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  • Every time I read the news lately, it seems I'm reading about another region plagued

  • by drought. But is the world really running out of water?

  • Hey guys, Julia here for DNews.

  • Here in the Western developed world, we like to think of water as a renewable resource.

  • It's everywhere and it's such a huge part of our lives. It flushes our waste down the

  • drain, keeps our power plants cool, and keeps our food growing in fertile plains. And we

  • basically get fresh and safe drinking water for free out of the tap. But many parts of

  • the world aren't so lucky. According to the UN, 85% of the world lives in the driest

  • half of the planet and hundreds of millions of people don't have access to clean drinking

  • water. And it could get worse. Way worse.

  • Over the next few decades, by 2050, the global population will grow by 3 billion more people.

  • And that means, global water demand is projected to increase by 55% as many nations become

  • more populous and more developed. At the same time, climate change will change weather patterns

  • across the globe, causing some regions to become wetter and others to become drier.

  • While a true global drought seems unlikely, I mean the water cycle is a closed system.But

  • as these changes occur, dry areas will become worse and larger. The water that used to flow

  • into fertile fields won't permeate the soil and evaporate into the atmosphere, eventually

  • finding it's way into the ocean. But how will these changes affect our we get our water?

  • Our earth is mostly water. But most of that isn't usable for us, because most of us,

  • including the UN, believe access to fresh drinking water is a basic human right. So

  • we want clean and cheap accessible water, and that leaves us less than 1% of the Earth's

  • water in the form of lakes, rivers, streams, and groundwater for us as potable drinking

  • water, and water for other uses like agriculture, manufacturing, and energy production.

  • If you're a frequent DNews watcher you might know that here in San Francisco we get our

  • water from Hetch Hetchy, a man-made reservoir high in the Sierra Nevada Mountains. Snow

  • falls onto mountains in the area, and when spring returns, the snow melts and runs into

  • hetch hetchy. But this past year we've only see a fraction of the amount of precipitation

  • we usually do.

  • California is in a major drought and at the same time the American West could be facing

  • the worst drought in a millennium. And we aren't the only ones left high and dry.

  • Many regions of the world are facing historic droughts. Brazil, China, Kenya, and Australia,

  • just to name a few.

  • One of the reasons for widespread droughts is a lack of snowfall. New research published

  • in the journal Environmental Research Letters found that snowpack is on the decline around

  • the world. So much of the Northern Hemisphere depends upon annual snowpack for its freshwater,

  • that accounts for nearly 2 billion people. Yet the researchers find that nearly 67% of

  • those people could have insufficient snowpack in the coming century. One the study's authors

  • said thatWater managers have to make arrangements at a lot of places for alternatives as the

  • snow reservoir will no longer exist.”

  • And it's not just a lack of water from above. Water supplies from below are dwindling too.

  • In June of 2015, NASA announced that the water table is dropping all over the world. Of the

  • 37 largest underground aquifers on Earth, 21 have passed their sustainability tipping

  • point. That means more water is being taken out than is finding it's way back in. And

  • the thing about aquifers, most of the water is old, really old and it takes a while to

  • refill. Some aquifers could take anywhere from 500 to 1,300 years to refill.

  • So it's a pretty large problem. Even the UN said that the world could suffer a 40%

  • shortage of water just 15 short years from now. In it's World Water Development Report

  • the UN highlighted high population growth and poor urban design as two main areas of

  • concern. And unfortunately, the report saysThis convergence is certain to intensify

  • the water insecurity of poor and marginalized people in low income countries.”

  • So what happens when we run out of fresh water?

  • Well here in California we've already started to adjust our lives. There's a state mandated

  • water conservation plan in place, to reduce consumption. So that means no washing the

  • car or watering the lawn. It means asking for water at a restaurant rather than having

  • it on the table. Relatively small changes for us, but losing most of the world's fresh

  • water could mean major upheaval and major costs for some countries. Especially when

  • to comes to food.

  • Most of the world's water, 70%, goes to agriculture!

  • So droughts have a huge impact on food availability. The World Economic Forum (WEF) estimates that

  • current droughts around the world cost six to eight billion dollars a year in agricultural

  • losses. And that can drive up the cost of food, causing a similar food crisis to one

  • in 2008, which saw prices of staples like rice double in just a few short months. As

  • food prices soared, people got hungry and nervous and soon unrest erupted around the

  • world as citizens demanded their government take action.

  • Droughts already cause tens of millions of deaths every year. If these trend continue,

  • millions more will needlessly die. But while this sounds all doom and gloom, there is hope.

  • The UN hopes that by 2050, we'll have learned new techniques like widespread adoption of

  • advanced agro-technology and highly efficient irrigation techniques that will ease the strain

  • on agriculture. Power companies will adopt water efficient techniques like dry cooling

  • and use more sustainable forms of energy like solar and wind. Cities will have more efficient

  • water systems which take full advantage of recycling water.

  • But that's a long way off. And in the meantime every day the earth gains more people and

  • at the same time the climate becomes increasingly volatile, causing many regions to be vulnerable

  • to drought.

  • If you want to know more about California's drought and how it affects the rest of the

  • world, check out my earlier episode right here.

Every time I read the news lately, it seems I'm reading about another region plagued

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B1 中級 美國腔

用光水(Will The World Ever Run Out Of Water?)

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    joey joey 發佈於 2021 年 04 月 15 日
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