Perhaps you didn't mean it in a literal sense, however you and I have a very different opinion on the term realistic.

I believe a deus ex machina type carbon capture solution is a far more likely scenario than getting industrialised nations, let alone emerging ones, to actually reduce their energy usage.

Good point, I meant "realistic" as the only technologically plausible scenario. Is it realistic from a human point of view, I don't know.

I see what you mean, but even if a magical carbon capture solution was invented, it would take several decades for it to be implemented on a sufficient scale - given that the current emissions don't increase even faster!! I can't consider it as part of any "likely" scenario.

Also, emerging nations don't really need policies to reduce their own energy usage, as long as most of their own energy usage is linked to the production chain of industrialized nations, it will decrease by itself.

That's not the only technologically plausible scenario, we can use nuclear now. It's also way more realistic from a human point of view to have populations accept this rather than a drastic and sudden lifestyle change.

"using nuclear now" is part of the scenario. Any technology that has brought more efficient, less co2-intensive energy thus far has been used to increase the energy usage at a limited impact, instead of decreasing the impact. Only a policy focused on reducing (or at the very least, stopping the increase) energy usage can have positive final results.

À significant part of the population accepted a drastic and sudden lifestyle change over the last few months. Suddenly remote work and visio conferences are acceptable alternatives to driving 2tons of metal through 30km of asphalt 2x a day. Change is possible.

I think your second paragraph is misplaced. It's my belief that people "accepted a drastic and sudden lifestyle change over the last few months" precisely because it was advertised as a temporary measure.

We're already seeing large numbers of people reject the "stay at home" narrative , simply because they want to, rather than it being driven by improving conditions.

Using this as evidence to suggest that people will adjust to a "new normal" is arguing against your point.

I see what you mean, and I don't think it's gonna be easy either, I don't have false hopes.

Technically though, being locked down is more restrictive than forcing people to move in small electric cars or e-bikes. Just like remote work has jumped up in the lead few months, if proper measures are taken and enforced, demand for bike /rail infrastructures will increase immediately.

People can adapt. How many will resist to change, is the question.

Expecting industrialized countries to reduce energy usage immediately by double digits to reach the climate change goal is everything but a realistic pathway.

In practical terms that means years of Covid19-style lockdown.

We don't have time to wait for a breakthrough in battery storage or carbon recapture. We have a solution now and it's nuclear power. It's a bit late for starting a nuclear programme now, but countries with current a nuclear power capacity (including Germany) should absolutely delay or cancel phasing it out until climate change is solved.