Waste not, want not.

Since moving to Arizona, I’ve been wondering what to do with my food scraps. As I’ve written about before, food scraps don’t biodegrade in landfills because that process requires airflow. Instead, food scraps petrify. Between 30% and 40% of the food we grow is wasted somewhere between farms and our bellies. And all the food waste that ends up in landfills generates a considerable amount of methane, a powerful greenhouse gas. Food waste is currently a hot topic within the food, energy, and environment sector. In fact, last fall, the USDA and EPA committed to halving the food waste in the US by 2030, and food waste was a talking point during last year’s World Food Day, held by the United Nations.

The first step in curbing food waste in my house is to deal with food scraps. Long ago, we tried worm composting. It is supposed to be easy, but like all things to do with food – deciding what to eat, grocery shopping, cooking, packing healthy snacks – easy can still be time-consuming. We never really got into the groove of working with the worms, and that was before we had two kids to keep track of! In addition, the climate in Arizona is not particularly hospitable to worms. For about six months out of the year, we’re in the triple digits (that’s over 38°C). We’re not keeping a worm bin in the house where it’s air conditioned, but it’s really too hot to keep them outside. And while many cities are starting food scrap recycling programs, we don’t have a program available yet.

As it turns out, some clever people have solved this problem for me. There are now dozens of companies that will pick up food scraps from your home or business and compost them for you. The one in our area is Recycled City. Once a week, a guy named Stan drops off a large plastic bucket (like a painter’s bucket) and a little bag of something called bokashi – it looks a bit like sand and helps break down food waste while eliminating odors. All week long, we throw our food scraps into a bowl on the counter, as needed. At the end of each day, we toss them into the bin in the garage with a little sprinkle of bokashi and snap on the lid so nothing gets out (or in!). At the end of the week, we set our bucket out in our driveway, and Stan replaces it with a clean, fresh one. It’s that simple.

Stan, from Recycled City, takes our food scraps and leaves us a fresh bucket.

Recycled City composts the food scraps it picks up from homes, businesses, and even restaurants. The nutrient-rich soil that results is used for urban gardens in downtown Phoenix, which is classified as a food desert by the USDA. They even offer CSA boxes from their partner farms, and we have the opportunity to get free soil back as part of the service. For the price of a few lattes, we get all of the perks of composting with very little work. Finally, a food system solution that really is both easy and quick!

There is likely some variability among different service providers, but the general idea is pretty universal. You can find a service in your area by doing a web search for “food scrap recycling service” or check out the interactive map by Compost Now.

Moldy veggies, egg shells, coffee grounds, and even bones can all go in the compost bin!

Finding an alternative destination for my food scraps won’t technically help the food waste problem, but it can help keep food out of landfills. And dealing with my food scraps keeps this issue more present in my mind than just dumping stuff in the trash. When I see how much of our produce or leftovers go to waste, I see patterns in what doesn’t get used – like that little bit of extra pasta or the baby onions from the CSA box that I wasn’t sure how to use. All that waste is FOOD, in a world of people who are starving. It’s also money – my money that I consciously devote to getting better food for my family. And it’s all of the water and soil and energy and farm workers and truck drivers and resources both human and mechanical that WE ARE WASTING. Seeing it on a daily basis makes me want to find a solution.

Because food waste is such a hot topic, there are several websites devoted to how you can limit your food waste (like this one and this one). The things that are key for us are making weekly menus and buying only what we need for the week. One issue we’re having right now is that we typically do our meal planning and shopping over the weekend but our CSA box comes mid-week. Some of our CSA produce doesn’t make it to the weekend or we end up doubling up on certain items that we purchased before the box arrived. Rather than letting all that food go to waste, we need to start building some flexibility into our menus – like incorporating a stir fry, curry, or veggie sauté into our menu later in the week. That way, at least some of the produce that arrives in our CSA box can be used right away. Another option is to make salads for lunch, which generally means more nutritious food for less money than going out to eat. Raw, steamed, or roasted veggies (all pretty quick options) make for great salad toppings. There are probably other options, too. Being aware of the problem – how and why food goes to waste in my household – is the first step toward a solution. Next time you clean out the fridge or scrape your plate into the trash, think about how you might solve the food waste problem in your home.

