Key facts about the drought that’s reshaping Texas

Summary: The farmers and ranchers of Texas exhaust its groundwater as they suffer from a severe drought, which activists blame our burning of fossil fuels. What do scientists say? How severe is the drought? What are its causes? How will this reshape Texas? It’s another test case of our ability to see and adapt to our changing world. {1st of 2 posts today.}

“Texas is a state of mind. Texas is an obsession. Above all, Texas is a nation in every sense of the word.”.
— John Steinbeck in Travels with Charley in Search of America (1962).

US Drought Monitor: March 2015
Click to expand.

Texas Seal

Contents

  1. Hysteria.
  2. Status report from Texas.
  3. Learning from the past in Texas.
  4. Let’s try science!
  5. Look to the future.
  6. For More Information.
  7. The Hydro-Illogical Cycle.

(1)  Hysteria

The media overflows with debates asking do you believe in climate change? As with evolution, much of America remains in denial. Some on the Right deny that it’s happening now; some on the Left deny that it’s omnipresent in history. Both use science as magicians use their wands: to confuse us. But we have reliable sources to guide us. How to find them is the subject of many posts on the FM website.

Today we look at the Texas drought. The New Republic gives us a well-written example of how not to do it: “Fear in a Handful Of Dust” by Ted Genoways — Excerpt:

Climate change is making the Texas panhandle, birthplace of the state’s iconic Longhorn, too hot and dry to raise beef. What happens to the range when the water runs out? … Soon, environmental activists and reporters {ed: not scientists} began to ask whether “drought” — a temporary weather pattern — was really the right term for what was happening in the state, or whether “desertification” was more appropriate.

… In fact, hydrologists estimate that even with improved rainfall, it could take thousands of years to replenish the groundwater already drawn from the South Plains.

… “If climate change is the real deal,” {Linden Morris} said, “then the human race as we know it is over. And I don’t believe that.”

Climate change is the “real deal”, but someone should tell Morris that few scientists believe we are “over”. Genoways’ confusing article mixes together several trends, most seriously conflating three important but largely unrelated trends: groundwater depletion, the current drought, and climate change.

Farmers and ranchers have been draining the Ogallala Aquifer (a finite store of water, part of a system underlying about 80% of the High Plains) at an ever-faster rate since the 1940s. In Texas they accelerated their pumping during the current drought. As scientists have warned for generations, at some point we will exhaust this great aquifer network and the Midwest economy will irrevocably change. It’s a phase in our history, like the California and Alaskan gold rushes. (For more information see this by the USGS; also seen the graph showing depletion levels here.)

But despite his apocalyptic language, Genoways doesn’t show that many climate scientists (let alone a consensus) believe that climate change, natural or anthropogenic, is largely responsible for the Texas drought. Let’s see review the evidence, and listen to what they actually say.

(2)  Status report from Texas

Droughts are cause by a combination of high heat and low precipitation. The “2014 National Climate Assessment” shows rainfall and temperature from 1895 to 2012. Texas was hammered by both during the worst part of the drought that began in October 2010.

Texas temperature and rainfall in Summer 2011
From the “2014 National Climate Assessment”.

Putting this hot year for Texas in context, the IPCC tells us that the world has been warming since the early 19th century, and “human activities caused more than half of the observed increase in global mean surface temperature from 1951 to 2010” (IPCC’s AR5).

The past 12 months have been Texas’ 22nd worst drought (per the Palmer Drought Severity Index) in the 120 years since records begin in 1895 (a moment in climate history). The past 4 years ending in March have been the 4th worst; ditto for the past 5 years. Since 1895 only the 1957 drought was worse (see the next section).  NOAA makes it easy for you to see the records.

The extent and severity of the drought have improved since a year ago (compare for yourself). See the Drought Impact estimator for the past 6 months: only 66 total impacts in Texas for the past 6 months, down from 175 for the past 12 months.

NOAA Dought Impact chart: October 2014 - March 2015
From the U of Nebraska’s National Drought Mitigation Center.

The Spring rains have been good to Texas, unlike California (see the picture). Texas reservoirs are 72% full, about 10 points less than their average at this week. Like California, they have not built new reservoirs for 20 years as their population grew (penny wise …). Here’s NOAA’s forecast through July (click to enlarge): continued drought for parts of Texas (more awful drought for the West).

