MR. KOJO NNAMDIFrom WAMU 88.5 at American University in Washington, welcome to "The Kojo Nnamdi Show," connecting your neighborhood with the world. When you grill out in your backyard, chances are it seems to you like a pretty simple affair. You've got meat or fish, some vegetables. You've got fire, and you've got an appetite. But when Barton Seaver looks at a grill, he sees enough going on to teach an entire public health class at Harvard.

MR. KOJO NNAMDISeaver has been educating eaters about sustainability and our relationship to our food sources since he launched his career as a chef here in Washington some years ago. But these days, he's literally traded in the kitchen for the classroom where he's leveraging the power of an Ivy League institution to help people learn about how their meals affect their health and the world around them, lessons you can start to learn and pick up yourself the next time you light up a grill to bring your friends and family together on a Saturday afternoon.

MR. KOJO NNAMDIBarton Seaver joins us in studio. He's a chef and environmental and public health advocate. He's the director of the -- this is going to take a while. He's the director of the Healthy and Sustainable Food Program at the Center for Health and the Global Environment at the Harvard School of Public Health. He's a National Geographic fellow and the author of several books, the most recent of which is titled "Where There's Smoke: Simple, Sustainable, Delicious Grilling." Barton, I've known you for years, but I've never known you to have such a long title before.

MR. BARTON SEAVERI know. I went from chef to something that doesn't even fit on Twitter, so.

NNAMDIFifteen words. We'll figure out how to say it in shorthand in a little while. If you're trying to figure out how to join this conversation, that's pretty easy. You can call us at 800-433-8850. How much of your knowledge about your health or about the health of the environment comes from learning about the food you eat every day? When was the last time you learned something about science from your daily routine in the kitchen or outside on the grill? 800-433-8850. Bart, it's great to see you again.

SEAVERIt's great to be back, Kojo. Thanks for rolling out such a beautiful day for my return to my beloved hometown.

NNAMDII do what I can.

SEAVERThank you.

NNAMDIThe first time we chatted on this broadcast back in 2000, you were a working chef in Washington who wanted to feed people great meals all the while teaching them something about their relationship to our food supply. You pioneered an emphasis on sustainability in everything you did, but earlier this year your mission to educate took you, well, in a different direction. You've left Washington for a position at Harvard where you're taking a deep dive into public health. What exactly is your role there, and how would you describe the challenges that you're facing?

SEAVERWell, you know, I never quite saw this evolution coming for myself, but, you know, in restaurants, in my work with National Geographic, it became very obvious to me that when we talk about sustainability, ultimately, it's ourselves that we're trying to sustain. It is maintaining our health, our wellness, our communities, our jobs, you know, our economic resilience, our environmental resilience upon which we are sustained.

SEAVERAnd so, to me, the confluence between environmental sustainability and human health is really it's one and the same. They're the same issue, just looked at through different lexicons.

NNAMDIAnd tell us about exactly how you're looking at it. What are you doing at Harvard?

SEAVERWell, I have a couple roles, and I'm still sort of creating and figuring out exactly how I can bring my knowledge and skills to bear in that community and...

NNAMDIWell, I've been watching your lectures on YouTube. I'm just asking you to explain to our listening audience what that's all about.

SEAVERWell, largely, what we're trying to at the Center for Health and Global Environment is to take ideas of environmental sustainability and recraft them as human health metrics. And so when we talk about greenhouse gas emissions, when we talk about climate change, when we talk about sustainable food systems, we're talking about environmental impacts. And so how do we take these narratives and rewrite them to be about humans, to be about our society, to be about reward mechanisms that human beings can invest in?

SEAVERAnd a lot of those works manifest itself in the form of work with corporations, with for-profit entities, groups that have existing and very robust infrastructures and investments built around mitigating environmental impacts. And we're now learning how to tell those stories, those efforts as they relate to humans.

NNAMDIYou indicated that when you were a chef here, you didn't realize that this track would take you through National Geographic and onto Harvard. You've said in so many ways over the years, however, that food is the language you speak, the way you're most comfortable communicating with the world. Why do you find it such a powerful tool to teach people about our ecosystems and how their own health is ultimately affected?

SEAVERWell, if I can start off saying a little bit of my history, you know, and how I became fluent in food, which is I was born and raised here in Mt. Pleasant and with two parents that were both very intrepid cooks. And so we would spend our days, you know, looking through all these little bodegas that service the needs of incredible diversity of cultures, from Eretria and Ethiopia, El Salvadoran, Guatemalan, Honduranian, the World Bank transients employees, embassy workers.

SEAVERI mean, you name it. This is the Noah's ark of people. And so I learned very early on that food is quite a literal physical exploration of our world. It is how we bring the world into our lives, onto our plates. And, you know, in many cases, it can also be considered as a transcommunication. We're literally taking the life of the world in order to sustain our own.

