A Modest Proposal 2008

So I just saw "The Day the Earth Stood Still" last night. It wasn't bad, but it also wasn't great. One thing that it was, though, was blatantly environmentalist. Not a big deal, just ended up making things quite corny. On multiple occasions, Jennifer Connelly said "we can change" and I half expected her to say "we'll start using energy efficient light bulbs" or "we'll all drive hybrid cars".
Which brings me to my reason for posting.
A big topic today in environmentalism is water and conservation of fresh water resources. I hear people talking all the time about "wasting" water. Every time I hear someone mention the "wasting" of water I'd think (or sometimes, say aloud), "you can't waste water, it's 100% renewable". If you think about it, the Earth is essentially a closed system. Nothing (save for some spacecraft) ever leaves the atmosphere, so you really can't waste water.
And then, one day, it hit me.
During our evolution as humans, we've started doing a large number of different things for various reasons that don't make sense from an environmental standpoint. You can probably think of any number of them just off the top of your head. But there's one thing that I bet you wouldn't think about, and it's a tremendous waste of resources with an extreme lack of reasoning behind it.
I think we need to change our burial practices. Today, in the United States and many other industrialized nations, human corpses are embalmed to preserve them, placed in a casket (which is usually elaborate and expensive), which is then encased in concrete, or something of the sort, which is then buried 6 feet under the surface. Could this make less sense environmentally?
Now, back in the day, say a hundred or so years ago, corpses were buried in simple caskets and were either not well preserved or not preserved at all. This practice allowed the wood and the corpse to decompose underground naturally, and all those nutrients were returned to the Earth, from which they came. However, with our current practices, it could take decades or even centuries for the concrete, fancy casket, and embalmed corpse to decompose.
I think we should go back to the old way, simple wooden box and unpreserved corpse. Is it really necessary to have the corpse present at the funeral? Personally, I'd rather not look at dead persons, and instead think about them when they were alive.