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):

 

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.


Stratigraphy

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]
Population

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=ln(2)/λ

where:

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]


Note:

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:


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:




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.

Anthropocene Markers

There is ample evidence in the rock record for demarcation of the Anthropocene; some of the markers are listed below:

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 the nucleus.

Common decay mechanisms include:

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).

Radiation

The Vermont 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

 

Ozone

Ozone, 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 ozone: Good 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 a dramatic 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

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.

 

Global Warming

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]

Monday: extinction

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]
The Milankovitch 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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