Grantee Research Project Results
Final Report: Integrated Assessment of Economic Adaptation Strategies for Climate Change Impacts on Midwestern Agriculture
EPA Grant Number: R824996Title: Integrated Assessment of Economic Adaptation Strategies for Climate Change Impacts on Midwestern Agriculture
Investigators: Randolph, J. C. , Mazzocco, Michael A. , Doering, Otto C.
Institution: Indiana University - Bloomington , University of Illinois Urbana-Champaign , Purdue University
Current Institution: Indiana University - Bloomington , Purdue University , University of Illinois Urbana-Champaign
EPA Project Officer: Chung, Serena
Project Period: October 1, 1996 through September 30, 1999 (Extended to September 22, 2001)
Project Amount: $1,393,897
RFA: Global Climate (1996) RFA Text | Recipients Lists
Research Category: Climate Change , Ecological Indicators/Assessment/Restoration
Objective:
The overall objective of this research project was focused on integrated assessment of potential adaptive responses available to the agricultural sector in the midwestern Great Lakes states (WI, MI, IL, IN, and OH) to maintain productivity and profitability. Using ecosystem and economic modeling, we assessed realistic scenarios of the potential impacts of global climate change and climate variability on midwestern agriculture and potential adaptive responses in the agricultural sector. The project was conducted by a multidisciplinary team of scientists from three midwestern research universities collaborating on interactive modeling of climate, crops, production enterprises, and institutional/policy systems. An important aspect of this project was the use of carefully selected expert panels to evaluate alternative scenarios and various adaptation strategies for midwestern agriculture. The specific objectives of the project were to:
(1) Develop detailed characteristics for representative firm farms in each of 10 agricultural regions chosen by spatial analysis of soils, climate, crop mixes, and production systems throughout the five states of the midwestern Great Lakes region.
(2) Use interactive crop production and ecosystem models and develop appropriate submodels to analyze representative firm farms in these 10 agricultural regions.
(3) Evaluate alternative farm decisions using a linear programming model for crop mixes and production factors such as irrigation, drainage, fertilization, pest control, and tillage. The resulting information about optimal or desirable systems provides input for the crop production and ecosystem models to determine the effects of such decisions on and within regionalized agroecosystems.
(4) Develop a number of realistic climate change scenarios from general circulation model output (Hadley Center model) for a more moderate and extreme climate change scenario, and for a number of different climate variability scenarios.
(5) Evaluate the effects of alternative production policies, either constraining or supporting, on crop mixes and production systems for both the economic impacts on regional producers and the ecological impacts on regional agroecosystems under current climatic conditions.
(6) Assess the effects of climate change, changing climate variability, and various adaptive responses to the changes in firm farm decisions in the 10 agricultural regions. Specific risk events common to different agricultural practices and systems were assessed and used to compare the desirability of alternatives. Aggregate results allow comparisons among the agricultural regions, as well as an assessment for the entire midwestern Great Lakes region.
(7) Assess the nature, extent, and consequences of adaptation strategies of representative crop producers in response to the effects of climate change.
Summary/Accomplishments (Outputs/Outcomes):
In a study of this duration and complexity, distilling the work of many to a concise set of conclusions presents a daunting challenge. As discussed above, we had a broad objective of using integrated assessment methodologies to examine potential adaptive responses for the agricultural sector in the Upper Midwest United States, and maintaining crop productivity and profitability under future climate change. We focused on the farm level, where adaptation decisions will be made.
There are two general sets of conclusions including: (1) our specific results for the Upper Midwest region, and the relationships between our results and the results of other researchers conducting similar research in Argentina and Australia, and on related topics, such as crop models and soil erosion; and (2) what we learned in the process of this study about how such analysis might be done.
Some of the general conclusions about the effects of climate change on the agricultural sector in the Upper Midwest include:
Despite large changes in individual crop yields as a result of climate change, the Upper Midwest is a relatively stable region for crop yields and agricultural systems at the farm level. This region has been a major producer of corn and soybeans, and a secondary producer of winter wheat. Under the climate scenarios we analyzed, dramatic shifts in crop productivity and cropping systems did not occur. Our judgment is that this region likely is to remain the heart of the U.S. cornbelt under future global climate change as it is being represented today.
