Media Briefings

Climate change impacts on U.S. agriculture

Journalists: Get Email Updates

What are Media Briefings?

U.S. agriculture is under stress because of climate change. Farmers are facing drought, rangeland wildfires, and shifting distributions of pests and diseases that are impacting crops and livestock, while fisheries are being affected by warming waters. On Monday, May 23rd, 2022, a panel of scientists described how climate change is affecting crop, livestock, and fishery operations in different regions of the country. They also discussed new approaches to help farmers predict and adapt to future change. These three experts made brief presentations and then took reporter questions on the record.

Journalists: video free for use in your stories

High definition (mp4, 1920x1080)




RICK WEISS: Hello, everyone, and welcome to SciLine’s media briefing on climate change impacts on U.S. agriculture, a topic that is only going to get bigger in the news as this year’s and future growing seasons progress with, I think, countless social and economic and political implications. I’m SciLine’s director, Rick Weiss. And for those not familiar with us, SciLine is a philanthropically funded, editorially independent free service for journalists and scientists based at the nonprofit American Association for the Advancement of Science. Our mission is pretty straightforward. It’s just to make it easier for reporters like you to get more scientifically validated evidence into your news stories. And that means not just stories about science but any story that can be strengthened with a dose of science, which means just about any story you can think of. Among other things, we offer a free matching service that helps connect you to scientists who are both deeply knowledgeable in their field and are excellent communicators. We do that on deadline as needed. Just go to and click on I need an expert. And while you’re there, check out our other helpful reporting resources, including a recently updated, very concise fact sheet on attribution science and how to report on the contribution of climate change to extreme weather events. Probably useful for this crowd.

A couple of quick logistical details before we start. We have three panelists who will make short presentations of up to 7 minutes each before we open things up for Q&A. To enter a question during or after their presentations, just hover over the bottom of the Zoom window, select Q&A, enter your name, news outlet and your question. If you want to pose your question to a specific panelist, be sure to note that. A full video of this briefing should be available on our website, probably by tomorrow, and a timestamped transcript soon after that. If you would like a raw copy of the recording more immediately, please just submit a request with your name and email in the Q&A box, and we can send you a link to the video by the end of the day today. You can also use the Q&A box to alert SciLine staff of any technical difficulties.

I’m not going to give full introductions to our three speakers today. Their bios are on the SciLine website. I’ll just say that we will hear first from Dr. Cynthia Rosenzweig, who­—among other positions­—is the senior research scientist leading the climate impact group at the NASA Goddard Institute for Space Studies and who, for us, will focus on the impact of climate change on crops. Next, we’ll hear from Dr. Mario Herrero, a professor of sustainable food systems and global change at Cornell University and a Cornell Atkinson scholar who will focus on the impact of climate change on livestock. And third, we’ll hear from Dr. Abby Lynch, research fish biologist with the U.S. Geological Survey’s National Climate Adaptation Science Center, who’s going to focus on the impacts of climate change on inland fisheries. OK. So, let’s get started with crops. And over to you, Dr. Rosenzweig.

Impacts of climate change on crops


CYNTHIA ROSENZWEIG: Thank you, Rick. I’m going to share my screen. It should be here. And making it big. There we are. Good afternoon. It’s great to be here to be sharing some of the key processes and finding out what’s up on impacts of climate change on crops. I’m speaking as one of the co-leaders of a big network of researchers who work on climate change and crops from the AgMIP Project, which stands for the Agricultural Model Intercomparison and Improvement Project. Now, you’re all good reporters. What’s the first question you’re going to ask? What’s a model? So, the models that I’m going to be sharing that­—the results that I’m going to be sharing are the kind of models that AgMIP uses a lot­—are mathematical representations of a system of agricultural processes. So, why is that­—why are these models helpful in understanding what’s up with climate change and agriculture? And they’re helpful because they’re­—when we think about climate change and increasing CO2 and other greenhouse gases and the effects on crops, there are some things that are possible benefits, while at the same time, there are possible drawbacks. And of course, these vary depending on which agricultural region you’re in. But just very briefly, we need models that include high CO2­—high carbon dioxide­—because high carbon dioxide increases photosynthesis and improves water use efficiency in crops. Warmer temperatures­—it used to be called global warming, you may recall. But warmer temperatures have longer growing season. And some places can’t grow crops because it’s just not­—the growing season isn’t long enough. In some places, the climate model projections­—the projections of climate change are showing increased precipitation. And in drier areas, this can be helpful. But at the same time, with climate change, there are possible drawbacks. Potential in some regions for more frequent droughts, increased pest infestations, heat stress during critical growth stages such as pollination. And here is one of­—a key one which we calling­—sometimes we call this the galloping growing periods because high temperatures speed crops, annual crops, through their growth stages, especially their grain-filling period. So, if it’s a shorter period, they’re not able to make as much grain. This is a big downward pressure of climate change on crops. And then, of course, in this­—in areas near the coast, increased flooding and salinization. Have to add one more possible drawback which has been coming to the fore lately, that high CO2­—crops grown in high CO2 actually can reduce the protein and micronutrient content in crops. So, that high CO2 is not all good. So, what we do is utilize­—develop and utilize models that take these key processes into account.

