One option is a "paperless" drywall product by Georgia-Pacific called DensArmor Plus® Paperless Fiberglass Mat. It is a highly mold-and mildew- resistant interior gypsum panel. "DensArmor Plus panels feature fiberglass mats on both the front and the back for the best in interior protection from moisture currently available. The moisture-resistant fiberglass mats [also] make DensArmor Plus panels the ideal replacement for paper faced greenboard, where greenboard is still allowed by code."
One drawback I saw in using the DensArmor was the fact that it contains fiberglass and you would need to be careful when handling it. But the contractor indicated that this wouldn't really be a problem and shouldn't be a deciding factor. The only remaining drawback I found then, was cost. Based on what I found, a typical 4'x8' sheet of DensArmor drywall costs about 60% more than a standard drywall sheet. That's a pretty significant cost increase so we will have to see if we have that kind of room in the budget. The way things are going though...I don't know.
Another option I found was a very new product called Eco Rock by Serious Materials. Actually, this product is not even out yet (scheduled for release in late 2008). There are two major differences I see between Eco Rock and other drywall. First, it uses a large amount of post-industrial recycled content. And Second, it uses a lot less energy to produce.
From the Serious Materials website:
"Over 30 billion square feet of drywall are produced each year in the U.S. and Canada. A single sheet uses between 100,000 and 400,000 BTUs of energy to produce, depending on the age of the plant, producing 16 pounds of greenhouse gases per sheet. Approximately one-quarter of the cost of a gypsum drywall panel is tied to energy, with likely long-term cost increases; carbon taxes are common in Europe and may come to the U.S.
By contrast, EcoRock uses 80% less energy in the manufacturing of its core. No heaters or dryers are used in production, nor calcining processes – resulting in 80% less CO2. EcoRock also uses 85% post-industrial recycled content and is fully recyclable. A plant built for EcoRock reduces energy use to a minimum."You might have heard of Serious Materials as they are the makers of Quiet Rock (a 'soundproof' drywall product). FYI...one sheet of Quiet Rock is acoustically equivalent to eight sheets of regular drywall. That's pretty amazing.
The Eco Rock product looks very promising but what I find even more compelling is the business philosophy held by Serious Materials' CEO, Kevin Surace. The following is a link to an article about him and his company (from about a year ago): Cleantech Article. Read it when you have a few minutes. I just wish there were a few more industry leaders like this around.