by Bill Gates
What can we do about all this pooping, burping, and farting? That’s a tough one. Researchers have tried all sorts of ideas for dealing with enteric fermentation. They’ve tried using vaccines to cut down on the methanogenic microbes living in the cattle’s gut, breeding cattle to naturally produce fewer emissions, and adding special feeds or drugs to their diets. These efforts have mostly been unsuccessful, though one promising exception is a compound called 3-nitrooxypropanol, which reduces methane emissions by 30 percent. But right now you have to give it to the cattle at least once a day, so it’s not yet feasible for most grazing operations.
Still, there’s reason to believe we can cut down on these emissions without any new technology and without a significant Green Premium. It turns out the amount of methane produced by a given cow depends a lot on where the cow lives; for example, cattle in South America emit up to five times more greenhouse gases than ones in North America do, and African cattle emit even more. If a cow is being raised in North America or Europe, it’s more likely to be an improved breed that converts feed into milk and meat more efficiently. It will also get better veterinary care and higher-quality feed, which means it’ll produce less methane.
If we can spread the improved breeds and best practices more broadly—especially crossbreeding African cows to be more productive and making higher-quality feed available and affordable—it’ll reduce emissions and help poor farmers earn more money. The same is true for handling manure; rich-world farmers have access to various techniques that get rid of the manure while producing fewer emissions. As these techniques become more affordable, they’ll spread to poor farmers, and we’ll improve our odds of driving emissions down.
A hard-core vegan might propose another solution: Instead of trying all these ways of reducing emissions, we should just stop raising livestock. I can see the appeal of that argument, but I don’t think it’s realistic. For one thing, meat plays too important a role in human culture. In many parts of the world, even where it’s scarce, eating meat is a crucial part of festivals and celebrations. In France, the gastronomic meal—including starter, meat or fish, cheese, and dessert—is officially listed as part of the country’s Intangible Cultural Heritage of Humanity. According to the listing on the UNESCO website, “The gastronomic meal emphasizes togetherness, the pleasure of taste, and the balance between human beings and the products of nature.”
But we can cut down on meat eating while still enjoying the taste of meat. One option is plant-based meat: plant products that have been processed in various ways to mimic the taste of meat. I’ve been an investor in two companies that have plant-based meat products on the market right now—Beyond Meat and Impossible Foods—so I’m biased, but I have to say that artificial meat is pretty good. When prepared just right, it’s a convincing substitute for ground beef. And all of the alternatives out there are better for the environment, because they use much less land and water and are responsible for fewer emissions. You also need less grain to produce them, reducing the pressure on food crops and the use of fertilizers too. And it’s a huge boon for animal welfare whenever fewer livestock are being kept in small cages.
Artificial meats come with hefty Green Premiums, however. On average, a ground-beef substitute costs 86 percent more than the real thing. But as sales for these alternatives increase, and as more of them hit the market, I’m optimistic that they’ll eventually be cheaper than animal meat.
Yet the big question on artificial meat comes down to taste, not money. Although the texture of a hamburger is relatively easy to mimic with plants, it’s much harder to fool people into thinking they’re actually eating a steak or chicken breast. Will people like artificial meat enough to switch, and will enough people switch to make a significant difference?
We’re already seeing some evidence that they will. I have to admit that even I have been surprised by how well Beyond Meat and Impossible Foods are doing—especially given their early hiccups. I attended an early demonstration by Impossible Foods at which they burned the burger so badly that it set off the smoke alarm. It’s amazing to see how widely available their products are, at least around the Seattle area and the cities I visit. Beyond Meat had a very successful initial public offering in 2019. It may take another decade, but I do think that as the products get better and cheaper, people who are worried about climate change and the environment will favor them.
Another approach is akin to plant-based meat, but instead of growing plants and then processing them so they taste like beef, you grow the meat itself in a lab. It has somewhat unappealing names like “cell-based meat,” “cultivated meat,” and “clean meat,” and there are some two dozen start-up companies working on getting it to market, though their products probably won’t be on supermarket shelves until the mid-2020s.
Keep in mind that this isn’t fake meat. Cultivated meat has all the same fat, muscles, and tendons as any animal on two or four legs. But rather than growing up on a farm, it’s created in a lab. Scientists start with a few cells drawn from a living animal, let those cells multiply, and then coax them into forming all the tissues we’re used to eating. All this can be done with little or no greenhouse gas emissions, aside from the electricity you need to power the labs where the process is done. The challenge with this approach is that it’s very expensive, and it’s not clear how much the costs can come down.
And both kinds of artificial meat face another uphill battle. At least 17 U.S. state legislatures have tried to keep these products from being labeled as “meat” in stores. One state has proposed banning their sale altogether. So even as the technology improves and the products get cheaper, we’ll need to have a healthy public debate about how they’re regulated, packaged, and sold.
There’s one last way we can cut down on emissions from the food we eat: by wasting less of it. In Europe, industrialized parts of Asia, and sub-Saharan Africa, more than 20 percent of food is simply thrown away, allowed to rot, or otherwise wasted. In the United States, it’s 40 percent. That’s bad for people who don’t have enough to eat, bad for the economy, and bad for the climate. When wasted food rots, it produces enough methane to cause as much warming as 3.3 billion tons of carbon dioxide each year.
