The location given for the 67-page report is www.gtp89.dial.pipex.com/FGD/Ch14.pdf. It appears that .pdf file is not currently online, however, the Google cache of the document is available.

Thanks! Clearly, you are a much better googler than I :)

Interestingly, not only is the pdf not available online, but the draft at the google cache says its a "final draft for government review" and says "CONFIDENTIAL: Do Not Cite – Do Not Quote" on the top of every page. Wonder what's going on.

Interesting. And much as I suspected. Rather than modelling they are simply observing present changes and present trends and extrapolating them into the future. If the popular mind has not even gone that far and is merely denying reality that's better than nothing. But basically the best-informed are simply at saying the future will be much like the present only worse.
In other words no one knows the future. Duh. But the authors have a bad feeling.