The problem is that it's very difficult to accelerate change without extreme measures because extreme measures are what is needed.
Looking at a massively extreme example, if we wanted to go zero carbon and I was dictator of the world, I could achieve it tomorrow (stop all ff generation or production, stop all motorised transport, kill all domesticated animals in one lightening bolt from my hand- sorry fido. ban fishing). Unfortunately I would also kill off half the population of the world in about 12 months and end civilised society so the people who were left would be like "thanks. I'd rather have had climate change in 50 years". Obviously, that's a stupid example as no-one would do that (or be able to) but between the status quo plan (not fast enough) and Soul Runner's Zero carbon Armageddon (instant but major collateral damage), there are millions of iterations.
The question is how far do you go before the "now" hardships overtake the "future" benefits, the structure of society changes too much (seen as regression) and people say "actually, no"? I would suspect not far enough. This is especially true as most behavioural nudges are financial and therefore disproportionately impact the poor.
People are generally causing climate change because it's convenient (15 min car journey vs. 45 mins on public transport in the rain with 2 kids in tow, twice a day, on top of your 9 hour working day), fun (long haul flight to dive in the Maldives) or necessary (food/heating/ lighting). The added complication is population growth which makes most vaguely palatable things non-sustainable, so for example I could easily bear a locally sourced, seasonal diet, and I could easily bear a vegan diet, but a locally sourced, seasonal vegan diet would seriously suck. I mean, what would you eat in January? Turnips? I follow quite a few sustainable living activists (because it's interesting and I respect people who put themselves out even if it's only for insta hits) and while I really admire what they're doing, their methods are mainly completely non-scalable and they all live in California.
Anyway, aware I'm coming across as either completely flippant or a total doom monger, so I'm going to wind up, but my point is, yes, I care about climate change (my house is below sea level) , yes, more should be done, but my question to the protestors is what concrete and practically achievable things do you think should be executed now that can go beyond the UK (because UK is largely irrelevant in the scheme of things)?