The Anthropocene Golden Spike: The Age of Humans
Lecture summaries for Spring 2018
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22–26 January 2017 [Week 1]
Introduction to the Course
The first presentation for this course will be held on Monday, 22 January 2018 and start at 10:00 a.m.; we will meet in Bentley 308.
Textbooks are not required for this course, yet there will be sufficient literature available online.
Student presentations will be assessed for the JSC Graduation Oral Communication Standard. The PowerPoint slides associated with the presentations must incorporate the Assertion-Evidence model (see the following two sites about the design of PowerPoint slides):
- A video by Michael Alley regarding PowerPoint presentations.
- A web site by Michael Alley entitled "Assertion-Evidence Approach".
Add the Printfriendly extension to the Chrome browser on your computer if you want to print web pages. This add-on removes extraneous advertisements, cleans up the page, and makes the document much easier to read.
A copy of the discussion outline is available here.
Assignment [due 24 Jan 2018] — Literature discussion
Biello, David (2016). You Have Been Living in a New Geologic Time All Along. Retrieved on 27 November 2016 from http://ideas.ted.com/you-have-been-living-in-a-new-geologic-time-all-along/
Come to class prepared to discuss the paper; take notes and print out the paper (or bring a laptop).
For additional background information, I suggest listening to the TED Radio Hour on National Public Radio, Anthropocene, at http://one.npr.org/?sharedMediaId=495657272:496016953
PowerPoint slides: Introduction
PowerPoint slides: Critical Reading
29 January–2 February 2018 [Week 2]
Watch the 25 January 2018 announcement from the Bulletin of the Atomic Scientists regarding the Doomsday Clock.
The goals of stratigraphy are to improve our knowledge and understanding of Earth's rock bodies and their history.
Eustatic changes refer to changing global sea levels; isostatic changes refer to the vertical movement of continents.
A transgressive sequence forms as the shoreline moves landward from either submergence of the land or an increase in global sea levels. The lithologic units deposited as a result of eustatic changes follows Walther's Law (diachronous rock units).
Marker horizons, for example widespread volcanic ash deposits, provide a time reference where the entire unit is deposited at the same time.
Assignment [due 31 Jan 2018] — Literature discussion
Crutzen, P. J. and E. F. Stoermer, 2000. The Anthropocene in The Global Change Newsletter, v. 41, p. 17-18.
[Introduction to the Anthropocene; moderate read; often cited; informative. It is this paper that is often referred to by others as one of the original source papers on the Anthropocene.]
Assignment [due 5 Feb 2018 by 5:00 p.m.] — Email and referencing style [5 points]
Please send a proper email that has the following characteristics:
PowerPoint slides: Stratigraphy
5–9 February 2018 [Week 3]
The demographic transition model was introduced (as was the suggestion of a universal basic wage).
Linear growth occurs when a fixed amount is added at a fixed time (for example, a car traveling at a constant speed). The result is a straight line when plotted on arithmetic axes.
Exponential growth occurs when a percent of the total is added at a fixed time (for example, population). In this case, growth is proportional to the present size and thus results in a J-curve when plotted on arithmetic axes.
Doubling time is the time it takes for a value, that grows exponentially at a constant rate, to double in value. The equation for calculating doubling time is:
tD is the time it takes for a quantity to double in value
λ is the growth rate
See the following web sites:
Some sad news... "Hans Rosling, Swedish Doctor and Pop-Star Statistician, Dies at 68" from pancreatic cancer; see https://www.nytimes.com/2017/02/09/world/europe/hans-rosling-dead-statistician.html?_r=0
Watch some of Dr. Rosling's TED talks at https://www.ted.com/speakers/hans_rosling.
PowerPoint slides: Population and exponential growth
Please read the following, short paper written by the Subcommission on Quaternary Stratigraphy, We will not dicuss this paper in class, yet it is important, and should be read. Use the guidelines for critical reading to help digest the information.
Subcommission on Quaternary Stratigraphy, 2016. Working Group on the Anthropocene. Retrieved from http://quaternary.stratigraphy.org/workinggroups/anthropocene/ on 27 November 2016.
[Geological basis for the Anthropocene; easy read; informative]
Please read about the Assertion-Evidence Structure for PowerPoint presentations. Some links to this model may be found in the notes from Week 1 (above) in this course. The Lightning Round presentations [20 points] are coming up soon (19 February 2018).
