How to Avoid a Climate Disaster: The Solutions We Have and the Breakthroughs We Need

Making material like concrete, steel, and plastic contributes the most to greenhouse gas emissions. These processes account for 31% of the 51 billion tons annually. Gates reviews each process individually to show how it creates carbon as a byproduct. Making steel requires heating iron ore with a type of coal called coke. The coke releases carbon. However, only a small amount is necessary to form steel; the rest of the carbon bonds with oxygen from the iron ore to form carbon dioxide. Producing one ton of steel emits nearly two tons of carbon dioxide. Likewise, making concrete involves heating materials that emit carbon dioxide; here, the ratio of concrete to CO2 is one to one. With plastics, the result is the same, except that about half the carbon stays in the finished material.

To figure out the Green Premiums on these materials, we need to look at the three steps that release greenhouse gases. The first is burning fossil fuels to power factories, which is why in the previous chapter Gates emphasizes the importance of electricity. Step two is producing the heat for manufacturing processes, and step three is the release of greenhouse gases during these processes. Today’s technology offers no practical way to avoid these emissions; the only possibility is carbon capture, which adds to the Green Premiums.

Concrete presents the hardest case, with a Green Premium of up to 140%. Several ideas might help reduce carbon emissions though not remove them altogether. One is to capture the carbon dioxide during the process and inject it into the concrete, trapping it there as the concrete sets. Another is to combine the CO2 that power plants emit with seawater for the chemical mix to make cement.

In short, getting to zero emissions entails lots of innovation that align with these four principles that Gates suggests: First, wherever possible, use electricity instead of fossil fuels. Second, make that electricity in a carbon-free way. Third, use carbon capture for any remaining emissions. Fourth, increase efficiency to use fewer materials.

This chapter examines activities like growing crops, raising livestock, and forest management, which together account for 19% of global emissions. Gates starts with food—and the fact that innovation has helped prevent rapid population growth from causing mass starvation, a fear that was common half a century ago. As an example of this innovation, Gates cites a new strain of wheat called “semi-dwarf,” which Nobel laureate Norman Borlaug developed, that increased yields per acre. Similar gains in cultivating rice and corn have also helped the food supply keep pace with the population.

Projections show that by 2100 the world’s population will reach 10 billion. Not only is this a significant increase, but many areas of world are seeing greater prosperity. Prosperity typically leads to increased meat consumption. However, if today’s methods of raising and slaughtering livestock continue, a climate disaster will result. All animals emit gas and waste that contribute to greenhouse gases, particularly methane and nitrous oxide. Improved breeding can help: For example, cattle breeds in North America emit less gas than those in South America and Africa.

A better solution might be plant-based meat. Companies like Beyond Meat and Impossible Foods are producing high-quality meat-like substitutes. Although their Green Premiums are currently high, they should come down over time. In addition, cultivating meat in labs (from real meat cells) is promising. Again, however, the current cost is prohibitively high. We must also drastically cut food waste. In the US, we waste 40% of food, and rotting food worldwide “produces enough methane to cause as much warming as 3.3 billion tons of carbon dioxide each year” (121).

In addition, Gates discusses the dangers of using synthetic fertilizer to help increase crop yields and food supplies (a practice that mostly occurs in developed countries). The drawback is that it consists of nitrogen, which can add to greenhouse gases. First, the process of making fertilizer requires heat, which currently comes from natural gas. Then, shipping and trucking it around the world uses more fossil fuels. In the soil, plants take up only some of the nitrogen, and what’s left causes water pollution as runoff or escapes into the air as nitrous oxide. This is another problem that we must solve to get to zero emissions.

All told, agriculture accounts for 70% of emissions in this category; the other 30% comes from deforestation. Much of this is happening in the Amazon rainforest, and here again meat consumption plays a role. With more demand for meat worldwide, creating pastureland for cattle has led to deforestation in Brazil, for example. When burning is the method, it releases all the trees’ carbon at once. Disturbing the soil (which holds a lot of carbon) only adds to that. Gates argues that we must change political and economic incentives to stop deforestation. While planting trees can help offset greenhouse gas emissions, this isn’t really a practical solution because of the substantial amount of land it would take to make a significant difference.

