The Insufficiency of Efficiency for Climate Adaptation: The Problem of Water

The aggressive pulse of climate change is skewering many of our truisms about what sustainability means. Perhaps the least questioned and most widespread assumption of a clear “good” is increasing water use efficiency — quite literally a mantra among many in business and agriculture for how we should respond to climate impacts.

Resilience is the emerging challenge to efficiency. I like to show the contrast between resilience and efficiency by pointing to the early response to Covid-19 in 2020: national decision-makers had decided pre-pandemic that maintaining stockpiles of N95 face masks and ventilators for our medical system was inefficient. And they were correct: spending money to acquire these assets in advance of their need and then to store them for years was horribly inefficient. But maintaining face masks and breathing support equipment would have proven extremely resilient at the onset of the pandemic, as hospitals and clinics struggled to keep pace with the quickening demand for basic medical equipment. Lives would have been saved, medical personnel less stressed, and scarce financial resources conserved in a crisis. What’s wrong with the assumption that efficiency is an unqualified good? I see two basic issues.

As described by Jevon’s paradox in the 1860s, increasing the efficiency with which we use a natural resource may actually increase the demand for and, ultimately, the rate of consumption of that resource. This pattern is clearly seen in many irrigation investments and programs. Increasing the amount of “crop per drop” makes a lot of economic sense, given the expenses associated with irrigation itself. But in most cases, we actually see farmers responding to increased water use efficiency by increasing the amount of land in production—which normally increases the volume of water being consumed. Less water per plant, but more plants overall, and thus more net water use. Efforts to make manufacturing more water-efficient likewise typically result in expanding overall production once water is removed as a rate-limiting input.

Jevon’s Paradox is not specific to climate change, however. Efficiency from a climate change perspective is an implicit prediction that we know what the future is going to look like and we can titrate our water use precisely to fit that future. There are no missing or unknown variables in our analysis; we can balance the equation in such a way that our water use will stay balanced and in check over time. Efficiency is climate hubris.

Climate change brutally challenges this assumption. The water cycle is proving to be exquisitely sensitive to the climate shifts we’ve seen to date, and our abilities to predict those changes with confidence have been limited. Many practitioners have noted the challenge of “deep uncertainty” with respect to the water cycle, where we might not even be able to choose between alternative opposite futures in many regions, such as a much wetter or much drier trajectory. Traditional engineering and design approaches to develop “robust” solutions may be incapable of spanning that range over the operational lifetime of most investments.

In effect, our analysis has many unknown variables, those variables are difficult to parameterize, or we may not even believe the parameters we are using. The future we predict through efficiency is likely to fail abruptly as a “brittle” solution. Highly efficient systems lack (almost by definition) qualities such as redundancy, flexibility, and — from a climate perspective — resilience.

Is increasing efficiency always wrong? Can we design systems that are resilient and efficient? Of course. But that also means that we need to design irrigation and manufacturing systems that look for potential breaking and sensitivity points, and we need to evaluate our projects against resilience criteria such as reliability across a wide range of conditions, the ability to alter and adjust the design over time, and to maintain the flexibility necessary to shift our efficiency as climate conditions keep moving. So-called bottom-up risk assessment methodologies are powerful tools for respecting the uncertainties around water and climate change while also seeking out inherent system vulnerabilities. Resilience is likely to cost a little more in the beginning, but the benefits will be clear with time.

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