Author
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Garbrecht, Jurgen |
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Nearing, Mark |
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Zhang, Xunchang |
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Submitted to: Transactions of the ASABE
Publication Type: Proceedings Publication Acceptance Date: 12/10/2014 Publication Date: 5/5/2015 Citation: Garbrecht, J.D., Nearing, M.A., Zhang, X.J. 2015. Deterministic modeling of future soil erosion within a framework of uncertain climate change and unpredictable producer adaptation. Proceedings of the Transactions of the ASABE, 1st Climate Change Symposium: Adaptation and Mitigation, May 3-5, 2015, Chicago, Illinois. Abstract Number: 152141136. Interpretive Summary: Conservationists are concerned that climate change in the Southern Great Plains may result in increased soil erosion. Effectiveness of soil conservation practices under a changing climate is assessed by application of the changed climate characteristics to a soil erosion model. The issue at hand is the significance, interpretation, and limitations of soil erosion predicted using a deterministic soil erosion model driven by weather representing future climate conditions. Events and conditions that lead to the realization of a particular future climate are inherently difficult to predict. The results indicate that estimation of future soil erosion rates is wrapped in layers of uncertainty and variability due to limited knowledge of future climate evolution, imperfect climate models, multiple climate downscaling methods, and the choice of storm intensification model. The potentially large uncertainty associated with projected future soil erosion rates limits the use of GCM climate projections to influence crop management or change in soil conservation practices. At the short time-scale of a decade or two, trends in climate and related impacts on soil erosion are generally small compared to the relatively large natural year-to-year variability of the climate and soil erosion. In such a situation, crop management and soil conservation decision support will likely not benefit much from climate change information. At a lead time of four or more decades, the change in soil erosion produced by a climate trend may rise above the inter-annual variability of soil erosion. Under these conditions, climate change projections could provide useful information on future soil erosion rates. However, practical conservation actions cannot benefit from long-term climate change and soil erosion projections because the projection lead time is beyond the planning and management horizon of soil conservation actions. Thus, climate projections have limited potential to provide actionable decision support for adaptation of today's soil conservation practices to climate change. Climate and soil erosion projections are best used as an exploratory tool to hypothesize what soil erosion would look like under alternative emission scenarios. The question as to which emission scenario and which projected climate will evolve over coming decades and what the future soil erosion will be like remains unanswered. Technical Abstract: Conservationists are concerned that climate change in the Southern Great Plains may result in increased soil erosion. Effectiveness of soil conservation practices under a changing climate is assessed by application of the changed climate characteristics to a soil erosion model. The issue at hand is the significance, interpretation, and limitations of soil erosion predicted using a deterministic soil erosion model driven by weather representing future climate conditions. Events and conditions that lead to the realization of a particular future climate are inherently difficult to predict. The results indicate that estimation of future soil erosion rates is wrapped in layers of uncertainty and variability due to limited knowledge of future climate evolution, imperfect climate models, multiple climate downscaling methods, and the choice of storm intensification model. The potentially large uncertainty associated with projected future soil erosion rates limits the use of GCM climate projections to influence crop management or change in soil conservation practices. At the short time-scale of a decade or two, trends in climate and related impacts on soil erosion are generally small compared to the relatively large natural year-to-year variability of the climate and soil erosion. In such a situation, crop management and soil conservation decision support will likely not benefit much from climate change information. At a lead time of four or more decades, the change in soil erosion produced by a climate trend may rise above the inter-annual variability of soil erosion. Under these conditions, climate change projections could provide useful information on future soil erosion rates. However, practical conservation actions cannot benefit from long-term climate change and soil erosion projections because the projection lead time is beyond the planning and management horizon of soil conservation actions. Thus, climate projections have limited potential to provide actionable decision support for adaptation of today's soil conservation practices to climate change. Climate and soil erosion projections are best used as an exploratory tool to hypothesize what soil erosion would look like under alternative emission scenarios. The question as to which emission scenario and which projected climate will evolve over coming decades and what the future soil erosion will be like remains unanswered. |
