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CITY OF SOUTH BEND OFFICE O F T H E CLERK
<br /> moderate scenario, RCP four-point five (4.5), is the blue line. There are a couple things I would
<br /> like to point out here.
<br /> He continued, First(1St) off, there is a big difference between RCP eight-point five(8.5) and four-
<br /> point five (4.5). What people do in the twenty-first (21St) century plays a very significant role in
<br /> how warm the climate gets in Indiana. So, it is very important what we do in terms of mitigating
<br /> or correcting the situation of too much greenhouse gas in the environment. At the same time, if we
<br /> look out just a few decades, for example looking out to about the 2040s, there is relatively little
<br /> difference between the very aggressive emissions scenario based on business as usual and the
<br /> strong mitigation scenario.This suggests that we very likely have brought already a certain amount
<br /> of warming and there is relatively little we can do in the context of a few decades. So, we need to
<br /> be prepared for significant warming, even if we successfully mitigate and create a better future for
<br /> our children.
<br /> He went on, The other thing I want to point out is that these changes are extremely large. So, even
<br /> for the ensemble mean, the mean of the thirty-one (31) realizations we have here, these models
<br /> suggest that we will see more than ten(10) degree Fahrenheit warming. And the high end of these
<br /> scenarios, again, the ninety-seventh (97th) percentile of all of that ensemble, shows nearly fifteen
<br /> (15) degrees Fahrenheit warming. Those are average conditions. Those are not the extremes. If
<br /> this happens, we will suffer severe impacts in Indiana, as a nation and as a globe. Lastly, these are
<br /> the actual observations of temperate. You'll notice in the Dust Bowl years, the 1930s and 1940s,
<br /> it was very warm, warmer than what the climate models say. They don't simulate, directly, the
<br /> Dust Bowl years. But, in general, the climate models do a pretty good job of reproducing the
<br /> climate that we had seen in the past. There is a pronounced seasonal cycle to these impacts, as
<br /> well. I won't talk about these too much but if you look at the pattern for the 2080s, the greatest
<br /> warming is in the summer month and this pattern just, essentially, intensifies through time from
<br /> the 2020s, the 2050s and into the 2080s. This is the seasonal cycle on the x-axis from January to
<br /> December.
<br /> He continued, Now, we could do the same analysis for precipitation that we have done for
<br /> temperature. What we see here is a more complicated pattern. We have very strong increases of
<br /> twenty-five to thirty percent (25% - 30%) in the winter and spring. Essentially, all of the climate
<br /> models give us the same answer. Indiana will be a wetter place during those seasons but in the
<br /> summertime, we have a mix. Some models say it will be wetter and some say it will be dryer.
<br /> Overall, on average, it will be a somewhat dryer climate. A better way to think about it is we will
<br /> see warmer and drier as well as warmer and wetter summers at different times in the future. We
<br /> should expect variability to be a dominant factor there as opposed to the winter and spring where
<br /> all the climate models are showing us that things are becoming wetter.
<br /> He went on, So, we have different levels of certainty about different kinds of impacts. How will
<br /> this affect Indiana in terms of impacts? I think, judging from the temperature projections I've
<br /> already shown you, you can imagine that extreme heat may become a very significant issue. In
<br /> fact,this is the case. In all of these slides I will be showing you,it will be three(3)areas of Indiana.
<br /> St. Joseph County, Vanderburgh County and Marion County. So, we have southern Indiana, the
<br /> middle part of the State and the northern part of the State. So, let's take the worst-case scenario
<br /> first (1St). If we look at places in Vanderburgh County, historically, they have about ten (10) days
<br /> per year that are above ninety-five (95) degrees Fahrenheit for the daytime high. If we go to the
<br /> RCP eight-point five(8.5), the worst-case scenario to the 2080s, we see almost one hundred(100)
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