I read about human composting quite a few years ago (30 or 40) and I believe it may have been in England where they were considering it. As I recall, the concept was to have the body interred in a biodegradable coffin with a tree was planted over it. The idea was that the person would be helping a tree to grow.....and a bare tract of land would eventually become a forest.
I have no idea if it ever came to fruition (depending on the tree's eventual size, the land to planting ratio might not be great) but I remember thinking: "Hmmm. Neat idea."
Interesting proposal. Here burials require metal lined waterproof coffins, to prevent heavy metals concentrated in the human body form leaching into the soil and potentially contaminating the ground water. (Whether this legislation is based on actual science or lobbying by the funeral industry to increase the cost of burial is open to conjecture.) However, there is no question that there is nowhere near enough water to support the number of trees required for a one person one tree burial pattern. Natural gas for crematoriums — yes, water for that many trees — no way.
I'm struggling to understand how this is a new idea.
Some traditions, such as orthodox jewery, require burial in plain pine boxes to adhere to the "ashes to ashes, dust to dust."
Everything old becomes new again…