The Region and the Regional Process

In the Fall of 1997, planning began for a workshop that would initiate a relationship between the stakeholders and researchers in the Great Lakes region. The workshop was one of 19 regional workshops that were being sponsored by the USGCRP. The workshop would address several questions, including how climate change would impact certain sectors. Thus, a key piece of information was knowing which sectors were important. While this could have ideally been addressed at the workshop, it was decided to choose broadly defined sectors beforehand and then let the workshop attendees decide what aspects specifically within each of the sectors were highly important. To this end, a steering committee was chosen to identify the sectors that would be discussed at the workshop. The steering committee consisted of people from academia, government, environmental interest groups, and industry. Over one hundred people from academia, government, environmental interest groups, and private industry attended the workshop, which was held at the University of Michigan during May 4-7, 1998. A series of invited talks ensured that participants had some common knowledge as they divided into breakout groups to discuss the four assessment questions and how they related to important regional sectors:

• water resources (WRES)
• agriculture (AGRI)
• water ecology (WECO)
• land ecology (LECO)
• economy (ECON)
• infrastructure (INFR)
• human health (HLTH)

The discussions from the breakout groups were summarized and used to determine some of the more important concerns regarding climate change (impacts) in the Great Lakes region. Although the discussions regarding stresses and the impact of climate change on those stresses were obviously sector-dependent, two common themes arose from all sector-breakout groups. One was that better models — not just better regional climate models — but better coupled models of climate and streamflow, for example, or climate and agricultural yields, as another example, need to be developed for the region. Another common theme was that stakeholders and the general public need to be better informed (educated) regarding the potential impacts of climate change. The choices for which sectors, and what aspects within those sectors to assess, and what goals to accomplish was decided by members of the workshop steering committee with input from the workshop results. Identifying members for the Great Lakes Regional Assessment Team with sufficient interest, expertise, and availability to address the most important aspects proved challenging and in some instances the choices for what to investigate were adjusted.

Part of the Great Lakes Regional Assessment strategy also involved engaging researchers from other institutions in the Great Lakes region. For example, while the University of Michigan hosted the Upper Great Lakes Workshop, and is the Central Headquarters for the Great Lakes Regional Assessment effort, other collaborating institutions have certainly collaborated. Because the bottom line of this assessment is to get the message about climate change impacts across to the stakeholders throughout portions of an eight-state region, it was deemed advantageous to involve researchers from The University of Minnesota (Minneapolis-St. Paul, Minnesota), The University of Wisconsin- Milwaukee (Milwaukee, Wisconsin), The Illinois State Water Survey (Champaign-Urbana, Illinois), Michigan State University (East Lansing, Michigan), the Army Corps of Engineers (Buffalo, New York),The Great Lakes Environmental Research Laboratory (Ann Arbor, Michigan), The Center for Environmental Policy, Economics and Science (CEPES), (Ann Arbor, Michigan), and of course from the University of Michigan (Ann Arbor, Michigan).

All the researchers involved in the National Assessment, not just those from the Great Lakes region, were asked to follow some “loose” guidelines regarding their assessment. One guideline was to use some of the latest output from General Circulation Models (GCMs). Prior to the mid 1990s, most climate change simulations by GCMs did not include effects from aerosols, which people believe to be the reason why the global temperature has not risen more rapidly, given the amount of additional CO2 that is in the atmosphere. The presence of aerosols effectively increases the albedo, and reflects some of the sun´s energy back to space. At the time, output from GCMs that included aerosols was available from the Canadian Coupled-Climate Model (CGCM1)C, and from the Hadley Centre Climate Model (HadCM2). These models have slightly different parameterization schemes for many of the sub-grid scale processes. A summary of their temperature and precipitation output for the Great Lakes region is provided on the Region page. Researchers were encouraged to examine output from both models—although time constraints prevented many from doing so. In the Great Lakes region, it was decided to focus more on analysis of output from the Hadley Model, owing to the fact that the Great Lakes were not included in the Canadian Model simulations. Some researchers in the Great Lakes region did examine output from the Canadian model as well, because of additional concerns. The climate scenario output from the models were available in several forms. Daily output from the Canadian model (3.75¡ latitude by 3.75¡ longitude) and from the Hadley model (2.5° latitude by 3.75 longitude) was available for sea-level pressure, winds, temperatures, and geopotential heights at selected pressure levels, as well as surface maximum and minimum temperatures and precipitation. Climate scenario output was also available from the VEMAP (Vegetation/Ecosystem Modeling and Analysis Project) process as monthly means and daily values at 0.5° x 0.5° resolution. The attraction to some researchers for using VEMAP output stemmed from its higher spatial resolution and more realistic (ranges of) daily temperature and precipitation values. The VEMAP monthly means were simply interpolated directly from the GCM monthly means. The daily values, however, were created in a more complicated way. Rather than use the daily output directly from the GCMs, the GCM monthly means were processed through a weather generator program, that created more realistic daily variations than the GCM could. Daily VEMAP output at each point was created using parameter values that were climatologically appropriate for that particular region. As a result, there was no attempt to assure that the fields were spatially correlated. The VEMAP fields consisted of surface maximum and minimum temperatures, precipitation, and some surface moisture and radiation fields. No sea-level pressure, wind, or geopotential height information was available in VEMAP form.

Researchers were also asked to consider future socioeconomic scenarios. This consideration was less straightforward than that of climate change. However, the strategy in the end was to make an attempt to account for changes in population, landuse, and overall wealth when considering the impacts of climate change on a particular sector. The socioeconomic data was provided on a series of three CD-ROMs from NPA Data Sources, Inc.

Owing to severe time constraints, most researchers used an overlay approach for assessing impacts. An overlay approach means that researchers evaluated the impacts from climate change as indicated from (quantitative) output from the GCMs by interpolating or extrapolating results from previous assessments. The overlay approach provided a simple, efficient, and accurate means to evaluate climate impacts from the newly available model output in most instances. However, one fundamental constraint of this approach is that the accuracy of the new results is inherently limited by the accuracy of the old results. Unfortunately, there was little time for a more fundamental approach, e.g., refining existing or developing new impacts assessment models—like stakeholders had suggested at the workshop.

This report has gone through an extensive review process involving other experts and other interested stakeholders.