Guest commentary by David Middleton
Just to demonstrate that the American Association of Petroleum Geologists (AAPG) maintains an open mind about things, I thought I would share an recent AAPG Explorer article on the notion of establishing a formal geological epoch in honor of human beings…
Defining the Anthropocene Era
New research identifies epoch-defining ‘golden spike’
February 2018 Barry Friedman, Explorer Correspondent
According to Jan Zalasiewicz, professor of inaugural lectures and paleobiology at the University of Leicester, a strong proponent of the Anthropocene and a member of the team, the recent work is promising.
The term “Anthropocene” was first coined, almost improvisationally, by Paul Crutzen, a Nobel Prize-winning atmospheric chemist, at a conference in 2000 in Mexico City. Literally meaning “the Age of Man,” its origins, according to proponents like Crutzen, began around the middle of the 20th century and rests on the assumption that humans are altering the planet, including long-term global geologic processes, at such an accelerated pace that a new epoch is upon us in the geological time scale.
(The late biologist Eugene Stoermer, who had been using the term informally for years, was quoted in The New York Times back in 2011 as saying he never formalized the term until Crutzen contacted him.)
The criticism of the Anthropocene comes from those who, for starters, think the term is arrogant in the thinking that human beings are a geologic force on par with nature, in fact superseding it. By proof, critics point to the named epochs covering the last 145 million years and how none are named for the cause of the changes to the planet – until now.
More substantive is this criticism, best described in a 2013 Smithsonian Magazine article by Joseph Stromberg, “What is the Anthropocene and Are We in It?”:
“Many stratigraphers (scientists who study rock layers) criticize the idea, saying clear-cut evidence for a new epoch simply isn’t there. ‘When you start naming geologic-time terms, you need to define what exactly the boundary is, where it appears in the rock strata,’ said Whitney Autin, a stratigrapher at the SUNY College of Brockport, who suggests Anthropocene is more about pop culture than hard science. The crucial question, he said, is specifying exactly when human beings began to leave their mark on the planet: The atomic era, for instance, has left traces of radiation in soils around the globe, while deeper down in the rock strata, agriculture’s signature in Europe can be detected as far back as A.D. 900. The Anthropocene, Autin said, ‘provides eye-catching jargon, but from the geologic side, I need the bare bones facts that fit the code.’”
AAPG login required to read the full article.
The article drew five comments, none of which were receptive to an Anthropocene Epoch (it would be an epoch, not an era or period, if adopted). Here are three of the comments, including my own:
AnthropoceneWe already have an “Anthropocene.” It’s called the “Holocene.” The only significant difference between the Holocene and the most recent Pleistocene interglacial stages is dominance of human civilization over much of the planet’s surface.
2/27/2018 7:34:42 AM David Middleton
Anthropocenic DetractorFirst, I am a climate denier due to my utter disdain for “climate scientists” that have completely ignored the scientific method and drawn conclusions based on policy and consensus. Now, I am an anthropocenic detractor by non scientists (what in the world is a professor of inaugural lectures – and paleobiology?). I mean really, who cares what a crowd of “environmental, anthropological, political, and social” non scientists think about the “age of man” and our effect on the geologic time scale? It starts with “the debate is healthy”, but will quickly progress to the consensus is clear and the debate is closed. Send in the Spanish inquisition for all of the detractors.
