How to Avoid a Climate Disaster
Page 10
*3 Think of transmission as the freeway and distribution as the local road. We use high-voltage transmission lines to deliver electricity from the power plant to the city. Then the electricity goes into the local, lower-voltage distribution system—the power lines you see in your neighborhood.
*4 There’s also seasonal variation for wind. In the United States, wind power tends to be at its peak in the spring and reach its low point in mid- to late summer (although it’s the opposite in California). The difference can be a multiple of two to four.
*5 Here’s how I got these figures: Between August 6 and August 8, 2019, Tokyo consumed 3,122 gigawatt-hours of electricity. For baseload power, I assumed 5.4 million iron-flow batteries with a system lifetime of 20 years and a per-unit cost of $36,000. For peak demand, I assumed 9.1 million lithium-ion batteries with a system lifetime of 10 years and a per-unit cost of $23,300.
*6 This model is available online for the public. See breakthroughenergy.org for more information.
CHAPTER 5
HOW WE MAKE THINGS
31 percent of 51 billion tons per year
It’s an eight-mile drive from Medina, Washington, where Melinda and I live, to the Seattle headquarters of our foundation. To get to the office, I cross Lake Washington on what’s officially known as the Evergreen Point Floating Bridge, although no one who lives around here actually calls it that; to locals, it’s the 520 bridge, named for the state highway that runs across it. At more than 7,700 feet, it’s the longest floating bridge in the world.
Every so often when I cross the 520 bridge, I take a moment to appreciate how marvelous it is. Not because it’s the longest floating bridge in the world, but because it’s a bridge that floats. How can this massive structure made with tons of asphalt, concrete, and steel, and with hundreds of cars sitting on it, float on top of a lake? Why the hell doesn’t it sink?
The answer is a miracle of engineering brought to us by an amazing material: concrete. At first glance, this may seem strange, because it’s so natural to think of concrete as this heavy block that couldn’t possibly float. Although it’s true that concrete can be made that way—solid enough to absorb nuclear radiation in the walls of a hospital—it can also be used to make hollow shapes, like the 77 air-filled, watertight pontoons that support the 520 bridge. Each weighs thousands of tons, is buoyant enough to float on the surface of the lake, and is sturdy enough to support the bridge and all the cars speeding across it. Or, more likely, inching across it, during one of our daily traffic jams.
This is the 520 bridge in Seattle, which I cross whenever I drive from home to the Gates Foundation’s headquarters. It’s a marvel of modern engineering.
You don’t have to look very hard to find concrete performing other miracles around you. It’s rust-resistant, rot-proof, and nonflammable, which is why it’s part of most modern buildings. If you’re a fan of hydropower, you should appreciate concrete for making dams possible. The next time you see the Statue of Liberty, take a look at the pedestal she’s standing on. It’s made of 27,000 tons of concrete.
The charms of concrete were not lost on America’s greatest inventor. Thomas Edison tried to create entire homes built out of the stuff. He dreamed of making concrete furniture, like bedroom sets, and even tried to design a concrete record player.
These imaginings of Edison’s never came to pass, but even so we use a lot of concrete. Every year, between replacing or repairing existing roads, bridges, and buildings and putting up new ones, America alone produces more than 96 million tons of cement, one of the main ingredients in concrete. That’s nearly 600 pounds for every person in the country. And we’re not even the biggest consumers of the stuff—that would be China, which installed more concrete in the first 16 years of the 21st century than the United States did in the entire 20th century!
China makes a lot of cement. The country has already produced more in the 21st century than the United States did in the entire 20th century. (U.S. Geological Survey)
Obviously, cement and concrete aren’t the only materials we rely on. There’s also the steel we put in cars, ships, and trains; refrigerators and stoves; factory machines; cans of food; and even computers. Steel is strong, cheap, durable, and infinitely recyclable. It also makes a terrific partner with concrete: Insert steel rods inside a block of concrete, and you’ve got a magical construction material that can withstand tons of weight and also won’t break apart when you twist it. That’s why we use reinforced concrete in most of our buildings and bridges.
Americans use as much steel as cement—so that’s another 600 pounds per person, every year, not counting the steel we recycle and use again.
Plastics are another amazing material. They’re in so many products, from clothes and toys to furniture and cars and cell phones, that it’s impossible to list them all. Plastics have a bad reputation these days, a reputation that’s partially fair. But they also do a lot of good. As I write this chapter, I’m sitting at my desk and can see plastics all around me: my computer, keyboard, monitor, and mouse, my stapler, my phone, and on and on. Plastics are also what allow fuel-efficient cars to be so light; they account for as much as half of a car’s total volume, but only 10 percent of its weight.
Then there’s glass—in our windows, jars and bottles, insulation, cars, and the fiber-optic cables that give you a high-speed internet connection. Aluminum goes into soda cans, foil, power lines, doorknobs, trains, planes, and beer kegs. Fertilizer helps feed the world. Years ago, I predicted the demise of paper as electronic communications became more common and screens became more ubiquitous, but it doesn’t show much sign of going away anytime soon.
