The ecologist who serves up climate science on a plate  » Yale Climate Connections

Imagine you’re at a dinner party organized by an ecologist who wants to help you understand how the food you’re eating is connected to the larger world. That’s the experience of reading “The Blue Plate: A Food Lover’s Guide to Climate Chaos,” by ecologist Mark Easter. 

Easter has written more than 50 scientific papers and reports related to carbon cycling and the carbon footprint of agriculture, forestry, and other land uses. 

Now, after a long career with the Natural Resources Ecology Laboratory at Colorado State University, Mark works independently as a greenhouse gas accountant and writer.

This interview caps a three-part Yale Climate Connections series on food, agriculture, and climate change. The two previous interviews, with Michael Grunwald (“We Are Eating the Earth”) and Kelsey Timmerman (“Regenerating Earth”), can be found here and here. 

This interview has been edited and condensed. 

Yale Climate Connections: Let me begin by complimenting you and Patagonia on one of the most beautiful covers I’ve seen in years–and on a thought-provoking title. “The Blue Plate” was your idea? 

Easter: It was.

YCC: So the blue marble in space is the plate on which we’re eating?

Easter: Basically. The premise behind the book is trying to understand what the greenhouse gas emissions from the food system are. Michael Grunwald has framed it as we’re eating the planet. The blue plate is my notion that we can eat from the planet without consuming the plate itself.

YCC: We’ll come back to Grunwald later. 

Your book is described in the blurb as follows: “Ecologist Mark Easter offers a detailed picture of the impact the foods you love have on the earth, organized by the ingredients of the typical dinner party, including seafood, salad, bread, chicken, steak, potatoes, and fruit pie with ice cream. Each chapter examines the food through the lens of the climate crisis.” 

I can certainly see that you organized the book by different types of foods: bread, salad greens, seafood (especially salmon), corn, meats (especially beef), dairy, and tree fruits. But are we meant to imagine a series of courses? An extended dinner?

Easter: Yes. The idea was to use a plate of food from a dinner party as the framework for the book so that as you go through the different courses, you examine how those foods are produced and what the greenhouse gas emissions associated with each of one are. Because as it turns out, there is an important emission that is unique to each one of those courses on the plate. 

So, for example, the story behind bread is very intimately tied to carbon in the soil because wheat and the other grains that are used to make different breads are some of the most widely grown crops in the world. The tillage of the soil wherever these grains are grown has a huge impact on the organic carbon in the soil. Also, there is an important story to tell around how we can grow those grains differently and how people already are doing that on millions of acres around the world. Because the soils on which grains have been grown historically often are so degraded, that’s where we have the greatest opportunities to draw carbon from the atmosphere back into that soil as organic matter and rebuild the carbon in the soil and the fertility that goes with it. 

YCC: What food surprised you most when you investigated its climate impacts?

Easter: Shrimp. I was most surprised when I started to dive into the carbon emissions that come from building the shrimp farms. Shrimp are generally farmed in the tropics, and they’re grown in areas that used to be mangrove wetlands. The process of clearing those wetlands in order to create the ponds where the shrimp can be farmed creates enormous carbon emissions. 

I worked as a greenhouse gas accountant for 25 years at Colorado State University and in private industry. And I was astonished to see the carbon stocks that mangrove forests hold, and thus what the consequences of clearing those forests really are for the climate. The total carbon consequences of shrimp are much greater than chicken, much greater than pork, and approaching the carbon footprint of beef from dairy, which is about half of beef just raised as a beef animal. It was really astonishing to me.

YCC: For each type of food, you then compare standard practices with regenerative practices. With what food did regenerative practices have the most impact? 

Easter: I’d say there’s two. 

Mussels and clams have a very low carbon footprint, among the lowest of any animal-based protein. It’s because they’re taking carbon dioxide that’s absorbed from the atmosphere and into seawater, and they’re converting that into their shells, which are functionally limestone, rock. 

