Young-Earth Creationists tend to agree that the Ice Age(s*) occurred after the Great Flood, but they have a variety of proposed explanations that seek to reconcile the Biblical record and artifactual evidence.
From Answer in Genesis's article When Was the Ice Age in Biblical History?:
Editor’s note: Biblical creationists have not reached a consensus on one Ice Age model. This article represents one view. Differences between the models have no major bearing on the overall timescale of a straightforward reading of Scriptures, i.e., the Flood of Genesis 6, which occurred roughly 4300 years ago, brought on one major Ice Age that lasted a few hundred years.
The remainder of this article from Dr Andrew Snelling and Mike Matthews argues for a fairly specific timeline that compresses the entire Pleistocene epoch to the period between the dispersion from Babel and the time of Abraham (190 years). It makes this argument based on: the assumption that the Bible is inerrant; the artifactual data indicating that geographically widespread stone age tool use dates from the beginning of the Ice Age; archeological data indicating that the Ice Age had finished prior to the building of the cities (civilizations) of Abraham's day. The approach of the article is geared towards convincing Biblical Inerrantists of their particular model.
CMI's article What caused the Ice Age?, while likewise (tacitly) based on assumptions of biblical inerrancy, engages with the scientific data and theories regarding glaciation events at a somewhat deeper level. It makes the following germane points:
- The science is by no means settled in this area:
...the Ice Age is a major challenge for secular scientists. There are over 60 ideas (theories) on the origin of the Ice Age. That is why David Alt, professor of geology at the University of Montana, stated: “Although theories abound, no one really knows what causes ice ages.”
- *There was only one Ice Age:
On land, most areas have evidence consistent with only one ice age. At the edge of the ice sheets, the glacial debris can be complicated, and it is here that they try to claim many ice ages. Yet, it is well known that the edge of an ice sheet advances, retreats, and surges rapidly forward creating complicated glacial sediments. It was admitted by five secular scientists that multiple ice ages are really an assumption. Instead of three or four ice ages in Alberta, Canada, these scientists concluded that there was only one.
- Cyclical orbital peturbations are insufficient to explain the widescale glaciation during the Pleistocene era - the primary driver was the catastrophic events surrounding the Great Flood theorised to include global scale volcanism:
Can the Ice Age be explained within the biblical worldview?
Secular scientists really can’t explain how an Ice Age happened, but can creation scientists? Yes, but first it needs to be placed within biblical earth history. The glacial features lie on top of sedimentary rock. This is a good indication that the Ice Age happened after the Flood. The conditions after the Flood were unique. Investigating them can help us find the answer.
The Flood was a very catastrophic global event that included massive volcanism. So, after the Flood, numerous small volcanic particles were trapped high up in the atmosphere. These particles cooled the earth by reflecting sunlight back to space. But the volcanic particles would slowly settle out over several years. It is well accepted from the physical evidence that during the Ice Age there were many more volcanic eruptions than we have today. These would continually replenish the upper atmosphere with fine particles, probably stretching the cooling to several hundred years. So, the cooler summer requirement for the Ice Age is fulfilled.