In short, we make materials that have become just as essential to modern life as electricity is. We’re not going to give them up. If anything, we’ll be using more of them as the world’s population grows and gets richer.
There’s copious data to back up this claim—we’ll be producing 50 percent more steel by mid-century than we do today, for example—but I think the two pictures below are just as persuasive.
Take a quick look at them. They look like two different cities, right?
These two photos capture what growth looks like—for better and for worse. Shanghai in 1987 (left) and 2013 (right).
They aren’t. They’re both photos of Shanghai, taken from the same vantage point. The one on the left was taken in 1987, the one on the right in 2013. When I look at all those new buildings in the photo on the right, I see tons and tons of steel, cement, glass, and plastic.
This story is being repeated all over the world, though the growth in most places isn’t as dramatic as it was in Shanghai. To repeat a theme that comes up repeatedly in this book: This progress is a good thing. The rapid growth you see in these two photos means that people’s lives are improving in countless ways. They are earning more money, are getting a better education, and are less likely to die young. Anyone who cares about fighting poverty should see it as good news.
But, to repeat another theme that comes up a lot in this book: This silver cloud has a dark lining. Making all these materials emits lots of greenhouse gases. In fact, they’re responsible for about a third of all emissions worldwide. And in some cases, notably concrete, we don’t have a practical way to make them without producing carbon.
So let’s look at how we can square this circle—how we can keep producing these materials without making the climate unlivable. For the sake of brevity, we’ll focus on three of the most important materials: steel, concrete, and plastic. As we did with electricity, we’ll look at how we got here and why these materials are so problematic for the climate. Then we’ll calculate the Green Premiums for reducing emissions using today’s technology, and we’ll examine ways to drive down the Green Premiums and make all this stuff without emitting carbon.
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The history of steel goes back some 4,000 years. The
re’s a long series of fascinating inventions over the centuries that got us from the Iron Age to the cheap, versatile steel we have today, but in my experience most people don’t want to hear a lot about the differences between blast furnaces, puddling furnaces, and the Bessemer process. So here are the main things you need to know.
We like steel because it’s both strong and easy to shape when it’s hot. To make steel, you need pure iron and carbon; on its own, iron isn’t very strong, but add just the right amount of carbon—less than 1 percent, depending on the kind of steel you want—and the carbon atoms nestle themselves in between the iron atoms, giving the resulting steel its most important properties.
Carbon and iron aren’t hard to find—you can get carbon from coal, and iron is a common element in the earth’s crust. But pure iron is quite rare: When you dig up the metal, it’s almost always combined with oxygen and other elements—a mixture known as iron ore.
To make steel, you need to separate the oxygen from the iron and add a tiny bit of carbon. You can accomplish both at the same time by melting iron ore at very high temperatures (1,700 degrees Celsius or over 3,000 degrees Fahrenheit), in the presence of oxygen and a type of coal called coke. At those temperatures, the iron ore releases its oxygen, and the coke releases its carbon. A bit of the carbon bonds with the iron, forming the steel we want, and the rest of the carbon grabs onto the oxygen, forming a by-product we don’t want: carbon dioxide. Quite a bit of carbon dioxide, in fact. Making 1 ton of steel produces about 1.8 tons of carbon dioxide.
Why do we do it this way? Because it’s cheap, and until we started worrying about climate change, we had no incentive to do it any other way. Iron ore is pretty easy (and therefore inexpensive) to dig up. Coal too is inexpensive, because there’s so much of it in the ground.
So the world is going to keep chugging along, making more steel, even as production basically plateaus in the United States. Several other countries now produce more raw steel than the United States does—China, India, and Japan among them—and by 2050 the world will be producing roughly 2.8 billion tons every year. That adds up to 5 billion tons of carbon dioxide released every year by mid-century, just from making steel, unless we find a new, climate-friendly way to do it.
As challenging as that may sound, concrete is even harder. (Sorry—no pun intended.) To make it, you mix together gravel, sand, water, and cement. The first three of these are relatively easy; it’s the cement that is a problem for the climate.
To make cement, you need calcium. To get calcium, you start with limestone—which contains calcium plus carbon and oxygen—and burn it in a furnace along with some other materials.
Given the presence of carbon and oxygen, you can probably see where this is going. After burning the limestone, you end up with the thing you want—calcium for your cement—plus something you don’t want: carbon dioxide. Nobody knows of a way to make cement without going through this process. It’s a chemical reaction—limestone plus heat equals calcium oxide plus carbon dioxide—and there’s no way around it. It’s a one-to-one relationship. Make a ton of cement, and you’ll get a ton of carbon dioxide.
