As Carbon Emissions Rise, Rice Nutrition Falls

Published Dec 17, 2019

Former USDA senior scientist Lewis Ziska discusses his research on rice and carbon dioxide—and how the Trump USDA suppressed his findings.

In this episode
  • Lew tells the story of how his research was sidelined under an anti-science administration
  • We learn about yet another thing being hurt by climate change: rice
  • At the end of the episode we announce UCS' 2019 Science Defenders
Timing and cues
  • Opener (0:00-0:40)
  • Intro (0:40-2:59)
  • Interview part 1(2:59-12:04)
  • Break (12:04-13:08)
  • Interview part 2 (13:08-24:11)
  • Science FTW throw (24:11-24:16)
  • Science FTW (24:16-27:58)
  • Outro (27:58-28:59)
Related content
Show credits

Science FTW: Cynthia DeRocco
Editing and Music: Brian Middleton
Research and writing: Jiayu Liang and Pamela Worth
Executive producer: Rich Hayes
Host: Colleen MacDonald

Full transcript

When we talk about the impacts of climate change, we usually focus on sea level rise and killer heat... not rice. To me, rice is more of a compliment to the main course... it doesn’t have a starring role. But for others, it means a lot more. Across the world, rice is the most widely consumed staple food and makes up a fifth of all calories consumed. So if climate change poses a threat to rice... we should be prepared for that.

This is why I’m grateful there are climate scientists like Dr. Lewis Ziska. He’s a plant physiologist who’s spent over two decades researching everything from food crops to the pollen in flowers to noxious weeds to understanding how plants are affected by rising temperatures and carbon dioxide levels. And when he turned his attention to rice nutrition, he discovered something astounding. As carbon dioxide levels rise, the nutritional value of rice goes down. Since there are over 600 million people in the world who rely on rice for the majority of their calories, Lew realized this was a very important finding. But he had the misfortune of doing this research at the USDA... under an administration that questions climate science at every turn. He went through all the proper procedures for sharing his findings. The science was vetted and reviewed vigorously, as all scientific papers are. But the day before publication, his superiors at the USDA, wrote that the data didn’t support the findings... despite having originally approved it. And when Lew offered to meet with them to discuss their concerns... he was ignored.

The pattern continued. The department tried to minimize media coverage by refusing to write press releases and rejecting reporters who wanted an interview. In protest over these attempts to bury his groundbreaking research, Lew resigned. But that doesn’t change the fact that Lew was researching something important. So I sat down with him to talk about how he did this research, what his team discovered, and what’s going to happen to Lew’s research now that he’s left the USDA.

Colleen: Lew, welcome to the podcast.

Lew: Thank you.

Colleen: So, tell me a little bit about the trajectory of your career and how you went through the USDA and landed here at Columbia?

Lew: When I finished getting my doctorate in plant physiology from the University of California, Davis, my wife was starting her doctoral program in music at the University of Maryland. And I was fortunate enough to get a Smithsonian fellowship. And during that fellowship, they were working with carbon dioxide effects on marsh grasses. I found it was really fascinating. And I also thought, "Hey, here's a way that I can make a difference." So following that, I continued to work on grasses, in this case, rice with a second postdoc between the University of Maryland and Duke University. And really interesting in terms of how rice was responding to climate but also to ozone depletion, ultraviolet radiation. And then that segued to getting a position in the Philippines and then eventually that segued into getting a position at USDA. And to quote Jerry Garcia, "It's a long, strange trip."

Colleen: So when you first started working with marsh grass and CO2, was there a climate connection, a strong climate connection?

Lew: We at that time...this was back in the late '80s, early '90s, we really thought that, yes, there was a climate issue. But it was a climate issue that we thought would happen for our grandchildren. We anticipated that it would be at least 50 to 100 years before we'd start to see any distinction in regard to what climate might be doing for marsh grasses. But we knew that they were responding to carbon dioxide and that that response was gonna be short term. So we could look at that and get a sense of how they were doing. So it's been interesting just, you know, in my own career to see how much that has shifted from, 50 to 100 years to now, and having to address some of those immediate issues.

Colleen: You thought you had all the time in the world back then. And now things have accelerated.

Lew: We were very conservative in our outlook. And I understand why we were because when you project something, you can only project as far as the most conservative person in your group. And I think that we need to go back and look at that and make a more accurate assessment, given what we've seen so far.