2/9/2018 7:22:16 AM
The AnthropoceneAgain a legitimate publication like the EXPLORER offers up an article on a piece of non-science and, in turn, makes it look like real science. As was stated in the article, some considered the idea of a time-rock period or epoch called the Anthropocene as nothing more than pop culture. In other words, it’s an idea that some advocates have decided sounds like a good and have decided to push this agenda. You can do all kinds of scientific research and the compilation of information from various pieces of literature, but that doesn’t make the idea of establishing a new time-rock period any more legitimate! To someone who doesn’t understand how the various geologic time boundaries were established, it all seems fine. They believe you can use biological, chemical, physical and any other data to prove that establishing something called the Anthropocene is possible and real. However, the very act of trying to do research that “proves” an idea is an act of strong bias and not scientific. It was also stated in the article that the data for establishing the Anthropocene existed in previous written articles all along. This is nonsense and demonstrates the bias and advocacy of Dr. Zalasiewicz. We should “not be going down this road again.” We tried this with the idea that CO2 is the cause of global warming without considering the physics of the issue, constructing incomplete and faulty climate predictive models and by forgetting the other factors that affect the atmosphere. It was a mistake and cost science very dearly by spreading pseudo-science and junk science over the internet and worldwide. Now we have to contend with advocates from every political and non-science realm who are pushing for mitigation of a gas, to the “tune” of trillions of dollars, that should really be thought of as relatively benign and low in atmospheric concentration when compared to its past atmospheric concentration over the course of the last 2 or 3 billion years!
2/7/2018 8:17:16 PM
- Jan Zalasiewicz, professor of inaugural lectures and paleobiology
- Paul Crutzen, a Nobel Prize-winning atmospheric chemist
- The late biologist Eugene Stoermer
It’s like a group of geologists lobbying to have the polar bear (Ursus maritimus) reclassified as a subspecies of brown bears (Ursus arctos). While I think the genetic evidence says that polar bears are brown bears with whitish fur… and the fact that they can interbreed with brown bears to produce genetically viable grolar bear cubs makes them the same species… As a geologist, I certainly wouldn’t try to tell biologists how to do their jobs. What’s that? Oh yeah, I guess I just did.
Back to the Anthropocene
There is still hope that the International Commission on Stratigraphy will reject this nonsense, or at least relegate it to a subdivision of the Holocene (which should, in fact, be a subdivision of the Pleistocene):
What is the ‘Anthropocene’? – current definition and status
- The ‘Anthropocene’ is a term widely used since its coining by Paul Crutzen and Eugene Stoermer in 2000 to denote the present time interval, in which many geologically significant conditions and processes are profoundly altered by human activities. These include changes in: erosion and sediment transport associated with a variety of anthropogenic processes, including colonisation, agriculture, urbanisation and global warming. the chemical composition of the atmosphere, oceans and soils, with significant anthropogenic perturbations of the cycles of elements such as carbon, nitrogen, phosphorus and various metals. environmental conditions generated by these perturbations; these include global warming, ocean acidification and spreading oceanic ‘dead zones’. the biosphere both on land and in the sea, as a result of habitat loss, predation, species invasions and the physical and chemical changes noted above.
- The ‘Anthropocene’ is not a formally defined geological unit within the Geological Time Scale. A proposal to formalise the ‘Anthropocene’ is being developed by the ‘Anthropocene’ Working Group for consideration by the International Commission on Stratigraphy, with a current target date of 2016. Care should be taken to distinguish the concept of an ‘Anthropocene‘ from the previously used term Anthropogene (cf. below**).
- The ‘Anthropocene’ is currently being considered by the Working Group as a potential geological epoch, i.e. at the same hierarchical level as the Pleistocene and Holocene epochs, with the implication that it is within the Quaternary Period, but that the Holocene has terminated. It might, alternatively, also be considered at a lower (Age) hierarchical level; that would imply it is a subdivision of the ongoing Holocene Epoch.
- Broadly, to be accepted as a formal term the ‘Anthropocene’ needs to be (a) scientifically justified (i.e. the ‘geological signal’ currently being produced in strata now forming must be sufficiently large, clear and distinctive) and (b) useful as a formal term to the scientific community. In terms of (b), the currently informal term ‘Anthropocene’ has already proven to be very useful to the global change research community and thus will continue to be used, but it remains to be determined whether formalisation within the Geological Time Scale would make it more useful or broaden its usefulness to other scientific communities, such as the geological community.
