The Ice Age theory is interesting when related to human beings. Among our ancestors are Denisovans. In the Denisova cave parts of the finger bone of a young girl and molar teeth of other people including adults of various ages and a young boy who lived at least 50,000 years ago (the girl) and that two other Denisovan individuals died in the cave at least 110,000 years ago and perhaps as early as 170,000 years ago have been identified by sequencing their mitochondrial DNA. The Denisova cave is in southwestern Siberia, in the Altai Mountains near the border with China and Mongolia. The last Eurasian Ice Age was approximately 110,000 to 112,000 years ago.
Neanderthal remains have also be found interspersed with Denisovans. The Neanderthals in habited Europe and southwestern to central Asia about 400,000 - 40,000 years ago. We know far more about them than Denisovans and have established they did not necessarily hang around to wear lots of animal skins during a number of periods of ice age, that means they migrated to warmer climes which explains the time dispersal of quantities of remains found.
Despite that part of Central Asia now being a notably barren and incredibly cold climate much of the time, the reason Denisovans and Neanderthals were there would have been the relatively temperate climate and abundance of food. Ice ages heavily reduce that potential, especially the general lack of vegetable matter. They would have evolved to a dead end, indeed they did die out, but most Europeans have a large percentage of inherited DNA from Neanderthals particularly with some evidence of Denisovan ancestry, particularly as one goes eastward. However, modern Central Asian and Siberian indigenous people have far less. The other palaeontological evidence shows that around 50,000 years ago there were at least four human groups: modern humans, Neanderthals, Denisovans and small , often called 'hobbits' who were found in Indonesia who actually carry Denisovan DNA similar to western Europeans, appearing roughly 95,000 years ago but dying out around 17,000 years ago. Their DNA is found in parts of Indonesia but even some in East and Central Africa, very little though.
All of this tells us about both human and climatic ecology with the key to timing some events showing lines of probable early human migration. In Africa it was the success of early modern Homo Sapiens along with a period of aridity that made food scarce, probably water as well. Europeans are probably the outcome of two or three groups coming together in a temperate and fertile area where food was plentiful then interbreeding rather than moderns killing off Neanderthals as the theory used to be pre DNA sequencing. If we take the remains, the artefacts and such things as 'cave art' we get a fairly precise picture of each group in its location. That also tells us a lot about the physical world.
Climatic changes we learn about alongside all of the above were rapid and radical. In some places we can see that in a single millennium a rich, fertile place could have become desert or tundra. However, we know from the marginal areas of deserts that desertification is a rapid process. The highest rate measured was in the 1980s where one place measured over 2km, that place is not nearly 5km into desert. Synonymously we can look at Greenland that was recorded as only ice cap early in the 20 century with very little vegetation against now large areas of forest and tundra, with some meadowland that are permanently ice free that is increasing rapidly.
So we know that there are climatic cycles and that a European ice age is 'due' but not exactly next week. We also see that ice ages are sometimes preceded by periods that are hot and arid, reducing vegetation that to an extent holds back ice capping. What is unique this time is that human activity has distorted climatic change thus the present global warming has happened too fast and all the wrong time so that instead of ice caps 'moving' to take ice ages to other parts of the world, we have polar cap melting that would happen normally during a period of far more volcanic activity where not so much the actual ambient temperature as the gases released led to melting. Measuring human migration is naturally difficult in the modern world for obvious reasons but being very recent in real terms we can predict that had we not reached our present evolutionary state that European species of homo sapiens might have migrated out leaving the rest of the group to go the route of Neanderthal and Denisovan humans into extinction.
All superb stuff but very dry reading. I am into it because my academic starting point was human migration and somehow I have become both professionally involved and personally interested again in the last two years. However, it helps inform me on the physical science parts that I do not understand. As for predictions, well they are very imprecise and even then usually in thousands of years so that we really do not need think about our own direct descendants who will adapt anyway as changes happen but for who we will be as obscure as Romans are to us.