It’s The Droughts, Stupid
by Dr. Doom

I just completed reading the latest of Brian Fagan’s several popular nonfiction books on the broad subject of civilizations and climate, “The Great Warming: Climate Change and the Rise and Fall of Civilizations” (2008). Fagan is an emeritus professor of anthropology at UC Santa Barbara. The book discusses several civilization’s response to changing climate conditions of an interval between about 800 and 1300 AD known as the Medieval Warm Period.

Wot dat, you say? Written weather records are next to nonexistent from back then, so archeologists use proxy records like tree rings, corals, and dated sediment cores taken from lakes and the ocean. They indicate a warmer than average temperature then, which was followed by the Little Ice Age, from about 1300 to 1850, a period of cooler average temperatures, followed again by the post 1850 warming attributed to human impacts, that are much higher. Hence, the constructed Mann temperature curve since about 1000 AD to present, or the infamous “Hockey Stick” (hit Google for further info).

Fagan’s view is global, so perhaps not so surprisingly, there are winners: the Europeans, especially a subset of exploring Vikings, the Arctic Inuit, the voyaging Polynesians, and a long list of losers: the Anazasi, the Maya, the Chumash of California, the Chimor of coastal Peru, peoples of the Sahel in sub-Saharan Africa, the Indians of India, the SE Asians of Angkor Wat, and lastly, but not leastly, the Chinese of the Huang He (Yellow River) Basin, also known as “China’s Sorrow” because so many died there from floods and droughts.

The winners won because in the case of Europe, especially the northern part, the warming was also a wetter time that benefited agriculture. It is likely no coincidence that the great cathedrals of Europe were constructed in this period, to give thanks to the Lord for the good times, the bountiful harvests. Calmer seas in the north and less ice cover also benefited the exploring Vikings and the Inuit, who met halfway into the New World and traded walrus ivory for steel on the northernmost islands of Canada. Weakened prevailing trade winds and a following wind from the southwest allowed the great voyaging Polynesians to expand from their roots in SE Asia across the vast expanse of the Pacific to points as far as remote Hawaii to the north, New Zealand to the south and east to far remoter Easter Island, their final frontier.

Tikal

The losers lost because of drought, and an utter defeat it was, as if great stone cities had been hit by alien neutron bombs or death rays. These were sustained droughts, lasting many years and into decades. The groups and civilizations fought back, in most cases with tremendous resolve and organization. The craftiest and most successful made amazing structures to fight against a lack of fresh water, i.e., the Maya and the Chimor. For example, the city of Tikal, a “water mountain” in what is now northern Guatemala, had enormous underground cisterns built that could store enough rain water to sustain a population of 20,000 for up to 2 years without rainfall. But at the same time, human overpopulation of the surrounding lands deforested the Maya region, which allowed no escape route to the primitive forests that had in earlier periods served as refuge in times of greatest need. So, when the prolonged several-year droughts arrived, Tikal and the surrounding lands could no longer sustain their population. Where did they all go? It’s a safe bet that they didn’t hop an ocean liner or aircraft carrier to the cozy refuge of a Club Med resort, say in nearby Cancun.

Cancun

Fagan relates the latest research of the “last stands” in the Mayan lowlands. Folks get testy and paranoid when they’re hungry, and wars break out, perhaps even among former allies and competing neighbors. It seems fortress cities were tried, but they also failed because lack of access to surrounding agricultural lands doomed the occupants, effectively reducing their ecological footprint when the opposite strategy was warranted. Something for the fortress mentality folks to consider.

The final chapter is the summary story of the reckoning that all authors and teachers with a message wait to deliver, having made their multiple cases beforehand. Here is where the cool scientist in Fagan gets emotional. One can hear his pleas behind the questioning of our present global-societal trends and pathways. He rightly brings to task those who champion the Climate Crisis (Al Gore, et al.) for their measured suggestions of response and over focus upon issues of sea level rise, even habitat loss, when drought is the silent “elephant in the room”. Fagan rightly points out that there were far fewer people to feed a thousand years ago, the average temperatures were lower than what we are experiencing now, and that the modeled climate effects of rising temperatures for later in this century and the next are dire, with even greater prolonged droughts projected than in the Medieval Warm Period.

Today, we harvest water on a vast industrial scale. Southern California steals water from the Owens Valley in Northern California and sucks the ever receding water of the Colorado River watershed, in competition with growing populations in Arizona, Nevada and Colorado. Southern Nevada wants to steal water from ranchers in the northern part of the state, and in the Midwest, eight states mine the fossil water of the enormous but finite and draining Ogallala aquifer, last recharged in the Ice Age some 18,000 years ago. Pictures of Lake Mead display a growing white band of mineral deposits on the rocks of the Hoover Dam Gorge, indicating that over half the volume of the lake has disappeared. To this, Fagan adds the sobering thought that the past 700 years of the Little Ice Age were the wettest for the US southwest since the Ice Age. He adds that vast border crossings are possible by migrating peoples attempting to escape hunger and drought.

Lake Mead

The lessons of the past are many fold, but perhaps the most pertinent one is that from the Khmer of Angkor Wat and the Maya, that the harder we try to master the natural world, the greater the risk of our “sliding down the hazardous slope of unsustainability”. Should we accept the reality that we are not the masters of our present and future world, or do we continue the high-stakes gamble, and erect even larger and more ambitious projects in vain attempts to sustain ourselves?

[Note to Doom - the first photo you sent didn't come through, it's embedded some weird way on the Word Document. Can you send that separate (I don't even know if there was anything there, the other three came through fine)]