Cooler Heads Need to Prevail on Texas Climate Predictions
For all its positive attributes, the great state of Texas has one major failing: the inability of its mainstream media to rationally discuss climate change. Unfortunately, Texas media are being used to implement the shock doctrine approach to environmental policy.
Back in 2014, one of us (S.R.) discussed this topic specifically in the context of the severe drought that was underway in north Texas. Readers may remember that at the time, Wichita Falls was ground zero for the drought, and its municipal drinking water reservoirs were being drawn down. Residents were understandably concerned.
However, what emerged during this drought was some potentially problematic policy advice from the George W. Bush Institute in Dallas. As S.R. wrote in response at the time:
The point of all this data is that we need to be cautious with precipitation and drought statistics in Texas. Anecdotal writing is more popular in the media today than ever. Sometimes this writing style can be useful, but very often it distorts reality by over-generalizing from an isolated case, in shock doctrine style[.] ...
The worst drought conditions in the state from a couple years ago are easing. Although east Texas is almost out of drought, everywhere else is still in a significant drought – but if trends continue, the pressure may lift over the next couple years. Now simply isn't the time to create comprehensive and far-reaching water policy in shock doctrine style. Following the advice of Rahm Emanuel to "never let a good crisis go to waste" will not lead Texas in the direction it needs to go, particularly when I see statements by the George W. Bush Institute such as "the trick is finding the right balance between planning and property rights."
Discussions over property rights are never best conducted when a crisis is at hand. Wait until the drought crisis settles down – which it undoubtedly will – and then begin examining proposals over this very contentious topic (especially in Texas, where property rights issues are taken more seriously than almost anywhere else)[.] ...
Patience is needed in the Lone Star State on water policy. Avoid the shock doctrine.
And sure enough, our recommendation for patience paid off. Within one year of our article being published, the reservoirs in Wichita Falls were already back up to effectively 100% of capacity, a point they have maintained ever since.
This brings us to a recent article in the Dallas Morning News predicting that "[c]limate change [is] to bring North Texas longer droughts, heavy rains, 120-degree temps within 25 years." And in this report, we find the following claims:
"Climate change is not just about polar bears," said Katharine Hayhoe, a climate scientist at Texas Tech University with an impressive YouTube following. "It will affect North Texas profoundly."
Between 2041 and 2050, Dallas-Fort Worth may see August temperatures rise from a mean of 86 degrees Fahrenheit at the end of the 20th century to 94 degrees, with extremes rising above 120, reports one study by scientists at the University of Texas at Arlington.
That's a bold prediction. Our concern with it is that there appears to be no evidence that extreme maximum temperatures in the Dallas-Fort Worth region for August will rise above 120 degrees by the 2041-2050 period. Using historical data from NOAA going back to 1899 for the area, there is only a very weak time trend in the data, as can be seen in this graph. In fact, the highest all-time August maximum temperatures occurred in 1909 and 1936 at 112 degrees. Since this latter date, the region has hit 110 degrees only twice (in 1943 and 2011), and the average maximum high over the past three decades (104.0 degrees) is essentially the same as the average maximum high for the entire period since records began in 1899 (103.3 degrees).
Consequently, Dallas-Fort Worth "may see" extreme August temperatures in the 120-plus range by the 2040s, but if the 120 years of data for the region is any indication, this appears unlikely and not a rational basis for founding public policy.
Similarly, the prediction that August temperatures may rise from a mean of 86 degrees in the late 1990s up to 94 degrees by 2040 appears unlikely if historical trends since the 19th century are any indication. There is a modest increasing trend in August temperatures for Dallas-Fort Worth since the late 19th century, but nowhere near dramatic enough to suggest that a rapid increase of 8 degrees will take place during the next 25 or so years.
For example, over the 120 years between 1899 and 2018, the average August temperature in this region of north Texas rose just 2 degrees from 84 to 86 degrees Fahrenheit. If the historical trend continues, perhaps an increase to 87 degrees by 2050 will occur, or if the upper 95% confidence interval of the historical trend is extrapolated out to mid-century, maybe 88 degrees. These slightly higher values are very different from a prediction that residents of Dallas-Fort Worth should prepare for an average August temperature of 94 degrees during the 2040s.
Drought is always an issue that ranchers are concerned about in north Texas, but more caution is warranted when considering the following predictions:
Along with heat will come stronger drought, which "has profound economic impacts," said Hayhoe.
The prediction that North Texas will have longer and more severe droughts is based on multiple factors, including the relationship between high temperatures and soil dryness and the presence of more frequent and longer lasting high-pressure systems in summer that suppress rainfall and deflect storms away from our area.
Hayhoe points to Texas' 2010-2013 drought as a probable sign of things to come.
Quite the contrary. In none of the four climate divisions that make up the northern half of Texas have there been any statistically significant trends toward increasing drought since records began in 1895 (see graphs for climate divisions 1, 2, 3, and 4; positive values [green bars] represent increasingly wet conditions, while negative values [yellow bars] indicate increasing drought). In fact, in divisions 2, 3, and 4 (the north-central and north-east regions of Texas), on the balance of probabilities, historical trends suggest less drought in the future, not more.
Climate predictions are hard, and the record in Texas has not been promising of late. In a time of scarce public resources and more pressing, and demonstrably real, national security concerns – such as the border crisis – policy-makers in Texas need to consider a more balanced examination of climate change impacts on the state and avoid deploying limited funds and enacting unwise policies in an attempt to ward off projections that hold a significant chance of not coming true.
One way of decreasing pressure on Texas's water resources would be to halt and reduce the massive influx of illegal immigrants into the state, whose "official" numbers increased by an order of magnitude to nearly 5 million between 1970 and 2014. The actual number of illegal aliens in Texas is likely much higher and increasing more rapidly than official statistics suggest. Curbing this population increase alone would go a long way to dealing with many of the issues raised in the Dallas Morning News article.