Humanity’s cosmic expansion is bound to run up against barriers, which could include the rise of a post-human species. This, however, is nowhere near as problematic as the possibility that the Universe is a fractal, and all life within it is doomed.
In the past, the space industry has been anything but green in its approach to environmental issues. But technologies and perceptions are changing fast in a host of areas. Engines can be designed to use less fuel, rockets developed to reach orbit without dropping stages back to Earth, and launch sites made more compact. All of which will not only help preserve the natural environment, but also reduce costs