- The beginning of the ‘Anthropocene’ is most generally considered to be at c. 1800 CE, around the beginning of the Industrial Revolution in Europe (Crutzen’s original suggestion); other potential candidates for time boundaries have been suggested, at both earlier dates (within or even before the Holocene) or later (e.g. at the start of the nuclear age). A formal ‘Anthropocene‘ might be defined either with reference to a particular point within a stratal section, that is, a Global Stratigraphic Section and Point (GSSP), colloquially known as a ‘golden spike; or, by a designated time boundary (a Global Standard Stratigraphic Age).
- The ‘Anthropocene’ has emerged as a popular scientific term used by scientists, the scientifically engaged public and the media to designate the period of Earth’s history during which humans have a decisive influence on the state, dynamics and future of the Earth system. It is widely agreed that the Earth is currently in this state.
The target date for the ICS to consider the adoption of an Anthropocene Epoch was in 2016, two years ago. So, this might indicate that the ICS remains unconvinced.
However, the campaign for the Anthropocene Epoch is still alive and well… And totally oblivious to any arguments against their position. After authoring this post in 2016, I contacted Dr. Colin Waters to verify that they were relying on the Hockey Stick blade in Marcott et al., 2013 as evidence of a Holocene-Anthropocene demarcation. We had a very cordial and informative email discussion; however they could not understand why the Hockey Stick blade at the end of the Marcott reconstruction was not statistically robust.
The authors of Marcott even realize that their Hockey Stick is broken…
One author, Jeremy Shakun (currently at Harvard) weighed in via Skype for Dot Earth. When more questions came in, the group of authors wrote that they would respond more completely to questions about the work and now they have done so, on the RealClimate blog. Here’s a short excerpt and link to the rest:Q.
What do paleotemperature reconstructions show about the temperature of the last 100 years?A.
Our global paleotemperature reconstruction includes a so-called “uptick” in temperatures during the 20th-century. However, in the paper we make the point that this particular feature is of shorter duration than the inherent smoothing in our statistical averaging procedure, and that it is based on only a few available paleo-reconstructions of the type we used. Thus, the 20th century portion of our paleotemperature stack is not statistically robust, cannot be considered representative of global temperature changes, and therefore is not the basis of any of our conclusions. Our primary conclusions are based on a comparison of the longer term paleotemperature changes from our reconstruction with the well-documented temperature changes that have occurred over the last century, as documented by the instrumental record. Although not part of our study, high-resolution paleoclimate data from the past ~130 years have been compiled from various geological archives, and confirm the general features of warming trend over this time interval (Anderson, D.M. et al., 2013, Geophysical Research Letters, v. 40, p. 189-193).Q.
Is the rate of global temperature rise over the last 100 years faster than at any time during the past 11,300 years?A.
Our study did not directly address this question because the paleotemperature records used in our study have a temporal resolution of ~120 years on average, which precludes us from examining variations in rates of change occurring within a century. Other factors also contribute to smoothing the proxy temperature signals contained in many of the records we used, such as organisms burrowing through deep-sea mud, and chronological uncertainties in the proxy records that tend to smooth the signals when compositing them into a globally averaged reconstruction. We showed that no temperature variability is preserved in our reconstruction at cycles shorter than 300 years, 50% is preserved at 1000-year time scales, and nearly all is preserved at 2000-year periods and longer. Our Monte-Carlo analysis accounts for these sources of uncertainty to yield a robust (albeit smoothed) global record. Any small “upticks” or “downticks” in temperature that last less than several hundred years in our compilation of paleoclimate data are probably not robust, as stated in the paper.
Even with the acknowledgement that the “uptick” was not statistically robust, Dr. Shakun then proceeded to say that their conclusions were not based on the uptick, but on a comparison of high frequency instrumental temperature data to their low frequency Holocene temperature reconstruction… Which is even worse than relying on the uptick.
I genuinely believe that these folks simply can’t grasp the concept of resolution. This is a pervasive problem in the climate “science” community and will continued to feed claims of “unprecedented” changes in [fill in the blank] until we have about 1,000 years of high resolution instrumental data.