So, we have root development and canopy development. It’s­—actually, what these models do is they actually grow the crop in the computer with the mathematical representations going all the way through the crop’s life cycle to produce grain yield through biomass, grain number, grain size protein. The inputs are weather variables, temperature­—min and max temperature every day, solar radiation every day and the carbon dioxide concentration­—which, as we know, is going up­—the soil properties and initial conditions of how much water is in the soil, what are the crops like? What crop is it, and what are the varieties like? For example, how many hours of warm temperature does it need­—does a crop­—a variety need to create the grain that is that ultimate yield? And then, of course, management because no farmer is sitting there and not managing their crops. So, things like water­—irrigation, fertilizer are all inputs into the crops grown in the computer. So, to give some examples, first on the climate side, the map on the left from the National Climate Assessment is showing projected change in number of consecutive dry days. This is at the end of the century. These are­—this is actually climate change projections but so, so important for agriculture. The browner areas are areas that are having longer dry periods. Not good for crops. So, you can see many of the U.S. agricultural regions are in places where it’s projected to get drier as the climate change plays out through the coming decades. Then here’s some examples from crop yield response to warming in­—just in one of the regions, California­—a very important region, California’s Central Valley. On the­—all the left-hand axis are the percent changes, and the bottom, the x-axis, is from current times to 2100. I’ll just­—I won’t go through them all, but you can see that the climate change is affecting different crops differently. And just calling out, too, that are in particular looking quite dire in regard to the projections are cotton and sunflower. By the way, the red line is for a higher greenhouse gas emissions scenario, and the brown line is lower greenhouse gases as we march into the future. Wheat and rice also are­—and tomato­—these are some very, very key California crops­—are projected to have reduced yields in the coming decades due to climate change.

Now, it’s important in the U.S.­—not only what happens in the U.S., of course, for our farmers but also for the world. So, we­—AgMIP does projections for the world, as well. And here, the colors are showing yield changes. The yellows and the oranges and the reds are decreases up to 50%. There are some places in high latitudes where it’s cold already. Remember, we said there’s some benefits. That’s what the blue areas are. But when we look­—and let’s just take wheat. When we see the red colors, where are they located? These are projections in decrease in yields. And they’re­—they tend to be in the lower latitudes. And these lower latitudes are where developing countries are. So, as we look beyond the United States, we see great vulnerability in the developing world from climate change, as well. So­—but we don’t­—also the­—our scientists in AgMIP and at­—all the great work being done in this area, we don’t just focus on the impacts. We’ve­—we work and we use the models to look at response options, as well. We have to solve climate change, not just learn about it. And the green stars­—here are some things that can be done in terms of solutions. Green stars are positive adaptation benefits. This is worldwide. This work was done by the IPCC­—Intergovernmental Panel on Climate Change. This is­—that have benefits to over 25 million people and­—for food security. This is really so that the food­—so food security is­—the food systems can be resilient to climate change so that food security can be really ensured for all the people in the world. That’s what the green stars are showing, which ones help especially with that. But at the same time, agriculture is also a big source of greenhouse gas emissions. And we can also combine practices to what we call­—to have what we call mitigation potential, reduction in greenhouse gases of more than 3 gigatons, which is a lot of CO2. So­—and other greenhouse gases.

So, increased food productivity clearly helps with food security. But at the same time, if we’re doing a better job growing crops where we’re growing them, we don’t have to do a deforestation, which helps to save the carbon in the trees. Agroforestry, same. Agroforestry can help to store carbon in croplands. Improved cropland management, water management, doing a better job, growing the crops that we would­—and we really know how to do this very well. The farmers around the world do, too. Diversifying­—so if one crop is­—or one variety­—very vulnerable to climate change, let’s plant a mix of crops. That’s shown to help with resilience. Increasing soil organic carbon content, which is bringing the soil­—the carbon down from the atmosphere into the soil, replacing the soil­—that carbon content is­—in some areas, in some settings can really help both on the adaptation and on the mitigation side and reducing soil erosion. And with that, I’m looking forward to hearing my colleagues talk about livestock­—Mario about livestock, and Abigail about fish. Thank you. Looking forward to the questions.


RICK WEISS: Fantastic, Cynthia. Thank you so much. Over to you, Dr. Mario Herrero on livestock.

Impacts of climate change on livestock


MARIO HERRERO: That’s great. Thank you very much. Yeah. So, I will talk to you about the impacts of climate change on livestock. Next slide, please. Yeah, when you think about the impacts of climate change on livestock, the first thing that you think about is, well, there’s going to be a reduction in milk production or in meat production. But what I want to tell you is that the situation is a little bit more complex. What you see here is the kind of exposures to climate change that the whole supply chain of livestock has from the resources that we have to the production, to processing, storage, transport and retailing and consumption. So, if you look at all these effects, we have, for example, very important changes in feeds, which is probably what has been estimated most of the times. You know, feed quantity and quality is likely to reduce, as well as water quantity and quality. But on the other side, we also have that pests and pathogens are changing their distribution. So, for example, what we see is that in some places that did not have ticks, now as they get warmer, they start having ticks, and that creates impacts of additional diseases that farmers had never been exposed to having to deal with. The same on the labor side­—you know, climate change has changed all the labor dynamics, and in many places, you find less laborers. There’s a lot of heat stress. There’s a lot of issues happening also as pests and pathogens have changed­—people getting sick of different things.

