WHAT THE PAST TELLS US ABOUT THE FUTURE
By Jay L. Banner, Ph.D. & Eric S. Hersh, Ph.D., P.E.
It can be said that as goes Texas so goes our nation, in terms of both the challenges and potential associated with economic, demographic, and natural resource changes that are common to our state and country. So much of what is possible for Texas is dependent on the availability of water for people, for industry, and for agriculture. The availability of water in Texas has undergone dramatic changes over the past millennium. We can look back to help see forward, as our history may portend our future.
Scientists study tree rings to build a history of past water availability in the region. Examining a core toward the center of a tree, these rings are thin where growth was slow, and in this way trees may reveal dry periods in the past. These dry periods include a decade-long drought in Texas at least once each century since the 1500’s. Going further back in time, we find the imprint of historically long 10- to 30-year ‘megadroughts’ during the 12th and 13th centuries. Archeologists infer that these megadroughts triggered the collapse of thriving civilizations in the southwest U.S. region. The drought-prone nature of Texas also left its mark in the recent past – the six dry years of the 1950’s, used by Texas as the ‘drought of record’ for planning purposes, and the ongoing drought that began in 2011 and reached historical intensities.
Will the periodic occurrence of major droughts that comprises the fabric of Texas’ history continue into the future? For the 21st century, an increase in the recurrence of the historical droughts, in terms of intensity and duration, is projected by researchers who apply computer simulations of Earth’s atmosphere-land-ocean systems to produce very long-range forecasts. The most recent of these applications project, for the southwest U.S. and central Great Plains toward the end of the 21st century, drought of heretofore unobserved high intensity and long duration over the past 1,000 years. Such changes would bring significant impacts to our state.
At the same time, the state is projected to double in population by the year 2065, with an increase in the density of existing urban cores and a concurrent expansion of the present suburban footprint. Globally, a majority of humans now live in cities – something that happened just over the past decade for the first time in our almost 200,000 year history as a species. In Texas, there is a north-south corridor bisecting the state and comprising large and rapidly growing urban areas – including San Marcos, presently the fastest growing city in the U.S.; McAllen, the second fastest growing city from 2000-2010; and San Antonio, Dallas, and Austin, all among the top 11 largest cities in the U.S. If history should repeat itself in the form of a megadrought or if the forecasted 21st century shift to drought as the norm, from where will all of these new and long-term Texans get their water?
Future water scarcity in Texas will be driven by the synergy of projected droughts and significant population and economic growth. Cascading from the impacts on water will be extensive impacts on other sectors, such as energy generation and public health. There is a clear need for investment in water infrastructure. This need has been estimated at $53 billion over the next 50 years by the Texas Water Development Board, and a $2 billion loan fund was created in 2012 to help address this need. Texans get about one third of their water from groundwater and the rest from surface water. Infrastructure alone, however, is not a solution to the multidimensional challenge of achieving water resiliency in our region. A sea change in terms of how we value and conserve water is also essential.
The 1950’s drought of record cost the Texas economy $22 billion in today’s dollars, and caused a drop in the farm workforce from 29 to 12 percent of Texans. The 2011 drought caused $5.2 billion in direct agricultural losses and an additional $3.5 billion in indirect losses. Thousands of megawatts of generating capacity were put at risk due to low cooling water levels and elevated water temperatures. At peak, 23 Texas water suppliers estimated they were within 180 days of running completely out of water, and a few small communities even turned to trucking of emergency water rations – exemplifying a lack of water resiliency. Fast forward to 2015, and over 25 percent of Texas water suppliers have imposed some level of water restrictions on their customers.
So, are Texas businesses that rely on water doomed? What can Texas business leaders do to respond and prepare? Certainly, some industries might suffer more than others – landscaping, irrigation, water-based recreation, agriculture and food production, and fisheries. Yet many solutions are known. These include diversifying a business’s water supply portfolio. One can develop a comprehensive analysis of their company’s water footprint, and at the same time assess the water footprint along the supply chain. As part of this analysis, learn how to be more water lean by sub-metering, and assess water risk and resiliency. Much has been done in projecting and responding to changes in energy sources and costs, assess likely rising water costs. Be aware of hidden subsidies and externalities in water pricing. Study and learn about energy conservation as an analog to industrial and commercial water conservation. Support public policy that encourages shared responsibility for water conservation, and consider water availability in relocation and expansion planning. The same industries that might suffer in a water-stressed region may instead thrive by innovating in areas such as technology-driven drip irrigation and drip fertilization with advanced sensor systems. Beginning now to adapt to the changes to come is key to achieving water resiliency for Texas.
Jay L. Banner, Ph.D. is the Fred M. Bullard Professor in the Jackson School of Geosciences, a University Distinguished Teaching Professor, and Director of the Environmental Science Institute at The University of Texas at Austin. firstname.lastname@example.org
Eric S. Hersh, Ph.D., P.E. is a Lecturer in the Jackson School of Geosciences and the Research Coordinator of the Environmental Science Institute. email@example.com