Colleen: So Lew, tell me about the work that you were doing at the USDA.

Lew: We were looking at a number of things. One of the primary research objectives was to try and understand how the increase in carbon dioxide was going to affect rice nutrition. So specifically, how it was going to affect protein, how it was going to affect minerals, how it was going to affect vitamins. And we had...we no longer do, but we had the facilities at the time to do carbon dioxide levels in the past. So if I wanted to see how the recent change in carbon dioxide had affected rice nutrition, I could do that. So that was one aspect. Another aspect that we were able to do was to look at not just rice, but also flowers. Why would we look at flowers? Well, because the pollen in those flowers is going to be affected by rising carbon dioxide.

So we worked with an entomologist at Harvard, who came down, we set up field plots to do high CO2 to see what effect that had in terms of flowering times, number of flowers, quality of the flowers, and what effect that had on bee health and bee survival. So bees are obviously an important pollinator in agriculture. And we wanted to understand what was happening with that. We wanted to do some work in terms of arsenic. Why arsenic? Well, if you get more flooding, what happens is the soil becomes...has less oxygen in it. And because it has less oxygen, it changes the amount of arsenic that's available. Why is that a concern? Well, because rice can take up arsenic. So is there a link between climate change and increased arsenic uptake in rice? That would also seem to be important from a qualitative point of view. There are all these different burning questions. There is no shortage of challenges and questions to begin to investigate.

Colleen: How do you actually set up these experiments? You said you had a plot. Where is this happening?

Lew: At the Beltsville location, which is the largest by area and by personnel location of USDA Agricultural Research Service in the United States. It's right outside of Washington, DC, because back in the day, if Congress had a problem with agriculture, which they often did, because we were very much an agrarian society, they went to Beltsville and said, "Hey, we're seeing this disease. We're seeing this pest. We're seeing this. Can you help us?" And they would do their work there. And they, because of their proximity, were able to convey that work to the folks in the capital.

Colleen: So they actually try to reproduce what was happening?

Lew: They do, and the interesting thing about that location is that it's still there. It's still many thousands of acres, little bits and pieces have been chipped off. The National Security Administration is chipped off from agriculture. And it's slowly being whittled away. But that location had more soil types than any other location I know. Many different resources there that they could do in terms of setting up the kind of field work that needed to be set up. And because of their proximity, I think they were, you know, able to...

Colleen: So is that where you actually set up your rice study? Were you growing rice there and?

Lew: Let me back up a step. The bee study, the floral study, we did directly there. The studies where we wanted to look at the recent change in carbon dioxide...I'm gonna be a little wonky here. So bear with me. It's easy to add CO2 to the air, you and I sitting here breathing are adding CO2 to this room. It's a pain in the butt to have to remove it, to scrub carbon dioxide out of the room takes a lot of effort and a lot of energy to do that. We had that facility at Beltsville, so we had walk-in chambers, where we could actually remove the carbon dioxide and set it to look at 1960. Here was the CO2 in 1960. Here's what it is today. Are we seeing a change in rice? And if so, what does that mean for the protein levels of rice?

Colleen: That's pretty cool.

Lew: Yeah, I'm a nerd. So I thought it was really cool. So we could do stuff there that we couldn't do anywhere else. We were looking at the bees, we were looking at rice. Another thing we were looking at are what are called invasive weeds, weeds like kudzu, if you're from the south, you are probably very familiar with kudzu does. The joke is that if you left your dog on the doorstep, it would be gone in the morning. Kudzu is this wonderful invasive vine that, you know, grows everywhere and over everything. There's another invasive vine. Oh, no I'm sorry, it's an invasive...not a vine, but it's an invasive plant that's causing huge problems globally, parthenium, and we wanted to understand how the changes in CO2 and other things are going to affect parthenium. So we had three or four things that were, you know, trying to get done. Both from a positive aspect of how can we increase production? How can we make rice and wheat more resilient? And at the same time try and understand what the threats are.

Colleen: How did you were also growing rice in China and in Japan?

Lew: Yes.

Colleen: Were there similar facilities to do that, or?

