The difficult assumption isn't that we have a stable ecosystem - we survive in a very broad range of ecosystems. The one that risks killing modern societies is the assumption that cheap and abundant energy is available. Sufficient energy could overcome any challenge.
That's why it worries me that scaling energy production is not getting the focus it needs. We don't need to reduce our energy needs and replace dirty sources of energy, rather we need to get at leas one magnitude of energy more & in a clean manner, to solve all our environmental issues.
Edit: some math https://dothemath.ucsd.edu/2011/07/galactic-scale-energy/
Case in point: the age of cheap oil. Without that abundance in energy there would have been no crisis now, and we'd be looking at a much lower number of people on the planet.
If you want to change 'sufficient energy' to 'sufficient clean energy' then the needle will shift, but maybe not as far as you'd like: even then there is a limit as to how much energy we can get rid off once it has been used and turned into heat.
Claiming otherwise is fundamentally dishonest. "The instruments say our jet engines are overheating. Let's wait to be certain, instead of heading for the nearest airport. Who knows, it might be nothing!" Said nobody ever.
That elephant-in-the-room aside, this season is arguably less catastrophic than bushfires from the late 19th and early 20th century [0]. To date there are less deaths, less houses destroyed and the economic damage is uncertain. Even the area burned is not unprecedented; yet (Victoria in 1851 holds the record). This might be weather rather than climate - bushfires in Australia are not exactly a jaw dropping development and a once-in-a-generation fire happens about once every generation.
It would be wise to wait for the benefit of hindsight and not try to guess while a crisis is still unfolding. That is just a fast way to form bad conclusions.
It took 349,800 years for us to install a toilet. Constructing a pyramid took 346,000 years. Granted, the survivors of climate disaster will have the benefit of legacy technology, but surviving in these new conditions well enough to create a society capable of widescale adaptation of our current society's abilities will take several thousand years at best. As they say, Rome wasn't built in a day.
Ancient Rome had indoor plumbing. What they didn't have is an industrial manufacturing base or the scientific insight that would have made sanitation effective. Those innovations are definitely recent, and something we could lose in a generation or two.
Please show any evidence that we are running out of energy.