Putting the life back in science fiction

Why more droughts matter more than some droughts
July 20, 2016, 9:53 pm
Filed under: climate change, Real Science Content, Speculation | Tags: ,

So I’ve finished reading 1177 B.C., The Year Civilization Collapsed, as I mentioned in the last post.  It’s a good book, and it’s also a good lesson in why I might want to wait until I’m done reading a book before blogging.

It turns out there’s multiple lines of evidence that there was a drought in the eastern Mediterranean around 1177 B.C.  However, if you know anything about Mediterranean climates, you’ll know that droughts happen.  Was this one different?  That part’s unknowable, but a book I read earlier this spring does point to how the eastern Mediterranean can get into a big problem when two droughts coincide, and that’s the little lesson for today: it’s not just the local drought that’s the problem.

Now, the basic causality is pretty straightforward: a sufficiently severe drought leads to crop failure, a sufficiently severe crop failure leads to famine, famines tend to lead to unrest and/or disease, and sufficiently severe famine, disease, and war lead to that fourth horseman, a lot of people dying, and sometimes their city-states or whatever dying with them (this is why the Four Horsemen are portrayed as riding together, at least in my opinion).

There’s an easy way around this, though: importing water, food, and medicine.  In the eastern Mediterranean, a bit of geographical hocus-pocus let them do this quite well.  According to Ronnie Ellenblum’s The Collapse of the Eastern Mediterranean, the eastern Mediterranean actually partakes of two fairly independent weather systems: the eastern Mediterranean and the Indian Ocean Monsoon.  The link is the Nile River, which gets its water ultimately from African mountains watered by the monsoon, not from the storms that hit the eastern Mediterranean.  As a result, when there’s a drought in the eastern Mediterranean, there’s seldom a drought in the Ethiopian Highlands or the Mountains of the Moon, so the Nile does not fail.  When there’s a drought in Africa and the Nile fails to flood, there’s seldom a drought in the eastern Mediterranean.  Since Egypt and the Middle east are right next to each other and a relatively short sea voyage away from everywhere from Byzantium to Rome (both of which depended on Egyptian wheat), there’s generally a lot of food available for import if local crops fail, so crop failure is more often a hardship than a catastrophe.  That doesn’t mean that things can’t get locally bad (cf: Syria right now), but it does mean that regional crop failure in that part of the world depends on the unusual coincidence of drought hitting both the eastern Mediterranean and eastern Africa simultaneously.  That apparently doesn’t happen very often.

Moreover, in the Medieval Warm period that Ellenblum is interested in, the weather was actually very good in Europe at the same time crops were failing in the Middle East.  He sees this as one cause of the Crusades, because the powers of the eastern Mediterranean (the Caliphate and Byzantium) were both weakened by crop failures throughout the region, and including crop failures in Egypt.  While I at least normally think of bad conditions as creating refugees on the move, Ellenblum suggests that really good conditions can also create emigrants looking for new lands to conquer, a variant on what’s now called disaster capitalism.

Did something like this happen in the Bronze Age collapse?  We can’t know, at least until we find out both that there were overlapping crop failures in the Nile watershed and the eastern Mediterranean, while there were unusually good conditions in the western Mediterranean and Europe.  Quite possibly the evidence is already published, but no one has put together the pieces yet.

A second thing to realize is that the Bronze Age kingdoms were tiny compared even with Medieval kingdoms and empires, which were small in turn compared to the states of today.  Back in the Bronze Age, Egypt was independent, not a pawn of empires.  It’s possible that Egypt’s many imperial adventures up into the Middle East were driven in part by bounteous crops along the Nile (and possibly bounteous surpluses of testosterone-charged young men), coupled with relative dearth in the Middle East.  The resulting power imbalance might have prompted the more power-hungry Pharaohs to enlarge their kingdoms, only to be driven back (or to have their descendants driven back) as conditions changed and different regions grew lush and productive.  This is all speculation, of course.   I suspect that environmental change was only one factor in social change, not the puppetmaster that caused all those ancient wars.*

Still, there’s an important lesson for our modern world.  Globalization is a two-edged sword.  On the one hand, it brings a lot of misery, through everything from lost jobs exported overseas to new invasive species.  On the other hand, it allows at least the possibility of smoothing out these crop failures worldwide, and does go a long way to keeping everyone fed, because we never seem to get worldwide crop failures.  So long as food can move around the world, at least theoretically we have the possibility of keeping everyone fed through local hardships.  Famines now are as much the result of political failure as they are of crop failure.  This is one reason why the fulminating xenophobia we see in things like the BRexit and the Trump campaign is worrisome.  If we become more isolationist, the world becomes more disconnected.  Problems that could have been solved by shipments of food become wars that invite shipments of weapons into the tormented region and mass flows of refugees flowing away.

