字幕列表 影片播放 列印英文字幕 [narrator] Turn on a faucet and clean water rushes out, as much as we want, anytime we want. It's easy to forget that the quest for this has been one of the defining struggles of human history. Civilizations that harnessed water, thrived. The ones that failed... fell. Today, seven in ten people on Earth can count on having running water in their homes. [man] The water flows from the risers to connecting mains, and finally through service connections into each building on the street. [narrator] At least, so they think. Cape Town. It could become the first major city in the world to run out of water. Cape Town, South Africa, is inching closer now to Day Zero. Just 92 days away from having to shut off most water taps because of a severe drought. [narrator] Cape Town is the first major city in the world to plan to indefinitely shut off its water supply. Four million people would stop getting running water. They'd get water rations, and they'd need to line up at city water stations to get it. And it's not just Cape Town. São Paulo, Melbourne, Jakarta, London, Beijing, Istanbul, Tokyo, Bangalore, Barcelona and Mexico City will all face their own Day Zero in the next few decades, unless their water use radically changes. There are perceptions that it is there in bountiful amounts and everyone has access to it because you can turn a tap, and that's a big problem. [narrator] In fact, by 2040 most of the world won't have enough water to meet demand year-round. We're facing a global water crisis and it's getting worse. We're at a real inflection point where, if we're not careful, we may actually get out ahead of our ability to manage it. [narrator] There's no substitute for water. Each of us will die in just a few days without it. How have we built a world where we don't have enough of its most valuable resource? And as this crisis grows, what will the new world look like? [man] Waterways, built by the people to free the land of the tyranny of nature. For some investors, what they see in this glass is liquid gold. Clean water. Now. [crowd chants] -[in Spanish] In defense of water. -[man 2] Water becomes a commodity. It takes on new value. People claim it, haul it, treasure it. [man 3] Dare we take our water supply for granted as we do the air we breathe? [narrator] Earth is the blue planet. There's no shortage of water. We have 326 million trillion gallons of it. Always have, always will. Water may freeze into ice or evaporate into air, but it doesn't leave our planet. If you sucked up all the water on Earth, it would fit into this sphere. But 97% of it is salty and 2% is trapped in ice at the poles, so all of humankind relies on just 1% of that water to survive. When people talk about running out of water, what they really mean is, do they have access to that very small percentage? [narrator] And the answer depends a lot on where you live. Kuwait is one of the poorest countries in terms of water per capita, and Canada, one of the richest, doesn't have twice as much or even ten times as much. It has 10,000 times as much. But it also matters where the water is. That 1% of Earth's water that we all rely on, most of it is underground and really difficult and expensive to get to, so humans have mostly settled close to surface water, like rivers and lakes. Around 90% of the world's population lives less than ten kilometers from a freshwater source. Hundreds of years ago, when the Aztecs settled on what is now Mexico City, they saw a giant lake. These are the last remnants of the canals they made. When the Spanish came in the 16th century, one soldier marveled at the Aztec city rising from the water that seemed like an enchanted vision. But then the Spanish started draining the lake, and over the next few centuries that space was filled by people. Like in most places, surface water in Mexico was treated as a public resource, key to development. And since 1950, Mexico City's population has exploded. It's now home to 22 million people. I would say some of the most important threats for Mexico City are related to water. [narrator] Mexico City gets more rain than notoriously rainy London. But the lakes that would have collected that water are long gone, so the city floods. But they still need to pipe in most of their water from other parts of Mexico. Or they pump it from underground. We've gotten a lot better at accessing groundwater. But there's a catch. Those water deposits, called aquifers, have accumulated over millennia and they'll take millennia to fill back up. Groundwater is sort of like the savings account, which it's fine to draw on sometimes, especially when you have a drought. [narrator] That's not what Mexico City's been doing. We take out from the local aquifer around 50% of our water supply. That means that probably we'll lose half of our supply of water in the next 30-50 years. [narrator] Sucking up that groundwater has another side effect. It compresses the soil. Mexico City is literally sinking. In some places, as much as nine inches a year. NASA satellite data shows aquifers in northern India decreasing by 29 trillion gallons in just a decade. There are simply more people on Earth consuming more water. This century, water consumption has increased sevenfold. And the rain and snow that we count on to water crops and refill lakes and rivers is getting less reliable. [Otto] Climate change is making available water much more erratic. We're seeing areas around the world that are experiencing much more extended dry periods. [narrator] But the problem isn't just that there's more people on Earth using water, it's how we're using water. Humans need to drink almost a gallon of water per day. Brushing your teeth, washing your hands typically uses about a gallon. [flushes] There goes three gallons. But the drinking, washing and toilet flushing of every person on Earth only accounts for 8% of our freshwater use each year. Most of the water goes to agriculture and industry, and into the food and products we use. Let's take a bottle of Coca-Cola. 98% of the water in that bottle is not what you see in that bottle. 