I just stumbled onto a bookmark for the article in question:
Discover Financial Services
Circles of Life
How far out of whack can the orbit of a planet like Earth get before we all die?
By William Speed Weed
DISCOVER Vol. 23 No. 11 | November 2002
There is nothing further to see at the above cited, if you are not a subscriber (which I am). But the article can maybe be looked up at your local library.
I'm not up to doing a major review right now, but the essence of the article is that there could be considerable variation in the earths orbit (could be much more eliptical), and earth would still be habitable.
To ID Man: No it is not a peer reviewed journal - Just a broad based science magazine.
Moose
ps: What kind of name is "William Speed Weed"?