Drought and Climate Change in Texas: Perspectives from a Climatologist, Atmospheric Scientist and Hydrologist
Freese and Nichols University hosted two Drought and Climate Change Seminars in Dallas on September 25, 2014. Speakers included Dr. John Nielsen-Gammon, Texas State Climatologist, Dr. Katharine Hayhoe, director of the Climate Science Center at Texas Tech University, and Tom Gooch, Vice President and Water Resource Planning Group Manager at Freese and Nichols.
Dr. Nielsen-Gammon presented on Texas drought in the past, the present and into the future. He discussed the driving forces behind our climate variability and the impact this variability has on our pattern of drought. From the past measured events dating back to 1895 and reconstructed tree ring data dating back to the 1550s, we can tell that Texas has experienced frequent and sometimes significant droughts. Dr. Gammon explained that these periods of drought are primarily driven by ocean temperatures in the Pacific and Atlantic Oceans, among other factors. As these temperatures fluctuate they have a profound impact on our weather. In Texas, these patterns lead to either floods or drought but rarely normal conditions. The Pacific decadal oscillation and Atlantic multidecadal oscillation combined with La Niña created a “triple whammy” to create favorable conditions for a prolonged drought. Based on his research, the 2011 drought is now the second longest in over 100 years of recorded history. He concluded by saying “we will have worse droughts than in the past and the science to predict them is improving.”
Dr. Hayhoe presented on drought, variability and long-term change. In Texas, we have extremes of floods and drought with our weather patterns trending toward these extremes. We are faced with the challenges of a semi-arid climate, highly variable rainfall and competition for already limited water resources. The problem of climate change is that the challenges we already face are changing with hotter temperatures and longer periods of extreme dry conditions interspersed with frequent extreme rainfall events. “As planners, it is like we have been driving by looking in the rear view mirror of historical records.” If we do not account for climate change in our long-term planning we will get the answer wrong. “Only by preparing for climate change will we be able to successfully adapt to it.”
Dr. Nielsen-Gammon and Dr. Hayhoe then engaged in a debate in which the only thing heated was their agreement that climate change will lead to increased temperatures in Texas. Both speakers agreed that climate change will lead to long-term increases in temperature, longer spells of drought and heavier precipitation. One conclusion is that water supplies that minimize evaporation like aquifer storage and recovery (ASR) will be important for dry regions like Texas.
Tom Gooch gave a hydrologist’s perspective on drought and climate change. He spoke about the “hydro-illogical” cycle, a concept explaining how the public is generally apathetic about water supply until times of drought. He outlined an approach to drought response that includes reviewing current supplies, communication with stakeholders, analysis of availability, implementation of strategies and monitoring/adjustment as necessary. One important factor driving implementation, permitting, is often the prime consideration for emergency supplies. Tom concluded that the same approach can be extended to planning for drought in uncertain conditions driven by climate change. He noted that to incorporate the uncertainty of climate change impacts on water supplies, entities should evaluate the possible effects of climate change on current and future supplies; keep demands in check through water conservation; maintain a margin of safety by developing more supplies than current demands; and maintain flexibility for response to both drought and climate change with diversified water supplies.