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).

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.

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.

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).

(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.

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.

(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.

(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. Recommended:  Key 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.