Another is tree-based crops, and in particular nuts. So much carbon is built up and stored in the trees as an orchard grows and develops that it provides an effective carbon offset for the other emissions associated with growing the crops.

YCC: You seem to take a great delight in describing the process of gathering all this data. That seems to be part of the message you deliver. You do express alarm at many points. But I think you also deliver a message of calm reassurance that food grown well is part of a life well lived, and we should strive for that. Is that just who you are, or is that a deliberate rhetorical choice you made in writing the book? 

Easter: That is such an interesting question. I made a deliberate choice to let my love for food come through in the writing of the book. I think food can be one of the most personal connections we have to the world around us, and in particular to the climate crisis because it’s something that we experience several times a day. 

I also decided that I did not want to come across as trying to judge other people’s food choices. I made that decision after talking with a number of physicians. I asked them, How do you deal with patients who are suffering from a chronic disease that may be related to their lifestyle, whether it’s diet or lack of exercise or some other thing? They told me that the least effective way to try to bring about change was to shame or judge them. The most effective way was to offer information in the best possible light with love and intention. This is the approach that Katharine Hayhoe, a scientist I admire, takes with climate communication. So it was very much a deliberate choice. 

YCC: You are also doing things with people. You take pleasure in the friendships and partnerships that form. Many of your meetings end with meals, with food eaten together with good conversation. Your book depicts a practice that is very attractive.

Easter: Well, I’m lucky to be able to study food for a living. I was also really lucky to be able to work with farmers, not just here in the U.S., but around the world, farmers and pastoralists and ranchers through my work at Colorado State University as a greenhouse gas accountant. And I can’t think of a single meeting with a grower on their farm that didn’t lead to some interesting revelation. There’s just so much to learn from how food is grown and how these different practitioners adjust to whatever it is, the crop that they’re growing, the livestock they’re raising, the markets that they’re growing it for, how they deal with the particular challenges that their land presents to them. And I was really grateful that so many of them invited me and my colleagues to talk with them and learn from them. I’m especially grateful to the growers who lent their stories to this book.

YCC: Yes, the book includes pictures of their settings, their crops, their workplaces. Any Patagonia book is well illustrated, well laid out, very smartly designed. That, I think, contributes to the message you’re trying to deliver.

Easter: I’m glad to hear you think so.

YCC: We’ve already alluded to a major book out there this year, “We Are Eating the Earth” by Michael Grunwald. Have you had a chance to read it? 

Easter: I have, yes. 

YCC: Grunwald seems very skeptical about claims about regenerative agriculture. What, in your view, does he get right? What does he get wrong?

Easter: I think Mike got a lot right in that book, and I think it’s a really important story to tell. Elevating Tim Searchinger and the impact that he’s had is also really important. He’s absolutely spot-on, I think, about biofuels and about the carbon footprint of harvested wood products and on other issues where he’s been a major critic of certain aspects of greenhouse gas accounting. 

I also appreciated how Mike tells the story about meat and the critical tie back to deforestation, how meat consumption and land use and deforestation are joined at the hip. That’s critically important.

Also, how Mike presented Tim’s arguments on the importance of intensification. We need to produce more food from the existing agricultural land base rather than clearing additional forests or plowing grasslands in order to create more cropland. I thought he did an effective and masterful job with that.

Finally, I appreciated the discussion of food alternatives. It’s important for people to see the role of venture capital in the development of these different food systems and food products, and some of the reasons why they succeed and why they fail. 

YCC: But? 

Easter: But I don’t agree with the way Grunwald and Searchinger express their concerns about soil carbon. I felt like they presented a straw man.

The notion that soil organic carbon could completely offset fossil fuel emissions from humans worldwide is not the scientific consensus. There are a few scientists and a few growers who are advocating this idea, but it’s not the scientific consensus, and it’s not what I present in my book.

But if the majority of agricultural acreage and grazed lands around the world pivoted to a regenerative model that increased organic carbon in the soil, it could potentially offset 15 to 20% of fossil fuel emissions. Regenerative agriculture can be a part of the solution to keeping the climate from warming to extreme levels, but it is not the whole solution. 

