Washington Governor Jay Inslee has recently signed a bill that allows the composting of human remains within the state as an alternative to green burials and cremation. It is the only state in the US—and possibly the only government in the world—to explicitly allow "natural organic reduction" of human remains.
Composting deceased livestock is already practiced by some farmers, and Washington State University conducted a trial run of the process on human remains, using six bodies that had been donated for research purposes. The process took about four weeks to complete, and it created roughly one cubic yard of soil per person.
Although composting itself is not emissions-free, Recompose, a company intending to offer composting in Washington Stage, says it has conducted a Life Cycle Assessment to compare conventional burial, cremation, natural burial, and recomposition. "In our preliminary findings, recomposition performed the best out of all four options in the majority of categories," the organization's website claims.
Although there are few public studies on animal or human remains to confirm Recompose's result, studies comparing composting to incineration of agricultural waste seem to support it.
Find out more here.