Saturday 17 September 2022

The Roman Warm Period

It is widely accepted by historians that there was a Roman Warm Period of a few centuries, straddling either side of AD 1. When it started to cool down, there were famines, unrest and wars for scarce (food) resources and the western Roman Empire in western Europe collapsed. The eastern Roman Empire aka. Byzantine Empire, being further east and south and a bit warmer struggled on for a few more centuries, but hey.

Then came the Dark Ages, when it was cooler and history is murkier, people were too busy fighting with each other or simply struggling to survive to leave much recorded history. Then was the Mediæval Warm Period, a time of exploration and expansion, formation of larger states (Vikings got as far as Greenland). The wheels fell off again in about AD 1300 when things cooled down (very quickly) and we had the Little Ice Age. Rinse and repeat, famines, unrest, wars etc, esp. in the 1600s.

The Little Ice Age ended in the mid-to-late 1800s, since when we have had the Modern Warm Period. There have been few weather-related famines, and certainly no global ones, for the past fifty years or more, apart from the fairly local ones caused by wars and/or incompetent or downright malevolent governments (which in turn lead to wars...). It's having plentiful food that we really care about. You can survive the cold if you are well-fed; warmth is no good to you if you are starving.

That's what history teaches us. No links because I assume that this is all widely accepted. Sorry for the Euro-centric view, but that's the history I learned. Chinese and Asian history, which is as well recorded as European history, seems to show a similar timeline of rises and falls of civilisations.

The Alarmists reveal themselves to be the true Climate Deniers and swear blind that temperatures remained unchanged for thousands of years until shooting up over past fifty or a hundred years (the Hockey Stick graph), with past temperatures being adjusted down and current temperatures adjusted up.

What is the point of this brief canter through history? The point is that the Alarmists now have the cheek, temerity and gall to use clear evidence of the Roman Warm Period as evidence that... there is sudden and unprecedented climate change:

From Reuters:

ZANFLEURON PATH, Switzerland, Sept 11 (Reuters) - A rocky Alpine path between two glaciers in Switzerland is emerging for what the local ski resort says is the first time in at least 2,000 years after the hottest European summer on record.

The ski resort of Glacier 3000 in western Switzerland said this year's ice melt was around three times the 10-year average, meaning bare rock can now be seen between the Scex Rouge and the Zanfleuron glaciers at an altitude of 2,800 metres and the pass will be completely exposed by the end of this month.


In other words, it's about as warm now as it was 'at least' 2,000 years ago. Which is not really Earth-shattering news, if you are prepared to learn from history. Whether the approx. 1,000 year warm/cool cycle since AD 1 is a coincidence or there is an underlying natural pattern, nobody knows. Records don't go much further back than that, although there is some ice-core evidence of a Minoan Warm Period about 1,000 years before the Roman Warm Period.

7 comments:

ontheotherhand said...

The period around 1875, at the lowest point of the Little Ice Age, marked the coldest point in the last 10,000 years, and yet the climate modellers input CO2 as the only factor responsible for warming since then, and extrapolate forward.

Sobers said...

It never ceases to amaze me that whenever these 'OMG the glaciers are melting' articles comes out that they often say that things are revealed by their retreat, and yet never make the connection that if evidence of human activity, or previous vegetation growth etc is being revealed then at some point in history it was at least as warm as today, if not more so, and that state of affairs arose entirely naturally, and moreover obviously resolved itself naturally without turning the planet into a fireball. If the warming we are seeing was 'unprecedented' then any melting glaciers would have nothing under them but rocks, because they would always have been there since the year dot.

Mark Wadsworth said...

OTH, the further back you go, the less reliable the temp estimates are, they argue it has never been hotter, not for [choose random time period], more rational people agree, as a matter of fact, it's been warmer, it's been colder, no way of really knowing.

"the climate modellers input CO2 as the only factor responsible for warming since then and extrapolate forward."

Yes, but in their worldview, CO2 IS the only relevant factor.

S, exactly! This is yet another specific example.

A K Haart said...

Another mini ice age followed the "536 event" which seems to have been volcanic and seems to have been followed by other volcanic events. These eruptions may have caused the Late Antique Little Ice Age, but nobody appears to know why it lasted for over a century, nor why it ended.

Mark Wadsworth said...

AKH, as you know, previous warm or cold periods have been airbrushed out of history. So recent modest warming MUST be caused by CO2 - we can steadfastly rule out ALL OTHER possible causes, even if that cause is "don't know".

JohnM said...

It is widely accepted by historians that there was a Roman Warm Period of a few centuries, straddling either side of AD 1. When it started to cool down, there were famines, unrest and wars for scarce (food) resources and the western Roman Empire in western Europe collapsed. The eastern Roman Empire aka. Byzantine Empire, being further east and south and a bit warmer struggled on for a few more centuries, but hey.

Whilst I'm 100% with you on the Roman Warm Period, I have to challenge you a bit on the potted history of the fall of the Roman Empire:
1. I don't think mono explanations stack up well. Why say climate change caused famine caused unrest caused civil wars caused etc etc etc. Why the root at climate change. Why not say civil wars caused famine caused unrest for instance. Gibbon blamed the fall on Christianity as a example of a different cause. I personally think multiple plagues might be one significant contributory factor. It makes more sense that multiple things caused the fall.
2. This search for a root cause sounds very like modern Greens. They would like your explanation and already echo it. Climate refugees anyone?
3. The Roman Crisis of the Third Century nearly resulted in an earlier collapse but the empire recovered for another couple of hundred years. Notionally the West might have survived. What if Valens had waited for Gratian for instance. What if the Goths had settled in the Roman empire (which was once on offer) like previous immigrant groups and become Romanised.
4. The Byzantine Empire lasted for another 1000 years [albeit not so much an empire for the last 250 years] and remained prosperous after the fall of the West. True Islam caused the loss of 3/4 of the Empire in the 600s but only after 30 years of virtually continuous wars between the Romans and Sassanid Empire had sapped the strength of both. Neither side being forced by climate or famine. The Muslim conquests caused the Empire to lose it's main food supplies from Egypt at that point but counterintuitively Byzantium began a slow recovery reaching a late peak with Basil II in 1025. My point being food shortages might be a soluble problem.

Mark Wadsworth said...

John M, sure, sure.

"I personally think multiple plagues might be one significant contributory factor"

Famines = weaker people, more susceptible to disease.