We ran out of time and did not discuss the following paper in class on Monday, 7 Feb 2018.
Assignment [due 7 Feb 2018] — Literature discussion
Finney, Stanley and Lucy Edwards, 2016. The "Anthropocene" Epoch: Scientific Decision or Political Statement? Retrieved on 27 November 2016 from http://www.geosociety.org/gsatoday/archive/26/3/pdf/i1052-5173-26-3-4.pdf
[Geological basis for the Anthropocene; moderate read; informative]
Zalasiewicz et al. (2016) commented on the paper by Finney and Edwards (2016). See their comments at http://www.geosociety.org/gsatoday/comment-reply/27/2/GSATG309C.1.pdf (note that the et al. component represents 25 other authors).
Finney and Edwards (2016b) replied to Zalasiewicz et al. (2016) at http://www.geosociety.org/gsatoday/comment-reply/27/2/GSATG326Y.1.pdf.
Autin (2016) is also an interesting read...
Assignment [due 7 Feb 2018] — Anthropocene marker [5 points]
Choose a possible Anthropocene marker to work with this semester as your topic of focus.
Submit a printed document with the following information:
-  Working title, name, date.
-  Introductory paragraph addressing the efficacy of geological markers.
-  Brief discussion of the marker of choice.
-  Use page numbers if the document is more than one page in length.
-  At least one properly cited reference referred to in the text. Be sure to cite the source in the body of the text. Put the (Author, Year) in parentheses at the end of the sentence where the ideas are used (but before the period at the end of the sentence). Follow the APA guidelines.
-  Use hanging indents for the reference list (try: control-t in Word) and closely follow the APA guidelines.
Assignment [due Wednesday, 14 Feb 2018] — Population and exponential growth [10 points]
The assignment was distributed in class and may also be found here. Please come to class on Monday, 12 Feb 2018 with questions about this assignment.
Note: When calculating future populations, assume that world population is growing at each of the three rates specified in the assignment. Clearly, it is not reasonable to assume that world population rates could grow at the same rate of Oman, yet, if it did, caclulate a future world population.
Assignment [due Wednesday, 21 Feb 2018 by 9:00 a.m.] — Lightning Round Presentations [20 points]
All students will make a short presentation about an Anthropocene marker horizon. Details of the assignment may be found here (and below the grading rubric).
The grading rubric for the presentations is presented below:
Some general comments regarding the Lightning Round presentations:
- Use the Assertion-Evidence model for PowerPoint presentations.
- Write a clear thesis statement (see the Purdue OWL page).
- Avoid cartoon images.
- Avoid unnecessary animation.
- Avoid bullets whenever possible.
- Avoid dark backgrounds (and avoid text that has similar colors as the background).
- Use cropping tool to modify images.
- Use a white box (or the snip tool) to cover extraneous information on images.
- Use large font (but do not yell), at least 28 point.
- Fit the text to the space and avoid orphans.
- Do not center-align text.
- While presenting, read what is on the screen.
- Practice your presentation (out loud).
JSC offers MS Office 2016 for a PC or Mac
for free to students
Click here to find out more.
12–16 February 2018 [Week 4]
Topics for discussion: doubling time, markers, and isotopes.
Yet, we will start on Monday with a discussion of the population growth assignment; please come to class with specific questions.
PowerPoint slides: Isotopes
Assignment [due 15 Feb 2018] — Literature discussion
Zalasiewicz, Jan, 2016. What Mark Will We Leave On The Planet: A History In Layers. Scientific American v. 315(3), p. 30-37.
19–23 February 2018 [Week 5]
Writing Assignment [due 7 Mar 2018] — First draft
The guidelines for the writing assignment may be found here and a copy of the grading rubric is below:
This week: Monday we will continue our discussion of isotopes and Wednesday the Lightning Round presentations will begin.
26 February–2 March 2018 [Week 6]
Winter Break–be careful.
Please note: class willl be canceled on the Monday we return from Spring Break; no class on Monday, 5 March 2018.
5–9 March 2018 [Week 7]
No class on Monday.
Nuclear energy (mechanisms of decay and half life), nuclear power, and types of resources (perpetual, potentially renewable, and non-renewable) were discussed on Wednesday.
