Plows, Plagues and Petroleum
Encyclopedia
Plows, Plagues and Petroleum: How Humans Took Control of Climate is a 2005 book published by Princeton University Press
and written by William Ruddiman
, a paleoclimatologist and Professor Emeritus
at the University of Virginia
. He has authored and co-authored several different books http://www.gsajournals.org/perlserv/?request=getdocument&doi=10.1130%2F1052-5173(2002)012%3C0023:ESCPAF%3E2.0.CO%3B2 and academic papers http://stephenschneider.stanford.edu/Publications/PDF_Papers/Ruddiman2003.pdf on the subject of climate change
. This book however takes a more controversial approach by challenging the common conclusion of climate scientists that human induced climate change began with the industrial revolution
through the widespread burning of fossil fuels. Scientists often refer to this period as the “Anthropocene
” and define it as the era in which humans first began to alter the earth’s climate
and ecosystems. Ruddiman contends that human induced climate change began as a result of the advent of agriculture
thousands of years ago and resulted in warmer temperatures that could have possibly averted another ice age
.
have been absorbed out of the atmosphere
due to interactions between monsoon
rains and ground up rock exposed by India
pushing into Asia
and creating the Himalayas
. Additionally it is believed that the melting ice that produced higher sea levels resulted in the ocean absorbing more carbon dioxide out of the atmosphere. These two natural occurrences resulted in less carbon dioxide in the atmosphere hence possibly producing the general cooling trend.
According to Ruddiman beginning about 900,000 years ago the earth has begun to go through regular glacial cycles in which glaciers or ice have covered approximately one quarter of the earth’s total surface. These conditions typically last for about 100,000 years and are followed by brief interglacial
periods of more temperate weather. Ruddiman cites various researchers in geology
and astronomy
who pioneered the understanding of earth’s climate as a function of its orbit. The various cycles of earth’s climate seem to be explained by the eccentricity
, axial tilt
, and precession of the Earth's orbit as well as cycles in the amount of solar radiation. Ruddiman primarily relies on the groundwork by Milutin Milankovitch to explain the effects of solar radiation and earth’s orbit on the climate. By examining ice cores from around the world scientists have been able to link levels of greenhouse gases such as carbon dioxide and methane
to the various cycles of earth’s climate history. The discovery of carbon dating aided a great deal in developing this understanding. Upon investigating the levels of carbon dioxide and methane in the earth’s atmosphere in the most recent interglacial period-10,000 years ago- Ruddiman noticed that levels of carbon dioxide and methane were steadily rising despite the fact that the earth’s natural cycles determined that they should have been decreasing. It was this discovery that lead to Ruddiman’s search for an explanation and ultimately the creation of this book.
Ruddiman’s central argument is that this most recent interglacial period has deviated from the natural cycle because of human
activities, most importantly farming. Approximately 10,000 years ago the ice that once covered large portions of the northern hemisphere
began to recede and gave rise to a new way of life for early humans. In the beginning these early humans had little impact on the environment
because they were primarily hunter gatherer societies that moved from location to location allowing previously inhabited locations to be reclaimed by nature. However, about 8,000 years ago humans first developed agriculture and a domesticated lifestyle that allowed them to continually inhabit regions and build large civilizations. Ruddiman claims that carbon dioxide emission records indicate that levels in the atmosphere began to rise at about this same time. This process was intensified as the centuries passed and new technologies such animal husbandry
and the plow made their way into more and more cultures. These new technologies allowed for more efficient methods of clearing forests and making room for increasing populations. According to previous interglacial periods the concentration of carbon dioxide should have fallen by about 20 parts per million instead of rising by 20 parts per million. Ruddiman uses estimates of population, forest cleared per person and carbon emitted per each square kilometer cleared to approximate the total impact and concludes that the magnitude is reasonably close to the extra carbon dioxide accumulated during the period.
Ruddiman also attributes the rise of methane gas in the atmosphere to human related activities. The most notable of these activities is the cultivation of rice in artificial wetlands in Asia and increased animal waste due to increasing populations of domesticated animals. According to Ruddiman methane concentrations should have peaked about 11,000 years ago slightly above 700 parts per billion and then declined to about 450 parts per billion today. Methane levels followed this cycle at first, but about 5000 years ago they began to rebound and currently the concentration is about 275 parts per billion above the previous trends.
