Ruddiman's hypothesis that humans prevented an ice age through early agriculture

Ruddiman's Account Of Ancient Human Influence In The Global Warming Phenomenon

Introduction and Context

The scientific arguments for humans affecting climate change seem to be all around us today in the news and in conversations. Whenever the topic of human-induced climate change does surface there are often many difference of opinion, many of which are tied to specific scientific evidence or beliefs about the Earth's climate and environment. Ruddiman's book takes a new angle on all of this. By shedding light on some very obscure and controversial scientific arguments, the author is able to place the reader's attention on the fact that humanity may have very well helped Earth avert an ice age, but not in the way that many scientists are currently willing to argue for. The book itself is an excellent critique of the modern scientific community's willingness to jump on a particular bandwagon and change the facts in order to create a fitting theory. Ruddiman (2005) uses data relative to Earth's orbit and cycles within the solar system as well as archaeological and palentological information and arguments to support his bold position. These concepts, while not new in any way, are relatively new and foreign to the global warming debate, and it is refreshing to see a scientist shed light on a new angle of thinking. Without a doubt, the concepts and arguments presented by Ruddiman and other scientists discussed in his book present a very convincing case that man has actually helped avert the natural cycle of ice ages.

Section II: The Author's Background

Author Ruddiman certainly comes from an academic background, but since his arguments are not often congruent with those of other scientists and historians, it is necessary to more closely examine Ruddiman's credentials and experience in order to obtain a clearer, more informed picture of him as an authoritative figure in the scientific field. To start off with, Ruddiman (2005) is a professor Emeritus at the University of Virginia, and works as a paleoclimatologist. This title, while seemingly complex and confusing, just means that he studies climate change on a very large scale, one that spans the entire length of global history. Many people would be convinced by his academic credentials alone, but Ruddiman's arguments, as unique and foreign as they sometimes are, come from a place of experience as well as academic credibility. He has been involved in numerous studies and research expeditions, one of which was to Tibet to study the tectonics of the region. He has authored many papers and books, and one of them even posited that the Indian monsoonal cycle was caused by the shifting plates and tectonics within the India-Tibet region.

He has also theorized about the melting of glaciers being caused by other factors besides global warming such as the Earth's orbital changes around the sun over long periods of time. Ruddiman is most famous for the hypothesis presented in this book about climate change, entitled, Plows, Plagues, and Petroleum: How Humans Took Control of Climate. This theory suggests that as humans developed more and more complex forms of agriculture and society that the balance of greenhouse gasses and carbon emissions was shifted and helped avert an impending ice age, which cyclically comes about every 10,000 years or so (Ruddiman, 2005). This theory is controversial because many anthropologists argue that there was not enough of a human population even 1,000 years ago to create such an imbalance of greenhouse gasses in the atmosphere. Other scientists argue that Ruddiman misses the point of much of the most recent research on climate change, and is chalking up the current global warming issue to a cause that does not have nearly enough influence to be the main driver of the warming trend.

The book itself is filled with excellent sources and information from other independent sources, and is very refreshing in that it refuses to capitulate to the current and most popular global warming arguments. But the book itself, coming from a paleoclimatologist does not hold water when compared to what many anthropologists and scientists already know about the potential for human influence on the environment some 8,000 years ago.

Section III: The Book's Argument

The book's argument is rather controversial and relatively new. In a nutshell, Ruddiman argues that the Earth's cycle of ice ages, typically occurring every 10,000 years or so, was disrupted by human activity (Ruddiman, 2005). This human activity is specifically related to the rise of mass agriculture and civilization some 8,000 years ago. He argues that the carbon and greenhouse gas footprints of these early human societies has averted the most recent ice age, and that the global climate change we are currently seeing today is a product of these activities coupled with the fact that the Earth's orbit and rotational axis changes in a cyclical pattern of about the same time frame. While his arguments are quite refreshing and intriguing, many other scientists, with experience and knowledge specific to other fields, tend to disagree with Ruddiman and his theory about global climate change being affected by ancient human activity.

How could humans have affected this current ice age but not have affected the previous one? Ruddiman's rebuttal comes from the fact that humans developed agricultural methods and behaviors only 8,000 years ago, and in doing so, drastically changed the footprint of humanity as a whole upon the earth's climate (Ruddiman, 2005). But Ruddiman's research does hold one key finding that cannot be explained away by most scientists or the anthropologists who are currently at odds with his theory. In Ruddiman's research he was able to take sample ice cores from the Earth's Polar Regions and glaciers and compare the amounts of greenhouse gasses in the atmosphere at different points in history. These differing levels showed that contrary to the widely-held belief that the Earth goes through a cycle of warming and cooling with greenhouse gas levels following this same cycle, the past 10,000 years have held entirely different sampling results (Ruddiman, 2005).

