[jonhendry18]

There is some discussion of the migration of the steppe nomads being due to some extent to climate issues.

Sorry that this is the best citation I can find:

https://www.vox.com/the-big-idea/2017/10/30/16568716/six-way...

"Tree rings suggest that a megadrought in the middle of the fourth century might have made these nomads desperate for greener pastures. As they migrated West, they terrified the highly developed kingdoms, such as those of the Goths, that had long existed along Rome’s frontier. Partly because of this climate-caused upheaval, the Goths challenged Rome’s frontiers as never before. Rome’s Western territories ended up being carved up and reconfigured as Germanic kingdoms."

The Roman Climatic Optimum is the name of a warm period from roughly 250 BC to AD 400. It wouldn't be a stretch to hypothesize that the fading of that warm period may also have had effects on the steppes, leading to the migrations.

The Visigoths may have been fleeing the Huns, but why were the Huns on the move in the first place?

[User23]

Droughts aren't really climate change, they are a normal part of the weather patterns in a climate zone. "Droughts becoming more severe or frequent" could be construed as climate change. Or it could just be mean reversion. Doubtless major climactic events have caused migrations. Desertification has many well attested examples.