A British newspaper argues that Romans were the first to invent eco-friendly homes, citing Oxford archaeologists who compared the typical Roman villa to typical 20th century homes and noted that the villa was more efficient in its heating, used more recycled materials, etc., etc.
Well, of course it did. Those of us in post-industrial, high-cost, consumerist, economically and politically powerful societies often seem to forget that "going green" is not (only) some high-tech wave of the future, it's a necessity for people who don't have the luxury to waste energy or resources. Whether you're talking about the poorest people of the modern world, or ancient societies, most people's homes are/were much more in tune with their environments, much more likely to use recycled materials, and more energy efficient than the average member of the Sierra Club's.
Obviously, this isn't always the case. There are ancient societies that stripped their landscapes bare of trees for wood, for example, and modern peripheral societies that burn highly inefficient fuel. My point is that much of what we think of as "green technology" is actually just being careful with limited resources, and we should expect that many ancient societies knew a great deal more about that than modern academics.