Comment

Response

1

(For pages 9-12) The results you present on the next few pages are clear enough, but the bases for them are not. I am particularly concerned with Table 1. I am unable,, based on prior knowledge to know whether these projections, and especially the ranges, make any sense. For example, the sea level projections have sensitivities based on the upper and lower estimate from one source. Is this source definitive? Are there alternatives which would find values outside these ranges? As to temperature, it appears from Figure 7 that there is an unusual correspondence between the two models on which you rely for about 2034, and therefore there is a very tight range for this year. Is this really indicative of the range of possibilities? It seems to me that when you present such ranges you a) need to define what confidence you have in the extremes, and b) what the extremes mean. And then you need to show why the extremes you choose are those that should be relied upon.

Chapter 3 has been revised substantially to clarify many of these questions – although a few will be addressed in the Foundations report because of the detail required.

2

By choosing as the extremes the point estimates on two models which drive your analysis, as I take it you do, this does not include the potential range around the point estimate that each of these models should likely exhibit. This method, it seems to me on first glance, would appear to force compression in the presentation of "what might be". Indeed, it seems to me that the drivers of your analysis are presented with greater certainty than they might justify.

Clarified by adding a new figure that shows projections from a broad set of climate models, and new language about plausible futures rather than predictions.

3

Be prepared for some criticism that the chart on p. 13 (which I think is quite innovative) is too general and not scientific. Good luck!

The revision clarifies the uncertainties yet emphasizes that the results are better than no information.

4

The effects of climate change could contribute to a shift in the fuels used to generate electric power in the next century, and could be a significant factor in reducing the amount of fossil fuels used, and increasing the amount of power generated from other sources. Since Pennsylvania is a major user of coal to produce electric power, this effect should be discussed in the report or could be included in the last section under What Do We Still Need to Know?

Assessing how to reduce GHG emission is not our research task – we were asked to assess what the MAR impacts might be, given a range of projections of climate change. We clarify this on p.1.

5

You note on page 3, item 3 the importance of looking for special populations. I believe this is critically important. Small average effects may mask some impacts that are very substantial for especially vulnerable individuals, households, communities, industries or regions. I think much important future work on human dimensions will emphasize vulnerability and may aid in this effort. In particular, I suspect we will find that the growing emphasis on extreme events and increases in variance will also show us that some populations and sectors are especially vulnerable to those changes.

The revision has more emphasis on distributional implications, especially as related to extreme events.

6

That page also talks about linkages, and one critical one is to better understand how suburbanization and climate change will interact in changing ecosystem function and structure. Good work seems to be ongoing on each of these topics but I've seen little to link them as yet.

Chapter 8 emphasizes the relationship between development and ecosystems and a new Box 10 links climate in urban areas to ecosystems.

7

Overall the report does a good job of formulating the problem in assessing the consequences of climate change but the report is more a qualitative than a quantitative assessment. Perhaps this reflects the uncertainty associated with this issue and the lack of useful data sets. It would have been useful to approach the assessment by developing stress-response curves such as the relationship of biodiversity effects plotted against maximum temperature or precipitation. I realize that such relationships are very difficult to construct and the response curve is probably not linear. Still, these types of relationships are the essence of a quantitative assessment. It is frequently necessary to construct a series of nested relationships and to tease apart the nest in order to understand the consequences. For example, the relationship of biodiversity to precipitation is probably best characterized by analyzing a series of nested stress-response curves such as precipitation to forest or habitat type and then habitat type to species associations thereby drawing some conclusions about species shifts. This type of nested construct was not developed in the report.

This represents a possible future thrust, although some of this will be in the Foundations Report.

8

Given that this is one of 19 regional assessments it might be neat to compare the Mid-Atlantic with other regions, so the lay public has a sense of how the Mid-Atlantic fares relative to other regions.

This is a major part of the task for the NAST.

9

In summary, I found the report to be very well done. My interests cause me to encourage you to consider some minor additions to describe the potential impact of weather extremes. This could include a paragraph describing someof the characteristics of hurricane Floyd offered as an example of extreme weather in the region, and a comment to state that there is potential for damage in the region that may be much greater than that due to Floyd. You may also consider a reference stating that research is continuing to determine the relationship between these risks and climate change.

The coastal chapter has a new box on Hurricane Floyd, addressing some of these issues.

10

Since this report is intended for the general public, the use of acronyms should be minimized if not completely eliminated. For example, MAR should be Mid-Atlantic Region and IPCC should be spelled out.

11

The overall format of the report seems in keeping with the other regional assessments I know. I might suggest that, to get peoples' attention and to generate appropriate concern with climate variability and change, you might place the "How People and Their Surroundings Will Be Affected..."right after the "Purpose" section of the Exec Summary.