So, in terms of resources, the whole agenda is changing, and the problem is exacerbated in the places that have had the greatest increases in living conditions. Where things that were once cooler, now you end up having a lot more warmer days, we see a significant impact. But these resources­—you know, there’s a whole cascade, and animal health and production also suffer. We’ve estimated recently that, you know, animal production revenues and costs have actually changed significantly and are projected to also change very significantly due to increases in the heat stress of the animals. So, on one hand, you could end up with less feed, but on the other hand, just, you know, as we get hot, as we humans get hot, animals­—cows, chickens and pigs­—also get hot. And their immediate response to dissipate the heat is to stop eating. It’s to stop eating because they cannot get rid of the heat produced by eating the food. So, that’s the main reason why they end up not producing enough. And what happens is that with less animal production­—what happens is that, you know, lots of people want livestock products, so there is an enormous demand. And as we change the supply­—as supply shifts due to climate change, then the result is that you end up with increased prices for the products. And this affects primarily vulnerable communities that will­—the poorer of people in society. This is a very, very important issue.

For processing, storage, transport and retailing, the same occurs. You know, it’s greater costs. Greater costs of what?­—of refrigeration, greater costs of spoilage. The cold chains end up not working as well. And this creates a real infrastructural challenge in many places, and notably in the U.S. You know, the increase­—the hotter summers, etc. will lead to very, very important changes in the way in which we can keep these livestock products. So, in terms of consumption, as I said, this leads to lower quantities, in some cases, changes in the nutritional quality. As Cynthia mentioned, you know, increased CO2 can change the nutritional quality of plants. Well, the same happens through feed in terms of the nutritional quality of the animal products. Safety changes because increases in­—you know, in diseases of trade and food safety also change the prices and the social acceptability. Next slide, please. You know, believe it or not, we’ve been very, very good­—and only recently­—at really putting a spin on climate change, on the feed side of things. We know that a third of the crop production in the world is used for feeding animals, and this is likely to increase to about 50% by 2050 because the demand for livestock products is increasing significantly. So, it is very important for us also to keep monitoring the effects of climate change on crop production because if this declines in the amounts or if it gets really expensive to have access to crop production as feed, we’ll end up with­—well, with increased costs or a reduced supply of animal products.

As Cynthia mentioned, these impacts are significant in the U.S. but also in the lower latitudes in low- and middle-income countries. And why is this important? Because, you know, trading feed is probably one of the biggest issues that will get affected by climate change. And here, the U.S. that has been typically an exporter will probably be able to increase exports of feed to other places, just like some places like Argentina and so on, places that perhaps because the climate­—the northern latitudes getting warmer will present opportunities for increasing the productivity of the crops, will create probably slight surpluses. That will actually help provide more feed for livestock in the future. So, that would be an economic benefit from the perspective of the United States. And this matters a lot for maize and soy, which are two of the key feeds for livestock production. Next slide, please. On the other hand, we also know that the climate change­—the impacts of climate change will also occur in rangelands. And in this case, if you look at the U.S., if you look­—if I were to give you an average of that map of what happens in the U.S., you­—we will end up­—this is primary productivity. This is a map of primary productivity. So, you will get increases in primary productivity in some parts of the U.S. but decreases in the Eastern Great Plains. But all in all, the effect is a positive one, a slightly positive one. So, from a rangeland perspective, we will not get a very­—a real impact on climate change in total. So, animals that aren’t grazing will actually not suffer as much as possible. But just look at what happens in many parts of sub-Saharan Africa, for example. This is where the highest population growth is going to occur, and this is where the demand of livestock­—for livestock products will be enormous.

So, you know, there will be significant deficits in production here. And this, combined with the lack of adaptation potential, will probably lead to, again, an enormous amount of additional trade occurring in terms of livestock products from regions that can maintain the surpluses and so on. Next slide, please. And, you know, very recently we developed these maps­—sorry­—these tables on the direct impacts of climate change on livestock production. And here I put for dairy three countries­—India, the USA and China­—just for you to have an idea of what may happen in different types of livestock systems, whether those­—some that are grazing or some that are in mixed systems under stall-fed conditions and then a weighted total that will give us the percentage reduction for the whole country. What you see here is that, for dairy, we’re talking about a 2.7% decrease in the production of livestock. And for beef, similarly, I make a comparison here with Brazil. We’re talking about a 7%. So, the impacts on the beef sector are going to be probably twice as they are in dairy. Why? Well, primarily because beef is­—beef occurs in places that are going to feel higher temperatures. And you can see here that­—and they will be grazing most of the time in comparison to the dairy animals that, in many cases, are totally confined, and so on. Now, you’d think that these are small numbers, but in reality, when you consider that the value of production of the livestock industry in the U.S. is around $140 billion, you are talking here of losses close to­—what is it?­—3­—between 3 and $10 billion per year. So, it’s not insignificant at all what we are talking about here. Next slide, please.