NNAMDIBecause when you get down to it, a kitchen is basically like one giant lab, a chemistry set you get to play with every time you set out to make a meal. To what degree did all your training as a chef prepare you to make such an aggressive foray into science, and what kind of catching up are you having to do to master what you need to know about public health?

SEAVERWell, you know, the first thing I have to do is admit that and acknowledge that I am not the expert on this. I'm not coming from a scientific perspective. I'm not, you know, speaking about educating about the exact physical attributes of nutrition and wellness and, you know, the epidemics of food-related diseases. I'm talking more about the social structures, the expectations that govern our use of the products that ultimately creates or diminish the healthfulness of our lives.

SEAVERAnd so this is really, you know, to my mind, health and sustainability are both social constructs. We can be no healthier than the environments that we live in, both the environment physically but also the environment of cultural expectations. What do we look to food to actually give us? Do we look to it to make us sick, to bring us diabetes and heart disease?

NNAMDII don't think so.

NNAMDIOr do we look to it to bring us joy and taste and delicious, you know, communion? Do we look to it to bring us health and wellness, to sustain and enable healthy productive thriving lives, communities and economies? And so when we begin to look at food not just as the science of nutrition but as the behavior of use and cultural expectations that govern it, I think we'll be into take a more holistic -- and I think ultimately more useful approach.

NNAMDII was watching a lecture online that you gave at Yale earlier this year where you quoted from a book by John Hersey who wrote -- I'm quoting here -- "In our quest for food, we begin to find our place in the systems of this world." Why does that quote resonate so much for you?

SEAVERWell, I think it quite accurately describes that we're not sovereign over our resources, but rather that we are because of them. And, you know, we need sustainable -- sustained and resilient environments in order to sustain ourselves, and food -- getting back to the exploration theme -- I mean, what an amazing way to interact with the world.

SEAVERThe problem with food that was when it comes down to conversations about the science of nutrition, the science of cultural use and expectations, we have to acknowledge that food is the second most subjective and intimate relationship that we have. First is our friends, family and, you know, our intimate relationships with other people, but food, I mean, it is such an intimate way in which we interact with everything around us.

NNAMDIIn case you're just joining us, we're talking with Barton Seaver. He's latest book is called "Where There's Smoke: Simple, Sustainable, Delicious Grilling." He's a chef and environmental and public health advocate, currently director of the Healthy and Sustainable Food Program at the Center for Health and the Global Environment at the Harvard School of Public Health.

NNAMDIWe're inviting your calls at 800-433-8850. Bart, your career has afforded you the opportunity to travel all around the world, but home for you up until recently has always been here in Washington where you learned, as you mentioned earlier, about our relationship with the Chesapeake, not just with your parents and cooking, with the Chesapeake, an intimate detail.

NNAMDINow, that you're in New England, you're learning about the food sources there what's got to be a very interesting time. The ground fisheries there are reacting to fairly drastic cuts to commercial harvest of cod. What do you make of what's happening, and how does it serve as an example of the kind of issue you're now following as an academic?

SEAVERWell, I think there's a number of ways to approach that story. The first is, you know, this is a food security issue. Right now, with the cod quota cuts that I believe are scientifically valid are necessary in order to sustain that which sustains us. But at the same time, these quota cuts are going to be paid for at a very high cost by the communities that provide us access to that resource, the fishermen and the microbusiness economy that exist in New England, you know, the ice guys, the fuel, the oil, the dock workers, all of this. New England...

NNAMDICod is New England.

SEAVER...is based on these microindustries. And so there's going to be a very dear price paid. And unfortunately, I think for the large vast majority of us, we're not going to notice that pain. And unfortunately, I don't think that we're going to to notice a lack of availability in cod.

NNAMDIWell, when you talk about diversifying our demand for something other than cod, you're really talking about engendering changes in our behavior that affect an ecosystem. So where can that demand be funneled to then? What else should people be excited about outside of cod?

SEAVERWell, you know, looking back at what we were just discussing, there's been a cut -- a quota cut for the fishery, and I think all too often we think of fisheries as ecological systems. They're not. It is an economic system. The environment is what the economy is based off of certainly, but it is an economic system. Now, for hundreds of years, cod has been king in New England. I mean the sacred cod that hangs in Massachusetts statehouse.

NNAMDIWhy did we make cod king in the first place? What is it about that fish?

SEAVERBecause of its availability, it is highly fish. There's a lot of -- there's a huge biomass of it. I mean, you know, large parts of this world were founded...

NNAMDII was about to say is there any culture in the world that doesn't have cod in it?

SEAVERWell, it was one of the staple food stuffs that allowed the exploration of the planet. You know, the salt cod, it was a healthful and nutritious product that could be taken for months, years on voyages when fresh food wasn't available. But the problem is cod has been king, and nothing else has been sort of raised up to take equal platform. Now, in a cod net, when the cod comes back in, a fisherman drags it up, what becomes back with it?

