How to Avoid a Climate Disaster

by Bill Gates

  Next is preparing for and responding to emergencies. We need to keep improving weather forecasts and early-warning systems for getting out information about storms. And when disaster does strike, we need well-equipped and well-trained teams of first responders and a system in place for handling temporary evacuations.

  Finally, after a disaster, there’s the recovery period. We’ll need to plan for services for people who’ve been displaced—services like health care and education—as well as insurance that helps people at all income levels rebuild and standards to ensure that whatever gets rebuilt is more climate-proof than what was there before.

  Here are four of the big headlines on adaptation:

  Cities need to change the way they grow. Urban areas are home to more than half the people on earth—a proportion that will rise in the years ahead—and they’re responsible for more than three-quarters of the world’s economy. As they expand, many of the world’s fast-growing cities end up building over floodplains, forests, and wetlands that could absorb rising waters during a storm or hold reservoirs of water during a drought.

  All cities will be affected by climate change, but coastal cities will have the worst problems. Hundreds of millions of people could be forced from their homes as sea levels rise and storm surges get worse. By the middle of this century, the cost of climate change to all coastal cities could exceed $1 trillion…each year. To say that this will exacerbate the problems most cities are already struggling with—poverty, homelessness, health care, education—would be an understatement.

  What does climate-proofing a city look like? For one thing, city planners need the latest data on climate risks and projections from computer models that predict the impact of climate change. (Today, many city leaders in the developing world don’t have even basic maps to indicate which areas of town are most prone to floods.) Armed with the latest information, they can make better decisions about how to plan for neighborhoods and industrial centers, build or expand seawalls, protect themselves from the storms that are getting more violent, shore up storm-water drainage systems, and raise wharves so they stay above rising tides.

  To get really specific: If you’re building a bridge across the local river, should you make it 12 feet tall or 18 feet tall? The taller one will be more expensive in the short run, but if you know the odds are high that a massive flood will come along in the next decade, it could be the smarter choice. You’d rather build a more expensive bridge once than a cheaper bridge twice.

  And it’s not just about renovating the infrastructure that cities already have; climate change is also going to force us to consider entirely new needs. For example, cities with extremely hot days and a lot of residents who can’t afford air-conditioning will need to create cooling centers—facilities where people can go to escape the heat. Unfortunately, using more air conditioners also means we’ll be emitting more greenhouse gases, which is another reason why the advances in cooling that I discussed in chapter 8 are so important.

  We should shore up our natural defenses. Forests store and regulate water. Wetlands prevent floods and provide water for farmers and cities. Coral reefs are home to the fish that coastal communities depend on for food. But these and other natural defenses against climate change are rapidly disappearing. Nearly nine million acres of old-growth forest were destroyed in 2018 alone, and when—as is likely—we hit 2 degrees Celsius of warming, most of the coral reefs in the world will die off.

  On the other hand, restoring ecosystems has a huge payoff. Water utilities in the world’s largest cities could save $890 million a year by restoring forests and watersheds. Many countries are already leading the way: In Niger, one local reforestation effort led by farmers has boosted crop yields, increased tree cover, and cut the amount of time women spend gathering firewood from three hours a day to 30 minutes. China has identified about a quarter of its landmass as critical natural assets where it’ll make a priority of promoting conservation and preserving the ecosystem. Mexico is protecting a third of its river basins to preserve the water supply for 45 million people.

  If we can build on these examples, spreading awareness about how much ecosystems matter and helping more countries follow suit, we’ll gain the benefits of a natural defense against climate change.

  Here’s some more low-hanging fruit, so to speak: mangrove forests. Mangroves are short trees that grow along coastlines, having adapted to life in salt water; they reduce storm surges, prevent coastal flooding, and protect fish habitats. All told, mangroves help the world avoid some $80 billion a year in losses from floods, and they save billions more in other ways. Planting mangroves is much cheaper than building breakwaters, and the trees also improve the water quality. They’re a great investment.

  Planting mangrove trees is a great investment. They help prevent some $80 billion a year in losses from floods.

  We’re going to need more drinking water than we can supply. As lakes and aquifers shrink or get polluted, it’s getting harder to provide potable water to everyone who needs it. Most of the world’s megacities already face severe shortages, and if nothing changes, by mid-century the number of people who can’t get enough decent water at least once a month will rise by more than a third, to over 5 billion people.

  Technology holds out some promise here. We already know how to take the salt out of seawater and make it drinkable, but the process takes a lot of energy, as does moving the water from the ocean to the desalination facility and then from the facility to whoever needs it. (This means that, like so many things, the water problem is ultimately an energy problem: With enough cheap, clean energy, we can make all the potable water we’ll ever need.)

  One clever idea I’m watching closely involves taking water out of the air. It’s basically a solar-powered dehumidifier with an advanced filtering system so you don’t drink air pollution. This system is available now, but it costs thousands of dollars, far too expensive for the world’s poor, who will suffer the most from water shortages.