RICK WEISS: Mario, I’m just going to ask you to try to wrap up. We’re over time, so if you could just quick wrap up on your last slide, and we’ll move on.


MARIO HERRERO: Yes, exactly. And here, well, you know, here we have­—there are many options to deal with this. But certainly, if you look at improved livestock management here, we can deal with feed and fodder banks. We can deal with thermal stress control practices, improved animal health and parasite control and, in many cases, also shifts between species. So, we have several options to be able to deal with the problem of climate change. Thank you.


RICK WEISS: Great. Thank you very much, and we’ll look forward to Q&A on that, as well. But for now, I want to jump over to Abby Lynch on fisheries.


ABBY LYNCH: OK. Just to confirm, I’m sharing the correct slide, and you can hear me?


RICK WEISS: Looks good. Sounds good.

Impacts of climate change on fisheries


ABBY LYNCH: Great. Thanks for the opportunity to speak with you all today. Again, my name is Abby Lynch, and I’m a research fish biologist with the U.S. Geological Survey’s National Climate Adaptation Science Center. And I’m based in Northern Virginia, just outside of Washington, D.C. And I wanted to begin my section of the panel here with this photo, not because I think it typifies climate change of fisheries but rather just because it reminds me of what everything is all about, and the work that I do, which is predominantly on inland fish, is important to people because of fun, like in this picture here of my husband and my son, but as food, as livelihoods, as indicators of environmental quality and many other reasons that are and can be impacted by climate change.

So, to begin, for today’s briefing, I hope to make the case that, first, fisheries and aquaculture have an important and growing role in food systems, secondly, that climate change is impacting fish, fisheries and aquaculture in many diverse ways, and then lastly, that science-based decisions can help fisheries and aquaculture adapt to changing conditions and support sustainable practices. So, to begin, when you think about fisheries and aquaculture, they really can be seen kind of at the two extreme ends of food systems. If you think of them on a spectrum, capture fisheries are really the last large-scale wild food, and aquaculture is really one of the fastest-developing food production sectors in the world. So, together, fisheries and aquaculture provide food for billions and livelihoods for millions of people worldwide. So, just to drill down with some numbers, according to the most recent estimates from the Food and Agriculture Organization of the United Nations, fish consumption accounts for about 17% of global animal protein.

So, Mario was talking about the remainder of the animal protein, and fish really are the 17%. But even that number, you know, it doesn’t take into account kind of other important factors regarding this as a food source, thinking towards vitamins and nutrients like omega-3 fatty acids and vitamin D and calcium. And these are especially important to those where other nutritional sources may not be available or may be cost prohibitive. In terms of economics, fish and fish products are now among the most traded food commodities in the world, totaling an estimate of somewhere around $145 billion. In terms of livelihoods, almost 60 million people­—so that’s more than 10% of the global population­—depend on capture fisheries and aquaculture for livelihoods, and the vast majority of these fish workers, somewhere in the range of 97%, live in low-income countries. And then lastly, women play a particularly prominent role in small-scale fisheries, accounting for about half of the workforce. And this is mainly in marketing and processing. And while these statistics in and of themselves are impressive, I think it’s important to note that they can underrepresent the social and cultural importance of fish to many communities, which cannot be comparatively valued in the same way. So, now turning to the impacts of climate change, there are well-documented relationships between climate and fish survival, growth and reproduction.

So, let’s just kind of take a quick look at a few of these key drivers. So, first, most fisheries and aquaculture are dependent on coldblooded species, so water temperature is really a very key metabolic driver. Because aquaculture is place-based, depending on the operation location, there can be either an increase or decrease in production potential with shifting temperatures. And then for wild fish, as well as their associated parasites and diseases, shifting distributions can cause major reorganizations of aquatic communities. And just as one kind of telling example, a brook trout habitat in Wisconsin is projected to decline by almost 70% by 2065. So, that’s not too far down on the horizon. As a second example, sea level rise, and also the human efforts to armor against it, can really shift habitat for wild fisheries. And also, when you think about kind of coastal aquaculture facilities where they have infrastructure in place that is tailored to specific conditions, those types of operations will likely be much more susceptible to damage and have increased costs associated with sea level rise. And, you know, these effects will likely be really very important along the mid-Atlantic and New England coasts, where sea level rise is increasing about 3 to 4 times more than the global average. So, that’s just something to keep account of. And then lastly, just to mention ocean acidification, this can have substantial impacts on corals and shellfish and other species that are dependent upon them in the wild. And it also has sizable implications for shellfish aquaculture, with increasing production costs associated with defective shell formation. And just as an estimate, you know, the annual economic costs of ocean acidification in the U.S. could be somewhere­—they’ve been estimated to be somewhere around the range of $400 million. So, you know, these are only three drivers. There are obviously many, many other drivers, like drought and storms and extreme events, and I’d be happy to touch on those further in the Q&A or follow up later on those topics. So, you know, just planning in the face of uncertainty associated with these and other climate drivers­—it’s really inherently risky. But we know that decisions will have to happen one way or another, and the hope is that with improved scientific understanding, the choices that decision-makers have to make can be more informed and more nimble to adapt with change. And so very briefly, you know, to think about these climate adaptation strategies, we’re not starting from square one here. In fact, many of the climate adaptation strategies really can map very nicely onto existing management actions to support sustainable practices. So, for example, you can use stocking for what are called put-and-take fisheries. This happens frequently where I live in Virginia, where they’ll stock cold water fish that we know can’t survive the warm summer temperatures here. But they still support, you know, very lucrative recreational fisheries.

