I have seen a variety of definitions. Nat Geo once published - sometime in the 80s, I think, a list of six or5 seven defining principles, the whole of which would demonstrate the best of our civilization that disks not5 yet entertain nuclear power, or nuclear anything, meaning a level of technology free-dsating nuke tech. Technology, itself, in the broad stroke, was near the last of the list, if not the last, others included oral, then written language, to achieve complex, and even legitimate theoretical science over and above "earth sciences" of thousand of years in development. Another feature was elevation above an agrarian, hunter/gatherer status to full agriculture [plant and animal husbandry] Another was the wheel, and then other mechanically driven devices to assist and simplify work. Establishment of politics/government. Development of formal education from childhood into adulthood, and freeing up children from necessary farmers/huntrers to be so educated. Ther3e are others, but these formed Nat Geo's suggest3ed meaning of civilization.
Russian astrophysicist, Nikolai Kardashev, proposed the Kardashev Scale of Civilization in 8 steps in 1964. This scale was developed on the basis of energy use, and began at Level 0 as a civilization depending on petroleum as the primary energy source, meaning that in 1964, earthlings were a level 0 civilization.
Today, 6 decades later, our energy dependence on petroleum to the tune of 60%-plus, keeps us at level 0. But, Kardechev believed global warming [now called climate change, but Kardashev used the earlier term] was indeed an existential threat, as some. like AlGore, still believe it, believing that man is too stupid to figure out what isn't there case anyway; that petroleum is not a renewable engergy source.
Our familiar Nat Geo still believes that, and yet, petroleum continues to be a readily available energy source, and does not seem to be exhausting itself as was predicted in the 1950s, to be exhausted within 20-30 years]. We'rter still pumping th4e stuff out of the ground at increasing rates, worldwide, with no end in sight, given just proven reserves, let alone what is unknown.
Meanwhile, wind power, claimed to be "renewable," is not producing 24-7, is it? And solar fails every single night of the world. These may be "renewable," but they cannot be said to be perpetually sustainable with so many interruptions.
That petroleum ceased to be produced with the death of the dinosaurs is just a convenient myth. So, Kardashev's scale is, at best, just another biased climate change theory that is failing to inundate us by invading oceans onto our landmasses, as predicted by AlGore. It was his "inconvenient truth," and that it has not come to pass in his lifetime,
AlGore is a woke relic who, though he invented the internet [?}, it seems he's never been able to invent AlGoreGooeyJuice to replace petroleum, which is supposed to be completely eliminated and replaced in four years, by the originally established green schedule, and as guarantee by An Occasional Cortex [AOC] back in the Oba'a administration. So, we're a 0-level civilization, no more civilized than Ug and Gut.
We'll cover the more advanced Kardashev civilizations in other topics by the numbers.