The Future Frontier of Agricultural Science

Last December, I was honored to attend the Japanese-American Frontiers of Science symposium in Tokyo, Japan. Frontiers of Science symposia (FoS) are organized by the U.S. National Academies of Science, the Kavli Institute, and leading science organizations from around the world – in my case, the Japan Society for the Promotion of Science. The symposia are designed to bring together young researchers from a wide variety of fields, which offers scientists the opportunity to learn the state of the art work being done in other areas and network across the typical boundaries of expertise. In my case, I was the only planetary scientist at a symposium of about 70 participants, and the range of topics included the mathematics and applications of origami, development of a new standard by which we define the kilogram, and the human microbiome. Although jam packed, the sessions were very stimulating and generated great discussions both during and outside of the sessions.

"Any time you do something new in origami, you have to make a bunny."

A little microbiome humor to lighten the mood.

The session I was most looking forward to was Climate Change and Food Security. I hoped the session would focus on agricultural methods that enhance crop resiliency and require fewer resources. The talks began with an overview of the many ways climate change will continue to challenge our abilities to grow food, as well as the growing concern over so-called “hidden hunger”, the widespread lack of nutritious food so severe that it impairs normal growth and function of human beings. An estimated 2 billion people suffer from malnutrition, and poor nutrition is responsible for 45% of deaths of children under 5 [1][2]. The speakers all acknowledged that it is lack of nutrition that will be the next big problem facing humanity. However (and somewhat inexplicably), they then focused on methods of producing “a bigger pile of corn”. That’s right, the session was all about the successes of biotechnology at developing more productive crop varieties.

Quantity vs. Quality

After the talks, the participants asked many critical questions about the biotech approach to food security such as its economic viability in poor countries and issues with soil degradation and water usage. What bothered me the most was that the speakers said nutrition is, and will continue to be, our biggest challenge, but the biotech advances they described do not address nutrition at all. In fact, in the US, most genetically-modified crops (especially corn and soy) are made into food additives and sweeteners, like corn syrup and soy lecithin, rather than actual food. In poorer parts of the world, as one of the speakers pointed out, even industrial-grade corn is used as a food – served as something like porridge. While still largely devoid of nutrition, at least corn does supply edible calories for the very poor.

After the session, I approached two of the speakers* to ask more about the challenges of nourishing the world. The first person I talked to often works in Africa and knew a lot about the particular hardships for poor farmers. She agreed that a good approach to creating nutrition security (rather than caloric security) would be to focus on crops that are inherently nutritious. Whether through changes in agricultural methods, selective breeding, or gene splicing between species, creating more resilient nutritious crops – think lentils and kale rather than corn and soy - must be part of the solution. Unfortunately, the speaker could not think of any researchers currently working on enhancing the yields or the sustainability of nutritious food.

She also pointed out a potential flaw in my analysis of the caloric needs of different countries, which was based on population studies by the United Nations’ Food and Agriculture Organization (FAO). In that study, the caloric needs of a population are determined by age and sex demographics. However, occupation is not taken into account. Farmers, day laborers, or women who trek tens of miles a day for clean drinking water are afforded the same caloric requirement as a typical person, but their actual needs are much higher. Even a person getting 1800 calories a day may be nearly starving because of the exertion required for their daily life. One of the findings of my study was that almost all countries, even those with 30-50% of their populations being classified as food insecure, actually had enough calories to feed everyone. However, based on this new information, it seems likely that income inequality means the poor not only have less access to those calories, they also need more than the FAO has estimated because of the hardships of poverty. In that case, having more available calories could, hypothetically, reduce food insecurity, but only if the impoverished people within the country can actually get more food. And, of course, none of this addresses the availability of nutritious food.

A Culture of Condescension

My discussions with the next speaker were much more troubling. When I broached the subject of growing or breeding more nutritious crop varieties for use in poor countries, he said it wouldn’t be effective because the people in those countries wouldn’t eat the food. They have a culture of non-nutritious foods, he said, using rice as an example. Better to engineer staple crops like corn and rice to have more nutrients and let the poor eat what they like.

