SS3.13 Natural Disturbances on Landscapes and Their Impacts on Aquatic Systems
Date: Thursday, June 13, 2002
Time: 4:15:00 PM
Location: Carson A
 
LeavittPR, University of Regina, Regina, Canada, Peter.Leavitt@uregina.ca
Chen, G, , University of Calgary, Calgary, Canada, gchen@math.ucalgary.ca
Rusak, J, A, University of Regina, Regina, Canada, Jim.Rusak@uregina.ca
Olson, O, G, University of Regina, Regina, Canada, 
Wunsam, S, , University of Regina, Regina, Canada, wunsam@merlin.math.ualberta.ca
Cumming, B, F, Queen's University, Kingston, Canada, cummingb@biology.queensu.ca
Laird, K, , Queen's University, Kingston, Canada, lairdk@biology.queensu.ca
 
THE PAST, PRESENT AND FUTURE OF PRAIRIE DROUGHTS AND THEIR IMPACTS
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Severe droughts displaced up to 20% of humans in central North America during the 1930s and caused agricultural losses of $35 billion USD in 1988-89. Similarly, water shortage is the largest source of crop insurance losses, yet drought risk assessments are based on fewer than 45 years of data. Here, we use 2000-year paleoclimatic records from saline lakes to estimate the risks of future catastrophic droughts for the northern Great Plains. Conditional probability analyses estimated up to a 45% likelihood of severe drought by 2030 AD, with 95% confidence limits of 33-67%, an expected duration of 5-12 years, and associated blooms of cyanobacteria. Strong correlations between fossils, crop production and climate (r2=0.28-0.65) during the 20th century show that risk assessments are relevant to agricultural economies and suggest that future losses may exceed $450 billion USD. Scenario analyses show that while global-warming may increase drought occurrence, its impacts will be indistinguishable from those of natural variance for at least 30 years. Rather, flexible economic and social strategies are needed to adapt society to the inherent variance of drought occurrence.