1) Let me explain this in a series of tweets. I'm not a spokesperson for @GretaThunberg. However, I was saying "change is coming whether you like it or not on my commenting on the Guardian for much longer than Greta as @john_vidal and @dpcarrington will testify. https://twitter.com/Peter_Strachan/status/1381873449946124292

2) Therefore, I can explain exactly what I meant by "change is coming whether you like it or not", or various versions of that, which means the same. I can't speak for Greta, but as her other arguments are almost identical to mine, I can explain what I mean.

3) There is a view, a narrative being peddled that the system as it is, is just how it is. That you will never stop overconsumption, carbon emissions etc. You are peddling this narrative. I doubt you could even explain what this means.

4) I see things from a systems perspective. I see all that has gone before like a great big long video, with a YouTube like timeline, that you can rewind, or even play forward. This is the thinking tool I use, to see things as they are. https://en.wikipedia.org/wiki/Systems_theory

5) The way I see things is as a whole integrated system, where everything effects everything else. That everything that happens is the product of myriad interactions, cause and effect.

6) No single person designed the current economic system. It merely arose from various wealthy people, working together, not via a committee, but simply following the principles of making themselves even wealthier and more powerful. That was the driving motivation.

7) The current system works on quite simple parameters, that it is possible for individuals and corporations to absolutely own great swathes of land resources, and to exploit it to the maximum, for profit and to grow their wealth.

8) The current system evolved out of the following of these simple principles and parameters. It developed a life of it's own. No one really controls it, but it does rely on many of these parameters like ownership and the ability to amass great fortunes being maintained.

9) In other words the parameters of this system, which are quite arbitrary rely on the maintenance of basic parameters. If these parameters were changed, the system would not operate like it does. This is why billionaires, politicians, are so desperate to main the status quo.

10) At heart, capitalism is quite simple. Capital is excess wealth that an individual can invest in ventures, and can grow their capital by getting far more money back than they invest. It has been the same since wealthy people financed voyages of colonialism to the "New World".

11) In other words at the heart of the present system are wealthy people investing their wealth to become even wealthier. This is what drives the whole system. Without these basic parameters, the system would not operate it like it does.

12) As I say, these parameters are quite arbitrary, and fairly knew in historical terms. When we lived under monarchies, and in other early civilizations, individuals could not just amass fortunes and operate like this. The monarch or whatever, had to grant these rights.

13) As an example, to engage in a trade you had to get permission from the monarch, who could just stop it. Even though barons own land, people had commoners rights to use it in many ways to collect water, to fish, to graze, to collect turves, firewood etc.

14) Therefore to create the industrialist/capitalist system, these parameters had to be changed to unleash this system. It didn't just happen. Royalty and the powerful allowed it, because they could themselves profit greatly from this.

15) Let's just take one component of this, investing your wealth to make more wealth, the driving motivation at the heart of the present consumerist system. Factories and corporations on exist to feed this process.

16) However, there are limits to this growth, in essence the ecological carrying capacity of the Earth to support our present financial system (please note I'm a graduate in scientific ecology, so I have a fair understanding of carrying capacity). https://en.wikipedia.org/wiki/Carrying_capacity

17) The present system, the financial system, the economic model, our civilization, is approaching the limits of the Earth's ecosystems to sustain it i.e. at some point this growth the whole economy relies on, will no longer be possible.

18) These ecosystems and their ability to sustain us are being diminished to a point where they will no longer sustain us, through our over-exploitation of them. https://en.wikipedia.org/wiki/Sustainability

19) As this carrying capacity is reached, the wealthy will no longer be able to reliably invest their wealth to make even greater wealth. In increasing trends, they will lose the wealth they invest, not make more money.

20) As this starts to happen, they will become inhibited at investing their wealth if they keep losing money. They will stop investing, and this will create a vicious cycle of less investment, and the financial system as it is will implode.

21) Investors will see the reality of the climate and ecological crisis, and this will further inhibit their investments. Instead they will try to cling to what they have got, instead of trying to create more wealth through investment.

22) As factories, corporations i.e. the drivers of consumption only exist to make profits, more money for their investors, this will grind to a halt. The political institutions that rely on these systems will start to crumble.

23) Therefore even if in your fantasy, this system will persist against the campaigns of environmentalists, it will actually start to fundamentally change anyway, because the basic parameters of the system will be irrevocably changed.

24) Sorry for going on, but this is a gross simplification of this and I have spent my whole life understanding how all this works. Your idea that all will persist regardless is simply because you don't understand how systems operate, especially ecosystems.

25) This is what "change is coming whether you like it or not". The present system, cannot persist, and will eventually be changed by system dynamics, no matter how much those profiting from it want it to persist. You can't have infinite growth in a finite system.

26) Fantasists like Elon Musk et al, may fantasize about colonizing Mars etc, to overcome the finite resources of the Earth. But this is simply not a practical way to overcome the finite limits of the Earth. They are running an intergenerational Ponzi scheme, and it won't last.