Lew: Well, those were done looking at projected changes. And so as I said, it's much easier to add CO2 than it is to subtract it. So in those instances, we used a methodology, and I'm gonna get wonky here again, called FACE, and FACE is Free-Air CO2 Enrichment, where you plant a ring of tubing around the field, and the ring is shooting carbon dioxide into the middle of the field and you have all kinds of sophisticated control. So if the wind is coming from the west, that means you may have to, you know, change the CO2 coming from the east and dot, dot, dot, dot, dot. But the idea is to maintain the carbon dioxide in the middle of the field. Now, there are issues with this, you're changing CO2, sometimes very rapidly. And that may not simulate, you know, a real life situation. But, you know, it's close to, "reality" as we can get, although I would argue that if you wanted to look at the recent change, and kind of get a sense of how yields and quality of change, that may be another way to do it.


Colleen: So Lew, going back to your rice study, you did the research, it was reviewed internally at the USDA, then it was peer-reviewed by external scientists. Then what happened.

Lew: And then the study gets published. And a day before it's ready to be published, I get an e-mail. "Oh, the data don't support your findings." "What? Seriously?" The e-mail comes from the national program staff, the same program staff that had originally approved this manuscript before it was sent out. And now they disapprove it? No.

Colleen: So it's already been approved?

Lew: It's already been approved. It's already gone through peer review. It's just about ready to be published. We did get a inquiry from the editor saying, "We want to publicize this," which, cool, "All right, you wanna publicize it great." So they asked us, you know, "Go to your communication staff and have them do a press release." So we did that. And that's when we got the feedback from the communication staff saying, "Oh no, the National Program staff says this is no good. We're not gonna do a press release. Oh, and by the way, we're gonna call up the other people and tell them not to do a press release either." Now, at this point, you've crossed the line. And at that point, I realized I can't stay here. Whatever God has given me in terms of my own talent. I don't have an opportunity to use that as a means of making a difference in this situation. I need to get out.

Colleen: But they've also attacked your work that you've done.

Lew: Yes.

Colleen: So there, it's a credibility issue, as well.

Lew: It is a credibility issue. If they attack my work under this circumstance, what other circumstances are they going to knock my work? The people that were saying that the data don't support the findings are not people that do climate change, work? And so to me...

Colleen: Are they scientists at all?

Lew: They are scientists. But this is not their area. And I was stunned by getting this feedback, so I, you know, "Hey, can we meet? Can we talk? No, nothing ever happened. So I was like, "Okay, this is the proverbial straw. I can't stay here anymore. I've got to find something else to do." And it was clear that in this administration, that anything related to climate change was not gonna be supported. And I'm very, very, very, add many more very's, fortunate to have found a place here at Columbia, where I can continue this work. Not only can I continue this work, but I can actually branch out and start looking at other aspects of food security and climate change, everything from after the plants are harvested and the temperatures are going up. What does it mean for food safety? What does it mean for food distribution? What does it mean for food nutrition? All of these are fundamental aspects of where, and how, and the quality, of the foods that you eat that need to be addressed, that need to be addressed.

Colleen: So what is happening to the rice crops that you have growing in China and Japan?

Lew: They're still ongoing. I'm scheduled go to China in a couple of weeks. And we're sort of doing the next analysis which is to look not only at carbon dioxide but also to look at rising temperatures. And to determine, okay, if CO2 is plant conservatives like to say, and it's true, it is plant food...then how does the combination of temperature and carbon dioxide mean in terms of yield, production for rice? And so we wanna work on that. And we have some initial data from my Chinese colleague, and we wanna, you know, build on that and get a further assessment.

We wanna do more, we're actually trying to look's easy to do, you know, models, and say, "Oh, our models are doing blah, blah, blah." Let's look at the past. Because remember, carbon dioxide is already gone up by between 25% and 30%. So if I look back 30 years or 40 years to yields of rice, would I see a change that's already happened? And if I do see a change, which varieties are showing that change? Can I learn from those? Can I breed for those that have certain characteristics that can then take some of this additional CO2 and increase yields? Many opportunities to do this, and I'm looking forward to it. And at the same time, I'm sad because the agency that I worked for for over 20 years, is not doing, what should be obvious. They're not doing it because of a political decision, not a scientific one.

Colleen: So what's happening with your research there now that you've left?

Lew: I still have a little bit of it going on. I still have some friends who are interested in making sure that the work that was begun will continue. I won't name their names. So we should probably finish that up in the next six months to a year. And then we're done. I mean, it's whenever you leave a place, as I'm sure you know, you don't just sever everything cleanly, there's gonna be some overlap. And so some of the work that we want to continue to do related specifically to nutrition and the rise in carbon dioxide and the observation so far that as CO2 is rapidly building up as the atmosphere is becoming carbon rich, the soil isn't keeping up. So many plants are becoming carbon-rich and nutrient-poor.