There’s also the issue of climate change, which complicates these patterns.  With the monsoon shifting and the Mediterranean zone becoming desertified (to give two examples of many), I don’t know how much longer people will be able to depend on at least one of these two always working.  And there are a lot of people living near the edge in that region now.    Worldwide, severe climate change could lower agricultural productivity, leading to worldwide crop failure if we don’t adapt thoroughly enough.  That’s really not something we want to see.  So long as the world’s thoroughly interconnected, a single drought doesn’t matter as much as multiple droughts.  Hopefully we won’t see that change.

*note that the ancients might actually have seen the weather, and the gods that controlled it, as the ultimate cause, and their own actions as those of the gods’ helpless playthings, as they made the best of capricious fate.  Religion was a bit different back then.



5 Comments so far
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Reminds me of info I dug up on emu movements in Western Australia, another region with a Mediterranean climate but influenced by Indian Ocean monsoons. Emus are nomadic and not very social (mostly solitary or family groups; in exceptionally good conditions groups of up to 40 have been observed feeding together), but when someone puts up a thousand-mile-long barbed-wire fence they can become wonderfully concentrated. Comparison of year-by-year records show (in contrast to simplified claims often made, e.g. by the state agriculture department) that migrations towards wheat-growing areas may occur in years with either widespread above-average-rainfall conditions, widespread drought, a combination of inland drought and coastal rainfall, or the reverse (there’s no available data on the direction of movements for most instances). One of these events in 1932 led to the ’emu war’ in which many crops, fences and vehicles were destroyed and vast amounts of machine-gun ammo expended by government forces, but the emus merely dispersed again after more rain, so I reckon they won.

Comment by John Scanlon FCD

Causality doesn’t have to run from crop failure->disease, e.g. the Black Death. Local disease outbreaks, e.g. cholera will be independent of food conditions. Pandemics are more likely when states are not isolated, but trade with each other.

What we might expect in some cultures, like Egypt, record keeping that indicates crop failures due to drought or other weather related conditions. Multiple year failures that draw down stores would be of particular note.

Comment by Alex Tolley

There are no records of pandemics from that time. There ARE records of people (the infamous Sea Peoples of the Egyptians) on the move, but they were known to be a mixed group of up to nine different groups of people. It’s unclear whether they were a giant coalition or a bunch of refugees from fallen cities mixed with invaders.

As for the Egyptian records, it is true that there is no record of a famine at that time. Unfortunately, the temple wall texts that survive from the period have more in common (IMHO) with the kind of propaganda one sees coming from places like modern North Korea than they do with recording warts-and-all history. Ramses V’s great victories over the combined invading fleets of the Sea Peoples are recorded, but the fall of other kingdoms (known from archaeological evidence) is not. Of course, if they wrote their true history on papyrus, it didn’t survive.

Comment by Heteromeles

I don’t know about that specific history. All I was trying to say was that famines are not necessarily the precursors of the other horsemen. As you point out, written records are sparse. Real histories weren’t made until the Roman period, I think. Prior to that, it was probably rather ad hoc, and records were likely to be ephemeral (as our electronic ones might be too).

Comment by Alex Tolley

Agreed. That’s the whole point of my analysis of the Four Horseman, that any one of the first three (war, famine, epidemic) tends to trigger the other two, and death of a good chunk of the population generally follows, leaving historians arguing for decades about what exactly caused the deaths (famine, war, or plague?).

So far as the known history of the Bronze Age Collapse goes, the evidence shows the presence of raiders from the sea some time around the fall of Ugarit, and the Egyptians beating off the “Sea Peoples” in two battles some time later. There’s paleo-environmental data supporting a drought in the eastern Mediterranean at the same time, a lot of former powers seem to disappear from the historical record in the 12th Century BC (1200 BCE-1100 BCE) and even Egypt comes through it severely weakened.

What I’m suggesting here is something similar to what may have happened immediately before the Crusades: crop failures caused by drought weakened the Eastern Mediterranean, while the Western Mediterranean (which was illiterate at this point, so there’s only the archaeological record) had good weather and a surplus of young men. Their troublemakers apparently had been going east to fight under the Pharaoh for years (some of the Sea People are thought to have been Sardinians, for example), and perhaps they decided to go a-viking in the very rich, and drought-weakened, civilizations of the Eastern Mediterranean. City-states crashed as a result, civilization more or less crashed in the region, and the iron-wielding Classical World as we know it rose from the rubble about 400 years later.

Comment by Heteromeles

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