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PWS 180: Section 4

What are the consequences for humans and ecosystems?
The worksheets, slides, and other materials for this section can be found in this Box folder: PWS180 shared.

This section is focused on how climate change is affecting the Earth's ecosystems, including human society. We could spend a whole semester on this topic. However, because we have already been discussing many of these consequences, here we will focus on how the various consequences interact.
  • 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:

    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?