SEAVERPollock and haddock, cusks, ling, flounders, some scallops, lobsters. You've got dogfish, skate, wolf eels, ray shark, whoa. All of this stuff comes back. And yet cod at market commands a premium. None of those other species have traditionally or historically been profitable for fishermen, although each of those species is equally profitable to the human body for the purposes of a delicious and sustaining meal.

SEAVERWe've developed an economy based on irrational demand for one species alone. And by diversifying our demand, what we do is we diversify the burden we place on the ecosystem through the economy we've created to access it.

NNAMDI800-433-8850. Where do things like sustainability or carbon footprints fit into the decisions you make at grocery stores or restaurants? What would it take for you start incorporating those issues into your daily food discussions, diversifying your seafood diet, if you will? 800-433-8850.

SEAVERWell, again, to the diversification, I think this is not an environmental cause. This is, you know, a human cause. And the response to this knowledge is to walk into a grocery store and say, what do you have that's freshest and best? What do you have that's most economical, fits my budget? What's going to make me look like a rock star tonight? And then listen to what's told to you and then say, OK, cool. Pollock. All right. It was caught two days ago, pristine freshness. This is going to be awesome.

SEAVERIt's $10.99 a pound. OK, I can afford that, great. But instead, what we do is walk into stores, and we say, I want cod. Well, I'm sorry. This is D.C. It's May. There is no cod here. And you say, yeah, but my recipe says cod. I'm going to go where I can find cod. When we find it easier to change the nature of our relationship with nature rather than changing our recipes, there is a problem there.

SEAVERAnd so by walking in and asking for the best product available, you're going to go home with the best value. You're going to get a product that you're going to enjoy the most because it's the best thing there. And you're going to participate more broadly, inherently more sustainably within the economy and the ecosystem.

NNAMDIThat enthusiasm you hear is Barton Seaver's enthusiasm for sustainability. He joins us in studio. If you're interested in joining the conversation, give us a call at 800-433-8850. His latest book is called "Where There's Smoke: Simple, Sustainable, Delicious Grilling." We're going to take a short break. When we come back, we'll continue with the conversation. You can also send email to kojo@wamu.org or send us a tweet, @kojoshow. I'm Kojo Nnamdi.

NNAMDIWelcome back. You're joining a conversation with Barton Seaver. He is a chef and environmental and public health advocate, director of the Healthy and Sustainable Food Program at the Center for Health and the Global Environment at the Harvard School of Public Health. He's also a National Geographic fellow. His latest book is called "Where There's Smoke: Simple, Sustainable, Delicious Grilling."

NNAMDIWe're taking your calls at 800-433-8850. How do you go about expanding this conversation beyond choices that individuals make about what they buy in stores or at restaurants? It's my understanding that a lot of your work at Harvard involves working with large institutions about the choices they make when it comes to food.

SEAVERAbsolutely. You know, you have corporations. You have institutions like hospitals that are inherently acting as community education hubs that are capable of purveying great amounts of information about behavioral choices and the reward mechanisms there. What's great is, also, within the corporate world, you actually have the ability to reward good behaviors because it enhances profitability and, you know, worker performance.

SEAVERWhen you a workforce that is dedicated towards wellness, when you have company policies that are really dedicated towards sustaining humans, you really build up a community of people that are acting in best interest of profit. But also by acting in self, you know, the best interest of themselves are really gaining and being rewarded for their behaviors.

NNAMDIIf we can go back to that lecture that I was referring to a few minutes back, I was struck by something you said about how modern environmentalism is sold to people. You take major issue with the idea of the tragedy of the commons, the resources we share, the idea that human acting in our self-interest will ultimately lead to the destruction of the commons. Why?

SEAVERWell, that idea, you know, Dr. Garrett Hardin, a seminal paper published in 1968 that elucidated that idea that men and women acting in rational self-interest will ultimately lead to the destruction of our commons. And I think that's come to largely describe and sort of present the scope of how modern environmentalism is sold, and that is it is a measurement of how we have impacted ecosystems, usually, to their detriment.

SEAVERAnd it's -- unfortunately, it's a guilt-ridden story. It's a story about human bad. And by making the story simply about how we impact ecosystems, we deny ourselves the opportunity to talk about how we are impacted by ecosystems, to talk about what humans need in order to thrive in our contemporary world, and to begin to address the question of, you know, is the human relationship with nature one that's based on abundance or based on scarcity?

SEAVERAnd this is a great stress that we feel, and that we're really trying to deal with. And I like to sort of shift that narrative away from the tragedy of the comments, which provides a very essential method to understand how we have impacted the science of, you know, how we have impacted ecosystems. I call that the biology. But what I call the communion of the comments, a measure of how we are impacted by ecosystems begins to help us write the biography of how our experiences in nature and in society are formed.

NNAMDIBecause you find reasons to be optimistic in the destructive impacts, the human decisions, particularly when they've come to food have had on our environments over the years, you don't think that we can have this conversation without talking about better use of existing resources.

