A scary thing happened to me about a year or two back. Having led over 15 years of research on how to utilize NASA’s Gravity Recovery and Climate Experiment (GRACE) mission to track water storage changes and freshwater availability around the world, I came to the following conclusion. We are, on many levels, completely and totally hosed. And here’s why.
First, groundwater depletion has emerged as a global phenomenon, to the point where water security will ultimately rival energy security for dominance on the geopolitical landscape. The GRACE data now make that abundantly clear. Our team has already used them to quantify current rates of groundwater depletion in California’s Central Valley, in the High Plains aquifer system of the Midwestern U. S., in northwestern India and in the Middle East.
Sure, we already knew that groundwater was being used at a rapid clip in these and other regions. For
example, the Central Valley has literally been sinking for decades, as the groundwater beneath its surface, which helps prop up the soil and landscape above it, continues to be removed. In the meantime, more and more wells have been running dry each year in the Central Valley and in aquifers all over the world.
However, we’ve never before been able to see, so clearly, the widespread nature of the depletion. From China, India, the Middle East, northern Africa, and Argentina, to the southeastern U. S., the High Plains and the Central Valley, groundwater is being ripped from beneath every continent except Antarctica (which has its own problems) at a frenzied pace.
Nor have we previously been able to estimate the rates of depletion, simultaneously, over all of the world’s large aquifer systems. A lack of ground-based monitoring, in particular in the developing world, combined with the ubiquitous reluctance to share available data across major political boundaries (for fear of very real socioeconomic, political and security consequences) have conspired to make this, until now, an impossible task.
I won’t sugar coat it. It’s not pretty. Stay tuned as our community continues to work diligently on mapping out these alarming rates of groundwater depletion across the globe.
The second reason we’re hosed is that the water cycle is changing. Computer simulation models predict, and observations, including the GRACE data, are beginning to confirm, that the water cycle is becoming more variable. This change is being realized in a couple of different, but related, ways.
As global temperatures climb, evaporation and precipitation are increasing, because the atmosphere can hold more water as it warms. It was Sir Isaac Newton who told us ‘what goes up must come down.’ Very literally then, we’ll be experiencing more ups and downs in the water cycle as more evaporation (the ups) will fuel more precipitation (the downs).
Since more of the sun’s energy is required to drive the increasing evaporation, more energy will be released when the water vapor condenses to form rainfall somewhere downwind. The result: rainfall will be delivered in more energetic bursts, that is, in more severe storms and floods; while drought will become more prolonged and intense, driven by more powerful drying from strengthening evaporation. In short, we will, and may already, be experiencing more extreme extremes.
Not only will rainfall be more variable in time, but it is changing spatially as well. Global patterns of precipitation are shifting with changes in climate. The wet areas in the tropics and the high Arctic are receiving more rainfall, but the already drier mid-latitudes are receiving less. In other words, the wet areas are getting wetter while the dry areas are getting drier. Which could be problematic for the wet regions if further wetting leads to additional flooding.
And is unquestionably problematic as perennial drought becomes the new reality for the already parched,
arid and semi-arid regions of the world. These areas already rely on an overstressed, dwindling groundwater supply to meet their domestic, agricultural and industrial water needs. Further drying means even less replenishment of the extracted water in the future, likely pushing an already tenuous situation over the edge, especially after population growth is factored into the equation. Consequently, we should fully expect that rates of groundwater depletion will accelerate significantly in the coming decades.
The full implications of our changing water cycle and freshwater availability are so profoundly compellingthat they could make the average noggin spin a full 360 degrees. Repeatedly.
Increasing flood risk will exert greater pressure on existing infrastructure, which in most instances has not been designed to accommodate the new extremes. Municipal water systems will become more vulnerable, subjecting human health to greater risk. Water management, the primary goal of which is to minimize variability in order to provide a reliable supply of freshwater, will face unprecedented challenges in adapting to the ‘new normal.’
The developing world may well see regular waves of displaced flood and drought refugees, who once scattered, are difficult to care for and govern. Cultural intricacies, especially those tied to seasonal cycles, will be thrown off-kilter, threatening livelihood systems. National plans for economic growth will be complicated by the need to deal with costly emergencies and reconstruction.
As groundwater supplies in the arid and semi-arid regions of the world approach depletion, access to available water will undeniably be more contentious than today. Will there be enough water to grow sufficient amounts of food to nourish our ever-expanding population? Let’s face it. Thirsty and hungry people get seriously grumpy, which spells C-O-N-F-L-I-C-T. Expect more water wars in the future.
If this strikes you as a bunch of science fiction, all I can say is that, I wish it were. But the reality is, the water landscape of our future will be defined by the need to move water from where it is in abundance to where it is in short supply, and by the need to most efficiently use and reuse water locally. And the only way that will ever happen is if we begin, now, to implement the technological, civil, policy and legal infrastructure required to peaceably and efficiently share and trade water across political boundaries.
Can we get unhosed? Doubtful. But I believe that we can manage the hosing and keep it to within tolerable limits. What can be done? Several steps can be taken now, but first and foremost, inaction is not an option.
Pass the data please. The need for transparency of water data has never been more pressing. Critical research and effective management absolutely depends on it. Collaborative, transboundary water policy dictates it, while the ability of satellites to assess the state of international water resources renders data denial policies nearly obsolete anyway. Sharing key datasets across political boundaries will form the foundation for new, modern-era water management strategies that consider both climate change and population growth in order to allocate limited resources amongst humans, the environment, and towards economic growth.
How much did you withdraw? Enhanced monitoring of water use, and in particular, of groundwater levels or pumping rates, is an essential step towards sustaining the life expectancy of groundwater supplies, especially in the drying mid-latitudes. In the developed world, this missing cornerstone amounts to gross negligence. How would you feel about a country where banks were not required to keep track of withdrawals and changing balances? Insane, right? Well guess what? That’s what we do with water, and we do it all over the world. My suggestion: let’s stop screwing around and get down to some fundamental accounting.
You want me to do what? What will make this all work? The Global Water Police? Hardly. A Global Water Policy? Sounds much better. Clearly, calling on our existing institutions to require collection of key measurements and sharing of key datasets is a step in the right direction. The UN, the WMO, the UNFCCC and other institutions and conventions are already in place. The trick now is to figure out how to use them to keep an already difficult situation from degrading into an explosive one. Do they have the will (and the teeth) to make it happen? I honestly do not know.
Consider this my global water challenge. If we don’t start getting our acts together on this today, I truly believe that we will see the emergence of hydropolitics on the world scene as a driving force behind new strategic alliances, economic realignment, and as a key determinant of international security.
Let’s start now to build the required international environmental policy and legal infrastructure to make our global water future unifying and sustainable, rather than divisive and short-sighted. Let’s plan for the next several decades rather than for the short term. And let’s apply what we now know about how the water cycle works when devising our new strategies, rather than continue to be saddled with centuries-old policies that were enacted long before we understood what we do today.
I thank Kate Voss and Richard Matthew for discussion and their input on policy and security issues.