The most important solution is behavior change—using more of what we have. But technology can help. For example, two companies are working on invisible, plant-based coatings that extend the life of fruits and vegetables; they’re edible, and they don’t affect the taste at all. Another has developed a “smart bin” that uses image recognition to track how much food is wasted in a house or business. It gives you a report on how much you threw away, along with its cost and its carbon footprint. The system may sound invasive, but giving people more information can help them make better choices.
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A few years ago, I stepped into a warehouse in Dar es Salaam, Tanzania, and saw something that thrilled me: thousands of tons of synthetic fertilizer piled as high as snowdrifts. The warehouse was part of the new Yara fertilizer distribution center, which was the largest of its kind in East Africa. Walking around the warehouse, I talked to workers filling bags with tiny white pellets containing nitrogen, phosphorus, and other nutrients that would soon be nourishing crops in one of the poorest regions in the world.
It was the kind of trip I love to take. I know it sounds goofy to say this, but to me fertilizer is magical, and not just because it makes our yards and gardens prettier. Along with Norman Borlaug’s semi-dwarf wheat and new varieties of corn and rice, synthetic fertilizer was a key factor in the agricultural revolution that changed the world in the 1960s and 1970s. It’s been estimated that if we couldn’t make synthetic fertilizer, the world’s population would be 40 to 50 percent smaller than it is.
Touring the Yara fertilizer distribution facility in Dar es Salaam, Tanzania, 2018. I’m having even more fun than it looks.
The world uses a lot of fertilizer already, and poor countries should be using more. The agricultural revolution I mentioned—often call
ed the Green Revolution—largely bypassed Africa, where the typical farmer gets just one-fifth as much food per acre of land as an American farmer gets. That’s because in poor countries most farmers don’t have good enough credit to buy fertilizer, and it’s more expensive than in rich countries because it has to be shipped into rural areas over poorly built roads. If we can help poor farmers raise their crop yields, they’ll earn more money and have more to eat, and millions of people in some of the world’s poorest countries will be able to get more food and the nutrients they need. (We’ll cover this in more depth in chapter 9.)
Why is fertilizer so magical? Because it provides plants with essential nutrients, including phosphorus, potassium, and the one that’s especially relevant to climate change: nitrogen. Nitrogen is a mixed blessing. It’s closely linked to photosynthesis, the process by which plants turn sunlight into energy, so it makes all plant life—and therefore all our food—possible. But nitrogen also makes climate change much worse. To understand why, we need to talk about what it does for plants.
There’s a huge gap in agriculture. Thanks to fertilizer and other improvements, American farmers now get more corn per unit of land than ever. But African farmers’ yields have barely budged. Narrowing the gap will save lives and help people escape poverty, but without innovation it will also make climate change worse. (FAO)
To grow crops, you want tons of nitrogen—way more than you would ever find in a natural setting. Adding nitrogen is how you get corn to grow 10 feet high and produce enormous quantities of seed. Oddly, most plants can’t make their own nitrogen; instead, they get it from ammonia in the soil, where it’s created by various microorganisms. A plant will keep growing as long as it can get nitrogen, and it’ll stop once the nitrogen is all used up. That’s why adding it boosts growth.
For millennia, humans fed their crops extra nitrogen by applying natural fertilizers like manure and bat guano. The big breakthrough came in 1908, when two German chemists named Fritz Haber and Carl Bosch figured out how to make ammonia from nitrogen and hydrogen in a factory. It’s hard to overstate how momentous their invention was. What’s now known as the Haber-Bosch process made it possible to create synthetic fertilizer, greatly expanding both the amount of food that could be grown and the range of geographies where it could be grown. It’s still the main method we use to make ammonia today. In the same way that Norman Borlaug is one of the great unsung heroes of history, Haber-Bosch might be the most important invention that most people have never heard of.*
Here’s the rub: Microorganisms that make nitrogen expend a lot of energy in the process. So much energy, in fact, that they’ve evolved to do it only when they absolutely need to—when there’s no nitrogen in the soil around them. If they detect enough nitrogen, they stop producing it so they can use the energy for something else. So when we add synthetic fertilizer, the natural organisms in the soil sense the nitrogen and stop producing it on their own.
There are other downsides to synthetic fertilizer. To make it, we have to produce ammonia, a process that requires heat, which we get by burning natural gas, which produces greenhouse gases. Then, to move it from the facility where it’s made to the warehouse where it’s stored (like the place I visited in Tanzania) and eventually the farm where it’s used, we load it on trucks that are powered by gasoline. Finally, after the fertilizer is applied to soil, much of the nitrogen that it contains never gets absorbed by the plant. In fact, worldwide, crops take up less than half the nitrogen applied to farm fields. The rest runs off into ground or surface waters, causing pollution, or escapes into the air in the form of nitrous oxide—which, you may recall, has 265 times the global-warming potential of carbon dioxide.
