How to Avoid a Climate Disaster
Page 14
Fuel type: Gasoline
Retail price per gallon
$2.43
Zero-carbon option per gallon
$5.00
(advanced biofuels)
Green Premium
106%
NOTE: Retail prices in this and subsequent charts are the average in the United States from 2015 to 2018. Zero-carbon options reflect current estimated prices.
Biofuels get their energy from plants, but that’s not the only way to create alternative fuels. We can also use zero-carbon electricity to combine the hydrogen in water with the carbon in carbon dioxide, resulting in hydrocarbon fuels. Because you use electricity in the process, these fuels are sometimes called electrofuels, and they have a lot of advantages. They’re drop-in fuels, and because they’re made using carbon dioxide captured from the atmosphere, burning them doesn’t add to overall emissions.
But electrofuels also have a downside: They’re very expensive. You need hydrogen to make them, and as I mentioned in chapter 4, it costs a lot to make hydrogen without emitting carbon. In addition, you need to make them using clean electricity—otherwise, there’s no point—and we don’t yet have enough cheap, clean electricity in our power grid to use it economically for making fuel. It all adds up to a high Green Premium for electrofuels:
Green Premium to replace gasoline with zero-carbon alternatives
Fuel type: Gasoline
Retail price per gallon
$2.43
$5.00
(advanced biofuels)
Zero-carbon option per gallon
$2.43
$8.20
(electrofuels)
Green Premium
106%
237%
What does that mean for the average family? In the United States, a typical household spends around $2,000 a year on gasoline. So if the price doubles, that’s an extra $2,000 premium, and if it triples, that’s an extra $4,000 for every conventional passenger car on the road in America.
Garbage trucks, buses, and 18-wheelers. Unfortunately, batteries are a less practical option when it comes to long-distance buses and trucks. The bigger the vehicle you want to move, and the farther you want to drive it without recharging, the harder it’ll be to use electricity to power your engine. That’s because batteries are heavy, they can store only a limited amount of energy, and they can deliver only a certain amount of that energy to the engine at one time. (It takes a more powerful engine—one with more batteries—to run a heavy truck than a light hatchback.)
Medium-duty vehicles, like garbage trucks and city buses, are generally lightweight enough that electricity is a viable option for them. They also have the advantage of running relatively short routes and parking in the same place every night, so it’s easy to set up charging stations for them. The city of Shenzhen, China—home to 12 million people—has electrified its entire fleet of more than 16,000 buses and nearly two-thirds of its taxis. With the volume of electric buses being sold in China, I think the Green Premium for buses will reach zero within a decade, which means that most cities in the world will be able to shift their fleets.
Shenzhen, China, electrified its fleet of 16,000 buses.
But if you want to add more distance and power—for example, if you’re trying to run an 18-wheeler loaded with cargo on a cross-country trip, rather than a school bus full of students on a route around the neighborhood—you’ll need to carry many more batteries. And as you add batteries, you also add weight. A lot of weight.
Pound for pound, the best lithium-ion battery available today packs 35 times less energy than gasoline. In other words, to get the same amount of energy as a gallon of gas, you’ll need batteries that weigh 35 times more than the gas.
Here’s what that means in practical terms. According to a 2017 study by two mechanical engineers at Carnegie Mellon University, an electric cargo truck capable of going 600 miles on a single charge would need so many batteries that it would have to carry 25 percent less cargo. And a truck with a 900-mile range is out of the question: It would need so many batteries that it could hardly carry any cargo at all.
Keep in mind that a typical truck running on diesel can go more than 1,000 miles without refueling. So to electrify America’s fleet of trucks, freight companies would have to shift to vehicles that carry less cargo, stop to recharge far more often, spend hours of time recharging, and somehow travel long stretches of highway where there are no recharging stations. It’s just not going to happen anytime soon. Although electricity is a good option when you need to cover short distances, it’s not a practical solution for heavy, long-haul trucks.
Because we can’t electrify our cargo trucks, the only solutions available today are electrofuels and advanced biofuels. Unfortunately, they have dramatic Green Premiums too. Let’s add them to the chart:
Green Premiums to replace diesel with zero-carbon alternatives
Fuel type: Diesel
Retail price per gallon
$2.71
$5.50
(advanced biofuels)
Zero-carbon option per gallon
$2.71
$9.05
(electrofuels)
Green Premium
103%
234%
Ships and planes. Not long ago, my friend Warren Buffett and I were talking about how the world might decarbonize airplanes. Warren asked, “Why can’t we run a jumbo jet on batteries?” He already knew that when a jet takes off, the fuel it’s carrying accounts for 20 to 40 percent of its weight. So when I told him this startling fact—that you’d need 35 times more batteries by weight to get the same energy as jet fuel—he understood immediately. The more power you need, the heavier your plane gets. At some point, it’s so heavy that it can’t get off the ground. Warren smiled, nodded, and just said, “Ah.”
