Climate, Computers, and Clay Tablets

R. Borger’s “Mesopotamishes Zeichenlexikon” (the definitive index of Cuneiform), A.R. George’s “The Babylonian Gilgamesh Epic”, a high-res print of the Atrahasis tablet (courtesy of the British Museum) and my computer cluster “PsiCorps” running a climate simulation.

Twenty thousand years ago the Earth was a very different place. Ice, in some places over a mile thick, covered large areas of the world. With a vast amount of water locked in the ice caps and glaciers, sea level was 300 feet or more lower than what it is today. In this alien landscape our ancestors lived, clustered then as now along rivers and near the ocean shoreline. But their world was changing.

By 12 thousand years ago the earth was warming, and the great ice sheets were melting. Sea levels started to rise, and rivers overflowed their banks. Areas populated for generations were quickly covered by the sea. In some places, huge lakes formed behind great dams of ice. When these dams ruptured, unimaginable floods swept the land with walls of water hundreds and even thousands of feet high moving down the river valleys, scouring the landscape at 80 mph or more. To the mesolithic humans who witnessed these events, it must have seemed that the entire world was being destroyed by great floods. For thousands of years after the glaciers retreated, perhaps as recently as 5000 years ago, less spectacular but locally devastating floods occurred as the earth’s hydrology and geology adjusted to the new climate regime. And even after that great floods occasionally swept more limited areas, much as they do today.

Our ancestors did not know about “normal” extreme weather, much less Milankovitch cycles, plate tectonics, or changes in the thermohaline circulation. They struggled to understand what happened, and as the centuries went by, the stories of the great floods were told and retold, passed down by an oral tradition that modern ears can scarcely appreciate. Some saw the floods as divine punishment directed at man, others as a great battle between the gods in which man was simply caught in the crossfire. Given the enormous destruction, it was assumed that those who survived must have had the favor of the gods. As time went by civilizations rose and fell, and the stories were adapted to fit the politics and beliefs of the times. But the core stories of a great Deluge were preserved, and events that were separated in space and time were merged between various cultures.

In the region we call Mesopotamia there was a story of a man named Atra-Hasis receiving a warning from the gods to build a great boat and save his people from the Deluge. Eventually another story was told of an arrogant young leader who struggled with the questions of life and death. It was an epic story of maturity, kingship, and the search for understanding, and seems to have been based on a real king. At some point it incorporated the tale of Atrahasis as the man the king Bilgamas sought at the end of his journey. Around 3000 BC, scribes began using the new technology of writing to preserve the stories, using a script we now call cuneiform. Over time the language changed a little, the story was fine tuned, but the story of Gilgamesh, and his maturity from despotic ruler to Great King was preserved. And on Tablet XI of the Epic was the story of his meeting with Ut-napishti (as Atrahasis was then known) and hearing of the great deluge; perhaps a lingering memory of the catastrophic flood events thousands of years earlier.

Other cultures also preserved memories of great floods, either directly or indirectly. The small kingdom of Judah was conqured by the Babylonians, and as was their custom, the royal families and priests of Judah were sent into exile elsewhere in Babylonian lands. The exiled priests eventually incorporated Babylonian stories of the creation of man, and of Ut-napishti and his great boat, in their own stories of creation, survival, and founding of their nation. But rather than being simply the interplay of many gods in which Man was a pawn, they placed these stories within the context of the revelation that there was only one God, and it was that God who guided human history in general and their destiny in particular. Thus a new religion, Judeaism, took form. With the coming of the Roman empire 500 years later, the Akkadian language, cuneiform, and the stories of Gligamesh were slowly forgotten. But the tale of Ut-napishti, now called Noah, lived on in the Torah and became part of the traditions of a new religion, Christianity. Eventually the story was absorbed into another religion also founded in the region, Islam. And so the stories lived on.

By the 1800′s the science of archeology was born, and long lost civilizations were rediscovered. Tablets containing what is now called the “standard version” of the Gilgamesh text had been found by Austen Henry Layard in 1849 in the city of Nineveh. The Epic was rediscovered and publisized by Hormuzd Rassam in 1853. Linguists and archeologists eventually recovered much of the ancient languages of Assyerian, Sumerian, and Babylonian. Over time more and more fragments were found, and much of the original poem has been restored along with earlier versions of the stories that comprise it.

So we reach the present day. In my office are banks of computers making billions of complex calculations every second, analyzing the climate of past years and projecting the climate of years yet to come. This work is in the hope that unlike our ancestors, we can shape our future rather than simply react to events beyond our understanding. While monitoring calculations in an analysis of historical rainfall patterns, I have been slowly working my way through the Epic of Gilgamesh and how it came down to us. I am struck that here at the leading edge of human technology, surrounded by devices our ancestors would have called magic, I am able to study copies of 4000 year old clay tablets that in their own way record past climate changes, stories there were passed down from my ancestors over the course of thousands years. Thus the human effort to understand and find meaning in our world continues. It is truly awe inspiring to consider that incredible journey, and humbling to contemplate my very small part in moving it forward.

The story of how we got where we are is remarkable. The above brief summary is based on over two centuries of accumulated research in sciences like geophysics and archeology, and one that probably isn’t too far from the “truth”. The only significant speculation is if the stories of a Great Flood that many cultures share trace all the way back to the dramatic environmental shifts that happened at the end of the last glacial epoch, or more “recent”, disconnected regional events (of which there have been many). I suspect some of the stories might go all the way back to the great post-glacial floods, but even if not, they still represent the human need to understand the past and explain how, and why, events happen. Oh, and if you’re curious, solving complex four dimensional equations is easy; reading Babylonian cuneiform tablets, now that’s hard, especially since most of the scholarly publications are in German!

PS – I just returned from two weeks in Iceland, and will be posting about that and the upcoming hurricane season.  This was a post on my old blog, but I think is still timely and reflects what it’s like to do this kind of research.

Where does the time go?

Well, it’s a monotonic nondecreasing function, so the physicist in me says that’s a stupid question … but I am a bit chagrined to realize my last post was in February. My only excuse is I’ve been working on a very complex (and interesting) climate modeling project that I hope to report on here over the next few months as stuff gets written up and published.  Meanwhile, it is already the northern hemisphere hurricane season so here is a reminder: my automated system that runs the Haetta/TC model puts KML (google earth) outputs showing storm impacts (not just wind speeds, but “plain english” impacts like “trees down, some roof damage”) at this web site:

Hope to resume more frequent posts towards the end of this month …