In Australia a small group of farmers have secured permission to bury dead people in a standing position. They'd be wrapped in biodegradable body bags and basically be used as fertilizer it seems. It saves burial space and no gas would be wasted in cremation.
Can't get much more eco-friendly than that, but it does raise some interesting questions. Not the least is the old phrase, "being laid to rest". No rest for these dead ones; they'll be on their bony feet working to help make the crops grow. At least until Mother Earth and her legion of worms and other subterranean fauna suck every last bit of human identity from them.
I don't see this being adopted in the rural midwest anytime soon where trips to the cemetary, decorating graves and communing with the dead can border on the obsessive.