Here's the https://twitter.com/TESOnline/status/265849694708719616.
@TESOnline Do you have an explanation as to why Tamriel isn't a jungle, or do you plan to tell us that in game (or not at all)?
@JackBartl3 #ESO's Cyrodiil is based on current Tamriel lore. The original "endless jungle" description is considered a transcription error.
As I said in the Marukhati Collected thread: There are four main "official" sources which deal with jungle Cyrodiil: the Morrowind savants, the Many-Headed Talos (Heimskr's speech), PGE1 and Mythic Dawn Commentaries. Two of these are told by people (one of which is in the 3rd era!) who would have seen jungled Cyrodiil first-hand: it's not a transcription error. The other two explain the interesting reasons for it. TESO invalidates all of them, as far as I can tell, unless you decide that Talos CHIM'd Cyrodiil in the past as well (affecting 2nd era), but did not affect books such as the Pocket Guide, then the forest grew back over the 3rd era, then was almost entirely destroyed between Oblivion and Morrowind...
There are a lot of problems arising from TES IV's cyrodiil. The main culprit is the game itself: it can't explain how savants in Morrowind who have seen it first-hand believe it's jungled. However, that's a subject for six years ago. TESO's issue is the complete unwillingness to try explaining it.
Worse than incorrect lore is an incorrect attitude to lore. This is why I'm looking forward to TESO's Q&A sessions starting soon. Hopefully there will be an opportunity to ask
santa http://elderscrollsonline.com/en/news/post/2012/10/18/reading-the-future-of-the-past-in-the-elder-scrolls about the game.