The most ecologically sound cadaver disposal is through the use of insects. This is how natural history museums clean the bones of animals that they wish to display, because such insects are very thorough.
When cadavers are moist, fly larva, maggots, are very efficient, so much so that sanitized larva are used medically to clean just the dead tissue from necrotic wounds on living people.
They would consume the bulk of the cadaver before the remainder dried out.
Once somewhat dried, there is a species of beetle, called the cadaver beetle, that takes over, leaving only clean, white bones and replacement parts. They even clean out the connecting tissue and bone marrow.
If all of this was carried out in optimal conditions, a cadaver could probably be reduced to a bare skeleton in just a few weeks. The bones then could be incinerated with just a fraction of the fuel needed for an entire cadaver.
That sounds great. Can we start with your mom or dad? Just kidding of course...trying to make a point.
Good, but would think that disposal at sea would be better.