Over the rest of this century, the climate in Texas will steadily become more extreme. A new study predicts that the state will endure increasingly drier summers, potentially leading up to the worst drought conditions that Texas has seen in 1,000 years.
The experts analyzed the most advanced climate models to forecast future drought conditions. They also projected relevant information for regional water planning districts, water suppliers, and stakeholders in the agricultural industry.
The results of the analysis clearly indicate that the state of Texas is getting hotter and drier, and now is the time to take action.
The study showed that Texas was much wetter about 10,000 to 15,000 years ago as the Earth emerged from the last Ice Age. Over the last 1,000 years, there have been multiple cases of megadroughts – prolonged droughts that persist for at least two decades.
Study lead author John Nielsen-Gammon is a climatologist and professor at Texas A&M University.
“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,” said Professor Nielsen-Gammon.
The drought of the 1950s was one of the worst natural disasters in Texas history. The seven-year dry spell remains the most severe drought in Texas in the past 125 years.
Despite a history of devastating droughts in Texas, the researchers found that current water plans do not account for potential declines in the state’s water supply.
“The state water plan doesn’t explicitly consider climate change in figuring out how water supply and water demand will both change,” said Professor Nielsen-Gammon.
“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 revealed that some regions of Texas will be disproportionately impacted by drier conditions. The researchers noted that West Texas is particularly prone to drought conditions.
“West Texas seems most likely to get a double whammy: decreased rainfall and increased temperatures,” said Professor Nielsen-Gammon. “Even though rainfall has increased statewide over the past century by about 10 percent, West Texas has seen little to no increase.”
“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.”
It is very likely that Texas will continue to become hotter and drier because any long-term changes in precipitation will be “dwarfed” by how much more evaporation will deplete the water supply, explained Professor Nielsen-Gammon. He said the severity of the future dryness will likely depend on local circumstances, and there are key questions that remain to be answered.
“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?”
Professor Nielsen-Gammon emphasized that droughts are temporary by definition, so it would not be correct to think of the future as a state of permanent drought.
“It’s really a change in the climate, with the normally dry conditions in West Texas slowly migrating toward East Texas.”
The study is published in the journal Earth’s Future.
By Chrissy Sexton, Earth.com Staff Writer