98% of the water is actually embedded in all the ingredients that were grown to make that bottle of Coca-Cola. [narrator] 74 liters of water goes into every glass of beer. A cup of coffee? 130 liters. Each of your cotton shirts - 2,500 liters. But nothing has as much embedded water as meat. Alfalfa is a common ingredient in cattle feed, and growing a kilogram of it takes 510 liters of water. An average cow consumes about 12 kilograms of feed a day. Divided up, just one quarter-pound hamburger takes around 1,650 liters of water to produce. The world is eating more and more like Americans. Higher calorie diets with more meat. But everyone can't eat like Americans. There actually isn't enough water in the world. Water doesn't abide by some of the basic rules of capitalism. Farmers hardly pay anything for it. So the true cost of water doesn't end up in the cost of the burger. Which is why those fast food places can offer you bargain burgers. [man 1] How can it be 99 cents? [man 2] For only 2.99. You heard right: 2.99. [narrator] In most places in the world, water is treated and priced like there will always be enough of it. So we end up using it in absurdly wasteful ways. Arid Southern California uses over two trillion gallons of water a year to grow alfalfa, which they get from the Colorado River, hundreds of miles away. The amount they pay for it doesn't even cover the cost of delivery. Just a fraction of the water used by South Africa's wine industry would be enough for Cape Town's taps. India and China both grow their most water-intensive crops in some of their driest regions. But as water gets more scarce, that may change. The bank Goldman Sachs predicted that water would be the petroleum of the 21st century. And private interests, like hedge funds, have started buying up water, prompting fears that they'll take advantage of scarcity to turn a profit. And if that sounds like a villain's plot in a James Bond movie, that's because it was. As of this moment, my organization owns more than 60% of Bolivia's water supply. This contract states that your new government... will use us as utilities provider. [narrator] But putting a higher price on water might have benefits. The benefit of valuing water as we should and sending, you know, a price signal, is that we wouldn't be growing alfalfa in the desert. [narrator] Remember that point. It'll be important later. We wouldn't be growing crops that don't make sense in really arid places. Because the economics of it wouldn't make sense. [narrator] And 95% of the irrigated farmland in the world probably wouldn't use the most inefficient irrigation method... just flooding the fields. And if water had a higher price, governments might decide it's worth the money to repair our water infrastructure. [Kramer] We are not investing the financial resources needed to make a good maintenance of the system. One critical result of this is that we have 42% of leakages in the water network. [narrator] Mexico City, which is facing an existential water crisis, loses close to half of its drinking water to leaky pipes. We value water so little, we dump two million tons of sewage and agricultural and industrial waste into it every day. There's no sense of value to what is really an incredibly invaluable resource in water. But then when we run out, we find what the cost of water truly is. [yelling] [speaking Spanish] [narrator] In 2017, the city of Mexicali finalized a deal with Constellation Brands, the maker of Modelo and Corona beers, to construct a brewery. It would be the biggest investment the region had seen in years, creating 750 permanent jobs. And, in exchange, the brewery was guaranteed a lot of water. But Mexicali doesn't have a lot of water to spare. Its main water source is the Colorado River, which starts in Colorado, in the U.S. Fed by melting snow in the Rocky Mountains, warmer temperatures in recent years have meant less snow, which means less river. You can tell how much less by that big bathtub ring. The river flows south, quenching a few American cities along the way, like Denver, Salt Lake City, Las Vegas, Phoenix and Los Angeles. Oh, and almost six million acres of farmland. By the time the Colorado River reaches Mexicali, it looks like this. [man, in Spanish] It's been a long time since we've had enough water. If the brewery settles in and starts producing, in a few years, we'll run out of underground water. [in Spanish] The farmers are the ones who get the worst of it. [in Spanish] They need 20 million cubic meters per year. If we compare that to, say, cities such as Ensenada, which need nine million cubic meters, it's more than double. More than double of a city. [narrator] The more scarce water gets, more access to it becomes a competition, with winners and losers, often with governments picking. In July 2018, the federal government of Mexico issued a decree making it easier for businesses like Constellation Brands to extract surface water all around the country. [in Spanish] We see this as a stick-up. It's also a warning not only for the Mexican people but the entire world. We know that many other parts of the world are fighting against these privatization projects that line the companies' pockets.