Noted, but we judge it important to include the science first.

12

No show-stoppers here, but maybe a few things to think about – especially the possible desirability of adding an impact summary from the perspectives of major urban areas....

A new Box 10 introduces the need to address urban areas.

13

The only reactions I had about stories *not* told have to do with the general preoccupation with agriculture and ecosystems vs. people and human settlements. For instance, the section on coastal (like the national sectoral study) is so heavily weighted toward ecosystem issues that it sounds a little as if the coastal areas are uninhabited. And I would be very interested in seeing some treatment of what climate change in your region might mean for your cities: Philadelphia, Baltimore, DC, etc., sea level rise increased risks of severe storms? Pressures on water supply systems, at least seasonally? health impacts on the poor, young, and elderly? Putting the pieces together somewhere for this audience would be very helpful in communicating with a one-person/one-vote world out there... And how about the possibility that as the Southeast gets more uncomfortable (heat stress up an average of 15 degrees by the end of the next century?), the Middle Atlantic will become more popular as a place to live and work as Sun Belt - type growth, retirement location choice, etc., migrate northward?

There now are new boxes on Hurricane Floyd and on cities. Both tie people to the potential impacts from climate variability and change. We also shall include more detail in future MARA work.

14

There seems to be little discussion of how changes in one sector may exacerbate changes in other sectors. It makes sense to treat them all separately, but there is also potential for a change in the coastal zone, for example causing (or contributing to) a change in the region’s forests. Many of the information needs listed in Chapter 11 concern these relationships, however, so such interactions have been considered.

The report mentions these linkages; additional work on them will be done as the MARA continues.

15

There is no assessment of the greenhouse gases, although CO₂ is mentioned as a leading contributor to the negative MAR impacts. For example, there is no analysis of sources or contributions of greenhouse gases in the region, such as automobiles or power generation. The models presented show that regional temperatures will rise but they do not provide any model predictions as to the increase in greenhouse gases. The models of temperature assume an increase of 1 percent per year in greenhouse gases but do not address the reasonableness of that assumption or how it was determined.

Separate activities are examining regional sources of greenhouse gas emissions. Chapter 3 now describes why the specific CCC and Hadley models were used.

16

A second major assessment issue that is missing is the role of science and technology policies that can help ameliorate the projected impacts. For example, the report states that "Manufacturing and Services are the largest economic sectors, accounting for 26 percent and 20 percent of MAR output respectively." If these sectors are the largest sectors, then one can presume that they contribute in a significant way to the environmental problems of the region. Also, the analysis points out the large population growth that is expected in the region, and by inference, the associated environmental impacts of population growth.

These items were addressed in the draft and continue to be addressed in the final version.

17

In planning for the 21^st century, as the report attempts to do, it would be much more effective by looking at environmental policies more broadly. The report does not address those policies that can promote major shifts in using current technology. New environmental policies can promote changes in the way and type of current technological approaches. These can include creating demands for fuels that move away from hydrocarbon and toward alternative renewable sources, such as hydrogen or solar. Also, policies that encourage the move towards dematerialization and decarbonization are equally important. Finally, policies that provide for market incentives need to be researched

Our charge was to examine the regional impacts from climate change, not all causes of environmental problems and their solutions. To the extent that our charge is consistent with addressing other environmental issues, these have been discussed in the Overview.

18

I also would recommend … making this document more "user friendly" for the citizens. …develop a fact sheet or summary that would provide the key points of the assessment in four pages or less and would be more of an advocacy piece (advocating learning about and getting involved in the issue of climate change and the assessment rather than advocating a specific viewpoint on the information). This document would be an introduction for those with a limited background in environmental, social, and political issues (which I would assume to be the majority of people in any given region of the country). It is my experience that the general public is not interested in reading such a lengthy, jargon-filled document such as the assessment; however, they generally are willing to read and respond to a fact sheet that is very targeted and factual. The two page appendix on stakeholder participation does help address this concern and specifically mentions, everyone in the region is a stakeholder in the MARA project because all of the regions "citizens could be affected by climate change." I think that this philosophy should be incorporated in the development of the fact sheet. In regards to the use of jargon in the assessment, it is unavoidable. … move the glossary and list of acronyms from the back of the document to the front of the assessment and [call] the glossary… Key Terms. This will allow people who likely are unfamiliar with the terminology to read through the terms at the beginning and thereby develop a level of confidence for reading and understanding the remainder of the assessment. I also recommend that the following terms be added to the glossary: atmospheric, biodiversity, invasive species, nutrient loading, point source, nonpoint source, vector, non-target species. I think that these changes would be helpful in encouraging stakeholders to fully read and understand the assessment.

