Sitting in a place they call the "mall" in the center of NASA's Jet Propulsion Laboratory campus in Pasadena, California, it's shady and relaxing. Scientists confab at tables with umbrellas, sipping coffee, laptops open to graphs and charts. That's where H2O Radio's Frani Halperin met
, to talk about NASA's latest missions. The space agency isn't just sending rockets to explore our galaxythey're launching satellites to look back at Earth. Missions with names like "GRACE" are "amazing"not just for their bird's-eye view of our home planet but for what that perspective is telling us about our challenging water future.
Frani Halperin, H2O Radio: NASA. The word evokes space exploration, rockets and missions to faraway planets. But one of the agency’s most intriguing ventures is what it learns by turning its view back at Earth. A perspective thatas it turns outcan tell us a lot about our changing planet.
Jay Famiglietti: Sadly the picture that our work is painting is one that is very compelling and points to a very complicated water future where the availability of water will become more contentious and groundwater in many parts of the world is disappearing.
Frani: That’s Jay Famiglietti, senior water scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California. His research team is using satellites to track how freshwater availability is changing around the world. One of those satellites is called GRACE.
Jay: GRACE stands for “Gravity Recovery and Climate Experiment.” It is actually a mission from the gravity community, the community that we call the geodetic community that studies the shape of the Earth and some of its more arcane properties like gravity. It turns out when you study the small changes in Earth’s gravity field that gives us a whole set of new information about how water is moving around on the Earth that we never had before.
Frani: So tell me how GRACE works. Apparently it’s a pair of satellites.
Jay: Right, it’s a pair of satellites. Neither of them are very big. They’re each about the size of a squashed minivan. They orbit at about 400 kilometers. They follow each other around in a straight line separated by about 200 kilometers. They function like a scale in the sky, meaning that when they fly over a region that has more water on the ground say there’s been a flood, that region has gained water weight and it exerts slightly greater gravitational pull...tug on the satellites and pulls them down just a little bit closer to the Earth. Conversely when they fly over a place that’s lost water because of groundwater depletion from a big aquifer, that region has lost water weight so that region exerts less of a tug on the satellites and they float just a little bit higher in their orbit. So what we’re doing is keeping track of the position of the satellites vertically and the distance between them. If we keep track of those positions we can literally make maps of the regions around the world that are gaining or losing water every month.
Frani: So it can measure groundwater, surface water...Can it measure water in the soil or snow?
Jay: GRACE gives us an integrated measurement of all the water in a large region. By integrated I mean it can’t distinguish between the snow and the surface water and the soil moisture and the groundwater. It’s kinda like you get on a scale and you’ve gained five pounds. You don’t know if you gained it in your head or your arms...You just have one number and you need other data to figure out where that weight gain or loss is coming from.
Frani: So GRACE was launched in 2002. What have you learned so far? It’s 2016.
Jay: With respect to water we’ve had a tremendous number of surprises. Some of the major ones are that we’re able to see what we call the intensification of the water cycle, which means there’s more water moving through the water cyclethere’s more precipitation, there’s more evaporation, there’s more runoff, so there’s more water that’s circulating around. We can see that, as predicted by climate change models, that the mid-latitude regions of the world are getting drier and the high- and low-latitude regions are getting wetter. That’s been predicted to happen by the end of the century from climate models but we’re seeing it now with the GRACE data.
And the third major contribution is that we have been able to expose that groundwater depletion is happening in most of the world’s major aquifers. It’s a truly global phenomenon and happening at rates that we did not know before and they’re kind of scary.
Frani: I want to get back to climate change in a minute, but first are there other JPL programs around water besides GRACE?
Jay: We do a lot with water at JPL. So we have some key satellite missions that have been or will be launched. So there’s the Global Precipitation mission, which measures precipitation around the world. There’s the “SMAP” mission, which stands for “Soil Moisture Active Passive” that maps the moisture in the upper few (five) centimeters of soil around the world. There’s an upcoming mission called “SWOT,” which stands for “Surface Water and Ocean Topography.” That is going to launch in 2020. SWOT is going to give us a picture, for the fist time, of how water spreads over the global land surfaces, meaning how river heights vary in time, how river widths vary in time. The same thing for lakes and reservoirs. We have a whole slate of new information that will be coming our way in the next few years.
Frani: What is it that NASA JPL hopes will happen with the data you collect?
Jay: It’s certainly our hope here at JPL and NASA-wide to have our data examined by environmental decision makers and water resource managers. We can never tell them what to do and we don’t make suggestions on policy, but we sure as heck do our best to get information on their radar.
Frani: It sounds like your work did impact policy though, for example the Sustainable Groundwater Management Act here in California.
Jay: The work that we do hopefully does impact policy because many of us, we’re so tied to the work that we do. We see that sea level is happening. Well of course we’d like to some changes about policy related to greenhouse gases that are just going to melt more ice and lead to further amounts of sea level rise. Some of our work on groundwater depletion in California has certainly caught the attention statewide and is likely one of the reasons why the Sustainable Groundwater Management Actnot was passedwe voted for thatbut I think it was just another piece of information that the State Water Resources Control Board here in California used to justify the need.
Frani: Let’s talk more about California since to me it’s like a laboratory about water. What’s the status?
Jay: It’s a varied status. You know we have been embroiled in this drought going back to 2011. We had great hopes this past winter for a big El Niño, which really didn’t materialize. Things are continuing along their trajectory of not much snow in the mountains, not a tremendous amount of water in reservoirs, and long-term disappearance of groundwater. The story in California really hasn’t changed for a long time. It’s just that we’re able now to see it better because of some of the satellite information we have and that is that we face chronic water scarcity. As long as we have a huge agricultural sector we’ll always be running short of water. So it’s going to become a societal and statewide decisionand a national decision about where we grow our food. Is it always going to be in California? If so, we’re going to run out of water so we’re going to have to bring more water over here somehow, or become super efficient, or both.
Frani: These are huge decisions about California’s water future. How do feel like your work has helped shape perception?
Jay: Well that’s a good question. I need to think about that. I think the public writing I do tries to take that extra step. The things that I’m writing are based on the science and the observations that we make. So, for example my comment about chronic water scarcity. That comes directly from analyzing our data. It’s not an opinion; you can see it in the data. But getting people to understand that is very challenging. Even getting some of our water managers to understand it is quite challenging. We’re at a challenging time in water management in California and the west because we have these new tools and the new tools are showing us some things that we don’t want to hear. And anytime you tell somebody something they don’t want to hear, there are a number of different responses. Everything from...
Jay: Right. I don’t want to hear it. Exactly. Or the hell with you, get me my water. Or oh, my gosh, I need to be super efficient so we have water for our grandchildren.
Frani: Or some might say, If can pay for it why can’t I use more. I think there’s a perception when we say we’re in a drought that it sounds temporary and things will go back to a time with abundant water. But my understanding is that the west was settled in an unusually wet period and we’ve built our towns and industry around an abundant water supply that may not be there. How do you help people who think the water’s coming back when your data show that’s not true?
Jay: That’s right. And it’s not just our data. The data that we look at are satellite data that only goes back to the early 2000s. You can look at the paleo climate data and see that there’s been very long periods of drought and that California is basically a very dry place, especially the southern half of the state. So we have built up this huge infrastructure around the availability of water, and now it’s disappearing. It points to some really interesting questions and an interesting future for our state as the water supply continues to dwindle and the population continues to grow.
Frani: I think you’ve described California as “a dry place with periodic wetness.”
Jay: Right. That’s exactly right. It is a dry place that’s been punctuated by these wet periods. Unfortunately for humanity in the western part of the country, we settled in a relatively wet period. We built all these dams and filled up our reservoirs and many of those will never be able to be refilled, like Lake Mead, returned to its former glory. Probably not gonna happen.
Frani: Speaking of Lake Mead, I want to talk about the Colorado River. I think you did a piece a few years ago about the Colorado River basin?
Jay: The Colorado River basin, of course, is the water lifeline for all of the western United States. We’ve been doing these studies of the disappearance of groundwater around the world and a few years ago we decided, hey we live out west we should take a look at the Colorado River basin. In particular because we know that a lot of groundwater gets used and we know that a lot of it goes unreported.
We also know that our focus on water management has been on surface water and the public’s attention has been on surface water. So we look at Lake Mead and we see the decline of water levels and the bathtub ring growing and growing and that’s an important symbol for the drought. But we asked the question: how much groundwater is being used? Is it more? Is it less than the declines that we’re seeing in Lake Mead? We did a study on this a few years ago, and, lo and behold, it showed that groundwater was disappearing at a rate of 6 or 7 to 1 compared to the rates of disappearance of water in Lake Mead. So that’s a huge eye opener. There’s a lot of groundwater use that’s happening across the west. A lot of it goes unreported. A lot of it is not really included in basin protocols, in the agreements about water use. So the point of the paper was that the disappearance of groundwatermost of this groundwater is not coming back. It’s non-renewable. It’s like taking money out of a big retirement account. You’re not going to get it back, so you’re threatening the security of the whole region by not managing and not dealing with this disappearance of groundwater.
Frani: From what I understand you’re not yet able to assess how much water is underground or how much is seeping from reservoirs, for example?
Jay: So the thing about a lot of the hydrology and putting together a holistic picture is we don’t have a lot of measurements. Now with measurements of reservoir levels from the upcoming SWAT mission or measurements of soil moisture from the SMAP mission that was launched in the winter of 2015, we now have numbers that we can put together to quantitatively understand how much water is there and how it’s changing over time.
There are some things we still don’t know and we should be clear about that. One of the things that we’ve tried to communicate is that especially when it comes to groundwater with the GRACE mission we can understand how the groundwater storage is changing, but we don’t actually know how much water is in the ground. There’s no way around that. That has to be explored with deep wells. There may be some things we can do with isotopes and age-dating or both, but the fact remains that we’ve never really done that exploration of Earth’s water environment the way we have its energy environment meaning like oil reservoirs, for example.
Frani: Speaking of deep reservoirs. I read recently about the Stanford work. Is “fossil water” an appropriate thing to call that?
Jay: The Stanford study was good and bad. The good part of it is that it brought attention to the fact that we don’t know how much water we have and that in some of these lower-quality aquifers, water in these deeper aquifers is of lower quality. We may need that water someday and therefore we shouldn’t contaminate it with oil wastewater now. That’s a good point. If we start thinking out several decades, that water will probably be important to sustainability in California.
The downside of the study was the claim that we would triple the amount of available groundwaterno pun intendeddidn’t really “hold any water.” The definition of what is freshwater was quite generous and actually included saline and brackish and highly brackish water and they looked at depths in the subsurface that we don’t have the technology to drill or is too expensive to drill or pump the water outsomething like 3000 meters. We have no more water in the Central Valley today then we did before that study came out.
Frani: My understanding is they found that potentially there’s some volume of water at 3000 meters, but there's a few downsides, like it’s incredibly saline so you’re looking at desalination, which is expensive...
Jay: We know that that water is there. Those authors didn’t tell us anything we didn’t know. They’re from a different field. They’re my colleagues. They are not hydrologists or hydro geologists. They discovered things that the community already knowsthat there is brackish water and saline water at depth in any big sedimentary basin. This is no surprise. The water is largely unrecoverable today. Maybe 100 years from now or fifty years from now the technology may advance to the point where we can drill deeper wells more cheaply or the energy cost of pumping will drop or the price of water becomes so astronomical that now this makes sense to do. But there’s no surprise on the water. There’s no new information about water availability in the Central Valley from that study.
Frani: Okay I didn’t realize that you already knew it was there.
Jay: We knew. Of course, we knew. Yeah. Yeah.
Frani: The salinity is one issue. Another issue is that potentially it could get contaminated by oil and gas activities.
Jay: That is important. In the study they looked at some data on deeper aquifers. Many of these aquifers are being used for disposal of oil wastewater. So someday we may need that water. Look, it’s a problem. Certainly the oil industry has enough money to treat the water before it is injected back into aquifers. There’s a paradigm out there that, sure, you can use this water in industry, but when you return it to the environment it has to be at the same or better quality then when you pulled it out.
Frani: I think our listeners would be shocked to know that they’re even allowed to do that.
Jay: Well it’s crazy but they are. And it’s time for our thinking on how to dispose of or treat this water and return it back to the environment; it’s time for us to update that thinking. Especially now that we realize every drop is valuable, especially in places like California.
Frani: Isn't there also a risk that the ground will just sink?
Jay: Right. It's not everywhere. Subsidencethe sinking of the ground when groundwater is withdrawnis kinda like letting air out of a bicycle tire. In some places when you pull water out of the ground, the ground deflates. It’s very localized to places that have clay minerals in their aquifers. The reason is that clay minerals are flat, and when you remove water the clay minerals stack up like plates in a sink and the ground subsides because it takes up less space as you stack up those dishes, those stacks of clay minerals. It doesn’t happen all over the world, but it happens a fair amount in California. What do you need for subsidence? You need a high percentage of clay minerals and a high rate of pumping. We’re seeing most of the subsidence in the San Joaquin Valley. In fact the eastern half of the San Joaquin Valley is really at risk over the next century because there is so much clay in the section of the aquifer that's there. So we have to be really careful about pumping because of the subsidence.
Of course, what I didn’t mention is when there is infrastructure on top of the ground and the ground is sinking then that infrastructure is damaged. That could be a building, a road, a bridge, or our canals, which are directly impacted by subsidence. Could be a high-speed train line, which is right now mapped to go right though some of the areas with the most subsidence.
Frani: So what’s the takeaway for people living in California?
Jay: The drought may end, but we still are not going to have enough water to do all the things we want to do. The chronic water scarcity problem that we face here, it’s chronic; it’s persistent: it's not going away. We have to adapt because it is not going to change.
Frani: I think some people would look at the ocean as a solution. What are your thoughts on desal?
Jay: Many people do look at desalination as the solution. It’s a partial and limited solution in some places. It’s very expensive. It’s very energy intensive, so there’s a lot of greenhouse gas emissions associated with it, so the net benefit when you look at climate change versus the additional water it could be a wash. The process leaves behind very toxic brines that have to be disposed of. Throwing them back in the ocean is not the right way to go. We’ve been diluting them and throwing them back in the ocean. We will find over time and we do see in other parts of the world that do a lot of desal, that it’s killing the marine life. Some of that is tractable. We can probably find something to do about the brines. We can probably do some work on membranes and the energy side. It may be a while before it becomes a viable large-scale solution. All that said, it’s probably only going to be a good solution for municipal areas and for cities. Agriculture uses so much water that things like sewage recycling and desalination are not going to make a substantial contribution.
Frani: What answer is there for agriculture, then?
Jay: I think the only answer is efficiency. Correct crop choices. And it depends on how expensive it is to move water around. Will the Central Valley be operating at the scale that it is today fifty years from now? It depends on how much water is needed to grow which crops. We’ll have to wait and see what happens.
Frani: So we're talking about aquifer depletion, but not just California. Your report showed that this is happening worldwide.
Jay: It really is and this is something we don’t lead in in the United States. The greatest rates of groundwater depletion are in India. In China, in fact, there was just a report about subsidence around Beijing and the north China plain. The Middle East. Around Argentina a big aquifer there, it's called the Guarani aquifer. As Africa becomes more populated and more developed we will see more depletion of those aquifers as well.