SEAVERYeah. You know, when we talk about, how can we feel seven billion people? How we can feed the coming nine billion people? If we look at just, you know, food itself, that doesn't provide all the answers. We have to look at our expectations, you know, and there are studies recently out that say, you know, somewhere between -- I've seen range of numbers, some 30 to 50 percent of all food produced on this planet is thrown out or is wasted spoiled before it can benefit a human.

SEAVERThere are examples in fishery, such as the Peruvian anchoveta. It's the world's largest single species fishery, 10 to 15 million metric tons on average. That quota just got slashed considerably this year, the largest single species fishery on the planet. And 98 percent of that never feeds a human directly. It gets milled up into fish meal that goes into, you know, salmon production. It goes into pigs, chicken, livestock. It's in linoleum, moisturizers, I mean, you name it.

SEAVERWe found every way to use it except for its highest and best use which is to feed people. I was down in Peru just last year at a plant. I got access to one of these fish meal processing plants. And there, they process 14,000 tons a day of this fish, milling it, cooking it out in these acrid, large, football field-sized pots that just bubble up the oil to the top where it's skimmed off.

SEAVERThe rest of it made into fish meal. Now, this plant, 14,000 tons a day, employed 28 people, 12 of whom were security guards. I walked down the street to another plant that does actual processing for human consumption, the salted filleted anchovies that I loved so dearly. And there, they process two tons a day, and they employ 150 people. Now, in a world of...

NNAMDIWhat's wrong with this picture?

SEAVERWell, in a world of, you know, increasing population and declining resources, we're looking for a loaves and fishes-type story, and it's not going to come from miracles. It's going to come from examining our expectations and examining how we can better utilize the products that we are so blessed and fortunate to already have access to.

NNAMDIGot to go to the phones. We'll start with Michael in Annapolis, Md. Michael, you're on the air. Go ahead, please.

MICHAELThank you for taking my call. I am curious what your guests thinks about a plant-based vegan diet and how that fits into this conversation.

NNAMDIBart.

SEAVERYou know, moving forward towards vegetables is something that we absolutely, absolutely must need to do. And we know this. I mean, you look at the myplate.gov website, you look at the Harvard Healthy Eating Plate, you look at all of the nutritional information that we are constantly deluged with.

SEAVERYou listen to what your mom told you when you were a kid, you eat your vegetables. I mean, this is the truth of the matter. And so, you know, a vegan diet, I think, is, you know, a great idea if that fits your lifestyle, if that fits the commitment that you wish to make. It takes a lot of effort, you know, in order to get a complete meal, in order to gain enough calories from vegetable sources.

SEAVERThat being said, it's probably the most delicious way to eat because you get such a range of textures and tastes and colors and seasonality, and, I mean, that's what makes eating fun. However, I do admit that, you know, while I often eat vegan, with the exception of, you know, small portions of sustainable proteins, most of my calories come from, basically, vegan preparations.

NNAMDIMichael, thank you very much for your call. So far, we have not talked about grilling, but it's time to do that. Communion is a word you see a lot in your new cookbook about grilling where there's smoke. You say that part of why grilling is your favorite way to cook is because it's celebratory, seasonal and communal all at once. What are you getting at here?

SEAVERWell, I think we should be so lucky to interpret our lives as such. You know, when we grill, it's -- we're inherently setting ourselves into a different environment. We are setting -- stepping out of our comfort zone of the kitchen where we know exactly where everything is. We're setting ourselves up for something new. And when we invite our friends and family over for, you know, for a barbecue or a cookout, inherently, it is focused around the food.

SEAVERAnd to me, when we use food to bring people together, when we focus on the ingredients, when we enjoy and can reflect upon the blessings that we have, I think that is the highest and best use of food, because we are feeding ourselves with far more than just calories. We're feeding at the complicated hunger that we look to food to satiate the need for community, the need for family and interaction and relationships, intergenerational, the need for us to acknowledge that which sustains us.

NNAMDI800-433-8850. What are your favorite things to grill in the summer, and are vegetables among them? Do you think people should look at grilling as a less meat-centric activity? Why or why not? 800-433-8850. We move on to Daniel in Brunswick, Md. Daniel, you're on the air. Go ahead, please.

DANIELOh, thanks for taking my call. I really love this conversation, and I'm a great believer on a lot of what he's saying. And I would also recommend Mark Kurlansky's book, "Cod," traces the history of cod, a fantastic one. I'm actually interested in a pragmatic question. I grill for a lot of the same reasons, bring people together.

DANIELI really like the opportunity to have that and share that. I eat the vegetables a lot, but there's nothing like a piece of flesh to really make that thing really pop for my friends. So I want a pragmatic list. What are the five things I ought to grill more? What are the five things I ought not grill very often? And I'll take my answer off the air. Thanks a lot.

NNAMDIThank you for your call, Daniel.

SEAVERYeah. And thanks for that suggestion on the book. Mark Kurlansky's micro-history of cod is really an utterly fascinating look at our history of our relationships with oceans.