Note that the first few pages serve as a stand-alone executive summary. Throughout the Overview, an effort was made to minimize jargon, define essential scientific terms and identify unfamiliar ones in the glossary. The suggested additions have been included. We also are developing a very short summary along the lines of a fact sheet, with lots of visuals, but based on the science.

19

Overall, the draft reads very well. However, it is sometimes hard to determine what level of analysis supports various assertions. Some statements appear to be based primarily on a literature review; others on more in depth case studies or quantitative modeling. But many statements are made in which it is hard to know if this is the "first cut" judgment of the research team or the result of extensive, specific research.

To the extent feasible in an Overview, this has been clarified. More detailed descriptions appear in the CR Special and the Foundations report.

20

Figure 1 (page 3) is very elegant. When looking quickly at the report I thought I understood it. Now I find that most of it is clear but some features are not. In particular, why or how does the bubble labeled Response Choices generate the "driving forces" which then impinge on the bubble labeled Human Activities? What are these driving forces? Are they somehow generated by the responses or are they, as one often thinks of them, originated otherwise (populations pressure, for example, would be such a "driving force"). To me, this needs to be clarified to make the diagram more self-explanatory. Also, what does the term "Existing and Anticipated Trajectories" mean, specifically? Some of these could be what I would normally call "driving forces", but what do the words mean here? It was also not clear how Policy Changes impinge on Driving Forces (at the bottom of the figure). If these matters can be cleared up then I would have no more questions about he figure and would find it an excellent representation of the dynamics of the subject of the report. It would not hurt, even at the expense of a slight lengthening of the report, to give some description of the figure and not just leave its interpretation to the reader. The questions I have just raised might then become unnecessary

Our judgment is that because these questions are covered in the Knight et al. (1999) reference, it would take too much space to cover them again in an Overview report. The purpose of the diagram is primarily to help the reader understand that there is a conceptual framework behind the assessment (even if the reader doesn’t grasp the framework’s details).

21

My final comment on the report may well be too much prompted by experience, in Austin, where we have environmentally sensitive areas in abundance and city and regional planning, as the Austin metroplex begins to make itself more and more evident, is therefore both complicated and necessary. Major effects affecting the Central Texas region have to do principally, today, with endangered species, water runoff handling, and aquifer recharge and protection. Austin, which has a large extraterritorial jurisdictional area, has just adopted a "smart growth" ordinance to address these problems; however, it is apparent that while some of the problems are addressed, others will arise; notably, lower density building will be required which, combined with growth, will require longer travel: more roads, more cars, more area covered with impervious parking, buses, etc… Clearly the current ordinance is not the final answer. In the report mention is made of the effects of population growth pressures. No explicit discussions address metroplex development as an environmental factor yet, given the nature of the region, this is happening and will surely continue to happen. Can this problem at least be alluded to? Can something be said about it in the concluding portions of the report? Or is Central Texas’ situation too different?

There is a new Box 10 on urban areas ad the linkages with climate change. The continuing MARA work will account for more of the interactions among development, environmental stresses, climate change, and quality of life.

22

Executive Summary: A brief explanation of why the region includes parts of New York, New Jersey, and North Carolina is needed here (even though it is given later). Otherwise it looks odd that the list of cities does not include New York City.

Proposed sentence has been added.

23

Chapter 2: Still not entirely clear from the text why the small portion of NY was included (I presume because it’s in the watershed). Also, although other regions are mentioned in general later, does it make any sense to say more about the neighboring regions, e.g., in terms of regional interconnections north, south, and west?

Some interconnections are mentioned, but this is primarily a NAST responsibility.

24

Table E1 needs to have some time reference, i.e., when these impacts are expected. Also, the widths need some sort of legend or definition in the table or its header. Finally, it’s not clear to me, even after reading the text, why all the positive impacts are considered equivalently small.

25

At the outset, the executive summary states that one of the goals is to identify how people are affected now by climate variability – yet this important goal is not evident in the rest of the report, for example in the integrated assessment framework (figure 1). … we know how much work it is to assemble and analyze appropriate datasets to determine the impacts of past climate variability, but such work provides an important foundation for interpreting climate-change scenarios. Perhaps this would be worth explicitly stating in "what we need to know."

The Overview now includes more on impacts of past climate variability; the CR Special and Foundations report will have additional details. Of course, knowing still more would be helpful.

26

Could say more about the inputs to table 1, specifically whether 2030 and 2095 refer to individual years (in which case the year-to-year variability shown in figure 7 gives cause for concern) or an average?

The additional explanations now in Chapter 3 provide more context for the information in the Table.