According to Ruddiman farming and related activities resulted in large amounts of greenhouse gases (carbon dioxide and methane) being released into the atmosphere at a time when natural cycles of the earth indicated they should have been falling. The result has been an unintended warming cycle that prevented the earth from entering into another ice age http://www.pik-potsdam.de/~claussen/papers/ruddiman+al_qsr_05.pdf. Ruddiman goes as far as to say that if these gases had not been released into the atmosphere, areas in northern Canada
such as Hudson Bay
and Baffin Island
would currently be covered in ice today. The implications of this theory are wide ranging and most certainly worthy of further exploration.
Throughout the record of carbon dioxide and methane emissions there are drops and rises in the amount of concentrations present in the atmosphere. Ruddiman explains these “wiggles” by claiming that they appear at times of major outbreaks of disease such as the bubonic plague
in the 1,300’s and the prevalence of old world
diseases in the Americas after the arrival of Columbus
. Both of these events resulted in large numbers of people dying and the land they once inhabited being reclaimed by the forest. This resulted in increased amounts of carbon dioxide being taken out of the atmosphere, hence causing global temperatures to cool down. Ruddiman claims that the little ice age
, starting in the 13th century and ending sometime in the early 19th century was caused by the decreased population and the re-forestation of previously cleared lands as a result from the diseases that killed off so many people.
The last aspect of Ruddiman's discussion of climate change relates to the future of petroleum use on earth. It is commonly known that the world’s supply of fossil fuels is rapidly depleting and even conservative estimates claim that the supply will not last much more than 150-200 more years. Ruddiman claims that when this sources of natural fuels has been depleted, human kind will have to resort to using the large quantities of coal that still exist all over the planet. This, according to Ruddiman, will result in a continued warming trend that will only stop when technology either produces a new source of fuel or figures out a way to separate the carbon dioxide emissions prior to being released into the atmosphere. Ruddiman is quite skeptical of both scenarios in the near future because of the increased costs and technological advancements that would have to be made in such a short time. Eventually carbon and methane emissions will be controlled and lowered a great deal and Ruddiman asserts when this happens the earth will most likely begin an era of cooling temperatures.
, a climate modeler at the NASA
Goddard Institute for Space Studies in New York, claims that is it extremely uncertain that early human populations could have had the enormous environmental effects that Ruddiman claims. He also claims that recent studies of methane emissions have shown that methane increases over the last 5,000 years could be attributed to the development of the boreal wetlands and major river deltas after the ice from the previous ice age melted and caused the sea level to rise to its current location http://www.giss.nasa.gov/research/features/methane/.
Other criticism suggests that Ruddiman shortchanged the impact of burning forests in his synopsis of early human activity. According to Michael Williams author of Deforesting the Earth, early humans used fire a great deal for either hunting and or clearing purposes. Ruddiman does not discuss the role of fire at any length and instead decides to focus on the impact of the plow on human agriculture http://books.google.com/books?vid=ISBN0226899268&id=mW8Fl2ieJFsC&pg=PA560&lpg=PA560&ots=1KkMUulerC&dq=book+review+of+deforesting+the+earth&sig=H-i8nnIoUpq8ywtAAuu81BjTwW0#PPP1,M1.
Princeton University Press
-Further reading:* "". Artforum International, 2005.-External links:* * * * *...
and written by William Ruddiman
William Ruddiman
William F. Ruddiman is a palaeoclimatologist and Professor Emeritus at the University of Virginia. Ruddiman earned an undergraduate degree in geology in 1964 at Williams College, and a Ph.D. in marine geology from Columbia University in 1969. Ruddiman worked at the US Naval Oceanographic Office...
, a paleoclimatologist and Professor Emeritus
Emeritus
Emeritus is a post-positive adjective that is used to designate a retired professor, bishop, or other professional or as a title. The female equivalent emerita is also sometimes used.-History:...
at the University of Virginia
University of Virginia
The University of Virginia is a public research university located in Charlottesville, Virginia, United States, founded by Thomas Jefferson...
. He has authored and co-authored several different books http://www.gsajournals.org/perlserv/?request=getdocument&doi=10.1130%2F1052-5173(2002)012%3C0023:ESCPAF%3E2.0.CO%3B2 and academic papers http://stephenschneider.stanford.edu/Publications/PDF_Papers/Ruddiman2003.pdf on the subject of climate change
Climate change
Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...
