A new analysis of ice-core climate data, archeological evidence and ancient pollen samples strongly suggests that agriculture by humans 7,000 years ago likely slowed a natural cooling process of the global climate, playing a role in the relatively warmer climate we experience today.
A study detailing the findings is published online in a recent edition of the journal Reviews of Geophysics, published by the American Geophysical Union.
“Early farming helped keep the planet warm,” said William Ruddiman, a University of Virginia climate scientist and lead author of the study, who specializes in investigating ocean sediment and ice-core records for evidence of climate fluctuations.
A dozen years ago, Ruddiman hypothesized that early humans altered the climate by burning massive areas of forests to clear the way for crops and livestock grazing.
https://www.sciencephoto.com/media/576718/view/prehistoric-flint-hand-axe
https://www.youtube.com/watch?v=UxmvLjWYyiY CARTA:Human-Climate Interactions and Evolution: William Ruddiman:How Humans Took Control of Climate - thanks for the recommendation! https://www.youtube.com/watch?v=VEN0XckAveU&pp=ygUwV2lsbGlhbSBSdWRkaW1hbiAiUGxvd3MsIFBsYWd1ZXMgYW5kIFBldHJvbGV1bSwi
55% of the public thinks scientists are "debating" global warming. ... Professor William Ruddiman dares to call Koch Brothers "major major villains" back 10 years ago! Exxon-Mobil scientists knew by 1980... they stifled their scientists....It's a case of "follow the money." This lecture has aged well.
Princeton University Press, 2005 book https://press.princeton.edu/books/paperback/9780691173214/plows-plagues-and-petroleum
I ordered the hardcover book used for $7.50 from Betterworld books.
The “Ruddiman Hypothesis” will spark intense debate. We learn that the impact of farming on greenhouse-gas levels, thousands of years before the industrial revolution, kept our planet notably warmer than if natural climate cycles had prevailed—quite possibly forestalling a new ice age.
Plows, Plagues, and Petroleum is the first book to trace the full historical sweep of human interaction with Earth’s climate. Ruddiman takes us through three broad stages of human history: when nature was in control; when humans began to take control, discovering agriculture and affecting climate through carbon dioxide and methane emissions; and, finally, the more recent human impact on climate change.
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While the "pause" in global warming, a period of slowed surface temperature increase between roughly 1998 and 2013, wasn't solely due to heat being stored in the Arctic Ocean, it did play a role. The Arctic, along with other ocean regions, absorbed a significant amount of heat during this period, contributing to a slowdown in observed surface warming. However, other factors like natural climate cycles (e.g., La Niña events and the Pacific Decadal Oscillation) also played a crucial role in this redistribution of heat within the Earth's climate system
https://evsc.as.virginia.edu/people/profile/wfr5c
the system kinds of sloshes around...and you have to average over time...now this is the surface of the Earth....people who use satellite data as a proxy for global temperature....it's much more complicated. The satellites are above the atmosphere - we live at the bottom of the troposphere and the stratosphere above that. The satellites measure from above ....so you have to subtract out the effect of the stratosphere and that has been done incorrectly....
At first they claimed Earth was cooling based on the satellite data since 1979....to 1995 and by 1999-2000 they still had it cooling. By 2001 they got it warming since they're putting different corrections on their data and they basically conceded that their data had been "miscorrected" and so it was warming...
Abstract
The Anthropocene Working Group (AWG) of the Subcommission of Quaternary Stratigraphy of the International Commission on Stratigraphy is moving toward recommending that the start of a formally designated ‘Anthropocene’ epoch be placed in the middle-to-late 1900s. This article summarizes three objections to this possible action. First, major human alterations of Earth’s environment long preceded the 1900s: extinction of most Australian and American mammals; extensive deforestation of arable regions around the globe; creation of extensive anthropogenic wetlands for rice irrigation; and, in recent centuries, plowing of prairies and steppes for conversion to croplands. Second, the formal chronostratigraphic rules followed by the AWG reject any recognition of these early changes a priori: the very rapid pulse-like extinctions because they were ‘merely’ continent-wide, and forest clearance, rice irrigation, and prairie plowing because they developed time-transgressively. Third, the classical approach the AWG follows – adding subdivisions to the standard Geologic Column – is largely disregarded today among scientists working in the younger geologic record, as is apparent from the rare mention of the Pleistocene subdivisions in paleoclimate textbooks. For these reasons, the use of an informal, flexible ‘anthropocene’ is preferable to the constraints that would be imposed by defining a formal ‘Anthropocene’.
https://journals.sagepub.com/doi/10.1177/0309133318783142
Ruddiman says that in contrast to the familiar view that human-caused greenhouse gases began with the industrial revolution, “the baseline of human effects on climate started earlier and that the total effect is larger.”
https://humansandnature.org/william-ruddiman-and-the-ruddiman-hypothesis/
"this is getting somewhere beyond alarming...It's way worse than I ever thought...I've probably driven you into terminal depression...but I leave you with the facts. What else could I do." - Professor Emeritus William Ruddiman
Some climate scientists, especially geochemists like the well-known Wally Broecker -- objected to Ruddiman’s explanation and claimed that geochemical ocean dynamics caused the unexplained rise in the carbon release. Importantly, Broecker and others claimed that the Stage 11 Interglacial was the best analogue to the Holocene and its comparison did not support Ruddiman’s claim. The objectors also held that before the 19th century, the less numerous humans could not have massively cleared forests with the carbon impacts Ruddiman suggested (see here; and for background on debate in media and science, see Richard Blaustein’s 2015 article).