The north-south temperature gradient in this region is important in influencing yields and for enabling or encouraging shifts to cropping systems that emphasize different crop mixtures and rotations. The limitations on crop growth are related to differences in temperatures, with temperatures ranging outside that for optimum crop growth in many of our southern locations. Precipitation does not appear to be a limiting factor for crop growth across the study region. Cultivars better adapted to the warmer climate would allow yields to be higher and returns to be increased under most scenarios.
CO2 fertilization is a positive factor. The relative improvements in the yield of each crop differ according to the dominant photosynthetic pathways-C3 or C4-of the crops. The differences in response of soybeans and wheat (greater effect) compared to corn (lesser effect) may influence the crop mix grown. This also is of supreme importance in the Australian example, where CO2 fertilization effects, specifically of increased water-use efficiency, play a major role in determining future yields in a water-stressed environment.
Specific responses of the three major commodity crops to climate change are dependent upon both the climate change scenario used and the representative agricultural area examined. Although the Upper Midwest will remain the center of the U.S. corn (maize) production, the level of production will decrease in most of our representative agricultural areas, particularly in the southern areas. Soybean and winter wheat production will increase in most of the representative agricultural areas, except under the most severe climate scenario. The north-south temperature gradient is an important factor in the conditions and adaptations in the region.
Increased climate variability results in significant differences in productivity of all three crops. Typically, the increased climate variability results in increased variability in crop yield and decreased production. The increased yield variability can be managed to some extent for some crops through adjustments in planting date. However, the yield variability presents significant management challenges at the farm level. Public policy may need to be designed to help manage yield variability. There also is an opportunity to develop cultivars that can sustain high yields under increased climate variability.
The issue of planting date is significantly important under climate change, as illustrated in both the Argentinean and Midwest United States analyses. Shifting current planting dates is a first line of defense, at the farm level, to mitigate potential yield decreases and maximize potential yield increases due to climate change.
In both the Australian and Midwestern United States examples, the occurrence of spring or fall freeze events is diminished under the climate change scenarios modeled. The issue of frost occurrence becomes a lesser concern, even with increased climate variability.
Widespread use of irrigation should not become necessary in the Midwest United States. This finding conflicts with findings in Australia, where water availability and water holding capacity of soils is limited and becomes a critical issue.
Relative price changes in commodities may bring about changes in cropping systems even as the climate changes. For example, double cropping of wheat and soybeans in the northern areas of the Midwest United States becomes possible as a result of warmer temperatures, yet profitability depends upon relative crop prices.
In most cases, modest adaptation (planting date, cropping system, and crop mix changes, without changing cultivars) enables farmers to maintain income levels largely intact under the climate change scenarios. However, it is clear that farmers will need to adjust their practices to either mitigate the deleterious effects of climate change or, in some instances, take full advantage of a climate more conducive to crop growth. These strategies include changing the crop mix and shifting planting dates to take advantage of better weather conditions.
Indirect impacts, such as climate change impacts on soil erosion, will become more significant, especially if national policy continues attempting to prevent the degradation of soil resources. This also is true in the Argentinean and Australian studies. In the Australian case, the concern extends to soil structure degradation as a significant issue.
The future climate change scenarios have less impact than might be expected because of flexibility in the agricultural system; improvements in crop physiology, hybrid choice, planting date, crop mix, etc. Our judgment is similar to that expressed in other studies; factors such as population, technology development, government agricultural policy, and international markets for agricultural products will have more impact on the agricultural systems of the Upper Midwest United States compared to global climate change as projected today. We think the same will be true for Argentina and Australia.
Technological improvements are critical-from improvements in machinery efficiency, to genetic manipulations to achieve more heat-tolerant corn varieties. Public investment in agricultural technology and public policy will be critical in those areas where the market is less effective in influencing innovative behavior. Conservation and soil erosion are adequate examples. There is a particularly important role for the private sector in areas such as the development of new cultivars that are heat resistant, or better able to withstand higher degrees of climate variability. In both instances, assessments of climate change alternatives must be communicated. Both public and private sectors need to learn about potential impacts and critical adaptations that may need to be made.