YCC: What about the question of yields? Grunwald and Searchinger argue that shifting to regenerative practices generally results in lower yields. 

Easter: That does not correspond to what I’ve seen in the data. There’s a widely held belief that organic agriculture has, on average, a lower yield than conventional agriculture. But in my own experience with the data, it’s not actually true to say that, across the board, organic agriculture and regenerative agriculture have lower yields than conventional agriculture. There are certainly cases where that happens, but that is not representative of the entire system. 

In fact, regenerative agriculture is often adopted by growers who, as one of the growers that I profile in my book, Curtis Sayles, says, my soils had hit rock-bottom. The principal marker he uses to assess the success of his practices now is the carbon in the soil and the microbial and the insect community that he’s fostering within his fields. And that’s what I’ve seen in my own work. There’s no amount of fertilizer or inputs that farmers can throw at their fields in order to increase yields when the soils reach a certain point. But when they start to tackle their fields and pastures as ecosystems, as opposed to merely a substrate for growing crops, the yields increase, and their fields become more resilient.

YCC: So you’re saying regenerative agriculture is often dealing with land that was no longer yielding or was barely yielding, and more of the usual inputs were not going to change that fact. But regenerative agriculture can change the equation. 

In these cases, new farmland isn’t being taken from forests or grasslands or wetlands. It’s degraded farmland that’s being brought back into production. Regenerative agriculture can be additive, rather than subtractive.

Easter: Exactly. In the book, I talk about a family in Indiana, the Rulon family, and they make increasing the organic matter in the soil the principal driver of their enterprise. And what they found is that degraded soil can’t produce more than maybe 90, 100 bushels of corn per acre or maybe 30 or so bushels of soybeans per acre. And that is soil that’s about 1% organic matter. Whereas if they spend 10, 15, 20 years increasing the organic matter up to 3%, they can more than double the yields: over 200 bushels an acre per corn, 60 bushels or more for soybeans. And they do this with significantly less fertilizer, less inputs. They’re making more money doing this. 

That is the promise of regenerative agriculture. Besides being a [partial] climate solution, it offers economic and ecological resilience to the growers who are practicing it.

YCC: What message would you like the readers of this interview to take away about your work on food and agriculture and climate? 

Easter: Food and agriculture contribute between a quarter and a third of the total human-caused greenhouse gas emissions. We can reduce that substantially, and we can actually reverse some of those emissions in a way that can help create a safer climate future. But we must still stop burning fossil fuels as quickly as possible and transform our energy, our transportation, our heating and cooling, the way we manage our buildings, everything, to zero carbon just as soon as we can. 

At the end of my book, I offer a list of things individuals and society can do beyond eliminating fossil fuels. Michael Pollan, in his book “In Defense of Food,” offers this wonderful dictum: Eat food, not too much, mostly plants. 

So pivoting to a plant-based diet is probably the most impactful decision any one person can make. In terms of the meat that we eat, consider pastured poultry as a low-carbon alternative to ruminants like beef and lamb. Seafood eaters can find low-carbon sources of animal protein in farmed mollusks like mussels, oysters, clams, and scallops. Keeping our food and yard waste out of landfills is another impactful choice; by composting that food directly or getting food waste into a composting system, you’re reducing methane emissions. Search for food that carries a carbon farming or regenerative farming label. Finally, avoid foods that travel by air. 

YCC: So eat more plants and eat more seasonally. I would note that your book is heavily documented, but that documentation is only available online. There’s a QR code at the end of the book that leads to those notes and references, which probably saved 100, 150, 200 pages?

Easter: It saved a lot. Patagonia reduced the carbon footprint of the book by about a quarter by putting that online. I really appreciate you noting that. 

YCC: It’s good when a book about reducing emissions follows emissions-reducing practices. Mark, thank you again. Your book was a pleasure to read, a pleasure to look at, and it has been a real pleasure speaking with you.