. This book however takes a more controversial approach by challenging the common conclusion of climate scientists that human induced climate change began with the industrial revolution
Industrial Revolution
The Industrial Revolution was a period from the 18th to the 19th century where major changes in agriculture, manufacturing, mining, transportation, and technology had a profound effect on the social, economic and cultural conditions of the times...
through the widespread burning of fossil fuels. Scientists often refer to this period as the “Anthropocene
Anthropocene
The Anthropocene is a recent and informal geologic chronological term that serves to mark the evidence and extent of human activities that have had a significant global impact on the Earth's ecosystems...
” and define it as the era in which humans first began to alter the earth’s climate
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...
and ecosystems. Ruddiman contends that human induced climate change began as a result of the advent of agriculture
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...
thousands of years ago and resulted in warmer temperatures that could have possibly averted another ice age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...
.
Synopsis
Ruddiman begins the book with a brief introduction to the science of climate change and the various individuals that have been key in influencing the field over the years. He also notes that the earth’s climate has been drifting toward cooler temperatures for the last 55 million years. The dominant hypothesis for this trend is that large volcanic eruptions have subsided while increasing amounts of carbon dioxideCarbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
have been absorbed out of the atmosphere
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
due to interactions between monsoon
Monsoon
Monsoon is traditionally defined as a seasonal reversing wind accompanied by corresponding changes in precipitation, but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with the asymmetric heating of land and sea...
rains and ground up rock exposed by India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
pushing into Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
and creating the Himalayas
Himalayas
The Himalaya Range or Himalaya Mountains Sanskrit: Devanagari: हिमालय, literally "abode of snow"), usually called the Himalayas or Himalaya for short, is a mountain range in Asia, separating the Indian subcontinent from the Tibetan Plateau...
. Additionally it is believed that the melting ice that produced higher sea levels resulted in the ocean absorbing more carbon dioxide out of the atmosphere. These two natural occurrences resulted in less carbon dioxide in the atmosphere hence possibly producing the general cooling trend.
According to Ruddiman beginning about 900,000 years ago the earth has begun to go through regular glacial cycles in which glaciers or ice have covered approximately one quarter of the earth’s total surface. These conditions typically last for about 100,000 years and are followed by brief interglacial
Interglacial
An Interglacial period is a geological interval of warmer global average temperature lasting thousands of years that separates consecutive glacial periods within an ice age...
periods of more temperate weather. Ruddiman cites various researchers in geology
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
and astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
who pioneered the understanding of earth’s climate as a function of its orbit. The various cycles of earth’s climate seem to be explained by the eccentricity
Orbital eccentricity
The orbital eccentricity of an astronomical body is the amount by which its orbit deviates from a perfect circle, where 0 is perfectly circular, and 1.0 is a parabola, and no longer a closed orbit...
, axial tilt
Axial tilt
In astronomy, axial tilt is the angle between an object's rotational axis, and a line perpendicular to its orbital plane...
, and precession of the Earth's orbit as well as cycles in the amount of solar radiation. Ruddiman primarily relies on the groundwork by Milutin Milankovitch to explain the effects of solar radiation and earth’s orbit on the climate. By examining ice cores from around the world scientists have been able to link levels of greenhouse gases such as carbon dioxide and methane
Methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...
to the various cycles of earth’s climate history. The discovery of carbon dating aided a great deal in developing this understanding. Upon investigating the levels of carbon dioxide and methane in the earth’s atmosphere in the most recent interglacial period-10,000 years ago- Ruddiman noticed that levels of carbon dioxide and methane were steadily rising despite the fact that the earth’s natural cycles determined that they should have been decreasing. It was this discovery that lead to Ruddiman’s search for an explanation and ultimately the creation of this book.
