PWS 180: Section 4

This week, we are focusing on how climate change affects ecosystems, including the humans that live within them. As you go through the readings below, try to organize your notes around the following themes: 1. Human health and wellbeing, 2. Human economy, 3. Biosphere integrity, 4. The Earth’s biogeochemical cycles. There are many excellent resources on this topic, and I encourage you to read a variety of sources in addition to the required readings below. Remember that it is easy to find extreme As always, take your time and ask questions in and out of class:

1. Reading: First read this brief overview by the National Aeronautics and Space Administration: The effects of climate change.
2. Watching: This nontechnical overview by Katherine Hayhoe describes what is changing in the Earth’s climate and why a “few degrees” matters.
3. Watching: This video by Climate Denial 101 is bland but rich in details and some useful framing.
4. Reading: The IPCC Fifth Assessment Report (AR5), Topic 2: Future Climate Changes, Risks and Impacts. You can download the report here or access the pdf in the shared Box folder. This week, we will read pages 56-76. As usual, the IPCC report is very dry, but it is packed with concentrated climate truth. Remember that their interpretations tend to be very conservative and that they say nothing casually (there are no filler sentences).
5. Reading: The executive summary of the Climate Science Special Report from the Fourth National Climate Assessment. The National Climate Assessment is the U.S. version of the IPCC. It is more focused on national issues, but also gives valuable perspective on the global situation.
6. Reading: This article from the Guardian entitled, Could biodiversity destruction lead to a global tipping point?

Here are some additional readings for those who want to dig deeper:

• This polished, interactive website by the Carbon Brief: compares the consequences of 1.5C, 2.0C, and more warming on various aspects of the Earth system as a whole and by region.
• The Skeptical Science article on the effects of climate change has a nice summary organized by categories. Remember that you can adjust the level of detail, showing interesting alternative formats and specifics.
• This article entitled, Climate change and human health: present and future risks by McMichale and others addresses the health hazards created by climate change.
• This article by Adger and others entitled, Cultural dimensions of climate change impacts and adaptation addresses how climate change and associated environmental degradation affects various aspects of cultural.
• This book chapter entitled, The Impacts of Climate Change on Ecosystem Services and Resulting Losses and Damages to People and Society covers just that.
• Here is the entire Fourth National Climate Assessment (NCA4).
• The Climate Science Special Report (CSSR) from the NCA4 is a really nice science-based summary of the effects of climate change.
• This article in the Guardian on a recent study published in PNAS finds that One billion people will live in insufferable heat within 50 years. Sometimes claims like this are just hype, but in this case it is based on careful, peer-reviewed analysis.
  

Questions to guide (or at least to start) your reading:

1. Is climate change an existential threat for humanity?
2. How do the hazards and negative consequences of climate change increase or decrease with more extreme warming (e.g. 1.5 versus 2.0 C of warming)?
3. Approximately how much has the Earth warmed since the Industrial Revolution?
4. How will climate change affect the area that you are from?
5. What are some of the most important consequences of climate change for
   
   • Human health and wellbeing
   • Society (economy, national security, etc.)
   • Biosphere integrity
   • The Earth’s great biogeochemical cycles (e.g. water, carbon, nitrogen, phosphorus)
6. What is the difference between mitigation and adaptation regarding climate change?
7. Compared to the authoritative reports you read (IPCC and NCA), do you find that media coverage of climate change tends to exaggerate or downplay the consequences of this issue?
8. T/F If we limit warming to 1.5 degrees, we will avoid the negative consequences of climate change.
9. T/F Climate change is primarily important because of how it threatens vulnerable species.
10. People often bring up examples of how climate change could bring about positive changes. Are they completely wrong and how would you respond to this line of reasoning?
11. What are the four ecological laws and how do they relate to the consequences of climate change?

This week, we are wrapping up our discussion of the effects of climate change. There is a midterm, so there won’t be a reading quiz. However, I encourage you to read the chapter below, which lays out really important terminology and concepts about modeling climate into the future.

• Reading: This chapter in the CSSR digs into the scenarios and simulations climate scientists use to explore possible future consequences of climate change (RCPs, SSPs, and emissions scenarios). These terms come up all the time in the IPCC and NCA reports, as well as in general climate change discussions: The Human Role in Future Climate Change.

Questions to guide (or at least initiate) your reading and thinking:

• What are RCPs and SSPs?
• How do scenarios of future climate account for the fact that there are so many variables, many of which are not completely understood?