  Until an idea like that becomes affordable, we need to take practical steps—incentives that will drive the demand for water down and efforts that will drive the supply up. That includes everything from reclaiming wastewater to just-in-time irrigation, a system that reduces water use dramatically while raising farmers’ yields.

  Finally, to fund adaptation projects, we need to unlock new money. I’m talking not about foreign aid for developing countries—although we’ll need that too—but about how public money can attract private investors to get behind adaptation projects.

  Here’s the problem we need to overcome: People pay the costs of adaptation up front, but its economic benefits may not come for years down the road. For example, you can flood-proof your business now, but it may not get hit by a big deluge for 10 or 20 years. And your flood-proofing isn’t going to generate bankable cash flows; customers aren’t going to pay extra for your products because you made sure sewage won’t back up into your basement during a flood. So banks will be reluctant to loan you the money for your project, or they’ll charge you a higher interest rate. Either way, you have to absorb some cost yourself, in which case you may simply decide not to do it.

  Take that single example and multiply it across an entire city, state, or country, and you’ll see why the public has to play a role in both financing adaptation projects and drawing in the private sector as well. We need to make adaptation an attractive investment.

  That starts with finding ways for public and private financial markets to take the risks of climate change into account and to price these risks accordingly. Some governments and companies already screen their projects for climate risks; all of them should. Governments can also put more resources into adaptation, setting goals for how much they’ll invest over time and adopting policies that remove some of the risk for private investors. As the rewards of adaptation projects become more clear, private investment should grow.

  You may be wondering how much all this would cost. There’s no way to put a price tag
on everything the world needs to do to adapt to climate change. But the commission I’m involved with priced out spending in five key areas (creating early-warning systems, building climate-resilient infrastructure, raising crop yields, managing water, and protecting mangroves) and found that investing $1.8 trillion between 2020 and 2030 would return more than $7 trillion in benefits. To put that in perspective, spread out over a decade, it’s about 0.2 percent of the world’s GDP, with a nearly fourfold return on investment.

  You can measure those benefits in terms of bad things that don’t happen: civil wars that don’t break out over water rights, farmers who don’t get wiped out by a drought or flood, cities that don’t get destroyed by hurricanes, waves of people who don’t become climate refugees. Or you can measure them in terms of good things that do happen: children who grow up with the nutrients they need, families who escape poverty and join the global middle class, businesses and cities and countries that thrive even as the climate gets hotter.

  Whichever way you think about it, the economic case is clear, and so is the moral case. Extreme poverty has plummeted in the past quarter century, from 36 percent of the world’s population in 1990 to 10 percent in 2015—although COVID-19 was a huge setback that undid a great deal of progress. Climate change could erase even more of these gains, increasing the number of people living in extreme poverty by 13 percent.

  Those of us who have done the most to cause this problem should help the rest of the world survive it. We owe them that much.

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  There’s one other aspect to adaptation that deserves a lot more attention than it’s getting: We need to be preparing for a worst-case scenario.

  Climate scientists have identified many tipping points that could dramatically increase the rate at which climate change happens—for instance, if the ice-like crystalline structures containing large amounts of methane on the ocean floor become unstable and erupt. In a relatively short time, disasters could strike around the world, overwhelming our attempts to prepare for and respond to climate change. And the higher the temperature goes, the more likely we are to reach a tipping point.

  If it starts looking as if we’re headed toward one of these tipping points, you’re going to hear more about a set of bold—some would say crazy—ideas that fall under the umbrella term “geoengineering.” These approaches are unproven, and they raise thorny ethical issues. But they’re worth studying and debating while we still have the luxury of study and debate.

  Geoengineering is a cutting-edge, “Break Glass in Case of Emergency” kind of tool. The basic idea is to make temporary changes in the earth’s oceans or atmosphere that lower the planet’s temperature. These changes wouldn’t be intended to absolve us of the responsibility to reduce emissions; they’d just buy us time to get our act together.

  For a few years, I’ve been funding some studies on geoengineering (this funding is tiny compared with the work on mitigation and adaptation that I’m supporting). Most approaches to geoengineering are based on the idea that to compensate for all the warming caused by greenhouse gases we’ve added to the atmosphere, we need to reduce the amount of sunlight hitting the earth by around 1 percent.*3

  There are various ways we could do that. One involves distributing extremely fine particles—each just a few millionths of an inch in diameter—in the upper layers of the atmosphere. Scientists know that these particles would scatter sunlight and cause cooling, because they’ve watched it happen: When an especially powerful volcano erupts, it spews out a similar type of particle and measurably drives down the global temperature.

  Another approach to geoengineering involves brightening clouds. Because sunlight is scattered by the tops of clouds, we could scatter more sunlight and cool the earth by making the clouds brighter, using a salt spray that causes clouds to scatter more light. And it wouldn’t take a dramatic increase; to get the 1 percent reduction, we’d only need to brighten clouds that cover 10 percent of the earth’s area by 10 percent.