SEAVERYou know, after all this highbrow stuff that I've been talking about the larger purposes of grilling, you know, when it gets down to it, grilling is my favorite way to cook simply because the heat itself becomes an ingredient in the food, that seductive, sexy, rustic, smoky appeal of things, adding a platform, a backbone to foods that just sets them off with such intrigue and, you know, and what a different flavor it provides. To your point about the, you know...

NNAMDITop five.

SEAVER…the hunk of meat on the plate, I -- before I get to the top five, I want to say something about sort of the way we use the meat itself, which is oftentimes in a grill, if you're thinking about a Weber grill, I've just got a little 18-inch -- it's the smallest upright grill that Weber makes -- and that's all I've ever needed.

SEAVERNow, you've got a relatively small amount of fire space there, relatively variable amount of heat going on here, you know. And unless you've got a fire the size of the entire grill, you're really going to end up with highly variable cooking. So what I do, instead of doing four rib eye steaks, eight to 10 ounces a piece, you know, which all have a surface area of, you know, a good eight inches or so, I do one large piece of meat.

SEAVERAnd I do, like, five ounces per person because you get that slow, seductive, smoky cooking, and it slowly caramelizes, absorbing all those flavors. And so you actually have more space on your grill to cook vegetables. You have more control over the cooking process, and so you're not reliant upon, you know, nailing it medium rare on every single steak, consistent all the way through. You've got one that you're trying to manage.

SEAVERAnd because you can cook it slower, you have more time to do so. And here's the real kicker, is that when you put -- I mean, Kojo, you come over the house, and I've got this big beautiful hunk of meat. It's a 20-ounce, you know, New York strip steak that I've slowly bathed in red wine and soy sauce and smoked over a mix of apple and peach chips. And I put this...

NNAMDII'm traveling to Boston later this month. We'll try that out.

SEAVERAnd I put this down on a plate, and there's this big hunk of meat. And there are six of us sitting around, everybody to themselves says, wow, Bart loves me. That's cool. That act, that visual of generosity of the large portion does so much to our psychology of satiety, that we check that box and we say, wow, OK. I feel like I've been taken care of. And then I take the steak, and, when I carve it into very thin slices, each of them like bacon, just rich and overflowing with flavor.

SEAVERAnd then the rest of the table is filled up with grilled kale and peaches and pasta salads and potatoes and tomatoes and all these great things. And you know what, when I do this for guests, oftentimes, those four or five ounces of protein that are cooked for them, some of that goes uneaten. So to the top five list now.

NNAMDIWe've already (unintelligible) named five things, but go ahead.

SEAVERSo -- well, we've been talking about beef there. You know, pork tenderloins are a great thing for me, especially if you can get them from, you know, in this area, my buddy, Bev Egleston, down in EcoFriendly Foods, Dupont farmer's market every Sunday. It's the perfect little portion. You have this beautiful thing. It's easy to cook, takes on flavors really well.

SEAVERI love that it feeds a bunch of people a small portion. Getting into seafood, you know, coming up into salmon season right now, wild Alaskan salmon, get a thick, rich, fatty piece. Leave the skin on it. Put it away from the fire. You know, put your coals on one side. Put the salmon on the other. Put the top on and just let it slowly smolder away. You get this sort of hot smoked/grill hybrid technique. All right. I'm getting excited (unintelligible).

NNAMDIThank you. He also wanted to know what not to grill.

SEAVERWell, I think try not to grill multiple portions because you're just introducing way too many variables. I would say there's not a single vegetable that I don't grill, and, in fact, the new book is really highlighting that. You know, we don't even hit proteins still halfway through.

NNAMDIAnd by the way, the new book is called "Where There's Smoke: Simple, Sustainable, Delicious Grilling." Here is Marty in Damascus, Md. who, I think, has a subject that's close to Bart's heart. Marty, you're on the air. Go ahead, please.

MARTYHi. Great subject today. It's something -- following up on your point about the how much food is wasted and the carbon footprint. I mean, I say this to people all the time, like, imagine how much it took to get that food to your plate. Somebody had to plant the food. You had to get the seeds. You had to put it in the ground. You had to plant it.

MARTYYou had to harvest it, tend to that the whole time. You had to harvest it, process it, ship it. You had to go to the store and buy it. You had to bring it home, cook it, and then you just throw it out. I mean, it's just, you know, to not overbuy and to not overcook and to try to, you know, use everything is just so important, I think.

NNAMDIHow important is it, Barton Seaver?

SEAVERWell, you know, what was left off that list is that you have to pay for it, too, and that -- Marty, thank you so much for your comment because you're absolutely dead-on with this. You know, we can't talk about how the world's going to feed and come up with new technologies before we take best use of what we already have. And I think what's exciting about looking at waste if, you know, if anybody believes that that's an exciting topic, is that there is -- waste, to my mind, is nothing but a misallocated resource.