NOAA Seasonal drought outlook thru July 2015
From NOAA’s Climate Prediction Center. Click to enlarge.

(3)  Learning from past in Texas

“We don’t even plan for the past.”
— Steven Mosher (member of Berkeley Earth; bio here), a comment posted at Climate Etc.

NOAA’s Drought in the United States page explains that although droughts are endemic to much of the US, precipitation increased during the 20th century.

The incidence of drought in the United States has varied greatly over the past century. From the dust bowl years of the 1930’s to the major droughts of 1988 and 2000, much of the U.S. has suffered from the effects of drought during the past century. While annual and seasonal precipitation totals have generally increased in the United States since 1900, severe drought episodes continue to occur.

Drought is temperature plus precipitation. See the trend in the NOAA Palmer Drought Severity Index for Texas. It’s now -2.20 vs the 1895-2015 average of -0.06. The current drought is severe but not extraordinary, even for this brief period of history. There has been no trend since 1985, except an insignificant improvement.

Palmer Drought Severity Index for Texas, from NOAA
Palmer Drought Severity Index for Texas, from NOAA. Click to enlarge.

For another perspective on this history see an excellent animated graph showing drought conditions in the US by county from 1900. Droughts come and go in the west. They are a natural aspect of Texas’ climate, as described in NPR’s “A History of Drought and Extreme Weather in Texas“. This list describes the droughts that have hit Texas since the early 1980s. NPR describes the worst of them in a report about “How One Drought Changed Texas Agriculture Forever“:

In Texas, there is still the drought against which all other droughts are measured: the seven-year dry spell in the 1950s. It was so devastating that agriculture losses exceeded those of the Dust Bowl years, and so momentous that it kicked off the modern era of water planning in Texas. … In 1957, in the seventh year of the drought, the rains finally returned.

Elmer Kelton’s novel  The Time It Never Rained (1973) describes how Texas suffered as the crops shriveled and livestock died. Here’s a report about their powerful public policy response to this event. Unfortunately, as shown by the graphic at the end of this post, people tend to forget and let their defenses against drought fail.

Science

(4) Let’s try science!

Journalists loyally report Leftist activists’ claims that all extreme weather is anthropogenic climate change, but scientists seldom agree — as shown by these studies about the Texas drought. They give strong warnings that past megadroughts that will reoccur, warnings which we ignore.

(a) North American drought: Reconstructions, causes, and consequences“, Edward R. Cook et al, Earth-Science Reviews, March 2007. Excerpt from their conclusions:

These reconstructions, many of which cover the past 1000 years, have revealed the occurrence of a number of unprecedented megadroughts over the past millennium that clearly exceed any found in the instrumental records since about AD 1850, including an epoch of significantly elevated aridity that persisted for almost 400 years over the AD 900-1300 period. In terms of duration, these past megadroughts dwarf the famous droughts of the 20th century, such as the Dust Bowl drought of the 1930s, the southern Great Plains drought of the 1950s, and the current one in the West that began in 1999 and still lingers on as of this writing in 2005.

… The extraordinary duration of past North American megadroughts is difficult to explain, but climate models strongly point to tropical Pacific Ocean SSTs {sea surface temperatures} as a prime player in determining how much precipitation falls over large parts of North America.

(b) Explaining Extreme Events of 2013 from a Climate Perspective“, Stephanie C. Herring et al, Bulletin of the American Meteorological Society, September 2014. Their last sentence:

Hence while we can provide evidence that the risk of hot and dry conditions has increased, we cannot say that the 2011 Texas drought and heat wave was “extremely unlikely” (in any absolute sense) to have occurred before this recent warming.

(c) A link between the hiatus in global warming and North American drought“, Thomas L. Delworth et al, Journal of Climate, in press. From the abstract (red emphasis added):

This suggests that anthropogenic radiative forcing is not the dominant driver of the current drought, unless the wind changes themselves are driven by anthropogenic radiative forcing. The anomalous tropical winds could also originate from coupled interactions in the tropical Pacific or from forcing outside the tropical Pacific.