When you’re trying to power something as heavy as a container ship or jetliner, the rule of thumb I mentioned earlier—the bigger the vehicle you want to move, and the farther you want to drive it without recharging, the harder it’ll be to use electricity as your power source—becomes a law. Barring some unlikely breakthrough, batteries will never be light and powerful enough to move planes and ships anything more than short distances.
Consider where the state of the art is today. The best all-electric plane on the market can carry two passengers, reach a top speed of 210 miles per hour, and fly for three hours before recharging.*3 Meanwhile, a mid-capacity Boeing 787 can carry 296 passengers, reach up to 650 miles an hour, and fly for nearly 20 hours before stopping for fuel. In other words, a fossil-fuel-powered jetliner can fly more than three times as fast, for six times as long, and carry nearly 150 times as many people as the best electric plane on the market.
Batteries are getting better, but it’s hard to see how they’ll ever close this gap. If we’re lucky, they may become up to three times as energy dense as they are now, in which case they would still be 12 times less energy dense than gas or jet fuel. Our best bet is to replace jet fuel with electrofuels and advanced biofuels, but look at the hefty premiums that come with them:
Green Premiums to replace jet fuel with zero-carbon alternatives
Fuel type: Jet fuel
Retail price per gallon
$2.22
$5.35
(advanced biofuels)
Zero-carbon option per gallon
$2.22
$8.80
(electrofuels)
Green Premium
141%
296%
The same goes for cargo ships. The best conventional container ships can carry 200 times more cargo than either of the two electric ships now in operation, and they can run routes that are 400 times longer. Those are major advantages for ships that need to cross entire oceans.
Given how important container ships have become in the global economy, I don’t think it will ever be financially viable to try to run them on anything other than liquid fuels. Making the switch to alternatives would do us a lot of good; because sh
ipping alone accounts for 3 percent of all emissions, using clean fuels would give us a meaningful reduction. Unfortunately, the fuel that container ships run on—it’s called bunker fuel—is dirt cheap, because it’s made from the dregs of the oil-refining process. Since their current fuel is so inexpensive, the Green Premium for ships is very high:
Green Premiums to replace bunker fuel with zero-carbon alternatives
Fuel type: Bunker fuel
Retail price per gallon
$1.29
$5.50
(advanced biofuels)
Zero-carbon option per gallon
$1.29
$9.05
(electrofuels)
Green Premium
326%
601%
To sum up, here are all the Green Premiums from this chapter:
Green Premiums to replace current fuels with zero-carbon alternatives
Fuel type: Gasoline
Retail price per gallon
$2.43
$5.00
(advanced biofuels)
Zero-carbon option per gallon
$2.43
$8.20
(electrofuels)
Green Premium
106%
237%
Fuel type: Diesel
Retail price per gallon
$2.71
$5.50
(advanced biofuels)
Zero-carbon option per gallon
$2.71
$9.05
(electrofuels)
Green Premium
103%
234%
Fuel type: Jet fuel
Retail price per gallon
$2.22
$5.35
(advanced biofuels)
Zero-carbon option per gallon
$2.22
$8.80
(electrofuels)
Green Premium
141%
296%
Fuel type: Bunker fuel
Retail price per gallon
$1.29
$5.50
(advanced biofuels)
Zero-carbon option per gallon
$1.29
$9.05
(electrofuels)
Green Premium
326%
601%
Would most people be willing to accept these increases? It’s not clear. But consider that the last time the United States raised the federal gas tax—imposed any increase at all—was more than a quarter century ago, in 1993. I don’t think Americans are eager to pay more for gas.
* * *
—
There are four ways to cut down on emissions from transportation. One is to do less of it—less driving, flying, and shipping. We should encourage more alternative modes, like walking, biking, and carpooling, and it’s great that some cities are using smart urban plans to do just that.
Another way to cut down on emissions is to use fewer carbon-intensive materials in making cars to begin with—although that wouldn’t affect the fuel-based emissions we’ve covered in this chapter. As I mentioned in chapter 5, every car is made from materials like steel and plastics that can’t be manufactured without emitting greenhouse gases. The less of these materials we need in our cars, the lower their carbon footprint will be.
The third way to cut down on emissions is to use fuels more efficiently. This subject gets a lot of attention from lawmakers and the press, at least as it pertains to passenger cars and trucks; most major economies have fuel efficiency standards for those vehicles, and they’ve made a big difference by forcing car companies to fund the advanced engineering of more efficient engines.
But the standards don’t go far enough. For example, there are suggested emissions standards for international shipping and aviation, but they’re almost unenforceable. Which country’s jurisdiction would cover carbon emissions from a container ship in the middle of the Atlantic Ocean?
