Genetic engineering by the super-elite

When the ecosphere began to fall apart, the world's elite thought their money and power would allow them to ride out the storm in relative comfort. Some of them even welcomed the climate crash because they were eager to be the founders and dictators of a new society run according to their own political preferences.

The obliteration of modern society did not happen overnight. For a few generations, disaster capitalists and oligarchs became the de facto rulers of their own pocket societies, defended by private armies of mercenaries, with absolute power over to decide which of the billions of Earth's climate refugees could take shelter in these new city-states. As you might expect, they only accepted people who had something to offer: advanced science skills, rare resources, appealing mates, etc; everyone else was turned away at gunpoint, forced to scavenge from the dying Earth.

Being a necessarily short-sighted and myopic set, the new tyrants believed this new state of affairs was sustainable. And so they continued to pour the Earth's resources -- over which they exerted total control -- into the same kinds of wasteful vanity projects they had amused themselves with before the apocalypse.

Of course, they also took steps to sustain their new "utopias." This included genetic engineering: to create food crops that could survive in this harsher environment; to create new medicines to defend themselves (and their chosen few) against the bugs that evolved among the oceans of fresh corpses outside the walls, and from biological attacks from competing tyrants; and, of course, to create better soldiers (and combat drugs).

As the wars between tyrants began to heat up, each craved a workable alternative to the petroleum-powered weapons platforms that now lielay rusting, their fuel tanks empty. The walled cities being few and far between, what was needed was a gunship that could feed itself, one that didn't require a massive logistics chain. In short: a biological version of the attack chopper. And, asbeing image-obsessed as they ever wereegomaniacs, the tyrants wanted something that would make a statement about their greatness and power.

And that is how real scientists in the real world were charged with breeding real versions of the dragons of myth.

The tyrants were wrong about the sustainability of their new world. Eventually the Earth failed to provide what the tyrants demanded, and each of their lawless little spheres collapsed. But the dragons existed now, and did not need permission from their former masters to go live in the wild.

The thing about Pandora's box is that it cannot be closed.