Climates Change - Empires Fall
A pattern is detectable through historical and archaeological research: Ancient civilizations have fallen due to climatic changes, mainly those depriving nations and empires of water. Paleoclimate research finds drought events in ancient history using such techniques as tree rings, sediment core analysis in lakes and carbon dating. The historical and archeological records often support such physical measurements and findings.
Archaeological evidence clearly shows that what is now the Sahara Desert was once a verdant savanna with plenty of water and wildlife. One aridification event was said to have started about 4,200 years ago, one of the most severe climatic events of the Holocene period in terms of impact on cultural upheaval. Starting in roughly 2200 BC, may have lasted the entire 22nd century BC. It probably caused the collapse of the Old Kingdom in Egypt and the Akkadian Empire in Mesopotamia.
For multiple reasons, there was much turmoil, invasion, drought and times of trouble starting around 1200 BC. The mysterious Sea People spread devastation around this time. The Greek Dark Ages started when the Greek Mycenaean civilization ended. The decline of the New Kingdom in Egypt it now appears was precipitated by drought, a weak annual Nile flood and sandstorms, precipitating cannibalism and civil anarchy. This transitory period lasted about 250 years. Then there is the decline and fall of the Hittite Empire, based in the highlands of modern-day Turkey, which similarly experienced the devastating effects of drought at the end of the Bronze Age. A super-volcanic eruption in Iceland may have cooled the earth down for some 18 years near this era.
The fall of the classic Maya civilization in about 900 A.D. had always fascinated me, and remained a mystery until Dr. Richardson B. Gill figured it out in his 2010 book The Great Maya Droughts – Water, Life and Death. The Maya were heavily dependent upon the rainy season in Central America, and when those lands were deprived of regular rainfall, they shriveled up and died. A few of the areas that had groundwater in cenotes survived, but not in the Guatemalan jungle where the most dominant city-states prevailed. The jungle returned with regular rainfall centuries later, but the great Mayan city-states never recovered their former grandeur.
The list of ancient empires, nations and civilizations brought down by climate change is liable to grow as modern science documents the events of centuries and millennia ago. Climate change in the past was due to changes in ocean currents, air currents, plate tectonics, solar variance, volcanic eruptions and any number of other factors.
Anthropogenic carbon dioxide is that portion of carbon dioxide in the atmosphere that is produced directly by human activities, such as the burning of fossil fuels. The question for modern climatologists is how to distinguish anthropogenic climate change from the climate change that has fluctuated and varied from region to region throughout all of recorded history, pre-history and geologic history. Until naturally occurring climate change is understood and measured, how can we ever determine what role anthropogenic climate change plays for a given portion of the planet or the Earth as a whole?
Recently, the polar ice cap was found to be one of the smallest on record, while the ice shelf in Antarctica was at the same time one of the most extensive on record. Clearly, climate change has never been uniform across the earth, and there is no reason to believe it will become so.
In past years, the issue was global warming. Lately, advocates have moved to a more general phrase, “climate change,” which might include global warming or global cooling. It’s as if the zealous environmentalists are hedging their bets, especially so after the extended period during which there was no measurable global warming at all. This move towards generality matches the misleading generality that the entire globe changes in the same way, and its corollary that all portions of the Earth need to act or refrain from acting in the exact same way.
Because there is no scientific consensus regarding the localized climate changes referred to above, how can there be a scientific consensus throughout the world concerning climate change? If a volcanic eruption in Iceland can cause or contribute to droughts in Egypt, Anatolia or Mesopotamia, then climate change is much more complex than a fairly simple scientific consensus that the earth is warming due to anthropogenic climate change.
It is equally unclear that climate change is always bad. The creation of the Sahara Desert is a case in point: Historians now believe that the gradual change to a desert in North Africa caused humans to gravitate towards the Nile River and create the most brilliant civilization the world had then yet known. Deserts on either side of the Nile River protected the young Egyptian civilization from intruders, allowing it to advance. And we cannot assume that warmer temperatures necessarily create deserts, because cold ocean currents can also produce deserts. Cold ocean currents cool the air that passes over them, which can cause the water in the air to fall as rain before it reaches land. Water vapor is itself a greenhouse gas, the most common greenhouse gas.
Perhaps the biggest presumption is the idea that the human race controls the climate. It has always been the other way around. If the climate changes, as it is bound to do, then perhaps humans ought to do what they have always done, adapt to the climate. The Earth’s climate has never stayed in the happiness business, nor has it ever stayed the same indefinitely.