And, just like with steel, there’s no reason to think we’re going to stop making cement. China is the biggest producer by far, outpacing second-place India by a factor of seven and making more than the rest of the world combined. Between now and 2050, the world’s annual cement production will go up a bit—as the building boom slows in China and picks up in smaller developing countries—before settling back down near 4 billion tons a year, roughly where it is today.
Compared with cement and steel, plastics are the baby of the group. Although humans were using natural plastics, such as rubber, thousands of years ago, synthetic plastics only came into their own in the 1950s, thanks to some breakthroughs in chemical engineering. Today there are more than two dozen types of plastics, and they range from the kind of thing you might expect—the polypropylene in yogurt containers, for example—to more surprising uses like the acrylic in paint, floor polish, and laundry detergent, or the microplastics in soap and shampoo, or the nylon in your waterproof jacket, or the polyester in all those regrettable clothes I wore in the 1970s.
All these different types of plastics have one thing in common: They contain carbon. Carbon, it turns out, is useful in creating all sorts of different materials because it bonds easily with a wide variety of different elements; in the case of plastics, it’s usually clustered with hydrogen and oxygen.
Since you’ve read this far, you probably won’t be surprised to learn where companies that make plastics tend to get their carbon. They get it by refining oil, coal, or natural gas and then processing the refined products in various ways. This helps explain why plastics have earned a reputation for being inexpensive: Like cement and steel, plastics are cheap because fossil fuels are cheap.
But there’s one important way that plastics are fundamentally different from cement and steel. When we make cement or steel, we release carbon dioxide as an inevitable by-product, but when we make a plastic, around half of the carbon stays in the plastic. (The actual percentage varies quite a bit, depending on which kind of plastic you’re talking about, but around half is a reasonable approximation.) Carbon really likes bonding with the oxygen and hydrogen, and it isn’t inclined to let go. Plastics can take hundreds of years to degrade.
That’s a major environmental problem, because the plastics that get dumped in landfills and oceans stick around for a century or more. And it’s a problem that’s worth solving: Pieces of plastic floating around in the ocean cause all sorts of problems, including poisoning marine life. But they’re not making climate change worse. Purely in terms of emissions, the carbon in plastics is not such bad news. Because plastics take so long to degrade, all the carbon atoms that go into them are atoms that won’t go into the atmosphere and drive up the temperature—at least not for a very long time.
I’ll pause here to emphasize that this quick survey covers only three of the most important materials we make today. I’m leaving out fertilizer, glass, paper, aluminum, and many others. But the key points remain the same: We manufacture an enormous amount of materials, resulting in copious amounts of greenhouse gases, nearly a third of the 51 billion tons per year. We need to get those emissions down to zero, but it’s not an option to simply stop making things. In the rest of this chapter, we’ll examine the alternatives, see how high the Green Premiums are, and then look at how technology might drive the premiums down so everyone will want to adopt the zero-emissions approach.
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To figure the Green Premiums on materials, you need to understand where emissions come from when we make things. I think of it in three stages: We emit greenhouse gases (1) when we use fossil fuels to generate the electricity that factories need to run their operations; (2) when we use them to generate heat needed for different manufacturing processes, like melting iron ore to make steel; and (3) when we actually make these materials, like the way cement manufacturing inevitably creates carbon dioxide. Let’s take these one by one and see how they contribute to the Green Premiums.
For the first stage, electricity, we covered most of the key challenges in chapter 4. After you factor in storage and transmission, and the fact that many factories need reliable power around the clock, the cost for clean electricity goes up fast—much more for most countries than for the United States or Europe.
Then there’s the second stage: How can we generate heat without burning fossil fuels? If you don’t need super-high temperatures, you can use electric heat pumps and other technologies. But when you’re looking for temperatures in the thousands of degrees, electricity isn’t an economical option—at least not with today’s technology. You’ll have to either use nuclear power or burn fossil fuels and grab the emissions with carbon-capture devices. Unfortunately, carbon capture doesn’t come for free. It adds to the manufacturer’s cost and gets pa
ssed on to the consumer.
Finally, the third stage: What can we do about the processes that inherently produce greenhouse gas emissions? Remember that making steel and cement emits carbon dioxide—not just from burning fossil fuels, but as a result of the chemical reactions that are essential to their creation.
Right now, the answer is clear: Short of simply shutting down these parts of the manufacturing sector, we can do nothing today to avoid these emissions. If we wanted to go all in on eliminating them using whatever technologies we have available today, our options would be as limited as they were in the second stage. We’d have to use fossil fuels and carbon capture—which, again, adds to the cost.
With those three stages in mind, let’s look at the range of Green Premiums for using carbon capture to make clean plastics, steel, and cement:
Green Premiums for plastics, steel, and cement
Material
Ethylene (plastic)
Steel
Cement
Average price per ton
$1,000
$750
$125
Carbon emitted per ton of material made
1.3 tons
1.8 tons
1 ton
New price after carbon capture
$1,087–$1,155
$871–$964
$219–$300