I found this attitude, frankly, appalling. The idea that poor people can’t recognize the value of a diverse, nutritious diet is insulting. Assuming that impoverished people in southeast Asia eat a diet of mostly rice because that is their culture neglects the role that poverty has played in restricting diet diversity over time. While the diversity of traditional diets is something I will need to learn more about, it seems unlikely that the nutrient deficiencies currently causing widespread blindness and stunted growth throughout poor populations have been present throughout their histories. In any case, people living in extreme poverty deserve better than to have their nutrition slipped into their rice like parents of a stubborn toddler hiding vegetables in their kid’s pasta sauce.

Another Seat at the Table

The issue of population growth came up many times throughout the session and side conversations throughout the symposium. Because population is increasing, proponents of biotechnology will say that we need to produce more calories even if they are not nutritious. Otherwise, people will starve. There are two problems with this approach. First, as long as the population continues to increase, food production will always have to increase to keep pace. Maybe we can keep squeezing our resources and reducing the nutritional quality of our food to produce more calories, but this seems like a race to the bottom. The other problem is that people need more than calories. It sounds unconscionable to let people starve, but is it any more ethical to give people just enough calories to survive knowing that the lack of vitamin A, for example, will lead to blindness and death? In my opinion, there is no point in creating more calories if we cannot produce nutritious calories because lack of either is too often a death sentence.

In addition to researching nutrition-based approaches to food insecurity, slowing population growth is critical to a sustainable food future. As one speaker pointed out, the advances of biotechnology are not expected to outpace the pressures of population growth on the food supply – not by a long shot. Luckily, the methods for slowing population growth are known. Lift people out of poverty, and they have far fewer children. This is especially true for women because impoverished women have so few opportunities. Becoming a wife and mother is their only value within a society. When women are educated and have access to jobs and careers outside the home, they have a source of economic stability that gives them more freedom to choose when and whether to have children, and they usually choose to have fewer children overall.

Nourishing the world is a harder and more critical long-term problem then feeding the world, but that is the actual problem facing humanity. Producing more calories that are not nutritious or raising crops in ways that degrade or deplete vital resources are false solutions. We need to focus on developing sustainable agricultural practices that produce more nutritious food. We also need to empower the poor, especially women, to both slow population growth and reduce the extra caloric burdens of poverty. This is the true frontier of science, a worldwide humanitarian effort, and a moral imperative.


*Although the names of the speakers are available on the internet, I’m withholding them here because some of what I describe stemmed from side conversations rather than their talks. It’s possible that I misunderstood their comments or that they would have provided more context in a different setting. In any case, I have tried to describe our interactions as best as I can remember them.

[1] http://www.gainhealth.org/knowledge-centre/fast-facts-malnutrition/

[2] http://www.wfp.org/hunger/stats

The Polyculture Project.

Conventional meat production has been (justly) criticized for the strain it puts on the environment and the deplorable conditions in which animals are kept. However, there is an alternative to conventional farming. Diversified, pasture-based farms, also called polycultures, work with the land such that the farm becomes integrated into the natural ecosystem. Multiple species of animals are raised together along with crops that can be used for animal feed and for human consumption. Overall, this type of farming provides many environmental benefits and a higher quality of life for the animals than conventional farms.

A criticism of polyculture farming is that it isn’t productive enough to meet the needs of our population, and thus, meat could only ever be a small part of a sustainable food system. Although often repeated, I have rarely seen this statement quantified, which has led me to ask the following question.

How much polyculture farmland would it take to produce enough meat to feed the US population?

Answering this question requires two types of data: the amount of meat we need for everyone in the US and the amount of meat, per acre, produced on polyculture farms. The USDA and FDA collect and distribute vast amounts of data on the productivity of US farms, but I couldn’t find anything on the productivity of pasture-based, diversified farms. So I set out to collect the data myself.

I first reached out to the farm where I currently get my meat: North Mountain Pastures (NMP), a polyculture farm in Pennsylvania. My family has been part of their Community Supported Agriculture (CSA) program for several years now. Every month, we get a box of meat with a variety of cuts from a variety of animals. The farm is run by Brooks and Anna Miller, who graciously contributed to this project.