27

The high level of detail in some of the boxes (3, 6, 8) seemed out of place given the cursory way in which other topics were treated in this short report

This strategy illustrates the kind of assessment that can be done, for a few topics likely to be of special interest.

28

Table 1, "reliability of prediction" -- I am uncomfortable with the word "prediction" in this context, and I think "scenario" or "projection" would also be more consistent with the terminology used in the text. Also, I believe a more usual term (in the context of the IPCC) than "reliability" would be "confidence."

The table has been revised in response to these suggestions.

29

pg. 2 - Goals of this report, #1: do you only want to include current environmental stresses? it seems from reading the report that other current stresses are considered.

30

pg. 2 - paragraph starting "The first step for the MARA...", 2nd step - some examples of components that are sensitive to climate may be beneficial for some readers.

31

page iii, first two paragraphs and Table E1: Two types of human health implications are discussed in the text, urban heat stress and cold stress, however the distinction is lost in Table E1 where temperature related health status is both most and moderately certain and very small and small in terms of impact. It would be useful to differentiate the two within the table.

32

Table E1: The table is intended to illustrate varying certainty and magnitude of potential implications. I discern four levels of impact in the "negative" column that aren’t really explained in the text very clearly. For instance, both the ‘most certain’ temperature related health status impact (heat stress) and ‘uncertain’ fresh water impact are noted as being moderate in the text yet have different sized arrows in the table – can one distinguish to this level? As well it is difficult to believe that there aren’t some moderately positive potential effects. I would suggest explicitly introducing the varying levels in the text or as a footnote to the table and possibly restricting to at most three levels of magnitude.

33

Page iv, left column, last sentence: Consider moving this sentence into the ‘purpose’ section. It seems to me that this (optimizing social well-being) is the key criterion against which impacts, both harmful and beneficial, are being assessed.

34

The subject of climate change has been politicized by national and international politicians and sensationalized by news media and others. A very badly flawed Kyoto protocol has been proposed as a solution. Despite considerable debate in the scientific community on the extent, causes and effects of global warming and despite the fact that the earth’s climate has been naturally changing forever, many so-called "stakeholders", including the sponsors of your study, have concluded that global warming is man-made and will be apocalyptic. For these reasons I believe that the MARA and other assessment reports will be used to further political goals and will be quoted frequently (mostly out of context). Therefore, inconsistencies should be minimized.

35

Having said that, it is fair to state that some of your writers did point out many of the uncertainties of future effects of warming on various things. But usually the writer then reverts to discussing worst case. Example 1: On page ii the report states that upper and lower bounds, as defined by the two models, would be used. On page 22 Figure 11 "shows how a 36 inch rise in sea level (which is near the high end of the estimates for 2100) might affect the shoreline of Delaware." My bet is that this map will be used extensively by the news media. Example 2: on page 14 a status quo (SQ) agriculture scenario was picked despite the fact that "it is realistic to expect that agriculture will become less important" for other reasons.

The SQ scenario reflects a (less likely) relatively large agricultural sector for the MAR, as one bound. The EFS scenario represents the other bound.

36

As a non-climatologist I find the case for predicting more extreme climate events to be confusing at best. In the face of such uncertainty why does virtually every chapter of the MARA report put such emphasis on extreme events?

Our downscaling suggests that there could be more frequent intense precipitation. However, we are less confident about how variability and extreme events might change than about the overall climate trends. On the other hand, the potential impacts due to changes in climate variability or extreme events might be more serious than impacts due to changes in average conditions. Thus we pay attention to these potentially serious impacts even though we are less confident in projecting that they would occur.

37

Table E1: Distinguish the impacts predicted from CCC and Hadley models by labeling them with different color, e.g. red for CCC and blue for Hadley model?

38

Table E1 shows moderate certainty that there will be a strong negative impact on biodiversity. This result is not consistent with VEMAP runs and Hansen’s biodiversity paper in forestry sector. Same comment applies to Table 2.

39

I have examined portions of the report sent to me. In general, it appears to be an introductory document as compared to the Southern Appalachian Assessment report issued in July 1996.

40

I think that the report needs a really short, flowing, catchy summary up front. A really simple way to do this would be to make page 35 (but giving the conclusions of Chapters 10 and 11 rather than the topics of them) into the Executive Summary and to call what is now the Executive summary the Technical Summary or Extended Summary or something like that, maybe following right after what is on Page 35. But what is on page 35 is what is key for Executives to read.

p. 35 is summarized on p. iv.

41

Page i: USGRP is only sponsoring 16 regional assessments, rather than 19, although there were 20 regional workshops (including the Native one which was national). Same comment for Page 1.