Ruddiman’s central argument is that this most recent interglacial period has deviated from the natural cycle because of human
Human
Humans are the only living species in the Homo genus...
activities, most importantly farming. Approximately 10,000 years ago the ice that once covered large portions of the northern hemisphere
Northern Hemisphere
The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...
began to recede and gave rise to a new way of life for early humans. In the beginning these early humans had little impact on the environment
Natural environment
The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species....
because they were primarily hunter gatherer societies that moved from location to location allowing previously inhabited locations to be reclaimed by nature. However, about 8,000 years ago humans first developed agriculture and a domesticated lifestyle that allowed them to continually inhabit regions and build large civilizations. Ruddiman claims that carbon dioxide emission records indicate that levels in the atmosphere began to rise at about this same time. This process was intensified as the centuries passed and new technologies such animal husbandry
Animal husbandry
Animal husbandry is the agricultural practice of breeding and raising livestock.- History :Animal husbandry has been practiced for thousands of years, since the first domestication of animals....
and the plow made their way into more and more cultures. These new technologies allowed for more efficient methods of clearing forests and making room for increasing populations. According to previous interglacial periods the concentration of carbon dioxide should have fallen by about 20 parts per million instead of rising by 20 parts per million. Ruddiman uses estimates of population, forest cleared per person and carbon emitted per each square kilometer cleared to approximate the total impact and concludes that the magnitude is reasonably close to the extra carbon dioxide accumulated during the period.
Ruddiman also attributes the rise of methane gas in the atmosphere to human related activities. The most notable of these activities is the cultivation of rice in artificial wetlands in Asia and increased animal waste due to increasing populations of domesticated animals. According to Ruddiman methane concentrations should have peaked about 11,000 years ago slightly above 700 parts per billion and then declined to about 450 parts per billion today. Methane levels followed this cycle at first, but about 5000 years ago they began to rebound and currently the concentration is about 275 parts per billion above the previous trends.
According to Ruddiman farming and related activities resulted in large amounts of greenhouse gases (carbon dioxide and methane) being released into the atmosphere at a time when natural cycles of the earth indicated they should have been falling. The result has been an unintended warming cycle that prevented the earth from entering into another ice age http://www.pik-potsdam.de/~claussen/papers/ruddiman+al_qsr_05.pdf. Ruddiman goes as far as to say that if these gases had not been released into the atmosphere, areas in northern Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
such as Hudson Bay
Hudson Bay
Hudson Bay , sometimes called Hudson's Bay, is a large body of saltwater in northeastern Canada. It drains a very large area, about , that includes parts of Ontario, Quebec, Saskatchewan, Alberta, most of Manitoba, southeastern Nunavut, as well as parts of North Dakota, South Dakota, Minnesota,...
and Baffin Island
Baffin Island
Baffin Island in the Canadian territory of Nunavut is the largest island in the Canadian Arctic Archipelago, the largest island in Canada and the fifth largest island in the world. Its area is and its population is about 11,000...
would currently be covered in ice today. The implications of this theory are wide ranging and most certainly worthy of further exploration.
Throughout the record of carbon dioxide and methane emissions there are drops and rises in the amount of concentrations present in the atmosphere. Ruddiman explains these “wiggles” by claiming that they appear at times of major outbreaks of disease such as the bubonic plague
Bubonic plague
Plague is a deadly infectious disease that is caused by the enterobacteria Yersinia pestis, named after the French-Swiss bacteriologist Alexandre Yersin. Primarily carried by rodents and spread to humans via fleas, the disease is notorious throughout history, due to the unrivaled scale of death...
in the 1,300’s and the prevalence of old world
Old World
The Old World consists of those parts of the world known to classical antiquity and the European Middle Ages. It is used in the context of, and contrast with, the "New World" ....
diseases in the Americas after the arrival of Columbus
Christopher Columbus
Christopher Columbus was an explorer, colonizer, and navigator, born in the Republic of Genoa, in northwestern Italy. Under the auspices of the Catholic Monarchs of Spain, he completed four voyages across the Atlantic Ocean that led to general European awareness of the American continents in the...
. Both of these events resulted in large numbers of people dying and the land they once inhabited being reclaimed by the forest. This resulted in increased amounts of carbon dioxide being taken out of the atmosphere, hence causing global temperatures to cool down. Ruddiman claims that the little ice age
Little Ice Age
The Little Ice Age was a period of cooling that occurred after the Medieval Warm Period . While not a true ice age, the term was introduced into the scientific literature by François E. Matthes in 1939...
, starting in the 13th century and ending sometime in the early 19th century was caused by the decreased population and the re-forestation of previously cleared lands as a result from the diseases that killed off so many people.
