Were Alpine glaciers much smaller in Roman times?

Question

In a critique (or possibly a rant) against modern climate science, Swiss geologist Christian Schlüchter makes a very specific claim that Alpine glaciers were essentially non-existent (or very much smaller than they are today) in Roman times. From a blog translating his original interview:

...the glaciers during the Roman times were at least 300 to 500 meters higher than today. “The mean temperature was one and half degree Celsius above that of 2005. The current development is nothing new in terms of the earth’s history.”

More specifically:

Early in the interview Schlüchter reminds us that during Roman times in the Alps “the forest line was much higher than it is today; there were hardly any glaciers. Nowhere in the detailed travel accounts from Roman times are glaciers mentioned.”

There are a number of contentious criticisms of climate science and some highly debatable claims about causality (is it all about the sun?). And I can't think of an easy way to verify Roman temperatures that wouldn't be controversial.

But the claim that Alpine glaciers were much smaller is surely a matter of history and should be verifiable from historical sources. So, is his claim that they were much smaller in Roman times correct?

Answer 1

This paper seems to suggest that the Romans didn't have a specific term for glacier, but their travel writers did describe things that are plausibly glaciers. This would imply that the claim "Nowhere in the detailed travel accounts from Roman times are glaciers mentioned." is ill-informed if not actually factually incorrect. This also implies that we can't expect to be able to unambiguously verify glacial extents from historical sources, and certainly can't use the absence of evidence that Schlüchter's claim is correct.

Does this mean that Alpine glaciers were smaller in Roman times? There seems to be some evidence that they were, e.g. Roman coins revealed by glacier retreat (reported by the BBC), however that doesn't mean the Romans didn't traverse the glacier, rather than that it wasn't there, or that the glacier had not transported them from higher up the mountain. However later in the article, we read "The fact that we still find these 5,000-year-old pieces of leather tells us they were protected by the ice all this time, and that the glaciers have never been smaller than in the year 2003 and the years following." which directly refutes the claims.

It is worth noting that the BBC article also says "The site is exactly at the point where the glacier responds most sensitively to short-term climate change and temperature variations," he explains. "So if we get more carbon datings from this site, we can get the most precise picture of short-term glacier fluctuations for the past six or 7,000 years.". This suggests we should be cautious in interpreting such regional changes in glaciers as strong evidence regarding global climate.