So, on the other hand, if that’s not the case, managers could decide to stop ineffectual stocking if they’re no longer having the desired effect. Another one is just modifying fishing practices so they can­—managers can modify harvest levels or even close fisheries during sensitive seasons. This might be, for example, a spawning season or when the waters are too warm or too low. Thirdly, looking to aquaculture, this can become more of an ally for wild harvest fisheries in that it could potentially supplement for lost wild fisheries or even considering new aquaculture ventures for species that might be better adapted to changing conditions. And lastly, when we think about all these species on the move, you know, intensive invasive species removal can try and get ahead of kind of these unwanted newcomers. Or you can look to translocate species that­—to potentially more suitable habitat. So, kind of to wrap up here on this end, I hope that I’ve helped kind of add to this discussion today. Again, just to summarize by highlighting that the fisheries and aquaculture do have an important role and a growing role in food systems in the U.S. and globally. Climate change is surely impacting fish, fisheries and aquaculture in many different ways. But hopefully, you know, we have science-based decisions to help the fishing communities, fisheries and aquaculture adapt to these changing conditions and support sustainable practices. And so with that, I’ll turn it back over to Rick.


What are some science-backed tips and pitfalls-to-avoid for reporters covering climate change impacts on U.S. agriculture?


RICK WEISS: Thank you, Abby. Thank you all three for great introductions to these three important areas. I want to remind reporters, if you have questions, you can go down to the Q&A icon and click on that and let us know your name and affiliation and question. And while we start processing those, I’d like to start these briefings with just one question from me to get things going. And it has to do directly with how you, the reporters, are handling this beat so far, in their opinion. So, if we could just go through the three of you, and briefly, if you could say something each about something you think is going well with the way the media has been covering the climate change and agriculture issue or something that you think hasn’t been going that well and could stand to use some improvement. And I’ll start with you, Cynthia.


CYNTHIA ROSENZWEIG: Thank you, Rick. I want to compliment the reporters. I think, you know, in general, you are doing a very good job of bringing forward the challenges of climate change. And­—but I guess what I would say is the solutions, as I think all three of us spoke about­—that there are many solutions out that are in the­—in agriculture and food that can be brought forward. So, while the­—while, clearly, the projections, as you can see in all three of the talks, are significant, are serious, but there are so many solutions that are being developed across all three aspects of the agricultural system. So, just an encouragement to focus on solutions. Thank you.


RICK WEISS: Great. And I think, as Abby emphasized, a lot of those solutions are good sustainable practices anyway, so could be a win-win. Mario.


MARIO HERRERO: Thank you very much. Yeah, you know, I think that you’ve done a phenomenal job in bringing the issues to the fore, and that is really appreciated. What I would say there’s room for improvement for is in­—especially with the livestock sector. It is really complex and very context dependent what you can do about it. There’s been a lot of emphasis on the reduction in consumption, which is something that applies to high-income countries, mostly. But probably the argument needs a little bit more balance because in many countries, in low- and middle-income countries, livestock are a real source of nutrients for people, and they play an enormous role in reducing stunting and wasting in small kids. And that really needs to be highlighted probably a little bit better. And as Cynthia said, you know, solutions­—on livestock, it’s been mostly about the mitigation agenda rather than the adaptation agenda. And I think that­—well, to keep viable industries in many places, we will need to think of all these solutions for adaptation, as well.


RICK WEISS: Great. OK. And Abby.


ABBY LYNCH: Yeah. So, I guess I’ll start by saying I was an English major as an undergrad. So, I think from my side, I know the power of a good story, and I know the power of good writing. And I think that reporters are able to use storytelling­—and, you know, I use that term liberally­—but that really helps humanize scientific research in a way that us in the sciences often don’t present it. And I think that, you know, the scientific community can kind of struggle with that because we’re­—you know, we’re trained to present information in a less narrative format. So, I think I would say that’s, yeah, what I think reporters are doing excellent.


RICK WEISS: Great­—telling those stories.



Are animal-based products­ expected to get more expensive in light of climate change? If so, how soon would price increases be felt by consumers?


RICK WEISS: OK. Let’s move to some questions. We have quite a few questions from reporters on the call today. I’m going to start with a question here from Michael Phillis from the Associated Press. Are all kinds of animal-based products­—meat, dairy, etc.­—expected to get more expensive? And how soon is that likely to be felt significantly? Let’s talk in the United States here. Mario?


MARIO HERRERO: Yeah. OK. In reality, we see two trends. Monogastric animals like pork and poultry will suffer very significantly because they’re very, very susceptible to the impacts of climate change. Although we have controlled environments­—they’re usually grown in barns and so on­—you know, the production costs for these types of animals will actually increasing significantly, probably more than for the cattle products and for milk. So, no, there are very significant differences between species. Probably the pork and probably the monogastrics will be more affected also because, you know, the impacts of crops will affect them directly, as well, which is­—which will be very significant, especially soy and maize. Those two products, which will experience significant impacts, will affect these­—well, will increase the prices of these two products more than for the other species.


