By the way, don't overdo the nerfing to Tibet. Much of it is today a cold desert, yes (desert tiles might be more appropriate for this than tundra- as there aren't large amounts of ice or snow), but significant amounts of it are also warmer and best simulated by Plains tiles. Further, the climate is nowadays a lot colder and drier than it used to be...
Like much of the planet, Tibet has been significantly affected by climate change due to deforestation...
In many arid, originally forested areas (Tibet is one of these), deforestation led to an irreversible drying out of the climate- trees increased humidity by bringing water from deep underground to evaporate from their leaves. When most of the adult trees were cut down (a certain threshold of deforestation had to be surpassed), the climate became too dry to support the growth of saplings: the climate became much drier, and the forests could not regrow as a result.
Trees also moderate the temperatures of a region, by mechanisms even I don't fully understand.
The dry, treeless, cold plateau Tibet is today is not the wetter, more mild and more heavily forested Tibet it once was.
Now DON'T mistake me- much of Tibet does lie at too high of an altitude for trees to grow at all. But processes of deforestation have pushed the treeline back- the forests were once more extensive than in the modern day. See the following article, which mentions how the forests were once more widespread under the subsection "Forest Relicts"
http://www.mushroaming.com/Deforestation_1998
"It is difficult to imagine that central Tibet's barren slopes once were forest-clad; yet in the Lhasa area, where the annual rainfall of around 450mm per annum is sufficient to sustain juniper forests, historically forests probably were widespread"
A bit later in the subsection...
"In addition, traces of human activity can be dated back some 5,000 years ago; for example, tools found indicate slash and burn agriculture at Karo (mKhar Ro) in the Mekong valley near Chamdo (Chab mDo)"
Note the mention of SLASH-AND-BURN agriculture 5,000 years ago. Humans have been deforesting Tibet for millennia...
It's
AMAZING how much ecological damage we've already done to the planet just by clear-cutting forests... It's also amazing how resilient the planet has been despite all the damage we've already done...
Regards,
Northstar