But in recent years that is what ecologists, botanists, and archaeologists have been establishing – massive and early preindustrial deforestation. Moreover, archaeobotanists, prominently Dorian Fuller of University College London, have documented the large expansion of rice patty agriculture thousands of years ago, explicating the methane rise. And offering strong support for the Ruddiman hypothesis, a consortium of over 250 archaeologists published a well-noted August 2019 Science article, “Archaeology assessment reveals Earth’s early transformation through land use,” that posited “a planet largely transformed by hunter-gatherers, farmers and pastoralists by 3000 years ago.” (Stephens et al., 2019)
It was in 2018 and the end of 2017 that Ruddiman’s hypothesis was most pointedly bolstered: a 2018 study identifying a pre-Stage 11 interglacial as the best analogue for the Holocene (thereby shedding light on human impact since the dawn of agriculture), a 2018 pollen-based study of historical deforestation -- and published research estimating global biomass potential and historical loss first published online in late 2017 together lent weighty support for Ruddiman’s argument.
Fascinating debate!!
ARTICLE
The Holocene CO2 rise: Anthropogenic or natural?
University of Plymouth paleoecologist Jesse Woodbridge carried out the data synthesis for "Europe's Lost Forests: a pollen-based synthesis for the last 11,000 years," the 2018 Scientific Reports paper that combined three advanced pollen-land use models and demonstrated large scale forest clearing in Europe going back thousands of years (Roberts et al. 2018).
“This is the first reconstruction for Europe at this level of detail,” says Woodbridge, who stresses that all this work is underpinned by availability of large databases, such as the European Pollen Database that amalgamates decades of contributions from hundreds of pollen experts.
The study found that Europe forest cover peaked 8,000-6,000 years ago, and that forests then covered around three quarters of Europe. Shortly after 6,000 years ago, significant deforestation began. The northern Europe needle-leaf forests persisted further in time, while deciduous forests in mid-latitude western Europe were felled in earnest for agriculture early, beginning around 6000 years ago. By 3,000 years ago, quite extensive European deforestation had taken place.
Ruddiman, too, sees his hypothesis’s present and future lines of work as a “beautiful example of convergence of different lines of science” both for biosphere understanding and now with mitigation pertinence. He adds that the tie-in of historical biomass, mitigation, and his work was an encouraging surprise. “The implication that Karlheinz Erb drew that there is a lot more potential to store carbon in land vegetation if we could let large amounts of it revert to a natural state, that’s to me the largest implication of my hypothesis, if you phrased the question what’s its importance for the future,” Ruddiman says.
https://as.virginia.edu/mounting-evidence-suggests-early-agriculture-staved-global-cooling
William Ruddiman talk again 2014 lecture
Wow - he's going into the debate about continental drift and plate tectonics - I wonder if he read Noami Oreskes book! 1964 Continental Drift was still being questioned... but from 1966 to 1970 it became accepted after "massive array of marine geophysical evidence" (meaning the Navy magnet readings).
Was Professor Ruddiman "targeted" by the Koch-Exxon disinfo campaign? B/c it was precisely this graph that was attacked - as I already blogged - with disinfo. Even my neighbor presented the Big Oil lie based on the disinfo graph.
So Professor Ruddiman explains - the stone axes were used to girdle the trees that then died and fell down and were set on fire...hence the ability for a relatively small population to have an amplified carbon footprint since there was a 20 year delay for the forest to recover....and then it was repeated as "slash and burn" farming.
The Two Eras of global warming....the Early Anthropogenic View
"I don't have much faith that humans are going to do all that much. We have, for instance in the U.S., individuals have heroic things. Cities, states have done good things. Government... you know what's the government doing....the government is not doing much. And down deep, I used to be an idealist. I think I've aged into a gentle cynic. I think we're very giving up to a point and then past that point we're really quite selfish. I don't think we're going to sacrifice our way back into minimal carbon emissions enough to keep a major warming from happening. My hope though is that technology, which is a bad word in some circles, that technology will bail us out. If something came up with a battery that stored ten times as much power for ten times as long, as any existing battery, it would change things in a major way. Suddenly solar would become a phenomenal thing."
Did China just create the EV battery breakthrough needed?
William Rees points out that the copper and rare metals needed does not allow EV technology to be scaled up. Besides we also need to be carbon negative to reverse the damage already caused! That can only be done by algae.
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