RICK WEISS: And to the timing aspect of the question, do you think we’re talking within, say, five years?


MARIO HERRERO: Oh, well, I think that we are already experiencing some price increases. Just look how fragile the trade system in relation to food is that you end up with the Ukraine crisis. You end up with a COVID crisis. And then all of a sudden, it’s very, very difficult to source feeds and to source all sorts of things. So, this is actually occurring already. And on top of that, we also have increases in climate variability. It’s not only the long-term means that are likely to change but also climate variability, which will create fluctuations­—significant fluctuations in the prices. In the past, trade would have dealt with this, but we’re not­—no longer in the same trade conditions as before.

With projected decreases in food production due to climate change, what are some big-picture solutions to ensure a stable food supply for the next century?


RICK WEISS: OK. Have a question here from Sara Hiles from the Mississippi [River Basin] Ag & Water Desk. And I think this­—we’ll turn to you, Cynthia and Abby, for this first. But with projected decreases in food production due to climate change, what are some big-picture solutions to ensure a stable food supply for the next century, and what will it take to get to those solutions? Specifically, Sara asks, for crops used for animal feed, can you talk about why this is happening, what the impacts will be, what the solutions might be? So, why don’t I start with you, Cynthia, to address some of those crop concerns?


CYNTHIA ROSENZWEIG: Yes. Well, we have a lot of those solutions already. The­—and the land-grant universities have been working on these for decades. So, increasing efficiency of crop production­—and we’re very good at that, and we need to do­—continue and do more­—heat- and drought-tolerant crops and livestock, as Mario said­—some of them are more vulnerable than others­—improved pest management, increasing use of agricultural biodiversity, efficient irrigation. And that links to the water question, also, that another reporter posed. But in order to get there, we need policy so that these are­—so these solutions are well known and are also being worked on and improved. But we need policy, as well, for­—to develop crop insurance. We have a program here, around the world. We need more risk-based insurance. And there’s a coming­—really, I would say, in terms of policy­—payment for ecosystem services. So, the food production system is an ecosystem service. And policies that reward farmers with incentives for resilience in­—and to basically protect the productivity of our food production system. So, those are the solutions in hand­—need to keep on improving­—and policies to go along to implement them.


RICK WEISS: And before I turn to you, Abby, for the fisheries side, Cynthia, if you could build on this. To the extent you’re talking about heat-tolerant varieties of crops, are we talking inherently about engineering and editing, or are these things that can be done through traditional agricultural practices?


CYNTHIA ROSENZWEIG: Well, there’s­—you know, there’s a whole spectrum. I would say there are heat-tolerant crops and drought-tolerant crops out there in the wild forms already. But there is potential, very carefully done, to utilize the new technologies­—to utilize those new technologies, as well.




ABBY LYNCH: Yeah. And just to speak to that briefly on the fisheries and aquaculture side, I think managing expectations will be kind of the predominant mode of operation that I think will be most successful, in that, you know, fisheries may change the species that will be kind of increasing in­—and those that will be decreasing may change. So, the major fisheries may alter from what they currently are. But if we, as a management community and as a fishing industry, don’t adapt to those changes, it may be more difficult to maintain in terms of the current food supplies. And I think, you know, actually how the fisheries industry and aquaculture have responded to COVID is­—exemplifies how things can potentially evolve with climate change, as well. There’s been a number of examples throughout the sector where, you know, different industries have been able to adapt very quickly to new conditions and new supply chains. And I think using that similar sort of resilience strategy will help address the growing demand for food supplies­—food supply with climate change.

Are the agriculture, livestock, and fishery industries making the necessary changes to adapt to climate change?


RICK WEISS: So, each of you have mentioned some solutions there, but we have a question here from Geoffrey Roth from Nebraska Public Media, who’s really asking whether you think this will happen, whether farmers will do it. He asks, while there is discussion about ways to adapt to climate change, do you see the agriculture, livestock, fishery industries actually willing to make the necessary changes, or have they already started to do this? Why don’t I go through you each in order. Cynthia?


CYNTHIA ROSENZWEIG: Definitely, yes. It’s already happening. You know the phrase. There are no dumb farmers. Because climate change is already happening, they’re adapting. They’re not resisting the actual changes. So, for example, the crop zonation of where maize is grown in the higher latitudes changes in North and South Dakota. And, you know, I can­—we can do follow-ups­—happy to do follow-ups to help document these changes. The mix of crops is changing. We have a student working on this right now in both South Dakota and North Dakota. So, the answer very much is yes. It’s happening now, and the farmers are adapting.


RICK WEISS: Mario, it’s expensive to air-condition barns. Are livestock farmers going to be able to actually put some of these solutions to work?


