字幕列表 影片播放 列印英文字幕 You may think of sand as part of your beach vacation, but it's used for more than just sand castles. It's a commodity like oil and copper and gold. If you look around you, everything is made of sand. It's a pretty crucial commodity. And even though sand can be found in nearly every single country on Earth, we could soon face a sand shortage. Turns out, sand is only second to water as the most consumed raw material worldwide. Sand mining is the largest mining industry in the world. And yet, it flies under the radar, largely unregulated and unknown. All of society is basically built on sand and how come there's no monitoring on that? And how come people are ready to kill someone else for sand in some regions? It's used in construction, like critical infrastructure, and President Biden is diverting a lot of his attention to America's infrastructure. Sand is also used in chemical production, water filtration, fracking, and of course, glass. So, all of your windows, computers and cell phones. You know, it's literally everywhere we're driving on it. We're sitting in it. We're looking through it. It's absolutely extraordinary. I'm really starting to be concerned about what happens if we don't have this anymore. Sand use around the world has tripled in the last 20 years. That's far greater than the rate that sand is being replenished. One of the biggest sustainability challenges of the 21st century simply because of the scale of the problem. The more I learned about it, the more alarmed I became. So, the world is facing a sand crisis. And that's a problem. I know what you're thinking: Yes, sand is everywhere. How can there be a shortage? Actually, in some places, the world was running out, and it's such a hard concept to get your head around because you think of coastlines and expansive deserts and just see so much of it, that to think of it not being there is very, very challenging. It's a classic example of the tragedy of the commons. An economic concept where everyone is incentivized to keep consuming a natural resource, even if it ends in overconsumption, and ultimately, the total depletion of that resource, So is it a crisis or not? And that's one of the hard things with this topic, that it's a problem that manifests in very different ways in very different places. So, I bet you if you were in a community where sand mining is going on like this is not a surprise to you at all. I grew up in Bangalore in South India. As I grew up, I constantly read reports about rivers being decimated because of sand mining. And at the same time, I saw hundreds and hundreds of sand filled trucks flying up and down the road in the city of Bangalore. That was when the city was being transformed to the Silicon Valley of India basically. A construction boom happening all over and all that sand was coming from precious places. Construction has caused a steep increase in demand for sand. And, a lot of sand is being extracted from oceans and rivers. It's not just shortage in the market at shortage in the natural environment that has to be talked about. The concern is that there's literally not enough sand on coastlines in a context of rising sea levels and increased storms. Sand crafted by water is more valuable than desert sand eroded by wind. That makes desert sand to smooth it doesn't bind together as well as other types of sand. Sand is sourced and extracted from seabeds, coastlines, quarries, or rivers is more angular, so it locks together. And, that's important because this kind of sand is a key ingredient in cement and concrete. And concrete is made up of 65 to 75%, sand and gravel. Then there's glass, sand, gravel and rock crushed together or melted down to make the glass used in every window computer screen and smartphone Glass is about 70% silica sand. So, there are very specific types of sand that are required for specific uses. And these places are limited. Even the production of silicon computer chips uses sand, but extracting sand can damage the environment. Extractions of marine sand, coastal sand, beach... beach is the worst. And rivers is something that is leading to tremendous environmental impact For oceans... Well, imagine you scrape sand off the bottom of the ocean. That's going to affect the microorganisms that live in the ocean floor. That's going to affect the fish that eat the microorganisms, and then the fish that eat those fish. Basically, the sand removal of affects entire ecosystem. Sand is the most extracted resource in the world by volume, surpassing even fossil fuels. Actually, even extracting oil and gas uses a lot of sand, like in fracking. And yet sand has been easy to ignore. Essentially, it's invisible in our minds and in the way that we manage the resource. We don't think about it like a strategic resource. And yet it is everywhere in our societies and our economies. And as a result, we're wasting these resources. And in 2019, we produced this report, which was submitted to the United Nations Environmental Assembly, and it was used for making a new resolution on a global mineral governance, and it was adopted by all countries. And it was first time that countries recognize that we have a problem with sand. This concept of panicking, it reminds me a little bit of Great Thunberg talking about I want you to panic I want you to panic. When she was talking to the World Economic Forum, and it didn't quite go that far. Panicking will never be a solution. We will need sand forever. It's something that we need a lot. So, we need to be much wiser on the way we use the resource. Right now, it's not really possible to monitor global sand use. We just don't know enough. We don't have that global picture or that holistic picture of the extraction sites, the extraction volumes, where it's coming from, where it's going to how it's being used. But it can be measured indirectly. Construction is the biggest demand sector. We know that. There's a very, very good correlation between the use of sand and cement. The UN estimates that 4.1 billion tons of cement is produced every year. And it takes roughly 10 tons of sand to create one ton of cement. Do the math, and... 41 billion tons of sand and gravel That's enough to build a wall nearly 89 feet high by 89 feet wide, that wraps around the planet every year. And that's just sand used in cement production. Demand for cement is driven primarily by China, where construction is booming. In the last two decades, the amount of sand that we've been using has been multiplied by three. More than 55, 58% is being used in in China. Part of the problem is some countries don't have regulations in place. And, then you have people who take sand from the beach. Take sands from anywhere because they have to make a living. If you have a shovel and access to your truck, you an entrepre eur, you taking sand and you re selling it in some parts of the world, there are even sand mafias There are sand mafia. It is a problem. That's for sure. And so in some countries where the governance, the policies do not exist, it's not even illegal to take sand. Plus, the world faces a rapidly growing population. By 2050, the world could reach nearly 10 billion people. Africa is going to see its population doubling from now to 2050. People are shifting from their villages to join the cities that will request more infrastructure in the cities. All of that will request the amount of sand Sand can't be extracted or sourced sustainably to meet demand from a world of 10 billion people without effective planning and regulation. If you are a local government, you need to have a solid land planning. Identify where the sand and gravels should be extracted. The challenge is understanding where it's okay to take it from and how much So it's important to plan ahead and to plan alternatives. It's a time for innovations in this area. There's no one size fits all solution for the looming sand crisis we need many solutions that, you know, will also work together. It's not going to be like one alternative material is going to make the difference. I think it's going to have to be a big group effort, a big push collectively to figure this out. Finding alternatives to sand, including recycled materials, may help We can recycle concrete so that we're not wasting that by dumping these resources as a waste. Because it's not a waste. It can be recycled Our current economy is geared towards mining this material at extreme cost to the environment and to society, but that isn't factored in. We kind of build things and then at the end of life, we simply toss it in the landfill. So it's a very linear economy. But changing this to a circular economy can be a significant solution. And the circular economy is a way that keeps materials in use for longer. We can improve extracting in a better way by doing environmental impact assessment prior to mine then ining in appropriate way respe ting social and envir nmental conditions, then we ca reduce the amount of sand y being much more clever on ho we use it, so that means planning for longer term in te ms of having a building that s not done after 20, 30 yea s. We extend that to 50, 60 y ars. Sand is a finite resource. Every time we remove sand from the ecosystem, we are taking away critical habitat. We ar taking away coastal securit because sand along the coas acts as a storm buffer. S , when we extract sand, it com s at a cost and this needs to e really really balanced wi h the needs of futu e generation
B1 中級 美國腔 为什么世界快要枯竭了(Why The World Is Running Out Of Sand) 16 3 joey joey 發佈於 2021 年 05 月 13 日 更多分享 分享 收藏 回報 影片單字