Climate change projections, in particular precipitation and temperature under different IPCC future emissions scenarios in Texas, were based on statistically downscaled multi-model ensembles. A comparison of downscaled model results with observations and reanalysis data for the present-day climate shows that all models simulate monthly variations in surface air temperature well (correlation coefficient: 0.98), while precipitation correlation coefficients vary widely across different models (from 0.79 to 0.92). We performed a detailed analysis for the Texas region with an emphasis on 5 sub-regions. Our probability analysis shows an overall increase in surface air temperature towards the end of the 21st century of 4.8, 3.6, and 2.2°C for A2, A1B, and B1 emission scenarios, respectively, relative to the mean of 1971−2000. Surface air temperatures in northwestern Texas increase more under various scenarios, while they are projected to increase steadily in southeastern Texas in response to the large thermal capacity of the Gulf of Mexico. The trends in precipitation are not as clear as those in temperature, suggesting more complicated mechanisms. Precipitation and surface air temperature changes are negatively correlated on an annual basis. This indicates that, as surface air temperature increases in Texas, most regions are projected to become drier. Precipitation changes correlate negatively with surface air temperature changes in summer, while no correlation appears between them for the winter season.
KEY WORDS: Downscaling · Emissions scenarios · Precipitation · Temperature · Future climate change
Resale or republication not permitted without written consent of the publisherClim Res 53: [229][230][231][232][233][234][235][236][237][238][239][240][241][242][243][244] 2012 the total amount of water in the atmosphere under a warming climate (Wentz et al. 2007), while mid-latitude regions, are projected to have less precipitation (IPCC 2007).The present analysis focuses on Texas, which is home to 4 of the top 10 fastest growing cities in the USA, and also a very productive agricultural state. Increases in climate variability could make adaptation by farmers more difficult. A warmer climate and in creased evaporation may increase the need for irrigation. As the state population is projected to double by 2060, demand for water is projected to increase by 27% (www.twdb. state.tx.us/wrpi/data/ proj/ 2012popproj. asp).Projected impacts of climate change in Texas have previously been assessed based on global climate model simulations and downscaled regional climate information. By use of a scaling method on global climate model simulations, Loaiciga et al. (2000) demonstrated the vulnerability of the Edwards aquifer, an important water resource for Texas, to climate change. Using geographic information systems, vegetation models, and general circulation models, Cameron & Scheel (2001) re vealed that climate change could have a large impact on regional distributions of vegetation and rodents. Based on simulation...