There is ample evidence in the rock record for demarcation of the Anthropocene; some of the markers are listed below:
- Chemical Signatures:
Unstable isotopes from weapons testing and nuclear power, medical and research wastes (60Co, 90Sr, 129I, 135Cs, 137Cs, 235U, 238U, 239Pu), and changes in atmospheric and oceanic chemistry (CO2, N2, H+).
- Physical Signatures:
Global temperature, increased deposition and disturbed soils (mine wastes), erosion (≈3x more than rivers), railroads, concrete, asphalt, plastic, fossil fuel wells, and cities.
- Biological Signatures:
Clearing forests, widespread agricultural burning, species extinction, and mono-cropping.
What are some of the other physical, chemical and biological signatures that will withstand the test of time and serve as markers, or traces, of human civilization on Earth?
Unstable Isotopes and Absolute Dating
The main thrust of today's lecture dealt with
absolute dating. Nuclear chemistry allows us
to date geological events by use of unstable isotopes. Isotopes can
be identified by use of a mass spectrometer. Unstable isotopes
generate radiation as the nucleus undergoes spontaneous decay. The
weak nuclear force controls the rate and mechanism of the decay of
Common decay mechanisms include:
- Alpha decay:
For example: 22688Ra → 42α
The emission of an alpha particle changes Ra into Rn.
The nucleus emits two protons and two neutrons.
The atomic number decreases by two; atomic mass decreases by
- Beta decay
For example: 21482Pb → 0-1 β + 21483Bi
A neutron is converted to a proton and an electron is emitted.
The atomic number increases by one; atomic mass is
- Electron capture
For example: 8136Kr
+ 0-1e → 8135Br
A proton is converted into a neutron and an electron is
The atomic number decreases by one; atomic mass is
- Gamma radiation
For example: 6027Co → Ɣ rays
Adjustment of the internal structure of an atom results in the
emission of energy.
Half-life is the average amount of time required
for one half of the original number of radioactive atoms (parent
atoms) to decay to child (daughter) products. Unstable isotopes
are used for absolute
dating. Each isotope has a defined half
life. After five half lives, only 1/32 of the parent isotope remains; this small
amount is difficult to measure accurately so we choose an isotope
that has a half life appropriate to the age of the feature of
interest (for example, depositional age, age of crystallization, or
age of metamorphism).
Department of Health can also test
your water for a large number of
contaminants. A Gross Alpha test (section 4 RA) costs $45. Click for forms and ordering information; get the order form for all water tests (and costs); read the supplement associated with the order form.
Radon is an unstable isotope that occurs as a gas
and forms from the decay of radium. Radon gas is a problem in many
dwellings because radium may often be substituted for other elements
that have two valence electrons. According to a report by the
National Academy of Sciences, radon is estimated to cause between
15,000 and 22,000 lung cancer deaths per year. It is the second
leading cause of lung cancer after smoking. Please read more about Radon found at the Vermont Health & The Environment website.
Read about a Russian spy
who exposed Russian President Putin's ring of corruption and was subsequently
poisoned by radioactive 210Po while in
London. Or learn more about the "Radium Girls" who are still glowing in their coffins
12–26 March 2018 [Week 8]
Ionizing and non-ionizing radiation were discussed in relation to unstable isotopes.
The distinction between perpetual resources, potentially renewable resources (aka sustainable resources), non-renewable resources, and non-material resources was made.
The discussion of climate change began with a description of atmospheric chemistry and a listing of the greenhouse gases.
PowerPoint slides: Global warming
O3, absorbs incoming ultraviolet
(UV) wavelengths (short), and re-radiated longer-wavelength infrared (IR) heat from Earth. The ozone in the stratosphere protects organisms from
the harmful UV radiation, yet is also a greenhouse gas that traps
heat from Earth, and is a major component of smog in the troposphere.
Chlorofluorocarbons (CFC), such as refrigerants, electronic parts
cleaners, degreasers, and blowing agents, destroy ozone.
Find out the UV
index in Johnson today, see a daily
contour map of the UV index for the
US, or learn more about the science of ozone
depletion. See the EPA's article on
up high bad nearby. Read a recent report that describes a slightly smaller ozone hole.
There is no such thing as a safe tan. See the
American Academy of Dermatology views on skin
cancer and tanning
booths. The Mayo Clinic recently reported
rise in skin cancer in young adults (and
particularly in women in their 20's and 30's). Read about the Mayo
Clinic's views on UV light.
