I’ve previously expressed my opinion (here and here, plus here) that the classic (conservative Christian) view of the Noachian flood — a worldwide immersion of liquid water, likely between 3000 and 2000 AD — is implausible due to a complete lack of geological, archeological, and ecological evidence for such an event (cf. this Dialogue article by Clayton White and Mark Thomas). On the other hand, as I explain in my posts, I do believe a major climatic shift happened that gave rise to the Flood narrative in the Old Testament as well as in many other cultures and traditions. However, I believe it had to do with event surround the end of the last ice age, in which a very sharp warming period was followed by a brief ice age resurgence (the Younger Dryas period), which in turn was followed by another sharp warming period. This climactic whipsaw appears to correlate with some significant human and fauna declines, especially in North America (where LDS doctrine places the pre-flood patriarchs).
I bring all this up because I ran across a diagram today, based on the Greenland GISP2 ice core data, that shows just how dramatic that climactic whipsaw was compared to climate changes since then (the temperature scale to the left represents a reconstruction of the temperature on the Greenland icefield based on oxygen isotope ratios; click on the image to read the original paper explaining the use of this ratio as a ‘global’ proxy):
Many debates are still going as to what triggered the sudden up-down-up shifts, each of which occurred very quickly. But I suspect the antediluvian and Noachian events occurred in this time period. ..bruce..