  There are other approaches to geoengineering; they all have three things in common. One, they’re relatively cheap compared with the scale of the problem, requiring up-front capital costs of less than $10 billion and minimal operating expenses. Two, the effect on clouds lasts for a week or so, so we could use them as long as we needed to and then stop with no long-term impacts. And three, whatever technical problems these ideas might face are nothing compared with the political hurdles they’ll definitely face.

  Some critics attack geoengineering as a massive experiment on the planet, though as the proponents of geoengineering point out, we’re already running a massive experiment on the planet by emitting huge amounts of greenhouse gases.

  What’s fair to say is that we need to better understand the potential impact of geoengineering at a local level. That’s a legitimate concern that deserves much more study before we even consider testing geoengineering at scale in the real world. Also, because the atmosphere is literally a global concern, no single nation could decide to try geoengineering on its own. We’d need some consensus.

  Right now, it’s hard to imagine getting countries around the world to agree to artificially set the planet’s temperature. But geoengineering is the only known way that we could hope to lower the earth’s temperature within years or even decades without crippling the economy. There may come a day when we don’t have a choice. Best to prepare for that day now.

  Skip Notes

  *1 CGIAR began life as the Consultative Group for International Agricultural Research. You can see why it started going by the abbreviation.

  *2 The commission is guided by 34 commissioners, including leaders from government, business, nonprofits, and the scientific community; and 19 convening countries, representing all regions of the globe. A global network of research partners and advisers supports the commission. It’s co-managed by the Global Center on Adaptation and the World Resources Institute.

  *3 If you want to know the math: Sunlight is absorbed by the earth at a rate of about 240 watts per square meter. There’s enough carbon in the atmosphere now to absorb heat at an average rate of about 2 watts per square meter. So we need to make the sun dimmer by 2/240, or 0.83 percent. However, because clouds would adjust to solar geoengineering, we would actually need to dim the sun a bit more, to about 1 percent of the incoming sunlight. If the amount of carbon in the atmosphere doubles, it would absorb heat at a rate of about 4 watts per square meter, and we would need to double the dimming to about 2 percent.

  CHAPTER 10

  WHY GOVERNMENT POLICIES MATTER

  In 1943, at the height of World War II, a thick cloud of smoke descended on Los Angeles. It was so noxious that it made residents’ eyes sting and their noses run. Drivers couldn’t see more than three blocks down the road. Some locals feared that the Japanese army had attacked the city with chemical weapons.

  L.A. hadn’t been attacked, though—at least, not by a foreign army. The real culprit was smog, created by an unfortunate combination of air pollution and weather conditions.

  Almost a decade later, for five days in December 1952, London too was crippled by smog. Buses and ambulances stopped running. Visibility was so low, even within enclosed buildings, that movie theaters were shut down. Looting was rampant because the police couldn’t see more than a few feet in any direction. (If you’re a fan of the Netflix series The Crown, as I am, you’ll remember a gripping episode in season 1 that takes place during this awful incident.) What’s now known as the Great Smog of London killed at least 4,000 people.

  Thanks to incidents like these, the 1950s and 1960s marked the arrival of air pollution as a major cause of public concern in the United States and Europe, and policy makers responded quickly. Congress began to provide funding for research into the problem and possible remedies in 1955. The next year, the British government enacted the Clean Air Act, which created smoke-control zones throughout the country where only cleaner-burning fuels could be used. Seven years later, America’s
Clean Air Act established the modern regulatory system for controlling air pollution in the United States; it remains the most comprehensive law—and one of the most influential—to regulate air pollution that can endanger public health. In 1970, President Nixon established the Environmental Protection Agency to help implement it.

  This police officer had to use a flare to direct traffic during the Great Smog of London in 1952.

  The U.S. Clean Air Act did what it was supposed to do—get poisonous gases out of the air—and since 1990 the level of nitrogen dioxide in American emissions has dropped by 56 percent, carbon monoxide by 77 percent, and sulfur dioxide by 88 percent. Lead has nearly vanished from American emissions. While we still have work to do, we accomplished all this even as our economy and population grew.

  But you don’t have to look to history for examples of how smart policies help solve a problem like air pollution. It’s happening right now. Starting in 2014, China launched several programs in response to worsening smog in urban centers and skyrocketing levels of dangerous air pollutants. The government set new targets for reducing air pollution, banned the building of new coal-fired plants near the most polluted cities, and put limits on driving nonelectric cars in large cities. Within a few years, Beijing was reporting a 35 percent decline in certain types of pollution, and Baoding, a city of 11 million people, was reporting a decline of 38 percent.

  Although air pollution is still a major cause of illness and death—it likely kills more than 7 million people every year—the policies we’ve put in place have undoubtedly kept the number from being even higher.* (They’ve also helped reduce greenhouse gases a bit, even though that wasn’t their original purpose.) Today they illustrate as well as anything the leading role that government policies have to play in avoiding a climate disaster.