Review state laws regarding use of tanning booths, or a recent article in JAMA Dermatology. The University of Vermont Health
Network just purchase a pulsed xenon UV disinfection machine that uses UV to sterilize rooms in the
hospital; click here for the Xenex website.
Chlorofluorocarbons (CFC) are used as refrigerants, fire suppressors, degreasers and more. It takes about ten years for these synthetic CFCs to rise into the stratosphere, into the layer where ozone is concentrated, and destroy ozone molecules. Ozone protects life on Earth from harmful ultraviolet radiation. The ozone layer is slowly being depleted by CFCs. The Montreal Protocol of 1987 proposed the elimination of CFCs and replacement with hydrochlorofluorocarbons (HCFC). As a result of this action, the destruction of the ozone layer is slowing, yet it still continues. Unfortunately, however, HCFCs are potent greenhouse gases and thus help to accelerate global warming. We, the people, make choices that have global significance.
Global Warming and the Ozone Problem: Two Different Issues
The greenhouse gases (CO2,
CH4, H2O, O3, NOx, and CFC)
absorb the heat radiated from Earth's surface and warms the atmosphere. Earth's
surface is warmed by a wide range of wavelengths coming from the sun and passes
through the atmosphere. Earth's warm surface radiates infrared (IR) radiation
back into the atmosphere. The greenhouse gases are just the right molecular size
to resonate (vibrate) with the infrared radiation and thus warms Earth's
atmosphere. Greenhouse gases trap IR coming from Earth's surface.
The ozone layer is slowly being depleted by chlorofluorcarbons
(CFCs). As the ozone layer thins, more ultraviolet (UV) passes through the
atmosphere and results in skin cancer.
The depleting ozone layer is not causing global warming, and
global warming is not a cause of the ozone problem.
Watch a visualization of how CO2 circulates in the atmosphere.
The heat from the sun warms the surface of Earth. The warm surface radiates
heat (long wave radiation — IR, infrared) back into the atmosphere. The long wave radiation interacts
with molecules of a specific size and structure; these types of molecules are
known as the greenhouse gases. The greenhouse gases (CO2, CH4,
H2O, O3, NOx, and CFC) absorb the heat radiated
from Earth and warm the atmosphere.
Mid-term Exam: Wednesday, 14 March 2018
19–23 March 2018 [Week 9]
Class cancelled on Monday, 19 March 2018 only. I am attending the annual meeting of the Northeastern Section of the Geological Society of America with four students from JSC. Their research has been accepted for a presentation on Monday morning at the conference, and as their faculty mentor, I will be there to support them. We will review the exam and talk more about climate change on Wednesday. Stay safe.
There are a lot of web sites related to global warming, see the greenhouse gas inventory, or the Global Climate
Change Student Guide for more detailed information about climate
change over space and time. See the Carbon Dioxide Information Analysis Center to find answers to
questions relating to the atmospheric lifetime of carbon dioxide and
methane, numerical estimates for sources and sinks of carbon, and
greenhouse gas atmospheric residency times. See CO2Now.org for up-to-date, refereed, and clear information regarding climate change. See
the NSF page for a video of carbon dioxide chemistry and function.
NASA reported that 2005 is the warmest year in over a century, later NOAA reported that Jan 2006 was the warmest January on record, later NASA reported that 2009 was the second warmest year on record, recently, March 2010
was reported as the warmest month on record, most recently 2012 was reported as the warmest year ever! Recently, it was reported that 2014 was the warmest year on record! In January 2017, NOAA reported that 2016 was the warmest year on record. What do you think the future holds?
Heat radiated from Earth is trapped by the greenhouse gases – the greenhouse gases are not trapped (however, gravity does hold Earth's atmosphere to the
planet, so, in one sense, the gases are trapped by gravity). Heat is generated (radiated) by Earth's surface (only minimal energy is reflected off Earth's
surface) and radiated into the atmosphere. Greenhouse gases heat up because they
trap the energy radiated from Earth's surface. This trapping of the long
wavelength energy results in an increase in the global average temperatures
(commonly referred to as global warming). The greenhouse gases let energy from
the sun warm Earth's surface but trap the energy generated by Earth's surface.
