Three Bags and One Planet

I suppose I am a true skeptic at heart. Recently as I have been reading Sachs and listening to his excitemement about new ecology-saving technologies, I've been wondering exactly what the draw backs to these technologies would be? For instance, if we moved to desalinate ocean water for drinking, what would we do with all that salt? Wouldn't that make the already too-salty oceans saltier? So it was that I decided to research the manufacture and use of cloth grocery bags. (For those of you who like citations, I got most of my information from: http://www.green-kits.com/paperorplastic.html)

I found to my surprise, that plastic bags are actually better than paper bags. I had assumed paper bags would be better because one can recycle paper bags but plastic bags aren't recyclable or biodegradeable (They break down in the sunlight into smaller and smaller pieces. Like an eggshell in fire--it never goes away, just gets smaller.) But it turns out that paper bags: 1. are heavier so cost more carbon (gas for shipping) to transport than plastic does. 2. are made of cellulose (tough plant fibers) that can only be broken down by bacteria. As a product of this biodegrading, methane gas is produced which is also a (though less notorious) deadly greenhouse gas. These things didn't surprise me.
What did surprise me was the apparently perfect cloth solution. (There was a small debate about the cleanliness of these bags, but after some testing, the risk appears to be negligible as long as one washes the bags periodically and after meat has been in it.) I could find nothing but the highest of praise for cloth bags. Nothing about manufacturing or transportation carbon-costs was mentioned. (Although more than one site warned the reader to check to make sure the cloth was made from renuable resources like hemp or cotton), I don't know who makes these bags. I don't know if these bags are as truly safe for the planet as 'everyone' seems to believe. But from the available data, it looks like cloth bags are the newest best thing.