(d)  Remember all the screams about CO2 causing the drought? As so often the case, eventually scientists debunk the claims, hidden by the news media: “An Interpretation of the Origins of the 2012 Central Great Plains Drought“, NOAA’s Drought Task Force, 20 March 2013. From the Executive Summary:

Precipitation deficits for the period May through August 2012 were the most severe since official measurements began in 1895, eclipsing the driest summers of 1934 and 1936 that occurred during the height of the Dust Bowl. This prolonged period of precipitation deficits, along with above normal temperatures, resulted in the largest area of the contiguous United States in drought since the U.S. Drought Monitor began in January 2000. By early September, over three quarters of the contiguous U.S. was experiencing at least abnormally dry conditions with nearly half of the region (the Central Plains in particular) experiencing unprecedented severe drought.

The central Great Plains drought during May-August of 2012 resulted mostly from natural variations in weather. … Neither ocean states nor human-induced climate change, factors that can provide long-lead predictability, appeared to play significant roles in causing severe rainfall deficits over the major corn producing regions of central Great Plains.

Forecasting with models

(5)  Look to the future

Unprecedented 21st century drought risk in the American Southwest and Central Plains“, Benjamin I. Cook et al, Science Advances, 12 February 2015. Forecasts by climate models. The bottom line:

In the Southwest and Central Plains of Western North America, climate change is expected to increase drought severity in the coming decades. These regions nevertheless experienced extended Medieval-era droughts that were more persistent than any historical event, providing crucial targets in the paleoclimate record for benchmarking the severity of future drought risks.

(6)  Useful Sources of Information

The Internet provides a wealth of information about climate. NOAA provides especially wonderful tools to understand these issues.

  1. Make your own climate map, showing precipitation or one of the drought indexes.
  2. Make your own animated climate map, showing the evolution of the drought over time.
  3. NOAA’s Seasonal Drought Outlook at the Climate Prediction Center.
  4. The U.S. Drought Portal — A wealth of information about past and present droughts in USA, and their impacts.
  5. US Drought Monitor — U Nebraska – Lincoln and Federal Agencies, ditto as above.
  6. Westmap — make graphs and maps of climate date. By the Desert Research Institute
  7. Paleoclimate Drought Resources – “What paleoclimatology tells us about drought”.

(7) For More Information

See the 1993 classic book forecasting our present problems Cadillac Desert: The American West and Its Disappearing Water. For a down to earth look at climate change see The Time It Never Rained by Elmer Kelton (1973), a novel describing the 1905s drought that re-shaped Texas as crops shriveled and livestock died.

If you liked this post, like us on Facebook and follow us on Twitter. See these Reference Pages for other posts about climate on the FM sites:  The keys to understanding climate change and My posts about climate change. Also, see these posts about droughts:

  1. RecommendedKey facts about the drought that’s reshaping California.
  2. Have we prepared for normal climate change and non-extreme weather?
  3. Let’s prepare for past climate instead of bickering about predictions of climate change.
  4. Droughts are coming. Are we ready for the past to repeat?
  5. Our response to California’s drought shows America at work to enrich the 1%.

(8) The Hydro-Illogical Cycle

From the SPEI website.

The Hydro-illogical cycle
From the SPEI website

11 thoughts on “Key facts about the drought that’s reshaping Texas

  1. Interesting post. Let me preface my comment by acknowledging the points you’re making in this post and saying that I offer the following as an addendum and not a counter (i.e., more food for thought).

    I think it’s important when considering climate change in relation to drought to clearly differentiate between causation and facilitation – as captured in the old Douglas Adams’ quote, It’s not the fall that kills you, it’s the sudden stop. The following excerpt is in relation to California’s current drought situation but illustrates my point.

    “In a new study, a team led by Stanford climate scientist Noah Diffenbaugh used a novel combination of computer simulations and statistical techniques to show that a persistent region of high atmospheric pressure hovering over the Pacific Ocean that diverted storms away from California was much more likely to form in the presence of modern greenhouse gas concentrations. […] The interdisciplinary research team found that the extreme geopotential heights associated with the Triple R in 2013 were at least three times as likely to occur in the present climate as in the preindustrial climate. They also found that such extreme values are consistently tied to unusually low precipitation in California and the formation of atmospheric ridges over the northeastern Pacific.”