Risk management and willingness to adapt are important parameters in decisionmaking under climate change, and need to be more adequately understood. These parameters are not just limited to a few factors in the operation of a farm. Risk management and adaptation involve all aspects of farming operation. These include not only soils, cultivars, and planting dates, but also machinery capacity and operation. Farmers worldwide have traditionally adapted to changes, including genetic improvements, market preferences, crop prices, and improved technology. This experience would suggest that global climate change may be another challenge.
We also learned several lessons about integrated assessment of climate change impacts on agricultural production systems:
Looking only at changes in yields as a function of climate change, even when those changes are large, will not reveal the potential impacts at the farm level. The flexibility of agricultural production systems allows for significant yield changes without potential changes in cropping systems. Conversely, a change in the cropping system can mitigate some of the impacts upon yield, or enhance those effects.
The implications of the impacts of changes in climate variability on Midwest agriculture cannot be understated. While adapting to mean changes in climate can be addressed fairly easily, the changes due to increased climate variability are much more difficult to address. As such, some of the greatest problems under future climates will be the increasing variability of the climate system, and the potentially disastrous results for agricultural systems.
If researchers model potential climate change due to increased atmospheric CO2 concentrations, the analyses also must include the direct effects of increased CO2 concentrations on photosynthesis. The results from the Australian, Argentinean, and Midwestern United States studies are excellent examples of this, with yield decreases being minimized due to CO2 fertilization and differences in crop types being highlighted.
In addition to the inclusion of appropriate climate variables, it is necessary to select climate and crop growth models suited to the questions being asked. In climate change studies, a daily time step and incorporation of daily temperature ranges, not just daily means, are important. This also is important because of differential increases in maximum and minimum temperatures being predicted by most general circulation models, and the importance of such changes on crop growth. If the model selected cannot incorporate such changes, then a major part of the future climate cannot be addressed. The analyses for the Upper Midwest, Argentina, and Australia all used climate models and plant growth models capable of representing discrete time steps short enough to allow analysis of different planting dates, and, in the case of the Midwest, field working days for planting and harvest. Changes in timing are a major adaptation strategy. Not all climate models and plant growth models can be used effectively in these types of studies.
Use of a limited number of detailed and well accepted climate scenarios from one well recognized climate model to project future climates, is essential. Simulating a vast array of potential future climates from several models yielding a wide range of outcomes may appear attractive. However, the number of combinations and permutations of climate alone become unmanageable. Much of the valuable information for potential adaptation strategies comes following the climate simulation. For example, looking at specific genotype characteristics that are critical to yields under climate change, as was done for Argentina, is extremely valuable. Doing sensitivity analysis to determine the characteristics that would induce shifts in cropping systems in the Upper Midwest has value in assessing adaptation. A vast array of very different climate scenarios from different models does not realistically permit this type of indepth understanding. Our bias, then, was to pick a climate model that is widely used and highly regarded, and to create a variety of climate scenarios from that one model. We then are able to devote more energy to the crop modeling and farm-level analysis using results from that climate model.
Using study sites representative of recognized ecological regions, with appropriate climate data, soil characteristics, and historical crop yield data, is essential. If a broad area is to be included in the analysis, it only can be meaningful if care is taken to include as much detail as possible about each site.
Expert panels provided critical information and insights into possible responses and adaptations. No project team has the capacity to understand the broad range of topics this type of integrated assessment presents. It is important to understand that the panelists also benefit from this interaction with peers and with project teams conducting the research.
