Let’s say that we approach the Singularity and as part of that transformative exponential explosion of technology we discover a way to quickly and efficiently terraform the planet Venus, reducing it’s atmosphere to earth-like densities and changing the composition to be nearly identical to earth’s nitrogen/oxygen/CO2/Water vapor mix.
As part of that a system of orbiting satellites provide a constant shade to reduce the sun’s intensity to be comparable to the energy the earth receives from the sun. (The ‘extra’ sunlight would be converted to energy for all the happy, busy Venusians to use.)
Let’s say that this can all be done in a decade.
Then, just as the engineering is about to begin, someone discovers that Venus’s atmosphere is populated with a family of “extremophile” bacteria which require the conditions of Venus’s current atmosphere to survive.
Would it be ethical to drive those extremophiles to extinction in order to have an entire new planet which could be populated with the entire rich diversity of earth? Or are we ethically compelled to allow the Venusian bacteria to stop our efforts to terraform Venus?