William F. Ruddiman is a palaeoclimatologist and Professor Emeritus at the

University of Virginia The University of Virginia (UVA) is a public research university in Charlottesville, Virginia. Founded in 1819 by Thomas Jefferson, the university is ranked among the top academic institutions in the United States, with highly selective ad ...

. Ruddiman earned an undergraduate degree in geology in 1964 at

Williams College Williams College is a private liberal arts college in Williamstown, Massachusetts. It was established as a men's college in 1793 with funds from the estate of Ephraim Williams, a colonist from the Province of Massachusetts Bay who was kill ...

, and a Ph.D. in

marine geology Marine geology or geological oceanography is the study of the history and structure of the ocean floor. It involves geophysical, geochemical, sedimentological and paleontological investigations of the ocean floor and coastal zone. Marine geolog ...

from

Columbia University Columbia University (also known as Columbia, and officially as Columbia University in the City of New York) is a private research university in New York City. Established in 1754 as King's College on the grounds of Trinity Church in Manhatt ...

in 1969. Ruddiman worked at the US

Naval Oceanographic Office The Naval Oceanographic Office (NAVOCEANO), located at John C. Stennis Space Center in south Mississippi, comprises approximately 1,000 civilian, military and contract personnel responsible for providing oceanographic products and services to al ...

from 1969 to 1976, and at Columbia's

Lamont–Doherty Earth Observatory The Lamont–Doherty Earth Observatory (LDEO) is the scientific research center of the Columbia Climate School, and a unit of The Earth Institute at Columbia University. It focuses on climate and earth sciences and is located on a 189-acre (64 ...

from 1976 to 1991. He moved to Virginia in 1991, serving as a professor in Environmental Sciences. Ruddiman's research interests center on climate change over several time scales. He is a Fellow of both the

Geological Society of America The Geological Society of America (GSA) is a nonprofit organization dedicated to the advancement of the geosciences. History The society was founded in Ithaca, New York, in 1888 by Alexander Winchell, John J. Stevenson, Charles H. Hitch ...

and the

American Geophysical Union The American Geophysical Union (AGU) is a 501(c)(3) nonprofit organization of Earth, atmospheric, ocean, hydrologic, space, and planetary scientists and enthusiasts that according to their website includes 130,000 people (not members). AGU's a ...

. Ruddiman has participated in 15 oceanographic cruises, and was co-chief of two deep-sea drilling cruises. Ruddiman is best known for his ' early anthropocene' hypothesis (or 'Ruddiman hypothesis'), the idea that human-induced changes in greenhouse gases did not begin in the eighteenth century with advent of coal-burning factories and power plants of the

industrial era The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...

but date back to 8,000 years ago, triggered by the intense

farming Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled peopl ...

activities of our early agrarian ancestors. It was at that time that atmospheric greenhouse gas concentrations stopped following the periodic pattern of rises and falls that had accurately characterized their past long-term behavior, a pattern which is well explained by natural variations in the Earth's orbit known as

Milankovitch cycles Milankovitch cycles describe the collective effects of changes in the Earth's movements on its climate over thousands of years. The term was coined and named after Serbian geophysicist and astronomer Milutin Milanković. In the 1920s, he hypot ...

. In his overdue-glaciation hypothesis Ruddiman claims that an incipient ice age would probably have begun several thousand years ago, but the arrival of that scheduled ice age was forestalled by the activities of early farmers. The overdue-glaciation hypothesis has been challenged on the grounds that alternative explanations are sufficient to account for the current warm anomaly without recourse to human activity, but Ruddiman challenges the methodology of his critics (see external links). Ruddiman is also known for his hypothesis in the 1980s that the

tectonic uplift Tectonic uplift is the geologic uplift of Earth's surface that is attributed to plate tectonics. While isostatic response is important, an increase in the mean elevation of a region can only occur in response to tectonic processes of crustal th ...

Tibet Tibet (; ''Böd''; ) is a region in East Asia, covering much of the Tibetan Plateau and spanning about . It is the traditional homeland of the Tibetan people. Also resident on the plateau are some other ethnic groups such as Monpa, Taman ...

created the highly seasonal

monsoon A monsoon () is traditionally 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 annual latitudinal osci ...

al circulation that dominates Asia today. With his then graduate student Maureen Raymo he hypothesised that the uplift of the Himalayas and Tibetan Plateau caused a reduction in atmospheric through increases in chemical weathering and was therefore a major causal factor in the Cenozoic Cooling trend that eventually led to our most recent series of

Ice Ages An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gree ...

. He was awarded the

Lyell Medal The Lyell Medal is a prestigious annual scientific medal given by the Geological Society of London, equal in status to the Murchison Medal. This medal is awarded based on one Earth Scientist's exceptional contribution of research to the scientific ...

of the

Geological Society of London The Geological Society of London, known commonly as the Geological Society, is a learned society based in the United Kingdom. It is the oldest national geological society in the world and the largest in Europe with more than 12,000 Fellows. Fe ...

for 2010. He has written several books: '' Plows, Plagues, and Petroleum: How Humans Took Control of Climate'', a textbook on

climate science Climatology (from Greek , ''klima'', "place, zone"; and , '' -logia'') or climate science is the scientific study of Earth's climate, typically defined as weather conditions averaged over a period of at least 30 years. This modern field of stu ...

, ''Earth's Climate, Past and Future'', and most recently ''Earth Transformed'', the subject of th
2014 American Geophysical Union's Tyndall Lecture
He has published over 125 scientific papers.Ruddiman's home page
at the

References

External links

Home page
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PDF
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Climate Changes at Geologic Time Scales: An Overview
by WF Ruddiman, 2008 conference presentation.
"Early Agriculture Has Kept Earth Warm for Millennia"
EOS, 2016, summarizes Ruddiman et al. 2016, ''Reviews of Geophysics'' 54, 93–118, doi:10.1002/2015RG000503 {{DEFAULTSORT:Ruddiman, William University of Virginia faculty American non-fiction environmental writers American climatologists Columbia University alumni Paleoclimatologists Year of birth missing (living people) Living people Williams College alumni Lyell Medal winners Fellows of the Geological Society of America Fellows of the American Geophysical Union