There are two forecasts at the end based on exponential growth. The thing to remember about exponential growth is that it is inherently unsustainable. Consider Moore's law. I once read part of a book from 2005-ish about the singularity whose basic premise was that by ~2050 or so we'd have enough computing power to stuff orders of magnitude of orders of magnitude more power into a now-sized CPU. And this was in a completely serious tone, mind you. Now we see the slow demise of Moore's law over the past 3-5 years and it seems ridiculous that we could have ever believed something like that just a decade ago!

The state of advancement in the fields of human society, technology, and science, at their current rates, is such that around 2500 all of human society will be overturned every week, day, hell, minute or so. Which obviously is nonsensical.

Note also, however, that forecast #2's best-fit line doesn't seem to fit the points very well...