A team of researchers, lead by John Nielsen-Gammon, the state climatologist and a Texas A&M University professor, found that Texans need to prepare for a near-future that is hotter, drier, and full of differing water challenges. The study was published in the journal Earth’s Future.
Using the most advanced computer models available, the data showed Texas was much wetter 10-15,000 years ago coming out of the last Ice Age. Since that time, the state's climate has been similar to what it is today, with the exception of a few wetter and drier periods, per Phys.org.
In the past thousand years, there have been multiple decades of extended drought periods called "megadroughts"—something Texas will likely see through the end of the century. "Our study shows that the drier conditions expected in the latter half of the 21st century could be drier than any of those megadroughts, depending on how you measure dryness," Nielsen-Gammon said.
The drought Texans experienced in the 1950s is still considered the "Drought of Record."This event occurred between 1949 and 1957 in which the state received 30 to 50 percent less rain than normal, while temperatures rose above average. The drought was described by a state water official as "the most costly and one of the most devastating droughts in 600 years."
Texas policy-makers have developed water projections and conservation plans for decades, however, current plans do not take into consideration climate change, according to Science Daily.
"The state water plan doesn't explicitly consider climate change in figuring out how water supply and water demand will both change," Nielsen-Gammon said. "As our paper points out, pinning numbers on either of those changes is a difficult challenge, and it's not simply a matter of estimating changes in precipitation."
"Tying future water supply to criteria established by the drought of record is a defensible choice, but policymakers should be aware that the chances of exceeding the drought of record are probably increasing year by year."
The study also notes that parts of Texas will experience drier conditions than the rest of the state. This is particularly true of west Texas - which is already prone to drought or even megadrought conditions, according to the report.
"Even though rainfall has increased statewide over the past century by about 10 percent, West Texas has seen little to no increase," said Nielsen-Gammon. "West Texas is already planning for what happens as one or more critical aquifers get depleted. Climate change is going to make that depletion happen a little bit faster, but the decline of the Ogallala Aquifer is primarily caused by water extraction for irrigation rather than by climate change."
Nielsen-Gammon also says the severity of any future dryness will depend on local circumstances, and that leaves many questions unanswered.
"These include ones such as, does it matter what time of year sees increases or decreases in precipitation? How much water supply is there? Is the most important issue the amount of water or the health of the crops and foliage? Is it more important to get runoff or to have the rainfall soak into the ground?" he said.