The best way to trigger a bottom-up consumption reduction would be massively brainwashing people. But I can't see the usual brainwashers (media, advertisers) interested in doing it, nor do I see why would they all want to do that, on a systems level. The incentives are not there.
Then there's a matter of effect size. As the climate saying goes, "a lot of people helping a little helps a little". How far are you willing to voluntarily reduce your quality of life? Are you willing to change your job just so that you could stop using your car? Because current predictions indicate that it's the least it would take, from everyone. Most people don't engage in enough spurious consumption to have a lot to cut back before it starts significantly degrading their quality of life, and possibly becoming a health issue. I do my best to reduce my carbon footprint; I even work remotely these days. But I also have several people depending on me, so you can bet that ensuring I'm physically and mentally capable of doing my job is one of my top priorities, and I'm not going to cut consumption down to the point it degrades my ability to support my family. Most people I know ultimately face the same situation - they could cut down on some trivialities of no consequence, but beyond that, it quickly becomes a matter of survival.
The situation is even worse if you consider the developing nations, who are slated to have the biggest carbon footprint in the near future. Asking them to cut down on consumption is asking them to go back to living in extreme poverty. Not going to happen.
So sure, let's talk to our friends and relatives some more. But we need systemic solutions, and we need more alternatives with smaller carbon footprint.
And plant forests, ecologically improved agriculture and use wood and sustainable biophilic materials where possible (all large wind turbine blades are currently almost entirely made of balsawood)
Also, a global alliance against military aggression, space industry for asteroid mining, lagrange point sun shielding if necessary. Promotion of therapeutic professions, reduction in accounting labor and financial wizardy to be replaced by modern informational and analytic technologies. Promotion of aspirations other than car driving and land ownership. Secure living spaces for everyone who seeks them and commits to respecting them. Quality of life guided by things which are actually known to improve quality of life, like education, recreation, arts, community spaces, rather than the psychologically marketed consumables which currently divert economies and fantasies ...
A bright future is very complicated and challenging to envisage, but no moreso really than any particular gloomy one :)
The absolute emissions reduction from individual lifestyle adjustments is not that important in itself. But it should create a cultural space required for the current and future politicians to take action. Politicians don't lead, they follow. We live in a democracy after all. But hopefully it apparently takes only 3.5% of the population to take an active stance on something to cause a change (https://www.youtube.com/watch?time_continue=1&v=YJSehRlU34w).
I want to be part of that 3.5%. And I will keep brainwashing (eh, I mean inspiring) people around me.
(We also have MEP elections today; I'm currently agonizing on who to vote. It so happens that the people with sanest (IMO) climate and energy policy goals are also the people I disagree with on other topics. I feel I'll go with the climate though - it's really a critical issue.)
The "brainwashing" part was a bit tongue-in-cheek - a better word would be "influencing" or "convincing", or maybe even "inspiring". But I like to take opportunities to remind people that all of those are, to an extent, the same things, and that we have an industry full of professionals whose job is to do that regardless of the content of the message they're delivering.
EDIT: Keeping with the spirit of your comment, I know there are some regulars here working in cleantech and energy sector. I won't name any names, you know who you are - but remember, your input in these topics is very appreciated and important!
After being told that electric cars were silly and impractical I had a thought experiment. We had just been using electricity for making cups of tea, plus there was that lighting, which was a practical use of electricity.
So what if I decided to go fully carbon wasteful and not use electricity but burn petrol for everything? Kerosine lamps, a petrol powered generator, LPG in the kitchen, to be fully off grid but in the most oil burning way possible. Have the place reek of bunker oil, make the back garden as nice as an oil refinery.
This isn't going to happen to win a point in the family, but people are deeply wedded to their planet trashing ways. There is no point arguing with them.
I got into super lean energy use thanks to a shared flat which had meters that needed topping up with hard currency, a trip to a convenience store a mile away being the only option.
If you only have $10 of energy before the lights go out you think about whether you want to boil wash and tumble dry your clothes a bit differently and opt for the 'mini 30' wash and drying rack instead. You don't have hot water every day, except with the kettle that boils just the one/two cups needed. All phantom power losses get seen to. You keep what matters - a light bulb and a laptop - and dispense with the rest.
If you live in this austerity mode it becomes a lot harder to go back to the standard way of living where electricity and other energy is continually on. Thermostats are good with heating timers, but, they themselves take electricity. Nobody turns the whole thing off. The advice is to turn it down a couple of degrees, not turn it completely off and wear a jumper + hoodie instead.
Socially it can be difficult to fit in if you prefer austerity energy use. In a workplace you can't just turn off the lights to enjoy natural daylight. Everyone else wants some horrid flickery lighting not the good stuff. Then, if you need to sweep something up, you can't just use a broom or dustpan, you have to get the hoover out.
Which brings me on to another point, there is no way for some people to do things the low power way as they have removed the infrastructure. In my relatives refurbished kitchen they have a dishwasher but no bowl or draining board to go with the sink. So you can't just wash up a few plates with the one bowl of water rinsing the soap off with room temperature water to let the crockery drip dry. The water from the hot tap is scolding hot and it just goes down the plug hole if you use it. This is the new normal and people insist that having a dishwasher on for a few hours a day is more efficient. Contesting this is fruitless.
Hence my thought experiment to have a house where everything is max wasteful and max polluting.