HONR 229L: Climate Change: Science, Economics, and Governance Introduction to Climate Change Your name here 2 October 2017

The reading states "Climate is the average of weather" and includes a statement that likely seems preposterous to many: Projecting changes in climate due to changes in greenhouse gases 50 years from now is a very different and much more easily solved problem than forecasting weather patterns just weeks from now. The field of actuarial science can be viewed as being analogous to the field of climate prediction: an actuary studies the life expectancy of large groups of people, allowing insurance companies to thrive financially, even though they will likely pay out a considerably large benefit upon the passing of everyone they insure. Some contend “actuarial science is to trying to predict when any specific person will pass away” as “climate science is to weather prediction”. Consider asking the class to weigh in on this matter. Then, state whether you agree or disagree with this contention and support your answer.

Using the chart on the following page, indicate: a) the most important anthropogenic GHG b) the second most important anthropogenic GHG c) the third most important anthropogenic GHG in terms of impact on radiative forcing of climate, between 1750 and 2005. Note: while the first and second most important anthropogenic GHG are clear, one could make a plausible argument as to which is the third most important GHG: please stop by and speak with me about this matter. I’d like you to indicate the most important GHG, then go over how we know human activity is responsible for the atmospheric rise in this gas Then, ditto for the second most important GHG. Then, lead a “discussion” about which among O3, N2O, or halocarbons is the third most important GHG. Following this discussion, provide a brief overview, from FAQ 7.1, about O3, N2O, and halocarbons

Radiative Forcing of Climate, 1750 to 2005 Question 2.1, IPCC, 2007

Discuss how sea level and Earth’s mean temperature have changed

Discuss how sea level and Earth’s mean temperature have changed

Discuss how sea level and Earth’s mean temperature have changed

We have spent considerable time in class talking about the importance of drought, which begs the question “is precipitation changing?” Prepare a slide or two, based on the material in FAQ 3.2, focused on historical changes in precipitation. Relate the changes in the Palmer Drought severity index to the instances where drought was implicated in the past “Collapse” of particular societies in Diamond’s book

Next, consider leading a discussion about the importance of atmospheric feedbacks. Can base this off the admission ticket, which reads: As the concentrations of greenhouse gases in Earth’s atmosphere rise, the surface temperature will rise, leading snow and ice to melt. First, state whether the melting of snow and ice acts as either a negative feedback, no feedback (null), or positive feedback to the initial perturbation and justify your reply with a sentence explaining your answer. Next, describe whether the feedback involving atmospheric water vapor is either positive, negative, or null. Finally, describe whether the feedback involving clouds is either positive, negative, or null. This can be a lead in to the next slide … in the opinion of your instructors, the key weakness in predicting future climate is our present inability to properly simulate cloud feedback

Finally, consider a two pronged discussion on: why scientists are confident the observed warming of the 20th century is primarily caused by human release of GHGs and is not due to the natural variability of climate (this of course is an Admission Ticket question) the strength and weaknesses of climate models This can constitute numerous slides and be sure to engage the class in a discussion about whether or not they feel comfortable with so much (i.e., future habitability of our precious Earth) relying essentially on computer simulations conducted using archaic languages such as FORTRAN.

CO2, CH4 & N2O time series What do these time series resemble ? You’re welcome to use this 2 slide sequence, as well CO2, CH4 & N2O time series IPCC 2007 FAQ What do these time series resemble ?

You’re welcome to use this 2 slide sequence, as well CO2, CH4 & N2O time series IPCC 2007 FAQ