Global warming

[pbrower2a]

It should be obvious by now that climatic change can shape historical events. It can force changes in how people live. The desiccation of the Sahara and Arabia eventually led to the establishment of agrarian civilizations in Egypt and Iraq, at least where water still flowed (Nile, Tigris-Euphrates valley... but it caused multitudes also to starve,  The hunter-gatherer way of life that flourished in the "Green Sahara" became impossible in the extreme desert that the Sahara became.

The Sahara was more extremely dry (if that is possible) and much larger during the Ice Age.

....Let's look at the smallest of the continents and some nearby (or 'sort-of-nearby') lands. Obviously another Ice Age would be one of the worst calamities possible for Humanity, and here is how Australia, New Guinea, and New Zealand would have looked during the Ice Age at its most severe:



The shallow sea between Australia and New Guinea was bared to become tropical grassland. Tropical forests had completely disappeared in Australia itself, and the Outback expanded, becoming even more barren (much like the Sahara today) in its center. Even temperate forests practically disappeared in Australia, with "semidesert" appearing in Tasmania (where the highest mountains were glaciated).

New Zealand's South Island became thin grassland where the glaciers did not take over. North Island became woodland, sort of a mid-latitude savanna.

This is recent Australia, New Guinea, and New Zealand.



This is when Australia had the greatest potential for settlement with the southeastern and southwestern corners, and maybe southern Queensland being suited to crop-growing. The Outback is at its worst like the Kalahari or Mojave deserts which are not quite as barren as the Sahara or most of Arabia... but Europeans obviously did not move there to become marginal herdsmen. The Darling Valley may be lost to farming this century. Signs of desertification include heatwaves and forest fires.

New Zealand is almost entirely temperate forest by nature, although the northern tip of North Island could become genuinely subtropical.

Well, here's climate in very recent times in Australia: