Q&A With Professor Famiglietti
As the head of the Hydrology and Climate Research Group at UC Irvine, James Famiglietti is an expert in the global water cycle change and freshwater availability according to measurements of groundwater depletion.
He is the director of the UC Center for Hydrologic Modeling at UC Irvine and the former director of the UC Irvine Branch of Institute of Geophysics and Planetary Physics.
In January, Famiglietti was named the Birdsall-Dreiss Distinguished Lecturer by the Geological Society of America for 2012.
When he is at UC Irvine, and not giving around 50 lectures throughout the US and abroad, he teaches in both the Earth System Science and Civil and Environmental Engineering departments.
Lauren Shepherd: Your research covers how hydrology interacts with the coupled earth system: can you explain those two terms?
James Famiglietti: In earth system science we have adopted the perspective that climate and the environment are actually driven by the interactions between the land and the ocean and the atmosphere. That’s kind of like the butterfly effect.
If you change something that is happening on the land surface, say you take the Central Valley and you change it from a beautiful wetland and floodplain into an agricultural region, what else have you affected? Have you affected the regional climate? The answer is yes.
LS: Can you give a more detailed description of what NASA’s Gravity Recovery and Climate Experiment, GRACE, does?
JF: So it’s a gravity mission. It is measuring earth’s gravity field. The gravity field, on long timescales doesn’t change. It’s controlled by where the mountains are, where the continents are versus the ocean, and ocean trenches and all the major tectonic and topographic features.
These are on long-time scales, but really on weekly, monthly timescales there’s a component of the gravity field that changes. And that’s the mass of water moving around the earth, all over, in the atmosphere, on and under the land surface as snow, rivers, groundwater pumping.
By moving water mass around you are changing the distribution of gravity, just a little bit. But the satellites are so sensitive that they can measure those very small changes in gravity that are due to the movement of water.
LS: I read that you addressed the House Committee on Science, Space and Technology, about the threat of drought to our nation’s food, health, economic and water security. What resources are you hoping for?
JF: The things that we need are better and more comprehensive observations. For example, we don’t measure the moisture in soils, and that’s something that’s really important for agriculture; because if you could measure moisture of the soil you can decide when to irrigate and how much, so we could be really using water more efficiently.
There’s the computer-modeling side: That’s why this center (UC Center for Hydrologic Modeling) exists. When you look at the various students in my group, that’s what they’re doing: one is working on rivers, one is working on lakes, one on water management, one on glaciers, groundwater.
For example, it is very difficult to predict with these models what is going to happen to glacial melt in the Himalayas, when there are no glaciers in the models. And it’s very difficult to predict how much groundwater will be in the Central Valley at the end of the century when there’s no aquifer’s in the models.
LS: In your most recent study, groundwater depletion, what have been the most surprising findings?
JF: I think some of the biggest — the most surprising stuff, and stuff that has gotten the most attention — is all the ground water depletion stuff.
Before the GRACE mission, we knew that there was groundwater depletion in the Central Valley, and we knew that there was groundwater depletion in China, and we even had some data to back up that it was happening in several places around the world.
But what the GRACE data has shown us is the fully global extent; that it is way bigger than we thought, that the actual rates of depletion are much bigger than we thought.
And the overall thing I like to say is that the human fingerprint on the water landscape — and that’s just a term I made up really, just to describe the global distribution of water — the human fingerprint is huge! We didn’t know that it was that bad.
LS: Can you elaborate on the strength of climate change?
JF: We’ve been looking at the water cycle and how it’s been increasing in strength, and by that I mean how precipitation has been increasing, how evaporation has been increasing and how river flows have been increasing.
One of the things that’s been happening is that more water is moving from the ocean to the land and back from the land to the ocean, every year. There has been a lot more ocean evaporation, which transports more water vapor to the land, where it rains out, and flows back into the ocean. That’s our basic water cycle but, well, we’re seeing that more is moving through it every year.
More water moving back and forth, and up and down translates into more rain and more flooding; and more evaporation, which means more drought.
LS: I’ve read that GRACE data may be a new method that could dramatically improve flood prediction times. How can you have the drought and floods in the same regions?
JF: More drought and flooding will be our future. We’ve seen it here in the United States this year.
First we have mega drought; all anyone was talking about last year was the drought, and now, bang, a monster hurricane, Sandy, which some people say is the biggest one ever to hit the United States.
I think that the likelihood is that we will be seeing more of that in the future. Time will tell — you can never tell with any individual event whether it was due to climate change — but, when you look over the whole time period, and see the increase in frequency and intensity, like we are seeing in our data, then you could say “Sure, without climate change, that wasn’t going to happen.”
LS: How can we adapt to the changing climate, can you talk about hydrology-driven food and energy issues?
JF: I think that a lot can be done. I think that we’re addicted to water, so we have to realize that there is some kind of addiction. It’s unsustainable, we’ll use it all, in places like California for sure.
The first thing is coming to terms, understanding the problem and understanding where it comes from. If you understand that the water in a particular aquifer is finite, then you may start to use it a bit more carefully.
Another thing to understand is that the biggest uses of water — outside the domestic use and municipalities is agriculture.
We absolutely have to focus — 80 percent of the water that’s used all over the world is for agriculture. We could be so much more efficient when it comes to that part. Whether it’s drip irrigation or better water pricing so people use it more carefully. Better crop choices, so crops can withstand drought.
In the home, the biggest use is actually outside; it’s for the landscape. We have to make that switch.
Second of all, psychologically, we have to get rid of the idea that grass, unless it is a grass that doesn’t need water, that manicured English garden look, all over the United States.
We have to move to native planting, and cutting the water use outside the home, because that is 50 to 75 percent of it.
A lot of people don’t realize this: saving energy saves water. So if you are doing things like turning off your appliances, and unplugging your computer, using less heat, that also saves a lot of water, because it takes a lot of water to make energy.
And visa versa, if you use less water, you use less energy. About 25 percent of our energy budget, at least in the United States, is used to heat, treat and transport.
So just turning on the faucet, if you don’t need it becomes a waste, and it’s more than just the water wasted, it’s the energy wasted.
I think we can educate people about this stuff. People want the best, they really do, and they certainly want the best for their kids. If we start adopting that mindset, I think we will be in much better shape.
LS: Do you find today’s student youth to be a useful voice to teach this mindset?
JF: It’s all about the future. Sustainability is really always about the next generation. It’s really, really important to engage young people. And I am so excited to have so many new students coming in, really wanting to make a difference.
It’s a stark contrast to a couple of decades ago, when students didn’t really care much about environmental change. They were much more interested in writing a very hard to understand technical paper, or solving some new equation.
Now it’s different, students come in and they don’t say that. They say, ‘I want to make a difference,’ and ‘I want to do something that can impact policy.’ And there is a lot of that in the next generation: they are driven to make the world a better place.
LS: Why do you feel the need to continue to research the issue of sustainability?
JF: There’s things that I want to accomplish, personal research goals that I hope to achieve because I know that they are important to the field. And I feel it’s in our wheelhouse in our group to get that stuff done.
But I think the biggest chunk is passing on that sense of reasonability and stewardship: training students to understand what’s important, to be environmental stewards and to be teachers themselves. So we really want this to pass this on so that it persists for a long time.