See an interesting article published in Scientific American entitled "Found: Thousands of Man-Made Minerals–Another Argument for the Anthropocene."
In the Guardian, see "Burning Coal May Have Caused Earth’s Worst Mass Extinction."
26–30 March 2018 [Week 10]
Global average temperatures (15.0ºC or 59.0ºF) have risen
approximately 0.7ºC in the past 100 years. Is the temperature rise a
result of anthropogenic emissions of greenhouse gases, the Milankovitch
cycles, global sunspots, volcanism, or something else? Increased global
temperatures will result in more floods, more storms, more droughts,
shifting climatic belts, and disruption to the food cycle. Could the
warming be due to the sunspot cycle or (here)? Geologically
rapid changes in Earth's atmosphere may indicate the onset of a new ice
age; read about the potential for a new ice age because of global warming, by Woods Hole
Oceanographic Institute. Read more about the discovery of rapid climate change. On 2 Dec 2003, two of the
nation’s premier atmospheric scientists, after reviewing extensive
research by their colleagues, say there is no longer any doubt that
human activities are having measurable — and increasing — impacts on
global climate. Read about the effects of Greenland's receding ice.
The Intergovernmental Panel on Climate Change (IPPC) has been established to assess
scientific, technical and socio-economic information relevant for the
understanding of climate change, its potential impacts and options for
adaptation and mitigation. The IPCC Fifth Assessment Reports may be found here. The 45th Session of the IPCC, held 28 - 31 March 2017, took place in Guadalajara, Jalisco, Mexico; click here for the reports.
Read about the Future of Humanity Project from Oxford University.
Watch the film, "Before the Flood", by Fisher Stevens, where Leonardo DiCaprio travels the world speaking to scientists and world leaders about the dramatic effects of climate change.
Wednesday: Discussion of paper by Waters et al. (2016).
Assignment [due 4 April 2018] — Final draft of the writing assignment.
2–6 April 2018 [Week 11]
Monday topics: stable isotopes and extinction events.
Wednesday: Discussion of paper by Zalasiewicz et al. (2017).
9–13 April 2018 [Week 12]
Spring Break—stay safe.
16–20 April 2018 [Week 13]
For Wednesday, please read (and be ready to discuss) Consensus For Action (2013) with a specific focus on pages iii, 1-3, and 19-20.
Saturday: If your schedule permites, please join the Introduction To Earth Science class and conduct some geological fieldwork in South Burlington, Winooski, and South Hero, VT. We will depart JSC at 8:30 a.m. and return to campus by 5:00 p.m.
Assignment [due 23 April 2018 by 9:00 a.m.] — PowerPoint presentation
Please submit the final version of your PowerPoint presentation to me by 9:00 a.m. on Monday, 23 April 2018.
Use the following format for the filename: lastnameTopic.pptx.
Attach the file to a well-written email (with appropriate signature block).
The grading rubric for the class presentation is presented below. Each presentation is expected to last for 8-9 minutes, followed by no more than three minutes of discussion.
Let me know by Friday, 20 April 2018 (by email) if you want the presentation to count toward the JSC General Education Program requirement for oral presentations. Each student needs to complete two successful presentations to meet this JSC graduation requirement.
end of assignment
23–27 April 2018 [Week 14]
Student presentations — 1)
practice your presentation, and 2) submit the evaluation forms for each presentation.
30 April–4 May 2018 [Week 15]
Student presentations — 1)
practice your presentation, and 2) submit the evaluation forms for each presentation.
7–11 May 2018 [Week 16]
Cycles describe long-term changes in planetary motion. Earth's axis of rotation is currently 23º26'
to the plane of the ecliptic. The angle varies between 21.5º to
25.5º during a 23,000 year cycle. The rotational axis currently
points toward the North Star. Earth orbits the sun in an
elliptical fashion and is farthest from the sun during northern
hemisphere summers; distance from the sun plays a minor role in
average seasonal temperatures. The temperatures are primarily
controlled by the angle the sun's rays make with the surface of
earth. The Milankovitch
Cycles attempt to explain variation in
solar insolation throughout geological time (click here for more information).
Discussion about decision making using the approach of Learn → Decide → Act.
Good luck on all of your finals
and thank you for participating in this class.
Final Exam: Wednesday, 16 May 2018 at 8:00 a.m.
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