42

Page i: In the last sentence of the Purpose, I think you might develop this point a bit more, making the point that stakeholder involvement is needed as part of a two-way dialogue or something, etc.-it just seems now as a last minute hanger-on.

43

Executive Summary Table E1--Some scientists (i.e. R. Mendelsohn, the Greening of Global Warming, the AEI Press, 1999) now state that global warming may cause more benefits than initially believed, or cause reduced negative effects than earlier projections that were made in the late 1980s and early 90s. Therefore we question the relative size of the arrows in Table E1. They do not seem to reflect that possibility that there will be significant benefits from climate change (and by implication, few opportunities) because all the benefits arrows are small compared to the large negative impact arrows shown in the table. We realize the arrow size is subjective and reflects a judgement from the discussion in the report, but we suggest another look at this, because this table is the key one of the report and the chapters that it summarizes do discuss possible benefits from climate change.

The report now stresses the difficulty in identifying potential positive impacts for the MAR.

44

Page iv and v: I wonder if the calls for improving models might focus on not just improving them, but on improving access to them and their results by the public-and we need to know how best to do this?

45

Executive Summary page iv, first full para.,--The statement "Economic analysis suggests the MAR economy will be resilient to projected climate change".--We suggest including the economy as a catagory in Table E1. with an arrow for it.

46

Executive Summary pages iv-v, What Do We Still Need to Know?,--More on the potential benefits of climate change could be listed as an unknown item here.

47

It would be helpful to note/highlight, in the Executive Summary and Setting the Stage, the key climate sensitivities with the MAR. Why should the MAR be concerned about climate variability and change? Where are the key sensitivities/vulnerabilities based on past experience (e.g., water supply - too much and/or too little, sea-level rise and storm surges, forest disturbances).

48

It may also be helpful to identify the existing climate variability and to explicitly show that the projected changes are outside that which has occurred in the past (i.e. that to which we have adapted). Once again this could be done in both the Executive Summary and Setting the Stage/The MAR: Present Status and Potential Future sections of the report. Possibly adding a few sentences and extending some of the climate curves back in time.

49

Second, there is little in the report about how you think that people might respond to these changes. You talk a lot about adaptations from the standpoint of physical interactions but very little from the standpoint of users -- of beaches, of forests, of drinking water. Thus, it is a little hard to go from the graphs to knowing how much my family and I, as residents of the mid-Atlantic region, will notice these changes. I don't quite want to see "a day in the life of your grandkids" but something like that might help to bring the issues home.

50

Third, I wanted to see a little about what types of information might be needed to help us learn about what is going on -- something about adaptive management strategies, or learning as an objective, as a strategy to be noted in Section 10

51

It seems to me that the issue of adaptation is huge -- how quickly will humans just adapt to changes in rainfall, temperature, the frequency of extreme weather events, new forest species or pests, etc. and just code it as the new norm AND what is our responsibility, as social scientists, to come up with good measures of change that make sense and can help to keep the knowledge of change in people's minds and hearts and discussions with neighbors or votes at shareholders meetings or for politicians? One part of this is also how people code uncertain events in the context of an incomplete knowledge on the part of scientists re. warming trends, changing rainfall trends, etc. It's like in a marriage, where one partner says "things are getting worse (or better)" and the other says "gosh, I haven't noticed a change." Then these folks can go off to a therapist and come up with some criteria to measure (forward or backward) progress and to decide at what point something big (a vacation, or a trial separation) needs to occur. In some sense, I think we as social scientists need to be that therapist and keep that measure of change in front of people, making it salient.

Comment

Response

1

Figure 5 – it was difficult to match the colors on the map to colors on the key. Would it be possible to use fewer classifications, or to reproduce the map much larger?

The land use figure has been enlarged and the number of land use categories has been collapsed, making it easier to identify locations of major categories.

2

Good notation that "the picture for the year 2100 is just as unclear." Perhaps also mention that the uncertainties associated with scenario generations increase dramatically as the time horizon increases. Impact scenario uncertainties derive from the interactions of climate change and variability with changing socio-economic trends (this is referenced on p. 9). 2nd and 3rd order impacts may be significant (see Dennis Ojima, Aspen, 1997); these are extraordinarily difficult to predict/model and mitigate.

3

Re: Economic analysis/resilient economy. With some 1/3 of the Region's gross output being import / export , -i.e. trade with other regions (see p. 7), then there may be more risk to the economy than implied. Again, the 2nd, 3rd order impacts could be significant. These external impacts could create new markets, thus positive.

4

P. 9: An additional graphic showing the economy's breakdown by sector would be helpful. If this were done with some historical tracking as the other graphs on this page it could capture some essence of the shifting sectors such as the huge decline in Ag/Forestry as a percent of the region's economy.

