrators don't have anything like that. Sure they are demonstrating against something that is immensely destructive of environment and communities, but they are not demonstrating for something that is a credible alternative.

We have reached the outer limits of a debt based money system and the people in power are struggling to rescue the system with more debt. It won't work - so what it the alternative? If a new money and exchange system is needed then it will have to be created. In the 1930s when the recession was at its depth a small town in Austria established a local non debt based money system and successfully abolished unemployment in the town. If that example had taken hold throughout Austria and Germany there might never have been a second world war. But guess what - the Austrian monetary authorities closed down the experiment. Unemployment returned to what it had been in the town of Woergl. Now that, I think, would have been would have been something work demonstrating for - that would have been something to defy the law over - a workable alternative that is closed down in favour of a system that is in breakdown.

If you want to do something that is going to be an adequate response to this crisis you can protest against the system or you can work to grow and foster tangible productive alternatives. That isn't something that you can do overnight. It requires different skills to organising a demonstration - you need to build trust between people, you need to get people to commit themselves to a process where there will be obstacles to be overcome and some degree of frustration. You need to take the risk that you will embark on a course of action and fail, seeing others lose confidence and melt away. The place for demonstrations is when your approach is showing its value, gaining support and the powers that be move to close it down.

If you don't like the current money system then develop another one in your neighbourhood, your district, your town and network them together. There are now scores of groups all over the world developing complementary currencies.

If you don't like the system of agriculture then develop an alternative model for your community garden or community assisted agriculture. When people enjoy and like what you are doing then get them to set up their own. Once you've shown it works and you are hamstrung for lack of land then start demonstrating if your political overtures for extra land are getting you nowhere.

The chief reason that there is no green in the green new deal is that the multinationals are too integrated into the carbon economy to want to participate and there are not enough real green community level projects and businesses with enough organisational and business skills to take the money, work their way through the obstacles, organisational and technical, to get them put up.

If you think that capitalist consumerism is an inferior lifestyle ethically and that we all have enough to live on comfortably and enjoyably - then show how this lifestyle works in practice - without condescending all those other moral inferiors who haven't had the benefit of reading them same radical tracts as the ones in one's own style club. Spread your ideas by example.

Will this achieve an anti capitalist revolution quickly enough to avert climate catastrophe? Frankly I very much doubt it. The Arctic is melting and our betters are too preoccupied with money making to notice or do anything about it. What I am describing takes time and we don't have much time.

However, while I doubt that we will turn the situation around in time, working to re-create the money systems, the garden and energy projects and the lifestyles that we need does stand a slightly better chance than smashing windows in Threadneedle Street and making the police, the bankers and the establishment politicians feel self important and self righteous......unless and until those demonstrations are promoting viable alternative arrangements that are already getting off the ground and shown to be arrangements that will help millions.