    — Excerpt from “Stanford scientists say drought linked to climate change“, Stanford press release.

    And below Diffenbaugh/Gleick make the distinction between causation and facilitation when responding for comment regarding a NOAA report finding that the California drought is caused by natural patterns, not climate change.

    “The [NOAA] study offers important insights about the role of sea surface temperatures, said Stanford University climate scientist Noah Diffenbaugh, who was not involved in the NOAA report. He called it “an important step forward in understanding the current drought, which is a complex, high-impact event.” But Diffenbaugh said the new report does not contradict his team’s findings, reported in September, that global warming increases the likelihood of high-pressure systems that block winter storms. The finding … does not invalidate the potential influence of global warming,” he said. What needs to be better understood, he said, is the role that global warming might play in boosting the probability of the drought-causing ocean conditions.

    But one expert criticized the study. “They’ve asked and then answered the wrong question,” said Peter Gleick, president of the Pacific Institute, an Oakland think tank that studies water policy. “This isn’t about ‘causality’ but about ‘influence,’ he said. “The evidence is clear that human-induced climate change is influencing the drought, no matter the cause.”

    — Excerpt from “California drought: Natural patterns, not human-caused climate change, federal study finds“, Mercury News.

    1. arguendo,

      Thank you for this comment, esp valuable with the citations. Two questions in reply.

      (1) “between causation and facilitation – as captured in the old Douglas Adams’ quote, It’s not the fall that kills you, it’s the sudden stop.”

      I don’t get the analogy. Not a surprise, as I’m not good at seeing analogies (or their cousins, jokes– which makes me fun at parties: “Could you explain why that punch line is funny?”). Could you explain?

      (2) I’m familiar with the Gleick rebuttal. But it makes no sense to me. Assertions that “X is consistent with warming” or “warming increases odds of X” (or worse, “warming linked to X”) seem of low utility. The first looks like chaff, unless given as rebuttal to an assertion that X is incompatible with warming.

      The second (warming influences/linked to X) is operationally useless without estimating the magnitude of the effect. The research I’ve seen suggests that the California and Texas droughts are largely natural events — as shown by multiple lines of analysis. If the “facilitation” is large, then attention should be paid to this dynamic. But what if it’s trivial, another instance of the anthropogenic effect swamped by larger natural variation? If so, shouldn’t we then focus on mitigation of extreme weather effects — rather than CO2 emissions reduction?

  2. FM,

    Thank you for your reply.

    1) Ha! I’ll give it a shot.

    Mr. Adams is correct in his observation that one could fall all day and incur little if any harm. It is only upon impact that their problems begin. So, although the fall itself didn’t technically cause death, it certainly facilitated the event that did. Using a similar line of reasoning, I postulate that although it’s true that anthropomorphic climate change may not be the direct cause of a particular drought, it has been demonstrated (via the Stanford study) that it facilitates (i.e., increase the probability of) the conditions for the direct cause to occur.

    2) You have me at a disadvantage as I’m not familiar with Gleick’s work so I’ll answer only in terms of the article describing the Stanford study.

    “The second (warming influences/linked to X) is operationally useless without estimating the magnitude of the effect…”

    From the article, “The interdisciplinary research team found that the extreme geopotential heights associated with the Triple R in 2013 were at least three times as likely to occur in the present climate as in the preindustrial climate.” I take this to mean that the probability of the “effect” (i.e., extreme geopotential heights – known to be the direct cause of drought) is increased by a “magnitude” of three times. So, does a facilitation of three times provide a sufficiently large operational utility to warrant factoring in this dynamic in the broader analysis? Or do you read that differently?

    Now that being said, rather than the causal factors of the drought itself, I’m much more interested in the causal factors of the public water shortages in times of drought. Although alternate examples are abundant, I think these droughts provide the perfect framework in which to observe the plutocratic modus operandi, propaganda techniques, and their general/ruthless disregard for the public good – as deftly described in your excellent post, Our response to California’s drought shows America at work to enrich the 1%. So I humbly defer to your analysis of the drought science.