5

Keeping in mind your injunction that this report is designed for non-specialists, the section on pages 9-12, especially the material on pp. 9-10, is simply too terse to be understandable. I read this section several times and I simply could not grasp your base line and scenarios discussion. For example, in Figure 6, what is the source of the baseline and of the upper and lower estimates – The description says the results shown are the "baseline" for the socioeconomic conditions in the absence of climate change. But what is the "baseline" that you use? Is it the "baseline" as shown in the graphs--or is it the suite of predictions that are found, including the upper and lower?

6

One area that would be helpful is for the assessment to provide more information regarding the monetary costs or savings of continuing current behaviors or adopting the recommended changes. The examples and recommendations in the assessment did not seem to fully communicate costs for all examples. On page 22, the costs of the National Flood Insurance Program are mentioned; however, no savings or benefits are mentioned about policies such as strategic retreat. On page 32, the costs of having to treat increases in diseases such as malaria or cholera would have been helpful in putting a value on this specific impact of climate change, rather than just that an individual would have an increased chance of contracting one of these illnesses. This type of cost-benefit information is an important component of developing appropriate policies in this area and would be relevant to all stakeholders, not just officials or businesses, in developing their own evaluations of the assessment and its information.

7

Under the discussion of how people and their surroundings will be affected by climate change, there really is not sufficient discussion of how society may well change over 40 years. Although the analogy to the past 100 years is apt, some specifics about the economic, land use, urbanization, and other trends expected for the region in the 40-year time frame would be helpful.

Future socioeconomic conditions are important to the consequences of climate change and we would like to do more about this in future assessment activities. In the Overview, however, we decided not to attempt a specific picture of what the region’s socioeconomic future will be like for this product. There are two reasons. One is time and budget constraints. Construction of plausible and consistent futures for each of the sectors that considers the range of demographic, social, economic, technological and institutional factors that will shape their futures requires considerable time and expertise. We have described and made what we feel is reasonable use of the NPA results for the region and have drawn on "futuring" exercises in some parts of the report (e.g., agriculture, health), but we simply did not have the time and resources for more than this. The second reason is our decision to avoid speculation that could open the team, our sponsors, and the process to damaging criticism. The specifics of medium and long term futures even without climate change are highly speculative. So too are the linkages between climate and the specifics of socioeconomic systems. We risk two types of errors when describing the specifics of socioeconomic futures. One is the obvious errors about the specifics themselves. But in choosing the specifics, we are implicitly accepting hypotheses that the socioeconomic specifics matter.

8

Chapter 3: This chapter is particularly thin on what exactly the socioeconomic and environmental future is envisioned to be and what the methodology was. [Indeed, in Chapter 4, there is a sentence that starts "Using the socioeconomic modeling approach outlined in Chapter 3…"; I had to flip back to see that I had not unintentionally missed this! I didn’t see much detail at all]. I know that some of the baseline projections were provided by NP to the USGCRP, but it’s not clear what if any additional quantitative scenario development you undertook for the region. In particular, there doesn’t seem to be any extension of the agriculture scenario approach discussed in Chapter 4 to any of the other impact areas.

9

pg. 35 - first paragraph - although buyers and sellers within MAR can adapt to changes in availability of ag and forestry products in general, this may make the region's economy robust, but what about individuals or sectors of society who may be differentially affected negatively? should this issue be addressed (or just mentioned) here? just because the region as a whole will survive, there may be subsets of people that do not fair [sic] as well.

10

Projecting future socioeconomic status and climate first par.: An illustrative sample of a socioeconomic scenario would make this paragraph consistent with the introduction of particular climate scenarios in the paragraphs that follow (e.g., a figure of overall economic output for the region as projected over the next 30 years).

11

Page iv par. 2, last sentence: The section would benefit by providing a regional example of how a technological, institutional and/or behavioral adaptation ameliorated the impact of historic climate or weather event (hurricane, drought, etc.).

12

Section 2, Page 5: The geography and economy discussion is very informative. Would it be useful to explicitly mention how these features will aid in the integration process? Coastlines, watersheds, cities or city-regions, mountainous areas – they all convey meaning to the public and in many ways are informally or formally institutionalized in current management issues that stretch across political boundaries. Something like this might add to the rationale provided in the text to warrant the boundaries selected for the MARA.

13

The other point that comes to mind is concern over applying today’s climate-sensitive relationships in assessments of the future – this is more fundamental than just socioeconomic scenarios as the climate-sensitive relationships themselves change over time with changes in technology that may not be captured by changes in overall economic output. The best example … relates to the January 1998 ice storm that affected southeastern Canada and the northeast US – the impact of this event would have been drastically reduced earlier this century before society became so reliant upon hydro-electric infrastructure. Maybe there’s a suitable MARA example?

