Venus

The smart people of the science stuff were less focused on terraforming Mars. They said we should seed Venus with genetically-modified bacteria to convert the atmosphere over into something more conducive to life than methane death trap.

No one has gotten down below the clouds to the ground surface. There was concept art once of floating, living things, like predatory blimps. It's hard to picture, now, how any life could flourish like that, because it seems large animals require small animals require smaller animals. Escher used to get these big lenses so he could draw tiny, tiny details of his algorithmic art, down beyond where they eye can see. It mattered to him to go deep like that. Go deep, then, beyond the blimps, and seek out the greasy sheen of semi-organic algae-like goo that clumps into tiny clouds and falls, only to rise up again when enough of the clumped proto-algae burns off approaching the toxic surface. This feeds the swooping and hovering pustules that feed and ooze, with no eyes or ears or sense of space. The pustules drop their waste matter down into the burning sands. From the stench, the herds of pustules are deduced by larger creatures that parasitically live on the back of the floating blimps. The blimps are predatory, and would eat the birds upon their backs, but they only have their scythes and jagged hooks on the bottom of the blimp. The bird-like things are on their billowing backs.

Look closer, at the bacteria that shimmers over everything. Below that, the rock dust and minerals and gases that warp into a slurry of life.

When we do send our terraforming rockets out upon the clouds to burn them all away and convert into something habitable, we'll see their fallen husks, their rotting heaps, and a forest of bones and tissues gone dry in the wind. The robots will stand upon the ground, and the people after them, and they will wonder at the disastrous extinction of a whole world hidden just below the clouds.

Of course, it doesn't matter. We terraform wherever we are, and cause death and life, reshaping our world to suit our comfort. What matter is it to flood a valley to make a reservoir, or to burn away a whole world in the heavens with genetically-modified bacteria? There is no difference but scale. Every step we take upon the grassy plain crushes bugs, compacts the soil, and twists the blades of grass. We cannot be sky clad men and women, standing still, with masks before our faces to prevent the inhalation of insects and not do harm. Life requires the suffering of the small for the larger.

The smaller will have their turn upon our bones, soon enough.