SEAVERThere's money to be mined in waste or money to be saved, money to be reallocated towards maybe purchasing a higher quality protein raised in a more, you know, environmentally friendly and economically friendly way. When we spend less, you know, through our trash cans, we can spend more through our directed ethical purchasing, and I think that's a really big opportunity.

SEAVERAnd some of the work that we're doing through the Center for Health and Global Environment is helping some of these large-scale, you know, companies with tens of thousands of employees who have food service operations or hospitals who want to engage in more of this community education about good food systems, who might not have the dollars necessary on the table right now in order to direct food purchases towards this more ethical sourcing. Well, fabulous, let's not start at the front door. Let's start at the back door. Let's find money to reinvest in these better systems.

NNAMDIMarty, thank you for your call. Here is Tyler in Arlington, Va. Tyler, your turn.

TYLERHi. I'm really enjoying the topic today, and it's something that I've been thinking about lately. And I was interested in your discussion about the cod, but I think you can make that a broader discussion about land animals as well. I grew up in the South and, you know, grew up, when I'd go visit my dad, we'd have squirrel and deer and things like that.

SEAVERYeah.

TYLERWhenever I mention eating squirrel to people up here, the initial reaction is always, that's disgusting. And I just -- it doesn't make any sense to me because, for the longest time in this country, organ meat and other woodland animals were food. And at some point we transitioned to where these things are no longer food. And a lot of times they're better for you, and I think that some of it also has to do with government regulation where they only allow certain food, certain animals to be processed on a large scale. So I just wanted to hear your thoughts on that.

NNAMDIYour take on that, Barton?

SEAVERWell, thank you very much for your comment on that. It's, you know, it's very interesting 'cause when we talk about agriculture, we're talking about really humanly built systems. When we talk about fisheries, we're really talking about the very last vestige of our hunter-gatherer phase. Within some cultures, there is, you know, a subset community that is engaged in hunting and still gathering food from the terrestrial wilds.

SEAVERAnd I think that is -- if that's part of your culture, that can be, you know, an effective and, you know, interesting way to sort of diversify. Now, obviously, part of the problem with that is that, you know, if we all went out into the woods, there would be great issues with that. And so we do have to look to managing systems so that our impacts don't outweigh the benefits.

NNAMDITyler, thank you very much for your call. If you have called, stay on the line. We'll get to your call. We do have to take a short break, however. In the meantime, we have a few lines open, so you can still call, 800-433-8850. What do you prefer when you grill? Gas or charcoal? Is your preference based on convenience, taste, environmental factors? Give us a call. Let us know. 800-433-8850. I'm Kojo Nnamdi.

NNAMDIWelcome back. Our guest is Barton Seaver. He is a chef and environmental and public health advocate, director of the Healthy and Sustainable Food Program at the Center for Health and the Global Environment at the Harvard School of Public Health. He's a National Geographic fellow, and his latest book is called "Where There's Smoke: Simple, Sustainable, Delicious Grilling."

NNAMDIWe're talking about culture in the conversation we had with our last caller because some people live in a culture where there's hunting, and they feel that that means that that helps sustainability, if you will.

SEAVERYeah, certainly, and I think that's how I tried to address that question. It really is a cultural mechanism there. And if hunting is part of what you do and your belief system, then, you know, if you are going to hunt, then, by all means, please do use what you hunt for the highest and best purpose. You know, use it to sustain your family or your body, give it away to soup kitchens, whatever it is, whatever use of it. One of my...

NNAMDINot for trophies.

SEAVERNot for -- you know, I myself am not a terrestrial hunter. I am a fisherman, so technically I am. But I think there's also a discussion about diversifying the farm animals that we look to, that we raise specifically for meat. And if you look to the American culture, we just -- beef, beef and that's it, you know? But what about goats? What about some of these other animals that can actually act to increase the overall productivity of farmlands?

SEAVERBecause they can exist on marginal land and create great productivity out of otherwise low-yield land. They can eat, you know, vegetable chaff and farm -- you know, biological waste in terms of what we don't eat as fruits or vegetables. And so there's a great opportunity, I think, to increase the efficiency of some of our existing systems by looking to a more diverse and broad set of meat species.

NNAMDIWhat about our relationship to fish we don't eat quite as often? We've talked on this broadcast before about the menhaden, the fish that a lot of people consider to be a cornerstone of underwater ecosystem because of how many other species depend on it for food. You've been very concerned about the fate of the menhaden for years. There were new catch limits put on it several months ago. How do you feel about where things are going with the menhaden?

SEAVERWell, I think just much like the conversation about the Peruvian anchoveta, the menhaden represents a resource that we are currently exploiting quite fully, and yet we are not benefiting from it in any measurable or remarkable way. Menhaden -- and I think this often gets left out of the conversation, this, you know, oysters in the Chesapeake and the clarity and water quality in the bay is a major topic -- I think many people are aware of, if not fully fluent in.

