Burying someone takes a plot of land, a finite resource. Cremation produces carbon dioxide and other toxic chemicals, which is not ideal for the environment. The greenest way to go? Apparently aquamation, which is like cremation but with water.
Aquamation is a 4-hour process in which a corpse is placed into a steel container with potassium and water added. The water is then heated to 93°C (199°F), which is apparently the most efficient temperature to decompose flesh and organs. The bones are leftover but that happens in cremation too. The benefits of Aquamation is that it uses 10% of the energy of cremation with none of the toxic side effects. It also preserves artificial implants (like hip replacements) for possible re-use.
It seems like a pretty thoughtful, and almost peaceful, way to go out. I'd consider it but think I still prefer either going six feet under or chilling in a freezer. [New Scientist]