14

I would like to have had a more explicit description of the development of the scenarios. …What remains unclear is how (or whether) the individual sector scenarios derive from or fit into an overall scenario for the MAR (or, even a broader one within which the MAR must fit). The descriptions beginning on page 3 seem to imply this but it is not clear that this is so (or that it isn’t so). For example, I participated in a study…which had as its objective defining what kind of training and education, at all levels, would be needed to fill positions, at all levels, in the chemical industry in Texas in the first couple of decades of the second millennium. Since the chemical industry anywhere is tied into world conditions, the study started by setting up three world scenarios; from these the corresponding scenarios for the U.S. were developed and, finally, corresponding scenarios were developed for Texas. These scenarios had implications for the nature of the chemical industry which were then translated into educational needs. Underlying all of this for Texas were demographic information projections (up side, down side and middle) as well as other socio-economic factors. This approach captures, as well as one can, both the worldwide and the corresponding local influences on the subject at hand, scenario by scenario. It is explicitly integrated across scales, from world-wide to local. The approach in this study followed the methods of Peter Schwarz…"The Art of the Long View" (Doubleday-Currency, New York, etc… (1991), ISBN 0-385-26731-2). … You may want to…note in your report the degree to which your methods are like (and unlike) Schwarz’s… Also, if some degree of large-picture to small-picture (and vice versa) scenario integration does take place (or does not do so) in your report, you might make that explicit (if you have not so integrated the scenarios, this will give the reader a feel for the limitations of the methods applied.)

15

Page i: Going to three significant figures on population of the region is likely too precise. Also on page 6. Maybe say about 35 million.

16

Page i: Isn't Long Island Sound bigger? Or maybe that is not an estuary?

17

I had to look up where the Albemarle-Pamlico Sounds were, and then was surprised they are in the MAR. Interesting. What about Delaware Bay as well?

18

Page 9: Should the title of the third figure be MAR income? On page 7 the term "annual output" is used. Is this the same or different? Consistency would help if appropriate.

Page 11: I am a bit confused by the figures. Do the January comparisons really show the region getting colder? I would think one might show the CCC results as the upper bound, with very little change as the lower bound. Showing the UK results as the lower bound seems to me to hide the potential changes that may occur. Or maybe go out further than 2025-2034 to show the size of the coming change.

Why were the Hadley and CCC models chosen? Have these models been tested against past data? Do other "state-of-the-art" models show less change in temperature and/or moisture? Why were different models used to produce the chart on page 31?

The text now explains why these models were used, and a new figure shows how their projections compare with those from then state-of-the-art models.

The 1% per year number is likely a bit confusing and is sometimes said to be an overestimate, but note also that the sulfate aerosol increase is also likely too large.

The historical record is only part of the picture. Although projecting extremes is uncertain, based on current climate models, we expect that the warmer average temperature would increase heat stress and decrease cold stress a bit. Both heat stress and cold stress will remain small factors in the region’s health status.

regular format?

In the last sentence, I think I might change "uncertainties" to "limitations in our ability to project future climatic conditions" and change "we use" to "analyses in this report are based on" or something similar.

the COP negotiators) tends to do this, but scientists have resisted this. You might recheck this. Also, in the text below the box, it is a bit confusing to say "year-to-year and decade-to-decade weather"-don't you mean climate variations? Also, mention time period for precipitation increase in the same sentence.

Comment

Response

1

General comment on Ag/Forestry - to devote 4 pages discussing two sectors which combined only account for 2 percent of the economy seems a little much. I think it’s easier for scientists to concentrate on these because, like other ecosystems, they are thoroughly studied by an established academic constituency and literature base. A "redeeming" rationale for this emphasis is found at the top of page 14: "[these resources] defines many rural landscapes. Rural and urban populations enjoy agricultural vistas valuable amenity." Tougher, but more relevant, would be to add a sector(s) dealing with more dominant economic sectors. Perhaps combine Ag/Forestry into one section.

More attention is devoted to these because they obviously are affected by climate and cover such large shares of the region’s landscape. Because their issues and potential impacts are distinct, each retains its own chapter.

2

Page 15: I think Table 4 may need some reworking to be more obvious to the scanner of the report-I even had trouble when reading the report. (And the reference to Table 2 for the summary seems a strange way to go-agriculture looks so hidden in the table. Maybe a separate figure could help?)

Also see #5 below.

3

The Assessment treats the impacts on forests of extreme weather, but fails to treat the same issue in the Agricultural sector, where extreme weather, such as drought, ice, and flood, can have a significant impact on output.