SEAVERHowever, oysters filter the bottom of the bay. We always -- you know, in history, we've relied on menhaden to filter the top of the bay, and that's a major part of that plumbing system of the bay and keeping that healthy. Now, the fishery for menhaden is, in this area, based out of Reedville, Va. It's owned by one company, Omega Proteins.

SEAVERAnd I think 434 million pounds of menhaden were landed in Reedville in 2008, I believe, at a total value of $36 million. If you do that math, you're talking about a biologically necessary fish. You're talking about a, you know, extracted resource that actually has very little benefit directly to the human diet, and it's worth, you know six, 7 cents a pound? Come on. We can find a better way to use that. It's not about Omega Protein.

SEAVERIt's about how we as a, you know, as a culture expect that resource to be used, and I know that they were considering canned, smoked products, trying to create a, you know, consumption market for it. And I applaud that fully. But we have to be -- we have to understand that when we're talking about oceans, when we talk about dinner, it's not just our dinner. I mean, everything in the ocean has two birds: It's eat and be eaten. And so when we take something out of the ocean, we are taking something else's dinner.

SEAVERAnd I just think that sort of close to this idea is that -- with the anchoveta example, with the menhaden example -- you know, it is a crime, by treaty of the sea, to take what we know of as waste, trash, you know, whatever it is, the off-cast from our culture, and throw it into the ocean. It's a crime to take trash and throw it in, and yet it's not a crime to waste what we take out of the ocean. And I think we really need to revisit that.

NNAMDIOn to Scott in Fairfax, Va. Scott, your turn.

SCOTTHey, thanks for taking my call. I got two quick questions. What about the potential carcinogens in charcoal smoke and the accumulation of mercury when you eat the larger species of fish?

SEAVERGreat questions.

SCOTTI'll take my answer off the air. Thank you.

SEAVERThank you, Scott. Well, you know, when cooking over charcoal, obviously there is some sort of input of carcinogens coming off that burning. A lot of, I think, that danger -- and I'm not a food scientist here, so I'm speaking to some of the research that I've done. But I've seen that much of the carcinogenic buildup is coming from searing meat and meat fats directly over flame, and that creates some really pretty nasty chemicals that can build up.

SEAVERSo the example that I gave of that large steak -- cooking one for many people -- actually helps to decrease, I believe, the amount of carcinogens present in your final meal because you've moved that steak away from the direct flame. So you're really cooking off the ambient heat created in an oven-like effect. So not only are you getting more flavor out of the fire, I believe you're moving towards an ultimately healthier product.

SEAVERNow in terms of other emissions from charcoal, gas is by far the most efficient way to cook on a grill. Turn on, turn it off, you still have to give it some time to heat up. Electric grills, which are now coming into market, infrared in terms of greenhouse gas emissions, those are sort of second on the list. It depends on where your energy is coming from to feed that and what's the source there. Charcoal being the third. But I think there are ways to mitigate some of that impact.

SEAVERYou know, airflow commonly and easily controlled on a grill. You can close off the vent at the top, shut off the airflow valve at the bottom, and within just a few minutes you've suffocated that fire, thus, leaving the charcoal for you to use next time, saving you some money, but also not burning a fire that -- and spouting out emissions that you don't need to.

SEAVERNow, on to the mercury question you asked, Scott, you know, methylmercury build-up as an environmental toxin. It happens in larger species because it -- bioaccumulation up the food chain. And, you know what, there's good evidence that we should not be taking mercury into our bodies through our diets.

SEAVERThat being said, there is also ample evidence about the benefits of omega-3s, selenium, magnesium, all of these other things that we find in seafood that actually bring, in some cases, more benefit than does mercury bring detriment. Now, this is a debate that is raging on. There are many sides to the story. And one of the assets that we've created with National Geographic and the Center for Health and Global Environment at Harvard is the Seafood Decision Guide. And this can be found at natgeoseafood.com. And it...

NNAMDISo you can find the link at our website, kojoshow.org.

SEAVEROh, fabulous. And what it does there is we have aggregated sustainability information via the Monterey Bay Aquarium Seafood Watch Program, methylmercury data via Stony Brook University, omega-3 data via USDA sources. And what these allows you to do is to create a context for you to make your own decisions 'cause I don't know what you care about. Food is so subjective. I don't know what angle you're coming at this from.

SEAVERSo we just give you most of the information that we think you need in order to make an educated decision. You can turn these filters on and off if you're pregnant, expecting or a nursing mother. You can click a button to populate a field of recommendations that are best suited to your needs, if you're just trying to maximize cardioprotective benefits in order to reduce incidences of disease and actually reduce incidences of mortality, live a longer life.

SEAVERWell, great. Click on the heart buttons in order to maximize those omegas. But the bottom line is, we should be eating the smaller seafood of the ocean: sardines, herrings, mackerels, anchovies. These things that tend to get diminished in popularity by the culinary field. And that's really where we need to be eating -- placing the most of our burden of our seafood consumption in the oceans.