The last aspect of Ruddiman's discussion of climate change relates to the future of petroleum use on earth. It is commonly known that the world’s supply of fossil fuels is rapidly depleting and even conservative estimates claim that the supply will not last much more than 150-200 more years. Ruddiman claims that when this sources of natural fuels has been depleted, human kind will have to resort to using the large quantities of coal that still exist all over the planet. This, according to Ruddiman, will result in a continued warming trend that will only stop when technology either produces a new source of fuel or figures out a way to separate the carbon dioxide emissions prior to being released into the atmosphere. Ruddiman is quite skeptical of both scenarios in the near future because of the increased costs and technological advancements that would have to be made in such a short time. Eventually carbon and methane emissions will be controlled and lowered a great deal and Ruddiman asserts when this happens the earth will most likely begin an era of cooling temperatures.
Criticism
Critics claim that more research needs to be done to correlate carbon dioxide and methane emissions to human activity. Gavin SchmidtGavin Schmidt
Gavin A. Schmidt is a climatologist and climate modeler at the NASA Goddard Institute for Space Studies in New York. He works on the variability of the ocean circulation and climate, using general circulation models . He has also worked on ways to reconcile paleo-data with models...
, a climate modeler at the NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
Goddard Institute for Space Studies in New York, claims that is it extremely uncertain that early human populations could have had the enormous environmental effects that Ruddiman claims. He also claims that recent studies of methane emissions have shown that methane increases over the last 5,000 years could be attributed to the development of the boreal wetlands and major river deltas after the ice from the previous ice age melted and caused the sea level to rise to its current location http://www.giss.nasa.gov/research/features/methane/.
Other criticism suggests that Ruddiman shortchanged the impact of burning forests in his synopsis of early human activity. According to Michael Williams author of Deforesting the Earth, early humans used fire a great deal for either hunting and or clearing purposes. Ruddiman does not discuss the role of fire at any length and instead decides to focus on the impact of the plow on human agriculture http://books.google.com/books?vid=ISBN0226899268&id=mW8Fl2ieJFsC&pg=PA560&lpg=PA560&ots=1KkMUulerC&dq=book+review+of+deforesting+the+earth&sig=H-i8nnIoUpq8ywtAAuu81BjTwW0#PPP1,M1.
Further reading
- Intergovernmental Panel on Climate Change website (IPCCIPCCIPCC may refer to:*Intergovernmental Panel on Climate Change, of the United Nations*Independent Police Complaints Commission, of England and Wales*Irish Peatland Conservation Council...
) - Global Change Master Directory at website of Nasa's Goddard Space Flight Center
- Carbon Disclosure Project website
See also
- Milankovitch cyclesMilankovitch cyclesMilankovitch theory describes the collective effects of changes in the Earth's movements upon its climate, named after Serbian civil engineer and mathematician Milutin Milanković, who worked on it during First World War internment...
- An Inconvenient TruthAn Inconvenient TruthAn Inconvenient Truth is a 2006 documentary film directed by Davis Guggenheim about former United States Vice President Al Gore's campaign to educate citizens about global warming via a comprehensive slide show that, by his own estimate, he has given more than a thousand times.Premiering at the...
- DeforestationDeforestationDeforestation is the removal of a forest or stand of trees where the land is thereafter converted to a nonforest use. Examples of deforestation include conversion of forestland to farms, ranches, or urban use....
- HoloceneHoloceneThe Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...
- Environmental securityEnvironmental securityEnvironmental security examines the threat posed by environmental events and trends to national power, as well as the impact of human conflict and international relations on the environment....
- GlacierGlacierA glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...
- Ice caps
- Global warmingGlobal warmingGlobal warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
- Effects of global warmingEffects of global warmingThis article is about the effects of global warming and climate change. The effects, or impacts, of climate change may be physical, ecological, social or economic. Evidence of observed climate change includes the instrumental temperature record, rising sea levels, and decreased snow cover in the...
- Carbon cycleCarbon cycleThe carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth...
- Guns, Germs and Steel
- Kyoto protocolKyoto ProtocolThe Kyoto Protocol is a protocol to the United Nations Framework Convention on Climate Change , aimed at fighting global warming...
- AnthropoceneAnthropoceneThe Anthropocene is a recent and informal geologic chronological term that serves to mark the evidence and extent of human activities that have had a significant global impact on the Earth's ecosystems...