All told, fertilizers were responsible for roughly 1.3 billion tons of greenhouse gas emissions in 2010, and the number will probably rise to 1.7 billion tons by mid-century. Haber-Bosch giveth, and Haber-Bosch taketh away.
Unfortunately, there simply isn’t a practical zero-carbon alternative for fertilizer right now. It’s true that we could get rid of the emissions involved in making fertilizer by using clean electricity instead of fossil fuels to synthesize ammonia, but that’s an expensive process that would raise the price of fertilizer considerably. In the United States, for example, using this process to make the nitrogen-based fertilizer urea would raise its cost by more than 20 percent.
But that’s just the emissions from making fertilizer. We don’t have any way to capture the greenhouse gases that come from applying it. There’s no equivalent of carbon capture for nitrous oxide. That means I can’t calculate a complete Green Premium for zero-carbon fertilizer—which itself is actually useful information, because it tells us that we need significant innovation in this area.
Technically, it’s possible to get crops to absorb nitrogen much more efficiently than they do, if farmers have the technology to monitor their nitrogen levels very carefully and apply fertilizer in just the right amount over the course of a growing season. But that’s an expensive and time-consuming process, and fertilizer is cheap (at least in rich countries). It’s more economical to apply more than you need, knowing that you’re at least using enough to maximize the growth of your crops.
Some companies have developed additives that are supposed to help plants take up more nitrogen so there’s less to wash into groundwater or evaporate into the atmosphere. But these additives are used with only 2 percent of global fertilizers, because they don’t work consistently well and manufacturers aren’t investing much to improve them.
Other experts are working on different ways to solve the nitrogen problem. For example, some researchers are doing genetic work on new varieties of crops that can recruit bacteria to fix nitrogen for them. In addition, one company has developed genetically modified microbes that fix nitrogen; in effect, instead of adding nitrogen via fertilizer, you add bacteria to the soil that always produce nitrogen even when it’s already present. If these approaches work, they’ll dramatically reduce the need for fertilizer and all the emissions it’s responsible for.
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Everything you’ve just read about—which I’d broadly describe as agriculture—accounts for roughly 70 percent of emissions from farming, forestry, and other uses of land. If I had to sum up the other 30 percent in one word, it would be “deforestation.”
According to the World Bank, the world has lost more than half a million square miles of forest cover since 1990. (That’s an area bigger than South Africa or Peru, and a decline of roughly 3 percent.) There’s the immediate and obvious impact of deforestation—if the trees are burned down, for example, they quickly release all the carbon dioxide they contain—but it also causes damage that’s harder to see. When you take a tree out of the ground, you disturb the soil, and it turns out that there’s a lot of carbon stored up in soil (in fact, there’s more carbon in soil than in the atmosphere and all plant life combined). When you start removing trees, that stored carbon gets released into the atmosphere as carbon dioxide.
Deforestation would be easier to stop if it were happening for the same reasons in every place, but unfortunately that’s not the case. In Brazil, for example, most of the destruction of the Amazon rain forest in the past few decades has been to clear pastureland for cattle. (Brazil’s forests have shrunk by 10 percent since 1990.) And because food is a global commodity, what’s consumed in one country can cause land-use changes in another. As the world eats more meat, it accelerates the deforestation in Latin America. More burgers anywhere mean fewer trees there.
And all these emissions add up fast. One study by the World Resources Institute found that if you account for land-use changes, the American-style diet is responsible for almost as many emissions as all the energy Americans use in generating electricity, manufacturing, transportation, and buildings.
But in other parts of the world, deforestation isn’t about turning out more burgers and steaks. In Africa, for example, it’s a matter of clearing land to grow food and fuel for the co
ntinent’s growing population. Nigeria, which has had one of the highest deforestation rates in the world, has lost more than 60 percent of its forest cover since 1990, and it’s one of the world’s biggest exporters of charcoal, which is created by charring wood.
In Indonesia, on the other hand, forests are being cut down to make way for palm trees, which provide the palm oil you’ll find in everything from movie-theater popcorn to shampoo. It’s one of the main reasons why the country is the world’s fourth-largest emitter of greenhouse gases.
I wish there were some breakthrough invention I could tell you about that will make the world’s forests safe. There are a few things that will help, such as advanced satellite-based monitors that make it easier to spot deforestation and forest fires as they’re happening and to measure the extent of the damage afterward. I’m also following some companies that are developing synthetic alternatives to palm oil so we don’t have to cut down so many forests to make room for palm plantations.
But this isn’t primarily a technological problem. It’s a political and economic problem. People cut down trees not because people are evil; they do it when the incentives to cut down trees are stronger than the incentives to leave them alone. So we need political and economic solutions, including paying countries to maintain their forests, enforcing rules designed to protect certain areas, and making sure rural communities have different economic opportunities so they don’t have to extract natural resources just to survive.
You might’ve heard about one forest-related solution for climate change: planting trees as a way to capture carbon dioxide from the atmosphere. Although it sounds like a simple idea—the cheapest, lowest-tech carbon capture imaginable—and it has obvious appeal for all of us who love trees, it actually opens up a very complicated subject. It needs to be studied a lot more, but for now its effect on climate change appears to be overblown.