MARIO HERRERO: Look. I think so. And as Cynthia said, it’s already happening. And here’s another spin. For example, lack of feed is one of the critical things. But now there is a lot of people investing in circular feed, producing feed from waste, either a microbial protein from fermentation or insects or a range of other ways of increasing the efficiency of resource use so that we can continue feeding animals. This is becoming to be very, very common in the poultry and in the pork industry that have very significant opportunities for consuming these kinds of products. That’s an example. And, you know, technology is an innovation, is being deployed at very accelerated rates with the increasing in solar and alternative sources of energy. It will be a lot cheaper to be able to cool down barns and a range of fodders to actually maintain the levels of production that we need. So, in reality, when we look at solutions, we shouldn’t think only of solutions coming from the sector. But this is true­—adaptation is a truly trans-sectorial issue. And, you know, there is incredible success in deploying things from alternative sectors in all cases, lots and lots of examples.


RICK WEISS: And what about fisheries? Are fisheries’ managers on the move, Abby?


ABBY LYNCH: Yeah. To keep things brief, I will say yes. And I think in some of the industries, it will be more difficult to transition the gear types and the infrastructure than in others. But there are already examples across both marine and inland systems where not only are the managers and the fishing communities themselves engaged, and there has been change already occurring.

Which crop pests or diseases are emerging or shifting in location due to climate change?


RICK WEISS: Question here. I’m going to try to squeeze a few more in in our last few minutes. We might run over a couple of minutes. And if we do, I want to remind reporters to please take the 30 seconds to fill out that survey at the end of this so we can get feedback from you. But let’s go a little further. We have a lot of questions. Greta Moran, a journalist at Civil Eats­—could you describe in a little more detail the crop pests or diseases that seem to be emerging or shifting in location due to climate change? What about on the crop front, Cynthia?


CYNTHIA ROSENZWEIG: Yes. I would call out aflatoxin, which doesn’t like dry areas. That one is one to very much keep an eye on. Worldwide locusts­—very much related to climate and weather pattern and climate-related. And the pressure of longer seasons having now not just one or two cycles of pests but three or four­—so these are­—we have an AgMIP team of crop pests and diseases that are studying these ones that are emerging now as well as projecting into the future.


RICK WEISS: Mario, are there animal pests or diseases that you’re most worried about besides this sort of heat stress and other things you’ve mentioned?


MARIO HERRERO: Well, from the animal side, just think of this. Any bug that bites­—mosquitos, ticks, flies­—all of those are basically changing the distributions. They’re very, very susceptible to changes in temperature and humidity. So, those are the ones that we are most concerned about. Especially for dairy animals, it’s an issue because, you know, what we’ve seen in many places is that diseases that were not in mountainous areas­—so in cold areas. Now they’re experience a lot of diseases that the animals, you know, are not prepared for. And this is actually leading to increased mortality and significant losses of productivity. So, those would be some of the ones we should be concerned about.


RICK WEISS: And what are the fish diseases or pests? I don’t think about mosquitoes.




RICK WEISS: I think they’re good food for…


ABBY LYNCH: I don’t think I know of any studies on mosquitoes and fish. But there are­—especially for cold water fish with increasingly warm temperatures, there are a number of different diseases and parasites that are just more impactful. There have been a number of studies that have looked at salmon in particular, and, you know, with increased disease and pest loads, they’re no longer able to return to spawn. And there’s been substantial consequences to populations as a result of that directly linked to climate change.

Are there any agricultural solutions to climate change in place that are misleading, ineffective, or fall short of making a difference?


RICK WEISS: And an interesting question here from Sarah Gibbens, National Geographic. Are there any solutions you think are misleading or ineffective in the ag sector, any that you would consider greenwashing, basically? In effect, what solutions out there fall short, if any­—anything from the three of you about things you see being boasted about but really probably not making much of a difference?




RICK WEISS: Do you care to specify?


MARIO HERRERO: Well, yes, of course. Yeah, I can specify. And, you know, some of these­—some of the intensification technologies that are typically going to increase efficiency­—what tends to happen is that they become very profitable. And as they become profitable, farmers, rather than, for example, increase just efficiency, try to do more, more of­—let me give you an example. Improved pastures in Latin America was the typical example whereby you could increase stocking rates. Of course, an environmentalist looks at that and says, wow, great. This could lead to less land being used for livestock production. But a farmer looks at that and says, oh, wow, I can triple my numbers of animals. So, he goes and increases deforestation and plants more pastures. So, there’s many of these technologies that, to be truly sustainable, we really need to plant them with associated policies because otherwise, for some of them, there are perverse incentives that would lead to indirect effects.


CYNTHIA ROSENZWEIG: If I could just very quickly add, we’re­—in AgMIP, we test the whole portfolio of solutions because for all different regions something, maybe work­—or different kinds of farmers, something may work, and something may not. So­—or really­—you know, really take hold. And, by the way, it’s not just one solution. It’s always­—we call them adaptation packages in AgMIP because it’s a combination of things. But that being said, we do need to be careful about establishing baselines for the practices that are being promulgated and make sure that we understand, here is the baselines. Modeling is very good for this. What are the baselines? And then what are the changes with the adoption? So, this is another area­—actually, AgMIP’s holding a conference for the next three days on how agriculture can really contribute to climate and how modeling can contribute to those adaptation and mitigation solutions.


ABBY LYNCH: And I’ll­—oh, go ahead, Rick. Sorry.


RICK WEISS: Nope, that’s it. Go ahead.


