Modeling the Effect of Elevated CO2 and Climate Change on Reference Evapotranspiration in the Semi-Arid Central Great Plains

Changes in evapotranspiration demand due to global warming will have a profound impact on irrigation water demand and agricultural productivity. In this study, the effects of possible future anthropogenic climate change on reference evapotranspiration (ETo) were evaluated using the Penman-Monteith equation. The combined effect of temperature and elevated CO2 concentrations on ETo was the major focus of this study. The ETo under the General Circulation Model (GCM) projected climate change scenarios was estimated for a location in Colorado. Multi-model ensemble climate change scenarios were generated from 112 Bias Corrected and Spatially Disaggregated (BCSD) projections from the World Climate Research Program (WCRP) archive, which cover different levels of greenhouse gas emissions. Results showed a decrease in ETo demand with increases in CO2 levels, which greatly moderated the increase in ETo due to increasing temperature. The effect of increases in CO2 levels up to 450 ppm offset the effect of about 1°C rise in temperature. Simulation results with projected climate change scenarios, without considering the effects of CO2 levels, showed an 8.3%, 14.7% and 21.0% increase in annual ETo during the 2020s, 2050s, and 2080s, respectively, when simulation was carried out using an ensemble of the 112 projections. When the effect of elevated CO2 levels was also considered in combination with projected changes in temperature, changes in annual ETo demand varied from -1.5% to 5.5%, -10.4% to 6.7%, and -19.7% to 6.6% during the 2020s, 2050s, and 2080s, respectively, depending on the different climate change scenarios considered and the relationship or equation used for estimating the effect of elevated CO2 on stomatal resistance term in the Penman-Monteith equation.

[1]  L. Brekke,et al.  A framework for assessing flood frequency based on climate projection information , 2009 .

[2]  Eike Luedeling,et al.  Climate change sensitivity assessment of a highly agricultural watershed using SWAT , 2009 .

[3]  Dennis P. Lettenmaier,et al.  A multimodel ensemble approach to assessment of climate change impacts on the hydrology and water resources of the Colorado River Basin , 2006 .

[4]  Dennis P. Lettenmaier,et al.  Long range experimental hydrologic forecasting for the eastern U.S. , 2002 .

[5]  Alan F. Hamlet,et al.  Statistical downscaling techniques for global climate model simulations of temperature and precipitation with application to water resources planning studies , 2010 .

[6]  N. Rosenberg,et al.  Sensitivity of evapotranspiration in a wheat field, a forest, and a grassland to changes in climate and direct effects of carbon dioxide , 1989 .

[7]  P. Gleick,et al.  Sensitivity of streamflow in the Colorado Basin to climatic changes , 1991 .

[8]  Alison L. Kay,et al.  Calculating potential evaporation from climate model data: A source of uncertainty for hydrological climate change impacts , 2008 .

[9]  Vincent R. Gray.  Climate Change 2007: The Physical Science Basis Summary for Policymakers , 2007 .

[10]  William E. Easterling,et al.  Preparing the erosion productivity impact calculator (EPIC) model to simulate crop response to climate change and the direct effects of CO2 , 1992 .

[11]  S. Long,et al.  Food for Thought: Lower-Than-Expected Crop Yield Stimulation with Rising CO2 Concentrations , 2006, Science.

[12]  Richard G. Allen,et al.  CO2‐Induced Climatic Changes and Irrigation‐Water Requirements , 1991 .

[13]  Jorge A. Ramírez,et al.  CO2 AND TEMPERATURE EFFECTS ON EVAPOTRANSPIRATION AND IRRIGATED AGRICULTURE , 1996 .

[14]  N. Arnell,et al.  Uncertainty in the estimation of potential evapotranspiration under climate change , 2009 .

[15]  K. Wilson,et al.  Sensitivity of stomatal and canopy conductance to elevated CO2 concentration - interacting variables and perspectives of scale. , 2002, The New phytologist.

[16]  R M Gifford,et al.  Stomatal sensitivity to carbon dioxide and humidity: a comparison of two c(3) and two c(4) grass species. , 1983, Plant physiology.

[17]  John R. Williams,et al.  A method for estimating the direct and climatic effects of rising atmospheric carbon dioxide on growth and yield of crops: Part I--Modification of the EPIC model for climate change analysis , 1992 .

[18]  T. Sinclair,et al.  Genetic variability of transpiration response to vapor pressure deficit among sorghum genotypes , 2010 .

[19]  L. S. Pereira,et al.  Crop evapotranspiration : guidelines for computing crop water requirements , 1998 .

[20]  D. Ojima,et al.  High resolution modeling of the regional impacts of climate change on irrigation water demand , 2007 .

[21]  A. J. Mcarthur.  An accurate solution to the Penman equation , 1990 .

[22]  Shuguang Liu,et al.  Hydrological effects of the increased CO2 and climate change in the Upper Mississippi River Basin using a modified SWAT , 2012, Climatic Change.

[23]  Mark West,et al.  C4 grasses prosper as carbon dioxide eliminates desiccation in warmed semi-arid grassland , 2011, Nature.

[24]  John F. B. Mitchell,et al.  THE WCRP CMIP3 Multimodel Dataset: A New Era in Climate Change Research , 2007 .

[25]  U. KyawThaPaw,et al.  Applications of solutions to non-linear energy budget equations , 1988 .

[26]  Ayse Irmak,et al.  Sensitivity Analyses and Sensitivity Coefficients of Standardized Daily ASCE-Penman-Monteith Equation , 2006 .

[27]  N. Rosenberg,et al.  Sensitivity of some potential evapotranspiration estimation methods to climate change , 1993 .

[28]  S. Wand,et al.  Responses of wild C4 and C3 grass (Poaceae) species to elevated atmospheric CO2 concentration: a meta‐analytic test of current theories and perceptions , 1999 .

[29]  N. Rosenberg,et al.  Evapotranspiration in a greenhouse-warmed world: A review and a simulation , 1989 .

[30]  E. Maurer,et al.  Fine‐resolution climate projections enhance regional climate change impact studies , 2007 .

[31]  B. Kimball,et al.  Evapotranspiration, Canopy Temperature, and Plant Water Relations , 2006 .

[32]  L. Hay,et al.  A COMPARISON OF DELTA CHANGE AND DOWNSCALED GCM SCENARIOS FOR THREE MOUNTAINOUS BASINS IN THE UNITED STATES 1 , 2000 .

[33]  Ragab Ragab,et al.  Climate change and water resources management in arid and semi-arid regions : prospective and challenges for the twenty first century. , 2002 .

[34]  D. Ellsworth,et al.  Tree and forest functioning in an enriched CO2 atmosphere , 1998 .

[35]  Prem B. Parajuli,et al.  Assessing sensitivity of hydrologic responses to climate change from forested watershed in Mississippi , 2010 .

[36]  Christopher B. Field,et al.  Stomatal responses to increased CO2: implications from the plant to the global scale , 1995 .

[37]  R. Toumi,et al.  Climate projections: Past performance no guarantee of future skill? , 2009 .

[38]  Luis S. Pereira,et al.  Evapotranspiration: Concepts and Future Trends , 1999 .