HONR 229L: Climate Change: Science, Economics, and Governance Paris INDCs Your name here 8 November 2018

As always, I suggest working the admission ticket questions into the presentation. While this not essential, it does provide a common point of reference for everyone. I’d be delighted if, after the 45 min discussion you lead, the class comes away knowing: The goal of the Paris Climate Agreement The basics of the Paris Climate Agreement, such as the fact the INDCs are “bottom up” non-binding commitments provided at a country level The INDCs are either “unconditional” and or “conditional” What CO2-equivalent emission means, since this is the basis upon which the Paris INDCs are based (please email Ross & Laura if you have any questions) Where the Paris INDCs will place us with regards to GHG emissions, in terms of the RCPs What conditions need to be met in order to place the world on what the UMCP EM-GC model indicates is the 2°C warming pathway Note: all of the figures and tables from the reading appear at the end of this powerpoint

Consider first leading a discussion of the goal of the Paris Climate Agreement (i.e., target of 1.5°C warming, upper limit of 2.0°C warming). Feel free to use in this discussion the figure below, which is from the Summary for Policy Makers of the recently released IPCC 1.5°C Special Report: http://report.ipcc.ch/sr15/pdf/sr15_spm_final.pdf If you use this slide, the purpose will be to remind students why we are attempting to limit global warming to only 1.5 to 2.0°C, relative to pre-industrial.

This is Q1 of the AT. If you’d like to use, I would hope you could lead a discussion of the numerous differences between these climate agreements. There are structural differences that can be related to terms such as “top down” and “bottom up” we’ve used in class, as well as “legalistic differences” that reflect the fact that, as of Nov 2018, the US is in fact still part of the Paris Climate Agreement and had never been part of the Kyoto Protocol (i.e., US Senate does not have to ratify) Q1. What aspect of the difference between the Kyoto Protocol and the Paris Climate Agreement do you think will turn out to be most important moving forward in time, either for better (i.e., helping the world avert climate catastrophe) or worse (i.e., preventing the world from averting climate catastrophe)? In your reply, please identify the difference and clearly state whether you think it will be for better or worse, with a brief explanation to support this view. There is of course no right answer here ... just looking for a thoughtful reply

Q2 of the AT could also lead to a segment of time devoted to a fairly open ended discussion. If you use, great if you can first be sure students understand what CO2-equivalent emission means. I will touch upon this at the very end of class on Tuesday, using slide 6 that follows. Please be sure to emphasize that the CO2 emissions consider two terms: fossil fuel (FF) and land use change (LUC). Be sure students understand what is meant by LUC: this is deforestation. Land Use Change is the “genteel” way of saying deforestation: nice of policy makers to tone down the word “deforestation”, don’t you think ?!? Q2. Fig. 3.6 shows maps of emissions of the 3 most important anthropogenic GHGs, CO2, CH4, and N2O, expressed as CO­2-equivalent, which uses the global warming potentials of CH4 and N2O to relate emission of these gases to CO2. Figure 3.7 shows maps of the per-capita emission of CO2, CH4, and N2O. Both figures show data for 1990 (earliest possible date) and 2010. a) State one aspect of these two figures you think will be vitally important to address, in order for the goal of the Paris Climate Agreement to be achieved b) State one aspect of these two figures you find to be surprising, given your knowledge prior to reading this chapter.

Rami, I will present and explain this slide next Tues, after Aicha speaks. I am including here in case you want to show again, as a reminder. Hopefully my explanation will be clear. Otherwise, we can chat  Table 1.1: Global warming potentials (GWPs) CO2equivalent emissions = CO2Fossil Fuel emissions + CO2Land Use Change emissions + 28(CH4 emissions)+ 265(N2O emissions) where 28 & 265 are the global warming potentials of CH4 & N2O on a 100 year time horizon, respectively and all of the book-keeping is conducted per unit mass, rather than per unit molecule. Giga is the scientific word for Billion, or 109 Collectively pump 52.5 gigatons (billion of tons) of greenhouse gases into the atmosphere every year Some text books give GWPs on a per molecule basis, rather than a per mass basis. If CH4 is 28 times more potent than CO2 on a per mass basis, then CH4 is also 28(16/44) = 10.2 times more potent than CO2 on a per molecule basis.