Added phrase in Ch. 4, new box on Hurricane Floyd, and mentioned in chapter 11.

4

In the chapter dealing with the Agricultural sector, the assessment indicates that "dairy and poultry are not expected to be affected by climate change." Was any consideration taken of the fact that a great deal of poultry production occurs in the coastal zone of the Delmarva peninsula and whether that would have any effect on the industry. In fact, there is a great deal of agriculture in low-lying areas in the Mid-Atlantic that could be impacted by being located in the coastal zone.

Initial study suggested no impact on dairy and poultry, but we shall consider the impacts on coastal agriculture in more detail in a later phase.

5

Chapter 4: I was surprised that more detailed assessment results were not presented in Chapter 4 (the reader is referred back to Table 2). Seems like there could be more detail than those generic arrows. More specifically, what methods were used in the analysis of the agricultural impacts? I realize that this summary is supposed to be non-technical, but some level of information about the analysis would seem to be important here. Other regions have conducted detailed agricultural impact studies using linked models of various sorts; was this the case here?

The relevant portion from Table 2 now is included within each chapter, making it easier for the reader to see the potential impacts. More detail about each chapter will appear in the CR Special and the Foundations Report.

6

Why does the SEF scenario define the lower bound for both negative and positive environmental effects (table 4)?

Because agricultural production will be so much smaller under SEF (now called EFS). Therefore climate would not have much of an impact, either positively or negatively, on the environmental externalities associated with agriculture.

7

Page 7: On page i, it said agriculture was only about 1 percent of the region's gross product, but page 7 lists Agriculture first among three sectors that make up the largest part of about 30 percent of the region's total gross output. I am a bit confused.

The page 7 material is about the region’s trading with other parts of the nation and the world. Agriculture accounts for a large share of this trading.

8

Page 14: Unless you have done a special recalculation, I would imagine that it should say "compared to the national average of about 13 percent" though the small contribution of the MAR may make the existing statement correct as well.

Revised as suggested for clarification.

9

Page 14, Table 3: For the first scenario, I think you might say "Higher agricultural productivity due to biotechnology, precision agriculture, and a higher CO2 concentration" to avoid a criticism of ignoring this influence. Or maybe the CO2 effect should be mentioned specifically on page 15 rather than just saying there is a climatic effect (well, CO2 is part of the climate change to some people, but not to others).

Not on page 14, because that is for what might happen even without climate change; the CO₂ fertilization effect is mentioned on the next page.

I was concerned about your presentation and discussion on forests. The reason is that you switch bases to the doubling scenario, which puts this on a different time frame than the rest of the report if I understand correctly. You say so, but the presentation could still mislead. For example, Figure 9 presents a truly dramatic shift in forest types, to which I first reacted, NO WAY. But then careful examination of the cut line says "equilibrium scenario" --which I take it means that you stabilize the climate at doubling and then allow the forests however much time it takes for them to reach a stationary state. This could be a very long time from now, and if given enough time, I could believe the shift. But as a somewhat casual reader, I was thinking in a much shorter time frame.

On P. 16, my initial impression in looking at the current forest type distribution was that there was too much maple-beech-birch down through WV. Having looked at a couple maps, there is some variation but what you have is generally correct. Obviously the boundaries of such major vegetation types will influence how dramatic the projected effect of climate change will be, and the complete disappearance of maple-beech-birch is pretty dramatic - thus my interest in making certain that the original distribution is as correct as it can be. The text reads like the vegetation distribution was taken from Jones et al. (1997), but I don't see a map of or reference to potential vegetation in that publication.

P. 16, Fig. 9. The figure caption should indicate that the CCC and Hadley model projections are for a CO2 doubling. Will results from the transient runs be available in time for the final report?

The figure caption has been modified accordingly. The transient climate scenarios were not available in time for use in the forest models. Text has been added to the report that compares the transient and 2xCO2 scenarios.

- Page 17: you mentioned "unlike other chapters in this report, the forest projections rely on equilibrium conditions for a doubling of CO2, rather than using transient climate models that assume a 1 percent per year increase in CO2 and target years of 2030 and 2100."  Why not use the VEMAP and biodiversity chapters in the Forest Sector chapter which has transient projections?

High spring stream flow following fertilizer application would further increase nutrient loads in agricultural watersheds. Coastal areas surrounded by such areas of high nutrient input will have greater risk of entrophication. Nutrient loads, however, might decrease under the CCC scenario as stream flows are projected to decrease in spring and summer. The MARA team is putting together flow-duration/recurrence interval curves for the major basins of the region, then nutrient loading for the basins will be reanalyzed.