Thursday, July 22, 2010

Climate Change - Patterns in Time
The Biology of Human Civilizations and the Climate







I am starting this blog first and foremost because I am fed up with the “climate change deniers”. But really it is more than that. It is also because I believe that even the people who know and understand the seriousness of the global climate change (that is happening now) are missing one very important reason for controlling our carbon dioxide output. It is more than the predicted increase in the severity of storms or a rise in sea level (and that is bad enough!). It is the very survival of our present day civilization that is in peril.

I am a plant pathologist and at the end of the last century I had the privilege of working with one of my graduate advisors on the development of college class to teach biology to undergraduates in the hopes of luring some of them into the field of Plant Pathology. I eventually ended up teaching the class online for several years and wrote a book specifically for that online class. In the process of writing that book, I learned just how important the world’s climate has been for past human civilizations.

Like many others, I have always had a fascination about past civilizations like the Maya, the Minoans, and the Moche, to name a few. What had happened to these once great civilizations? As I was doing the research required for this new biology class, taught from the point of view of a Plant Pathologist, I found a new insight into what must have happened to these civilizations.

It is this insight I would like to share with any who will find and read this blog. So here goes…..

Introduction

To understand why global warming today is so important we have to go back about 10,000 years to another time of global warming.

Like human beings all over the globe 10,000 years ago, people in a place called the Levant were living in mountain caves and making their living by hunting and gathering. They fed themselves by fishing, hunting gazelle and other mammals, and by gathering fruits, roots, and seeds including the intensive gathering of many wild cereal grasses. Then, between 13,000 and 9000 BCE, their world began to change. The global climate was warming and these people began to settle in villages and build houses of stones and mud bricks. By 7000 BC these people were evolving into the world's first farmers. From that time on, most human beings have been feed by agriculture not by hunting and gathering.

This is important for several reasons. First, agriculture can support higher population densities than hunting and gathering. Second, the transition to agricultural set the stage for the next step in the story of human evolution – the development of what we call civilization. There are many definitions of civilization but basically civilization means the presence of densely populated cities/states, and the bureaucracy to run them.

The very first civilization, or state society, evolved just east of the Levant in the river valley of the Tigris and Euphrates Rivers south of the Zagros Mountains. (You know… IRAQ!) Over the next 2000 years, agriculture spread from the Levant. It spread eastward down the river valleys of the Tigris and Euphrates of today’s Iraq and to the Indus Valley in Pakistan. It spread south to the Nile Valley of Egypt. It spread north into Turkey and Southern Europe and into Greece. Civilizations all across the Middle East flourished.

However, somewhere between 2000 and 1200 BCE, these civilizations descended into chaos. They left us with grand monuments (Sumer, Egypt, Minoan) and a great mystery to ponder…What happened?



Guess what…. the global climate changed!




Except for the global warming that happened 10,000 years ago, the climate changes of the last 8000 years have been times of global cooling, not warming. However, what you need to know is this. For modern humans, it does not much matter whether the global temperature is going up or going down.



What matters is that it is changing!



Why? It’s because both global warming and global cooling change where it rains and we humans put our civilizations where it rains.

And why is that? Simple put, it is because we build our civilizations where people can be fed. And guess what - the plants we eat and the plants we feed to the animals we eat need water to grow!!!!! And just enough water, not too much and not too little! Putting it another way…..



It’s Agriculture!!!!




2 comments:

  1. Very interesting and very true! Ecosystems we depend on are defined by the weather patters. If the rain moves and the city doesn't how will we have to compensate? More pipes, trucks, and canals or will cities like Las Vegas become ghost towns?

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  2. Hmmm, good question. Today we can live anywhere because we have most of our food "shipped" in by trucks etc. Most of the first civilzations could not do this and founded their cities next to rivers (posts to come). However the farms where our food comes from still require rain/water or they will have nothihg to ship to us in the city.

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