That would be hard to measure, but I'm sure if we all started cremating our dead the environmental cost would go up significantly. I found a list [1] of cremation rate by country. For quite a few countries, the majority of people cremate their dead (religious reasons, usually), but there's still a minority elsewhere.

I think the freezing and shaking method sounds pretty good in terms of environmental cost.

1.https://en.wikipedia.org/wiki/List_of_countries_by_cremation...