Figure 2.1 GHG abundances, 19502100 Should you so desire, you can use this chart, first shown on 30 August (slide 27 that day) to remind folks that the Representative Concentration Pathways prescribe future level of GHGs used by the climate models  Future abundances of CO2, CH4, N2O & minor GHGs provided, for use as input to climate models  Scenarios are called Representative Concentration Pathways (RCPs); number represents increase in RF of climate (units of W m2 ) that will occur at end of this century Figure 2.1 GHG abundances, 19502100 ppm  parts per million Today, CO2 is at about 410 ppm, which means 410 out of every million molecules of air are CO2 (rather than N2, O2, argon, etc) https://www.co2.earth

Next, should you so desire, you could use the next three slides to remind class where the climate model my team has developed would project global temperature would lie, should atmospheric GHGs follow either RCP 8.5, RCP 4.5, or RCP 2.6. The figure on the top shows the probability that global mean surface temperature (GMST) will warm by at least a specific amount, into the future, where the colors denote probability between 1 (sure to warm that amount), 0.5 (most likely outcome), and 0 (not going to warm more than that amount. We also show results from the large (i.e., more complex) climate models (labeled CMIP5) and the assessment of likely future warming over the next two decades projected by the 2013 IPCC report (green trapezoid). The figure on the bottom shows computed probability (defined by height of each box) GMST will be within a certain range (defined by the width of each histogram) for 2100, from, our model (blue) and the more complex climate models used by IPCC. Note IPCC stands for Intergovernmental Panel on Climate Change and CMIP5 stands for Climate Model Intercomparison Project, Phase 5.

EM-GC Probabilistic Forecast, RCP 8.5 Probability  in GMST stays below 1.5C: 0 % 2.0C: 1 % Paris Upper Limit Paris Target After Fig 2.17 & 2.19, Salawitch et al., Paris Climate Agreement: Beacon of Hope, 2017.

EM-GC Probabilistic Forecast, RCP 4.5 Probability  in GMST stays below 1.5C: 21 % 2.0C: 65 % Paris Upper Limit Paris Target After Fig 2.17 & 2.19, Salawitch et al., Paris Climate Agreement: Beacon of Hope, 2017.

EM-GC Probabilistic Forecast, RCP 2.6 Probability  in GMST stays below 1.5C: 80 % 2.0C: 98 % Paris Upper Limit Paris Target

You could use Q3 of the AT, or else summarize Section 3 You could use Q3 of the AT, or else summarize Section 3.3 of the reading. I am hoping your discussion will guide students to understand: a) INDCs are “bottom up” emission reduction pledges by each country, which is a very different structure than used for the Kyoto Protocol b) the difference between unconditional and conditional pledges, which plays into a central theme of “moral responsibility” of the developed world to help the developing world reduce GHG emissions c) that the pledges for emission reductions tend to extend out to year 2030 d) in order to have even half a chance of achieving the goals of the Paris Climate Agreement, nations must continue to “improve” the carbon intensity of their economies, by continually reducing emissions out to year 2060 (and beyond) d) of course, anything else you find to be of interest Q3. Section 3.3 presents an analysis of the Paris INDCs (Intended Nationally Determined Contributions) to reduce the emission of GHGs. Summarize the primary message of this section in a few sentences.

Below is Q4 of the AT. This could possibly be a strong, sobering way to end, since the answer is the U.S. Should you decide to go this route, could steer away from our current President and focus instead on long-term, structural changes that would need to occur for the US to have it’s per capita emission drop from present day value of about 20 tons CO2-eq per person per year, do about 8 tons CO2-eq per person per year in 2060. If you go this route, there is a wealth of info on this website https://www.americaspledgeonclimate.com which I have added to the auxiliary material for this reading, from which you could draw an image or two. Totally your call on how to fill the 45 mins! I only ask that discussion leads focus mainly on the content of the reading, and conduct the presentation in a manner that facilitates class participation. Good luck! Q4. Based upon your analysis of panel c of Fig 3.8 (Business As Usual) and Fig 3.11 (Attain and Improve), what nation (or group of nations) will have to make the largest fractional improvement in its per-capita emission of GHGs by year 2060, for the goal of the Paris Climate Agreement to be achieved? Please also state whether or not you think it is realistic for this country (or group of countries) to achieve this goal, along with an explanatory sentence or two.

Figure 3.1 Total global emission of atmospheric CO2

Figure 3.2 Total global emission of atmospheric CO2, CH4, and N2O

Figure 3.3 Total global emission of atmospheric CH4 and N2O

Figure 3.4 Atmospheric fossil fuel CO2 emission maps, 19502010

Figure 3.5 Per-capita fossil fuel CO2 emission maps, 19502010

Figure 3.6 Atmospheric GHG emission maps, 1990 and 2010

Figure 3.7 Per-capita GHG emission maps, 1990 and 2010

Figure 3.8 Future GHG projections, Business as Usual (BAU)

Figure 3.9 Future GHG projections, Paris Unconditional INDCs, Attain & Hold

Figure 3.10 Future GHG projections, Paris Unconditional INDCs, Attain & Improve

Figure 3.11 Future GHG projections, Paris Unconditional & Conditional INDCs, Attain & Improve

Figure 3.12 Atmospheric GHG emission maps, Paris INDCs, 2030

Figure 3.13 Atmospheric GHG emission maps, Paris INDCs, 2060

Table 3.1 Annex I nations of the Kyoto Protocol

Table 3.2 Top Emitters, CO2FF + CO2LUC + CH4 + N2O