Besides, although making and using more efficient vehicles are important steps in the right direction, they won’t get us to zero. Even if you’re burning less gasoline, you’re still burning gasoline.
That brings me to the fourth—and most effective—way we can move toward zero emissions from transportation: switching to electric vehicles and alternative fuels. As I’ve argued in this chapter, both options currently carry a Green Premium to one degree or another. Let’s look at ways to reduce it.
How to Lower the Green Premium
For passenger cars, the Green Premium is on the way down and will eventually shrink to zero. It is true that as higher-mileage cars and EVs replace today’s vehicles, the revenue from gas taxes will go down, which could reduce the funding that’s available for building and maintaining roads. States can replace the lost revenue by charging EV owners an extra fee when they renew their license plates—19 states are doing this as I write this chapter—though it means it’ll take a year or two longer for EVs to be as cheap as gas-fueled cars.
EVs are driving into another headwind too: America’s love for big, gas-guzzling trucks. In 2019, we bought more than 5 million cars and 12 million trucks and SUVs. All but 2 percent of these vehicles run on gasoline.
To turn things around, we’ll need some inventive government policies. We can speed up the transition by adopting policies that encourage people to buy EVs and creating a network of charging stations so they’re more practical to own. Nationwide commitments can help drive up the supply of cars and drive down their cost; China, India, and several countries in Europe have all announced goals to phase out fossil-fueled vehicles—mostly passenger cars—over the coming decades. California has committed to buying only electric buses by 2029 and to banning the sale of gas-powered cars by 2035.
Next, to run all these EVs we hope to have on the road, we’ll need a lot of clean electricity—one more reason why it’s so important to deploy renewable sources and pursue the breakthroughs in generation and storage that I mentioned in chapter 4.
We should also be exploring nuclear-powered container ships. The risks here are real (for example, you have to make sure the nuclear fuel doesn’t get released if the ship sinks), but many of the technical challenges have already been solved. After all, military submarines and aircraft carriers run on nuclear power already.
Finally, we need a massive effort to explore all the ways we can make advanced biofuels and cheap electrofuels. Companies and researchers are exploring several different pathways—for example, new ways to make hydrogen using electricity, or using solar power, or using microbes that naturally produce hydrogen as a by-product. The more we explore, the more opportunities we’ll create for breakthroughs.
* * *
—
It’s rare that you can boil the solution for such a complex subject down into a single sentence. But with transportation, the zero-carbon future is basically this: Use electricity to run all the vehicles we can, and get cheap alternative fuels for the rest.
In the first group are passenger cars and trucks, light and medium trucks, and buses. In the second group are long-distance trucks, trains, airplanes, and container ships. As for cost, electric passenger cars will soon be no more expensive to own than gas-powered ones, which is great; but alternative fuels are still quite expensive, which isn’t great. We need innovation to bring those prices down.
This chapter has covered how we move people and goods around from place to place. Next we’ll talk about the places we’re headed to—our homes, offices, and schools—and what it takes to keep them livable in a warmer world.
Skip Notes
*1 Of course, for people who rely on their cars, gasoline is more of a necessity than the other things I’ve listed. If you’re watching your spending, you will feel the crunch of higher gas prices more than a rise in the cost of, say, olive oil, which you can always decide not to buy. But the point remains that among the things we consume on a regular basis, gasoline is relatively inexpensive.
*2 As a reminder, I’m counting only emissions from the fuel that various vehicles burn. Th
e emissions from manufacturing them—making the steel and plastic, running the factories, and so on—are counted under “How we make things” and covered in chapter 5.
*3 Air speed is usually measured in knots, but most people (including me) don’t know how much a knot is. In any case, knots are pretty close to miles per hour.
CHAPTER 8
HOW WE KEEP COOL AND STAY WARM
7 percent of 51 billion tons a year
I never thought I’d find something to like about malaria. It kills 400,000 people a year, most of them children, and the Gates Foundation is part of a global push to eradicate it. So I was surprised when I learned a while back that there is actually one nice thing you can say about malaria: It helped give us air-conditioning.
Humans have been trying to beat the heat for millennia. Buildings in ancient Persia were equipped with wind catchers, or badgirs, which helped keep the air moving and the temperature cool. But the first known machine to produce cold air was created in the 1840s by John Gorrie, a physician in Florida who thought cooler temperatures would help his patients recover from malaria.
Back then, it was widely believed that malaria was caused not by a parasite, as we now know it is, but by bad air (hence the name, mal-aria). Gorrie set up a device that cooled off his sick ward by moving air over a big block of ice suspended from the ceiling. But the machine went through ice quickly, and ice was expensive because it had to be shipped in from the north, so Gorrie designed a machine to make it himself. He eventually received a patent for his ice maker, and he left medicine to try to market his invention. Unfortunately, his business plans didn’t pan out. After a series of misfortunes, Gorrie died penniless in 1855.