Ruddiman (2005) noted that the cores showing the past 10,000 years of atmospheric evidence told an entirely different story. While humans were developing modern types of farming and agriculture, the greenhouse gas levels never really plateaued as they had in millennia past. Instead, these greenhouse gas levels increased, almost in exponential fashion. It is this evidence that Ruddiman uses to back up his claim that humans have influenced the course of the ice age cycle. Specifically, instead of the methane levels cycling back upwards approximately 11,000 years ago, but instead have declined to their present levels today (Ruddiman, 2005). At first, the cycle of methane production was followed in terms of the historical expectations of rise and fall associated with the ice age cycle. But about 5,000 years ago this cycle was suspended, and Ruddiman feels as though human beings are to blame. Ruddiman argues that one of the most influential civilizations relative to his theory is that of the Asian subcontinent. Their cultivation of rice from artificially created wetlands, according to the author, has contributed more to the ancient greenhouse gas emission than many other civilizations combined.

Another interesting development with the Ruddiman's research is the idea that while the ice cores did show a steady increase in greenhouse gasses when there should have been a cyclical decrease, there were "wiggles," as Ruddiman (2005) puts it in this record of atmospheric change. These drops and rises in the atmospheric record, according to Ruddiman, are the result of human-centric activities and events. Ruddiman (2005) argues that the bubonic plague as well as a host of other plagues and sicknesses that became globally widespread account for these small variations or pattern corrections. This assumption may or may not be correct. It is hard to believe that the bubonic plague could have such an effect on the atmospheric gas levels, but it does seem plausible. It would be interesting to see if there existed any other major "wiggles" in the greenhouse gas records within the ice samples that could not have corresponded to human activity or existence. This would help to prove, one way or the other, whether or not these "wiggles" are reliable as evidence of the ancient human activity theory of global climate change.

Ruddiman takes some time in his book to discuss the future of fossil fuel usage as well. This topic ties in closely with the previous topic of global arming caused by human activity over the millennia. The author posits that humans have about 150 to 200 more years worth of fossil fuels at our current rate of consumption (Ruddiman, 2005). This means that other technologies will have to be utilized in order for humanity to have the same kind of transportation and energy expectations and usages. Ruddiman's connection of the fossil fuel question and the global climate change topic also has meaning in that he assert without so much of a human fossil-fuel induced atmospheric footprint, humans may no longer be able to stave off the next ice age. Humanity might not have the same effective power over the environment when fossil fuels run out. While this assumption is certainly believable, humans will not doubt reach a point where the greenhouse gas absorbing plants and bodies will no longer be able to keep up with human activity. This will further exacerbate the problem of human-caused global climate change. On the other hand, if humans are able to develop non-fossil fuel alternatives that do not have a negative effect on the environment on a global scale, the warming trend might very well be reversed in a generation or two. Either way, Ruddiman's arguments will likely be proven to be wrong or right, on a long enough timeframe.

Section V: Synthesis and Evaluation

Ruddiman's arguments hold weight, at least as far as his methodology and ice core samples are concerned. But it is difficult to assign so much influence to the activities of a relatively small ancient human population, as Ruddiman describes. But his should not entirely be thrown out. Science is an ever-changing field and theories are just that, theories. Ruddiman has made some very insightful connections between human activity that took place 8,000 years ago and the world today. I would present a more moderated model for the cause of the current global warming trend. Perhaps an approach that incorporates pieces of Ruddiman's and other author's arguments. It is much more likely that many different factors all played roles in creating the current global warming crisis that Earth is currently facing, and it is often very imprudent to blind one's self from other arguments entirely, refusing to recognize that perhaps other factors, such as the clearing and burning of forests as well as the agricultural development that occurred within ancient human civilizations, all helped play a role in the way the Earth's environment appears today. The black and white world that Ruddiman and others live in can be quite dangerous, at least academically. The ice core samples are hard to disprove, and Ruddiman effectively constructs his argument around this very concrete evidence.

Sources

Allen, Robert, Scott Seaman and John DeLascio. "Emerging Issues: Global Warming Claims and Coverage Issues." Defense Counsel Journal 76 (2009): 12-9. Web. 10 Apr. 2010. .

Bast, Joseph. "Eight Reasons Why 'Global Warming' is a Scam." The Heartland Institute. The Heartlander, Feb. 2003: n.pag. Web. 10 Apr. 2010.

Bert, Ray. Rev. Of Plows, Plagues, & Petroleum: How Humans Took Control of Climate, by William F. Ruddiman. Civil Engineering 78 (2008): 73.

Morgan, Sally. Global Warming. New York: Heinemann, 2009. Print.

Ruddiman, William. (2005). Plows, Plagues, and Petroleum: How Humans Took Control of Climate. Princeton University Press: New York.

Silver, Cheryl Simon. One Earth, One Future. Washington, D.C.: National Academies Press,

1992. Print.

Turner, B.L. Rev. Of Plows, Plagues, & Petroleum: How Humans Took Control of Climate, by William F. Ruddiman. Geographical Review 96 (2006): 516-9. Web. 10 Apr. 2010. .

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