That has some major implications not just for nutrition, as you might imagine, but also for things like plant-based medicines. Other materials that you get for plants. What does it do to cotton in terms of the quality of the cotton you get as CO2 rises? What does it do for the quality of the wood that you use for your house as CO2 rises? What does it do for pollen in terms of your allergies? All of these are major issues that need to be addressed, that aren't being addressed. And so I'm hoping, in a small way here at Columbia, that I can start to do some of that and to really get folks interested in it from the public health point of view. And so it's not a...nothing against polar bears. Seeing those pictures of polar bears, you know, clinging to an iceberg, is a way of communicating the urgency of climate change. But sometimes the human race is very selfish, and the best way to communicate it to them is saying, "Here's how it can affect your health. Here's how it can affect your allergies. Here's how it can affect your nutrition. Here's how it can affect your medicine." If you do that, then people will pay attention because they have skin in the game.

Colleen: So the work that you're doing at the USDA, how critical is that for farmers in terms of their every day or every crop cycle,?

Lew: If you're talking short term versus long term? What we would argue is that ways to adapt to climate, it does have some very strong relevance and with long term issues. So we did some work looking at a trans sec and rice growth from Lewisiana up to Missouri, showing that as the temperatures rise, when or approximately what date will farmers be able to retune rice at x, y and z locations along this north-south transect? And we, you know, see that there are opportunities that may arise by 2025 for say the middle of Arkansas to begin retuning as a normal basis for their growth.

Colleen: Which is sort of like a bumper crop.

Lew: It's a bumper crop.

Colleen: More or less...

Lew: It's not a double crop. It's just simply, you know, getting 50% more yield by having another month or two of growing season. So, you know, the work we're doing on breeding, trying to identify different varieties of rice or different varieties of wheat or soybean that can convert more of this carbon dioxide into yield. And what does that mean for the quality of what you're getting? What's happening in terms of chemical control of your weeds? Big issue right now, because we've overused glyphosate so much that we have over 100 different weed species that are resistant to it.

We found that as you increase temperatures, that has an effect in terms of pest demographics, the warmer it gets, the more pests you have. I know that seems very simple, but it's really true. And so frost freezing is a way of keeping your pests slowed down. And so when you exceed freezing, you're gonna get a lot more pests. Well, what do you do if you're a farmer? Chances are you're not gonna be out there on your hands and knees pulling out weeds. You're gonna spray more. "Well, if I spray more, what's the chance that whatever I'm spraying will start to induce resistance in whatever it's being sprayed on?" That's another thing for companies to take into consideration. They're all these different aspects that come in as part of climate and food security that again need to be recognized, from the yields that you get to the pests that you have to deal with to the quality of the food and so forth and so on.

Colleen: How do farmers get that information? I mean, are farmers actively looking or coming to the USDA? Or how does it work?

Lew: To some extent they are, and the extension service through USDA and some of the climate hubs that are still, as far as I know, in place, if they have a question, they go to there and say, "Hey, what are we doing?" So my favorite story is one that was relayed to me about a phone interview that was done an Iowa for farmers. And so I think it was Iowa State, the professor called up the farmer and said, "Are you seeing more extreme weather events in the springtime when you plant?" "Oh, yeah, no, we're seeing that. We've got a 30-row planter now instead of a 10-row planter." "Okay. Are you seeing new pests and diseases that you haven't seen before?" "Oh, yeah, no, we've got this and we've got that and I'm seeing this resistance and..." "Okay. Are you putting in anything for infrastructure for because of these extreme events?" "Oh, yeah. I'm putting in tile drains, I'm putting in..." "Is it climate change?" "Oh, no, that's Al Gore."

So...they know, they recognize, and I think more and more they recognize that this is not a hoax. This is something that's real and it's having an effect on their bottom line. Let USDA help. Let Columbia help, let Bill Gates help. Let's put our resources together to begin to address these challenges. It's not a one person's gonna solve the problem. It's many of us working together are gonna solve the problem. But I do think it's solvable.

Colleen: Lew, that's a great positive note to end on.

Lew: Okay.

Colleen: Thanks so much for joining me.

Lew: You're welcome.

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