"Unsustainable" means... "change is coming." And, you might not like the form change takes.
By the time people start talking about the sustainability of something--like spreading salt on streets--you can bet it's been going on for a long time. And, you can bet there's a good reason why people don't want to change. So, sustainability issues always involve tough choices. And if we don't make those tough choices, then reality forces change upon us.