ABBY LYNCH: I was just going to add very briefly on the fisheries side, often, aquaculture is seen as a silver bullet and that if we have declining fisheries, ah, that’s OK. We can just, you know, aquaculture our way out of this problem. And that’s often masking broader, complex dynamics within kind of the wild fisheries and then also implications for aquaculture. Apologies about the dog. And so I just want to say that, you know, aquaculture can be a sustainable solution. But, you know, how it’s implemented definitely makes a difference.

What is one key take-home message for reporters covering climate change impacts on U.S. agriculture?


RICK WEISS: Great. Great point. Thank you. So, we’re really just over time. And I want to have a chance here to ask you each one last question, which is just a take-home message. If the reporters were going to walk away here and quote you once or say one thing that you’ve­—that you want to say about the impacts of climate change on U.S. agriculture, why don’t I just go around the horn and hear a quick finale from each of you? Cynthia, I’ll start with you.


CYNTHIA ROSENZWEIG: Yeah, I would say bringing the mitigation part, reduction of greenhouse gases within crop production, as well as developing resilience, not to silo them but bring them together. Soil carbon sequestration helps on all of that. So, having an integrated and holistic view rather than­—as we were just saying, that’s really portfolios of practices and linking both mitigation and adaptation. That’s what really­—the crops in the fields and the farmers can really, really help with.


RICK WEISS: Great. Thank you. Mario.


MARIO HERRERO: Yeah. For me, it’s a call for urgency. You know, it’s­—we need to act now and primarily because if we don’t, it will be incredibly expensive to deal with this problem with the impacts of climate change later. You know, that’s message No. 1. Second, that there is a broad arsenal of solutions and that they are emerging constantly. You know, it’s not that we are in a technological void. There’s all sorts of things occurring. And if we deploy them in packages and if we really look at all the sectors also for solutions, we will find lots of really useful game changers.


RICK WEISS: That’s encouraging. And Abby.


ABBY LYNCH: Yeah. And I think the uncertainty surrounding climate change impacts can make the whole sector or all of these sectors very difficult to manage proactively. And so I just want to leave everyone with a little analogy. If you think of­—you know, if you think of playing pin the tail on the donkey, if you actually want to win the game, do you want to have the blindfold on and spin yourself around a couple of times? Or would you rather have clear eyes and clear-headedness? And I think science really can be that second scenario where we can help inform decisions and help anticipate and adapt to change.


RICK WEISS: Fantastic ending. And I want to thank our three experts today for all their contributions to reporters understanding these issues. I want to remind the reporters on the call here­—first, as I mentioned, please take that half a minute to answer three questions on your way out. It really helps us keep these media briefings to be the kinds of things that are most helpful to you. Please do follow us on Twitter at @RealSciLine. And check out our website, Thank you all so much for your help, Cynthia, Mario, Abby. Really informative briefing today. And we’ll see you all next, reporters, at our next media briefing, actually, on Thursday, looking at drug abuse in youths and teens. Going to be a very interesting briefing Thursday. See you then. So, long.

Dr. Cynthia Rosenzweig

Senior research scientist, NASA Goddard Institute for Space Studies & Columbia University Earth Institute’s Center for Climate Systems Research

Dr. Rosenzweig is a senior research scientist at the NASA Goddard Institute for Space Studies and the co-located Columbia University Earth Institute’s Center for Climate Systems Research. Dr. Rosenzweig’s specific area of expertise is climate change and food systems. At NASA GISS, she heads the Climate Impacts Group, whose mission is to investigate the interactions of climate (both variability and change) on systems and sectors important to human well-being. In 2019, Dr. Rosenzweig was coordinating lead author of the food security chapter for the IPCC Special Report on Climate Change and Land. In May 2022, Dr. Rosenzweig was announced as the World Food Prize Laureate.

Dr. Mario Herrero

Professor of sustainable food systems and global change, Cornell University

Dr. Herrero is a professor of sustainable food systems and global change in the Department of Global Development, a Cornell Atkinson Scholar, and a Nancy and Peter Meinig Family Investigator in the Life Sciences at Cornell University. His research focuses on increasing the sustainability of food systems for the benefit of humans and ecosystems. He works in the areas of sustainable intensification of agriculture, climate mitigation and adaptation, livestock systems, and healthy and sustainable diets. Dr. Herrero is a regular contributor to important global initiatives at the heart of the sustainability of global food systems, such as the Intergovernmental Panel on Climate Change, the Lancet Commission on Obesity and the EAT-Lancet Commission on healthy diets from sustainable food systems.

Dr. Abigail “Abby” Lynch

Research fish biologist, U.S. Geological Survey

Dr. Lynch is a research fish biologist with the U.S. Geological Survey’s National Climate Adaptation Science Center. She conducts science and science syntheses on the impacts of global change to inland fishes at local, national, and global scales. Her work aims to inform conservation and sustainable use and to help fishers, managers, and other practitioners adapt to change. She is the coordinator for the international ‘InFish’ research network, associate editor for fisheries management and ecology, and an adjunct/affiliate faculty member at Michigan State University, New Mexico State University, North Carolina State University, University of Florida, and University of Missouri.

Video: high definition

(mp4, 1920x1080)


Video: standard definition

(mp4, 960x402)


Panelist presentations