Board Thread:Online Discussion/@comment-109.78.74.133-20140222001044/@comment-16047389-20140414180457

Here's the simple answer: Bethesda and Zenimax screwed up. Basically, they had Cyrodil as a jungle before Oblivion and realized they wanted a temperate zone instead. So they retconned it via Talos. Unfortunately, they only works from that point forward, and not for events in the past i.e. ESO. It's an oversight I'm sure they'd like us to just ignore. And personally, I think we should. Retcon is never a pretty thing. Personally, I'd much prefer to fight in a temperate Cyrodiil than in a jungle.

I'm actually more annoyed at their whole "Talos reshaping the climate" explanation than the reason for why they did it. If they had just said "We're making Cyrodiil a temperate zone now because we didn't actually want a jungle environment so please just ignore the change" I would've been fine with that.