    1. arguendo,

      A 3x increase in drought occurrence is more than warming “influence”, in any usual sense of the word! That is, however, far out of consensus. This is the problem with looking at individual papers: they give little sense of the consensus of climate sciences, or the trend in their thinking (which is, of course, why activists do so). Which is why I cite multiple papers plus work of the major climate agencies.

      What does AR5, the most recent IPCC report, say about droughts? From chapter 2:

      Confidence is low for a global-scale observed trend in drought or dryness (lack of rainfall) since the middle of the 20th century, owing to lack of direct observations, methodological uncertainties and geographical inconsistencies in the trends. Based on updated studies, AR4 conclusions regarding global increasing trends in drought since the 1970s were probably overstated. However, this masks important regional changes: the frequency and intensity of drought have likely increased in the Mediterranean and West Africa and likely decreased in central North America and north-west Australia since 1950. {Reference: 2.6.2.2}

      The IPCC regards “low” confidence as 4th highest on a scale of 5, and probability of “likely” as over 66% (3rd highest on a scale of 7). No support there for a 3x increase in probability for events that began in the past few years.

  3. FM,

    Thank you for your reply.

    “No support there for a 3x increase in probability for events that began in the past few years.”

    Agreed. But the Stanford study isn’t comparing the probability for events that began in the past few years. The probability increase they found is between the present climate and the preindustrial climate. So, not a 3x increase since 1950, but a 3x increase since circa 1800.

    The Stanford study isn’t suggesting a direct drought causality. Instead it finds that extreme atmospheric high pressure in [the Pacific] region – which is strongly linked to unusually low precipitation in California – is much more likely [3x] to occur today than prior to the human emission of greenhouse gases that began during the Industrial Revolution in the 1800s. Granted, that doesn’t mean the same holds true for Texas/globally, but the findings are at least compelling enough to warrant serious consideration and continued research into anthropomorphic climate change as a facilitator of the conditions conducive to drought.

    Also, I hope you’ll keep in mind my initial acknowledgment of the points you made in this article and that my comment was meant only as a minor addendum. The individual paper cited was in context, and the entire point, of that minor addendum. I merely found the study interesting enough to have thought it worth a mention. The study makes no obviously outrageous claims that I could find, nor does it appear to be in direct conflict with your broader analysis. Where does it stray far out of consensus? The tone of your replies seem to imply an attempt to debunk it (or at least to dismiss it as conjecture). If that truly is your intention, it remains unclear to me where you have succeeded.

    1. arguendo,

      “The tone of your replies seem to imply an attempt to debunk it (or at least to dismiss it as conjecture).”

      The authors clearly state it as a conjecture. More broadly, it’s a mystery to me why laypeople bother with individual papers. As many studies have shown, much research is wrong (studies in several fields have found that over half cannot be replicated). That’s a good thing, showing that scientists are exploring the edge of what’s known.

      Hence when people mention individual papers I put them in context of the climate science consensus as described by the IPCC, the major climate agencies, and the major trend in peer-reviewed research.

      (2) As so many people have noted, press releases are an unreliable guide to the content of research. They’re seldom written by scientists. This press release is misleading at best. Let’s look at the paper: “SEVERE PRECIPITATION IN NORTHERN INDIA IN JUNE 2013: CAUSES, HISTORICAL CONTEXT, AND CHANGES IN PROBABILITY”, Bulletin of the American Meteorological Society, September 2014 – Conclusions:

      Our statistical analysis, combined with our diagnosis of the atmospheric environment, demonstrates that the extreme June 2013 total precipitation in northern India was at least a century-scale event. Precise quantification of the likelihood of the event in the current and preindustrial climates is limited by the relatively short observational record and by the resolution and ensemble size of the small subset of models that credibly simulate the seasonal rainfall distribution over northern India. Indeed, an attempt to quantify the probability of the unprecedented four-day precipitation total would present even greater analytical challenges.

      However, despite these limitations, our analyses of the observed and simulated June precipitation provide evidence that anthropogenic forcing of the climate system has increased the likelihood of such an event, a result in agreement with previous studies of trends in rainfall extremes in India (Goswami et al. 2006; Krishnamurthy et al. 2009; Ghosh et al. 2012; Singh et al. 2014).

