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

In this chapter, Gates explains why it’s crucial to get to zero carbon emissions, not just reduce emissions. The data is clear, and Gates tells it bluntly: Adding any carbon to the atmosphere warms the planet, mostly because it stays there for thousands of years. Greenhouse gases come from burning fossil fuels, and it’s unlikely that we can stop using them altogether. Thus, getting to zero realistically means “net zero,” in which we still emit some carbon but then remove it from the atmosphere.

The rest of the chapter details how global warming happens and what’s known about its effects. Several gases cause the warming. While the most well-known one is carbon dioxide (CO2), others—such as methane—are worse because they create more warmth and have an immediate effect. Together, these gases create heat—“carbon dioxide equivalents” (22), or CO2e—when sunlight warms up the Earth and the resulting heat hits certain molecules. These molecules absorb the heat because they consist of different atoms (like CO2), whereas those with the same atom (like O2) let the heat pass through.

This warming presents many challenges, including an increase in hot days per year and stronger storms. As an example, Gates cites temperatures in Albuquerque, New Mexico. In the 1970s, the annual number of days over 90 degrees Fahrenheit was 36. By 2050, it will be twice that many, and by the end of the century it could be over 100. Note that slight changes in the planet’s temperature make big differences; for example, the last Ice Age was colder than today by an average of just 6 degrees Celsius.

Other results of global warming and climate change are more wildfires and rising sea levels. Wildfires are increasing, and sea levels will rise due to both melting glaciers and the expansion of water as it warms up. In addition, evidence shows that a hotter planet will affect water supplies and reduce the range where plants and animals can exist. Drought could affect the global food supply, causing food prices to rise. Livestock will be less productive, and fish will become scarcer. All this and more will happen simultaneously, snowballing into major problems.

Gates concludes the chapter with hypothetical and actual examples of scenarios resulting from global warming. He envisions what intensified droughts might be like for farmers in Nebraska and India, and he recounts what happened to farmers in Syria due to severe drought. As extreme weather events wipe out communities and displace people, the number of refugees will increase around the world. Because Gates authored this book the year COVID-19 hit the world, he compares the deaths from the pandemic to those that will occur from climate change. The data reveals that “by mid-century, climate change could be just as deadly as COVID-19, and by 2100 it could be five times as deadly” (34). In terms of the economy, the near future will see damage on the scale of the pandemic every 10 years.

This chapter explains why getting to zero carbon emissions will be difficult. Gates stresses that he thinks we can do it but wants to be clear about the challenges that lie ahead. He starts with the fact that we use fossil fuels constantly in ways that we don’t even realize. For example, the world is swimming in things that contribute to our heavy consumption of oil, which is 4 billion gallons a day. In addition to fueling vehicles, oil is in plastic, asphalt, steel, and synthetic fabrics. One reason we use so much is that it’s extremely inexpensive—gallon for gallon, cheaper than soda, Gates points out.

Energy use is increasing worldwide in both developing and rich nations. Gates sees this as a good thing because it means growth and increased opportunities. Having energy available improves people’s lives and drives economic growth. The key is substituting clean energy sources for dirty ones—and that’s the difficult part. Reviewing past energy transitions reveals how slow the process can be. For example, oil itself took some time: Fifty years after its first use, it was only a tenth of the total global energy supply, and after 80 years, it was still only a quarter of the total supply. Gates argues, however, that we don’t have the luxury of time now.

Changing to clean energy realistically takes time because the technology necessary to make the transition doesn’t happen overnight. In addition, the energy industry is huge, and “[a]nything that big and complex will resist change” (46). Moreover, understandably, we’re risk averse when it comes to energy, as it must be reliable and safe. Unfortunately, too, the US has outdated energy legislation and policies. They don’t focus on climate change, so the tools to combat it just aren’t there—and because administrations and their policies potentially change every four years, we lack the continuity for a concerted effort. Most importantly, the sense of urgency is missing. Too few people see climate change as an existential threat, and many think that the tools and technology we currently have are sufficient to manage it.

In Chapter 3, Gates shares five questions he finds essential to any informed discussion of climate change. When he first started learning about the issue, he found it confusing because data often lacked context or consistent metrics, so he developed the five questions to help understand the data. He shares these questions in the hope that they’ll help others see things more clearly too.

The first is to ask how much of the 51 billion tons of annual greenhouse gas emissions something refers to. Cutting those 51 billion tons is the larger goal, and it helps to not take your eye off the ball. Converting numbers to a percentage of 51 billion tons shows how much of the annual goal they are. Gates gives an example of a program that promised to reduce emissions by 17 million tons each year. As a percentage of the annual total emissions, that’s only 0.03%. It’s not a lot, but whether it might go up and by how much also matters.

Second is the question “What’s your plan for cement?” as a kind of reminder that emissions come from many things, not just vehicles, which tend to get a lot of focus. Cars, for example, represent less than half the emissions from all forms of transport, and that “in turn is 16 percent of all emissions worldwide” (54). Producing things like cement, steel, and plastic accounts for 31%, the greatest source of greenhouse gas emissions of all the categories. Hence the question about cement.

Gates’s third question is how much power something refers to when talking about electricity. The basic unit for this is a watt, and rather than try to explain in technical terms what that is, he uses comparisons. A watt is a flow of energy much like a faucet, which produces a certain number of cups of water every second. He cites average usage numbers in watts for different entities, like a house or a city, and advises, “Whenever you hear ‘kilowatt,’ think ‘house.’ ‘Gigawatt,’ think ‘city.’ A hundred or more gigawatts, think ‘big country’” (57).

Since the Earth has limited land and water, the fourth question to ponder is how much space a given source of energy will need—or “power density” in terms of the number of watts per square meter. The power density of fossil fuels is high, which is one reason they’re in demand, while alternatives like wind and wood power are on the low end of the spectrum. Gates explains that this number doesn’t make one source better or worse than another—it’s just a crucial factor in any discussion of energy.

The final question is how much something will cost. Changing from fossil fuels is hard because we ensure that they’re cheap. Thus, Gates argues, in assessing the full cost of using fossil fuels, we don’t consider factors such as damage to the environment. If you substitute a green source of energy for a fossil fuel right now, it will cost more. The difference in cost is what Gates refers to as the Green Premium. The decision then is whether it’s worth paying a given premium. Rich countries may be able to, while poor countries may not; the goal is to lower Green Premiums enough so that everyone can afford them.