It would not make sense to project prices and economic conditions half a century into the future. Many recent studies that have assessed agricultural responses to global climate change recognized this problem. We expect that the general quality of the land in the Upper Midwest is high enough that agriculture will remain a major land use, and the existing cropping systems will be well represented in the future. The key question then becomes what changes in crop mix or cropping systems will be driven alternatively by climate change and productivity changes, and by changes in relative prices. The Australian study recognized that the world wheat trade is a determining factor for Australia, and there is no sense in attempting to predict the situation and its impact on Australia's wheat production. This is especially true for those areas where present crops are by far the best-suited crops compared to fringe areas.
It is important not to be myopic and to concentrate only on climate change impacts. There is a critical set of other drivers if one is focusing on adaptation decisions: relative prices, production logistics, ancillary technology like harvesting or planting speed, as well as indirect factors like soil erosion.
Our results are specific to individual agricultural areas in the Upper Midwest United States. However, some general points concern the importance of: (1) examining interactions of heat and moisture where warmer temperatures will require improved cultivars, (2) defining critical environmental gradients spatially, (3) determining whether the region has core and fringe areas of agricultural productivity, and (4) using sensitivity analysis in examining responses to climate change.
Finally, integrated assessment research such as described here requires substantial resources and time. The resources include the collective knowledge and interactions of the participants, physical resources such as computer systems, and adequate funding from sponsors. Other researchers can learn from analyses such as ours, those presented in the Australian and Argentinean examples, and previously conducted assessments such as the Intergovernmental Panel on Climate Change (IPCC) and European studies, rather than starting from the very beginning. Hopefully, our book will help other researchers that are developing similar studies. Integrated assessments of climate change on various sectors and resources should not start at the groundlevel every time; they should build on previous research and the experiences of those researchers. This would indeed generate a truly integrated assessment of past, current, and future research knowledge and application.
Journal Articles on this Report : 4 Displayed | Download in RIS Format
Other project views: | All 41 publications | 7 publications in selected types | All 4 journal articles |
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Type | Citation | ||
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Doering OC, Habeck M, Lowenberg-DeBoer J, Randolph JC, Johnston JJ, Littlefield BZ, Mazzocco M, Kinwa M, Pfeifer R. Mitigation strategies and unforeseen consequences: a systematic assessment of the adaptation of upper Midwest agriculture to future climate change. World Resource Review 1997;9(4):447-459. |
R824996 (1998) R824996 (2000) R824996 (Final) |
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Southworth J, Randolph JC, Habeck M, Doering OC, Pfeifer RA, Rao DG, Johnston JJ. Consequences of future climate change and changing climate variability on maize yields in the midwestern United States. Agriculture, Ecosystems & Environment 2000;82(1-3):139-158. |
R824996 (2000) R824996 (Final) |
Exit Exit Exit |
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Southworth J, Pfeifer RA, Habeck M, Randolph JC, Doering OC, Johnston JJ, Rao DG. Changes in soybean yields in the midwestern United States as a result of future changes in climate, climate variability, and CO2 fertilization. Climatic Change 2002;53(4):447-475. |
R824996 (1999) R824996 (2000) R824996 (Final) R825433 (Final) |
Exit Exit |
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Southworth J, Pfeifer RA, Habeck M, Randolph JC, Doering OC, Rao DG. Sensitivity of winter wheat yields in the Midwestern United States to future changes in climate, climate variability, and CO2 fertilization. Climate Research 2002;22(1):73-86. |
R824996 (Final) |
Exit Exit |
Supplemental Keywords:
land, soil, global climate, ecosystem protection, agro-ecosystem, terrestrial, integrated assessment, public policy, decisionmaking, agricultural economics, agriculture, agronomy, biology, climatology, ecology, modeling, crop models, climate models, linear programming, Midwestern United States, Great Lakes states, EPA Region 5, Argentina, Australia., RFA, Scientific Discipline, Air, Geographic Area, Midwest, climate change, State, Economics, Ecological Risk Assessment, Agronomy, ecosystem models, environmental monitoring, integrated assessments, adaptive technologies, hierarchical systems aggregation, farming, farm income, climate models, agroeconomics, agriculture, environmental stressors, GIS, vulnerability assessment, Wisconsin (WI), ecosystem sustainability, Midwestern agriculture, climate variability, crop production, Global Climate ChangeProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.