I received an email about the high fire risk in Victoria and much of southern Australia, and they explained how they are considering earthbag domes as a fire safety strategy. Wooden roofs, especially houses with roof overhangs, would be at much higher risk of fire than domes. Fire would go right on past a properly built earthbag dome with a little preparation.
Here is my email reply:
In addition to normal fire prevention strategies like planting fire-resistant plants around your house, creating a fire break by clearing brush a safe distance, and not storing combustibles such as firewood next to the home, all you really need to know is domes are much safer against brush fires than houses with roofs. Add metal shutters so you can close off windows and doors in case of fire. You might also want to add an air filter and stock up on water and other supplies so you can stay at home until the emergency is over. Please keep us posted of your project. Your home could be a model home for others in the area. This is really important to me. I hate seeing all the needless suffering caused by inappropriate building methods.