NNAMDIOn to Sharon in Arlington, Va. Sharon, you're on the air. Go ahead, please.

SHARONYes. You addressed the charcoal versus the gas, but I have a wooded lot with lots of wood, and I use -- which I use for smoking shoulders -- pork shoulders and fish. But I wanted to start using the wood to just -- for my whole fire in my Weber. Any reaction to that and whether it's an environmentally-friendly thing to do?

SEAVERWell, you know, here's -- it's sort of the difficult thing because when we look at greenhouse gas emissions of grilling strictly through that lens and without a broader context, wood is the worst choice. However, think about it this way. If that wood in your Weber grill, which, by the way, I don't think Weber recommends, but I actually do this all the time, so -- but don't take my advice.

SEAVERWood fire in there -- if that seductive, sexy, smoky flavor actually gets you to eat a lot more vegetables because they're so interesting and charismatic now that you've introduced that flavor to him, fabulous. That's a pretty good use of carbon, to my mind, not only for the health benefits of it. But consider this, more than 30 percent -- I think about 35 percent of all greenhouse gas emissions in the United States come from livestock production.

SEAVERThe most effective thing you can do to minimize your greenhouse gas, your carbon footprint and methane footprint is to eat a smaller portion of protein and a lot more vegetables. And that will far outweigh any negative impacts you have from shifting the source of your fire from charcoal to gas to wood, whatever.

NNAMDIThank you very much for your call. Speaking of shifting the source of your fire, even though gas grills may have a gentler environmental impact, you're a big fan of charcoal fire. How much of that has to do with the taste the charcoal fires produced?

SEAVERPretty much all of it.

NNAMDIYeah, I thought as much.

SEAVERYou know, I understand the convenience of gas. I've used gas grills plenty of times in my life. Most restaurant kitchens, in fact, have gas grills. I've had always used wood grills in my restaurants and basically cooked everything over them. But, you know, in gas grills, they're highly effective and fun ways that you can introduce that smoke flavor while, you know, maintaining the convenience factor. You have -- there's a number of different little smoker boxes.

NNAMDII was about to suggest -- to ask about that, yes.

SEAVERYeah. I mean, those are great. They're not the exact same thing as cooking over charcoals, you know, a wood spike charcoal fire, but they're highly effective. They're fun, and, you know, can be introduced easily.

NNAMDIReplicating wood smoke flavors. Finally, here is Sarah in Highland, Md. Sarah, you're on the air. Go ahead, please.

SARAHHi. I was just calling because I was interested in your guest's thoughts on GMOs or the center where he works on GMOs because he talks about the health of -- you are only as healthy as what you eat or the environments that is -- you're eating your food from.

SEAVERWow.

SEAVERA loaded question. Thank you for very much for that and the opportunity to speak to this. It's -- genetically modified organisms, I think, is a science that is exciting, in that it can yield some understandings about the very nature of our food system. That being said, I am not a big fan of implementing genetically modified organisms without proper and due course scientific and rigorous studies that I don't think we're setup to really have right now. But there's also this further question of why do we need them.

SEAVERAnd I think there is compelling arguments depending on which side you are from on this. But the bottom line is, we're trying to genetically modify cows right now that don't emit as much methane as part of their digestive process, because cows and livestock contributes so much to global greenhouse gas emissions. Well, is the solution to change the nature of nature?

SEAVEROr is it maybe to eat less beef and to eat more vegetables, things that are not producing as much methane? We tend to think that technology is the only solution when, in fact, behavior is inherently at least 50 percent of any solution that will ever work in terms of finding the best highest efficiency and most healthful way for humans to feed each other.

NNAMDIThank you very much for your call, Sarah. We're running out of time, but it's my understanding that part of what you're studying, Barton, is the difference between behavioral carbon and physical plant carbon. What is that?

SEAVERWell, so often time, you know, we think of greenhouse, you know, climate change and greenhouse gases just turning on and off the light bulb or going with the high-efficiency water heater or the, you know, the new thermostat. We don't think about maybe putting on another sweater in the house to not have to turn the heater up so high.

SEAVERAnd so I think that there is -- as much getting back to this idea of production, but also use. It's not just the products. It's how we use them, what we expect from them. And I think there is such simple, practical cost-saving ways for us to re-examine our use of products that will lead to greater (word?).

NNAMDIThat will reduce our carbon footprint. Barton Seaver is a chef, an environmental and public health advocate. His latest book is called "Where There's Smoke: Simple, Sustainable, Delicious, Grilling." He's the director of the Healthy and Sustainable Food Program at the Center for Health and the Global Environment at the Harvard School of Public Health. He's also a National Geographic fellow. Barton Seaver, thank you for joining us.

SEAVERKojo, what a wonderful, wonderful return to D.C. Thank you so much.

NNAMDIAnd thank you all for listening. I'm Kojo Nnamdi.