The Shareholders by HS Down

"Decades earlier, back when the rich wanted the poor to work, the treatment might have been offered to everyone. Imagine the immortal, disease-free worker, imagine how profitable that would have been. However, the treatment came just when it was truly apparent that too many of us were surplus to requirements. What was to be done with the new dispossessed? Nobody knew, but extending their lives indefinitely certainly wasn't the answer.

Then the tipping points finally tipped for real. The tipping points. They came like waves from a nameless shore adumbrated by distance and by our habitual and weary attendance to our own mortality. What would make it all real, we wondered? Then the Great Thaw came, the permafrost and northern ice gave way, and the world ran away from us."

In the late 21st century, Earth is ravaged by climate change. The billionaires have bioengineered immortality, fled to Mars, and rule Earth's last biospheres as their personal shares. Those left on Earth struggle to find balance as the planet tumbles into its terminal years of habitability. Ian Gateman, one of Earth's last bureaucrats, is tasked with finding a buyer for a fledgling colony of newly settled ecological refugees. As Ian travels to the estates of several visiting shareholders, it becomes clear the shareholders have other plans for humanity's future.