Frani: This goes back to the water cycle because these mid-latitudes are drying out and getting less rain to replenish the groundwater but people are doing more pumping. It’s like a vicious cycle, right?
Jay: It really is. It’s what we call a positive feedback. It’s already dry and getting drier. And we’re using more groundwater and there’s less water available so we pump more groundwater. We use groundwater in these regions because they're arid; they were arid to begin with because of Earth’s atmospheric circulation. And because of climate change these places are getting drier. Yes, it’s a vicious cycle.
Frani: Where’s the water going if it’s not in the mid-latitudes?
Jay: When water leaves those mid-latitudes areas it goes somewhere else. The amount of water we have on the planet hasn’t changed; it’s moving from one place to another. So it is possible within a region to actually run out of water, but that water is moving somewhere else. So globally a lot of the water from the mid-latitudes ends up at higher latitudes or lower latitudes. So Arctic and the tropics. High latitudes and the low latitudes getting wetter.
That's another area where it's difficult to get the message out because now you're talking about a global phenomenon. But water is managed regionally and nationally. To whom are you speaking when you write a opinion piece on global groundwater? How do you get nations to collaborate?
Frani: Right. It’s a global issue. Is that what you mean when you call for a “One Water” approach?
Jay: When we talk about One Water it’s just really the idea that surface water and groundwater are not separate things. It’s unrealistic to think if you’re managing surface water and not groundwater that you’re having an impact on overall water availability. You’re not. That’s what that Colorado River basin paper showed. You can pay a lot of attention to managing surface water...but if you’re not paying attention to groundwater...What’s that expression? It’s like the fox guarding the hen house? That water is disappearing. People will take it because it’s unregulated.
Frani: What are the solutions then in your opinion?
Jay: We have to get engaged. We can’t stick our heads in the sand as much as we’d like to do that and as easy as that’s becoming with a big swatch of land areas getting drier. The first thing we need to do is raise awareness. It’s really important to understand that there are a couple of things conspiring against having an easy water future. They are climate change, population growth and the need to grow food. We can do all of that, or at least the food part more efficiently. Anything that we do to slow the rate of climate change is going to help the water cycle.
On a local basis we can impact our water supply. Many people ask the following question: Why should I do anything since agriculture uses 80% of the water supply? Why should I do anything? The reason is because many of our municipal water supplies are separate.
So we need to act locally. One of the biggest things that we can do as homeowners is kill the grass. Get rid of the lawn especially in the western United States. It’s basically where all the water use is. You can make that change and switch over to native landscaping. That’s huge.
Frani: As you said, people get frustrated about how much water agriculture uses, but the biggest crop in America is our cherished lawns.
Jay: Grass is far and away the biggest crop. And we should also remember that we all love to eat. It’s not us versus them...Darn that agriculture they use so much water...No. We can do the accounting. We know that it takes a lot of water to grow food. We also know that we want to eat today and tomorrow and a decade from now and a century from now. It’s in all our best interest to sustain agriculture for as long as we can, and part of that is sustaining the water supply.
The other thing we can do on a larger scale when we start to think about the state and the region and the country, is to start pressuring our elected officials to think about water. Ask them what their water platform is. That's really important. Would you want to elect a new senator here in California without understanding what that person's water platform is? Do they even have a water platform? We the people need to take some ownership of this problem and let our elected officials know it’s important to us.
Frani: So...are you optimistic?
Jay: Sometimes. Depends on the time of day and what I had for lunch. I’m optimistic that we have a tremendous amount of technology. The work that we do here at JPL has been a game changer. It really has. So I’m really optimistic about that. I’m optimistic about the young people that are studying environmental science and are doing hydro-geology and climate change and the young people that I work with here. That gives me a lot of hope.
We’re not going to change climate change. Climate change is happening. We have no choice but to manage our way through it. I’m very hopeful and quite optimistic that we can do a good job. It just might take a while. 💧