Good day. I'm Jonathan Tomkin from the University if Illinois. In this course, we are going to ask what sustainability is. It is different from earlier ideas like environmentalism? As an example, consider the fact that this region of the world, the midwest, is suffering its worst drought in 50 years, but the prairie around me is doing fine. That's because it's adapted to drought conditions, it has very deep roots. If we were environmentalists, we wouldn't really worry about the state of this prairie. But human systems aren't doing as well. The local farmers are suffering because the corn crop isn't going to be coming in anything like what it should be. Humans use corn for lots of things. We eat it, but also we have it in our industrial processes, we feed animals with it. This corn was mown down because the kernels didn't grow. All it's good for, is silage. Unlike the prairie, the corn needs particular set of conditions that are much narrower. Corn requires lots of rain and we didn't get it this year. And so, the corn just didn't grow. So, are the human systems more fragile? Are we relying on particular circumstances? If the climate changes, does that mean that our processes won't work in the future? Will this corn crop look like this, year after year? So, when we think about differences between sustainability and other ideas like environmentalism, we realize that sustainability is really thinking about humans place, societies place. How we're going to respond to changes? Are our systems adequate? So, when we look around at a prairie like this, we're not worried in a sustainability sense. This is a sustainable system. But we are worried when we look at the farmers field and see plowed over corn. Because that might suggest that our systems aren't sustainable. So, in this course, we're going to consider what is it--what makes human society, human economies, sustainable? Produced by OCE Atlas Digitial Media at the University of Illinois, Urbana- Champaign.