Curious, I just ran a very superficial search and didn't even pick up any secondary links about such an article except this one on the US message board. I'll try again later this evening.
EDIT- I think I may have found the article, at least it carries part of the graphic you posted,...I don't, however, see anything in or linked to this article which claims "unprecedented," do you have any reference to the claim of unprecedented?
Sorry, forgot to post the actual link -
Drought?s Footprint - Graphic - NYTimes.com
Yep, that is the article, thanks for finding it.
Seems I made a mistake, having read the article at work and then typed up the summary when I got home (not supposed to post at work).
While the article struck me as a bit hysterical, it was the comments I read on a message board that got me into the 'unprecedented' perspective on it, but that is unjustified and mistaken.
Thank you for helping me to be more acurate on my quotation.