Science fiction has a number of common concepts and themes that have been reused by numerous authors. Some have become cliches, and only truly novel treatments of them gain attention, whilst others have become "part of the furniture"—they can be included in a story without much explanation because readers are already familiar with the core concept.
Science Fiction is used to raise awareness of Ecological ideas. Lends itself well to dystopian futures. Frank Herbert and Kim Stanley Robinson are known for their serious concern with ecological issues.
Post-"Age of Scarcity" (arguments over how to distribute resources are irrelevant since anyone can have anything they reasonably want, e.g. The Culture, and the problems of excessive wealth as in Frederik Pohl's The Midas Plague)
There is a space based civilization variant of this theme. This plot device allows writers to write soft science fiction while accounting for the lack of technological advancement and thus similarity to the present day.