Chapter 7 looks at transportation, which makes up 16% of the total yearly emissions of greenhouse gases. Gates begins with some surprising facts: Gasoline has more energy than either a hand grenade or a stick of dynamite, and it costs less per gallon than milk and orange juice in the US. It’s a reminder, he says, that gas is the “gold standard” because of how much energy it produces.

He breaks down transportation by category (in a pie chart on page 134), which shows that the greatest emissions among modes of transport come from passenger cars. Gates examines each category and calculates their Green Premiums. Two options exist for replacing fossil fuels. One is to use alternative sources of energy. We’ve done this for a while in the form of electricity, and the cost has come down a lot in recent years: The Green Premium averages about $1,200 for an electric car, a sum many Americans are willing to pay.

The other choice is to use carbon from material already in the environment to make alternative fuels. Ethanol made from crops like corn and sugarcane is already in use, but it’s not carbon-free. And if we scaled that up, we’d have to shrink the land we dedicate to food production. Fuels from other biomass materials hold more promise if they become cheaper. Since they consist of mostly scraps and byproducts, they wouldn’t displace food crops. In addition, if we can use such biomass materials to make “drop-in fuel” (simply replacing gas), cars wouldn’t need modification, and we could distribute the fuel through existing pipelines and other systems. Currently, however, fuels from other biomass materials are too expensive for widespread use.

Another consideration, Gates notes, is that the greater a vehicle’s weight, the harder it is to substitute another energy source for gas. Past a certain vehicle weight, batteries aren’t a practical solution because the quantity of batteries needed for the energy required makes them too heavy. Thus, only passenger buses and lighter trucks (like garbage trucks) for use in cities can run on electricity. As a positive example, Gates cites the city of Shenzhen, China, which uses electric buses for its entire fleet. However, long-distance trucks, airplanes, and cargo ships will require alternative liquid fuels like biofuels (made from plant or animal material). Their Green Premiums are extremely high: almost 300% for planes and double that for ships.

Lowering emissions from transportation will require four things: using less fuel and encouraging more carbon-free modes like bikes, reducing emissions from the many processes that produce the materials in cars (steel, plastic, etc.), improving fuel efficiency, and using electricity and alternative fuels instead of fossil fuels. The last, Gates argues, is what we should focus on—but we must also find ways to lower the Green Premiums. They should be nonexistent soon for electric vehicles, especially with the right government policies. For alternative fuels, the premiums can come down only with intensive research and development (R&D). In short, Gates writes, getting to zero emissions involves two steps: “Use electricity to run all the vehicles we can, and get cheap alternative fuels for the rest” (147).

Another 7% of the total emissions per year comes from cooling and heating our homes and offices. Air conditioners account for the single largest use of electricity in the average US home, and projections show that worldwide use of air conditioning will jump in the coming decades. By mid-century, “air conditioners will consume as much electricity as all of China and India do now” (151). Thus, running them on clean electricity is essential.

One simple solution that helps is for consumers to buy the most efficient equipment. In many countries, the main reason we don’t is simply lack of information. Another problem air conditioners pose is that their coolants, known as F-gases, leak out, adding to global warming. We must do much more to develop harmless coolant substitutes.

Dealing with water heaters and furnaces is more difficult because most use fossil fuels. Here, the goal—as for passenger cars—is to electrify as many processes as possible and use alternative fuels for the rest. A key part of the solution is to replace both furnaces and air conditioners with heat pumps. These work on the same principle as refrigerators: Pumps circulate a special refrigerant in a loop through the machine, and as the pressure changes, the refrigerant absorbs heat in one place and discharges it in another. In winter it moves in one direction to heat our homes, while in summer it reverses to cool them. In fact, depending on location, this can even create a negative Green Premium, meaning that it saves money over conventional methods.

Gates points out that current government regulations are outdated and disincentivize electric systems like heat pumps because electric sources used to be more expensive. The good news is that simply updating policies will encourage greater use of heat pumps. Another reason for their slow adoption is that furnaces last a long time, and people typically don’t replace them until they reach the end of their life. Consequently, a push to develop cheap biofuels and lower the Green Premiums on them is also important.

Having reviewed the five principal areas of greenhouse gas emissions over as many chapters, Gates sums up the situation as extremely complex. In addition to existing tools that we can employ now, we need to develop new tools to bring down Green Premiums in each category, “which means we’ve got a lot of inventing to do” (158).