      The closest thing I see from a quick read of the paper to the press release’s claim: “Further, the model with the largest 20C ensemble demonstrates a ~50% likelihood that the probability of the extreme June total precipitation has at least doubled in the 20C climate.”

  4. FM,

    Thank you for your overly generous replies. Much appreciated and enjoyed. I’ll preface by saying I agree with your overall assessment of individual papers and further, the tendency of the press to sensationalize and/or misrepresent, intentionally or not, the associated findings (a near systemic problem that applies to much more than just individual papers).

    “The authors clearly state it as a conjecture.”

    By conjecture, I meant an opinion or idea formed without proof or sufficient evidence. If we share that meaning of the word, I did not read the authors to clearly state their findings as such. While I do agree they did not purport show definitive proof, to interpret that as mere conjecture seems a bit specious. For example, from the article, “We’ve demonstrated with high statistical confidence that the large-scale atmospheric conditions, similar to those associated with the Triple R, are far more likely to occur now than in the climate before we emitted large amounts of greenhouse gases, Rajaratnam said.” – If you consider such statements to be those of someone intentionally/honestly offering only conjecture, then so be it. However, it doesn’t sound that way to me.

    Although their offering may not have provided definitive proof, it certainly had ample amounts of what, at least they thought be, evidence in support of their conclusion. In any event, time (and more research) will tell.

    “Hence when people mention individual papers I put them in context of the climate science consensus as described by the IPCC, the major climate agencies, and the major trend in peer-reviewed research.”

    This is very helpful in understanding the context of your replies. I took you to be dismissing, out of hand, any findings in support of any possible relationship between climate change and drought. And because no broad climate science consensus had been reached to this point, you consider all research to gain a better understanding of any such relationship meaningless to pursue. I agree, more definitive proof is needed. So fair enough, in context of separating the wheat from the chaff to get at exactly what is currently, more definitively accepted to be true, I take your point. Sure, why not.

    1. arguendo,

      I strongly recommend that you not rely on press releases. Scientists, just people, often make big statements that they do not make in the peer-reviewed literature. You quoted from the press release. I quoted from the study, in which the authors clearly stated a conjecture — an explanation with some evidence, but not widely considered to have sufficient evidence to be designated as theory (this schema originated with Karl Popper).

      This is a single paper looking at one specific kind of event in a small area, using it to conjecture about this process on a global scale. To consider this as well-established is a serious misunderstanding of the scientific process.

      “you consider all research to gain a better understanding of any such relationship meaningless to pursue”

      I don’t know what that means. I said that imo laypeople should focus on the summaries of the major climate agencies and the IPCC. In practice laypeople tend to rely on cheery-picked studies fed them by their tribal leaders. I’ve seen hundreds of examples here of people who have read intensely on a subject but know little about it (i.e., they have strong opinions quite at variance with the consensus of scientists, and usually understand neither the consensus or why scientists disagree with them). This is common on the politicized fields, economics and climate.

  5. I don’t get why people are so consumed with understanding the why of climate change because there is next to nothing that anyone can do about it whether it is anthropogenic or natural. Guess what? it’s both.

    It’s happening and it’s going to keep happening, we need to worry about how to handle it instead of bickering over why its happening, because we aren’t going to stop 4 billion people in China from burning stuff anytime soon!

    Global warming is a poor term, we will see more extremes at every level (dry, wet, hot, cold) in the next 50 years than we have seen in the last 500-1000. We need to learn to deal with it, because it is.

    1. Scott,

      “It’s both”

      Yes, the IPCC is quite clear about that. As for mitigation, I agree that’s the key. As so many posts say, “we’re not prepared for the past” to reoccur. We’re unprepared for the extreme weather of the past to reoccur, as it certainly will.

      “global warming is a poor term”

      It is the correct term for the underlying problem, which is CO2 emissions increasing the global surface temperature. Climate change is the result. Also note that the IPCC reports do not say that “we will see more extremes at every level”, esp over the next 50 years. The severe effects are in the 2nd half of the 21st century if we continue CO2 emissions at the current rate (which imo is unlikely).

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