Brooks and Anna put together this table of their farm’s output in 2013, which includes all of the animals they raised and the edible pounds of meat typically provided by each animal. The total weight they compute is consistent with a rough estimate based on the amount of meat supplied through their CSA. Brooks and Anna also calculated the acreage of their farm and the land required to produce some additional grains they feed their chickens and pigs. Dividing the total number of pounds (49,855) by the total acreage used (114), gives an annual output of 437.33 pounds of meat per acre.

The other key piece of data is the amount of meat required for the entire US. The USDA recommends that typical adults get about 6 oz of protein each day, which is 0.375 pounds (see MyPlate for more info). For this analysis, let’s assume that all of the protein comes from meat. Throughout a whole year, we would need to produce 42 billion pounds of meat to feed all 308 million Americans their recommended 6 oz. of meat every day. Americans actually consume about 52 billion pounds of meat each year (Earth Policy Institute).

Assuming the productivity of North Mountain Pastures farm, we would need just under 100 million acres of land to produce 42 billion pounds of meat each year and 119 million acres to match current demand for meat.

Those are such big numbers that it’s hard to interpret them without some context. So, let’s compare them to the amount of land we currently use for grazing. According to the USDA (as cited by the EPA), the US devoted about 600 million acres to animal grazing in 2007.

That means we could produce enough meat for the entire US population by converting 16% of our current grazing land to polyculture farming. We would need to convert 20% to match current meat demand.

That doesn’t seem like a lot of land at all. In fact, it seems like diversified farms could actually reduce the amount of land we devote to meat production without reducing the amount of meat people eat. Now, that doesn’t necessarily mean that meat is totally sustainable. There are other environmental impacts we should consider, such as water usage and carbon emission. From the perspective of land use though, diversified, pasture-based farms can provide more than enough meat without requiring any additional land.

If people choose to get less of their protein from meat, it would further lessen the land burden of raising animals. For example, North Mountain Pastures also produces eggs, which we did not include in their meat production numbers. Fish, nuts, seeds, and legumes are also high in protein and can serve as alternatives to meat. However, if sustainability is the goal, we would need to consider the relative environmental impact and scalability of obtaining these other foods to that of meat raised on polyculture farms.

Another benefit of diversified, pasture-based farming is that it hasn’t yet been fully optimized. Farmers and scientists around the world are working on advances that can boost efficiency and lessen the environmental impact of raising animals for food. At North Mountain Pastures, they are working with grain farmers who use no-till agriculture and other ecofriendly methods, exploring ways of reducing off-site feed, and adding an orchard. In a much broader effort, the Savory Institute is devoted to restoring badly managed grazing land and promoting ecologically-sound land management. If we actually wanted to convert current grazing land to polyculture farms, the Savory Institute’s research could help bring the productivity of marginal land closer to a farm like North Mountain Pastures. Additional improvements, as well as more widespread adoption, are also likely to lower the cost of producing meat in this way, a savings that can be passed on to the consumer. Currently, members of the NMP CSA pay about $8 per pound for their meat.

One other potential barrier to producing all our meat on polyculture farms is that we would have to change the way we eat meat. North Mountain Pastures raised 7 different animal species with a wide range in the number of animals of each species. For example, they raised only 12 cows and 10 goats but 240 turkeys and 5200 chickens. To take advantage of a diversified farm requires that we diversify both the types of animals and the cuts of meat we that we regularly eat.

For this analysis, I’ve assumed that any diversified farm could be as productive as North Mountain Pastures. Without any additional data, it’s hard to know if this assumption is reasonable. I will say that I didn’t know how productive NMP would be when I approached them about this project, although that doesn’t necessarily mean that their productivity is typical. And productivity can vary a lot depending on the location of the farm. That’s why I would like to expand upon this study to include as many polyculture farms as I can find. That way, I can better quantify the productivity and scalability of polyculture farms, assess additional environmental concerns, and help develop a pathway to a food system that produces meat without destroying the environment or abusing animals.

It’s a lofty goal and one that I can’t achieve on my own. If you, or someone you know, has data on the productivity of a polyculture farm, please consider sharing it with me. Together, we can turn the polyculture project into a polyculture solution.

Note: This material was originally presented at the 2014 Ancestral Health Symposium. I am so grateful to have had the opportunity to participate in this terrific event and for all of the interest and feedback I received from my fellow attendees.