もし海水の塩分が無くなったら...

もし海水の塩分が無くなったら、世界の水不足問題は解決するでしょうか？

そんなうまい話は...

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3.8 billion gallons – that’s how much water people drink around the world every

00:13                                                       3.8b gallon s/

day. It might sound like an entire ocean, but it only counts for about ½ of 1% of the

00:20                      水が不足してきている

water on Earth… And we’re running low! So what if, we had entire oceans of fresh

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water instead of the undrinkable salty kind?

00:30 (海って)一見すると

At first glance, it seems like a fairy tale. You see, people live on land that’s surrounded

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by ginormous puddles of H2O and Sodium Chloride that’s pretty much useless to us, if we’re

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talking about drinking and consuming the stuff, that is. (By the way, those are the chemical

00:48 (化合物の名前を覚えて)化学の単位を取れるね

compound names for water and salt, if you’re hoping to earn some extra credit here.) Lots

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of people on certain parts of continents don’t have access to fresh water from rivers or

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lakes, and this crisis is getting more and more serious each year. Every 7th person on

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the planet suffers from a lack of access to clean drinkable water right now. And some

01:12                                                                                   7人に1人の数字が急騰して

experts say that as the world population doubles by 2030, that statistic will skyrocket to

01:18 2人に1人になる！

one-half!

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So, wouldn’t it solve the problem if we had an unlimited ocean of fresh water? The

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short answer is, nope.

01:28                                                                                  =salt water

But first, it’s important to understand why our oceans are briny to begin with. It

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seems so disappointing that we have all this water around us, yet we can’t drink it,

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so people go without. Well, let me break it down for you…

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Rivers constantly bring fresh water to the oceans. You’d think these sources would

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dilute the sea and decrease the salt content. But in fact, it’s quite the opposite. Water

01:57                =black

in rivers is also brackish – it’s just 70 times less salty than in the ocean. On

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its way to the sea, rivers wash out salt from rocks and carry it with them. Once the water

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reaches its destination, that salt remains in the ocean, but the extra water doesn’t

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dilute the overall salt content because it evaporates. This is the same reason why rivers

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aren’t that salty. They carry and dump it all into the sea!

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Each year 4 billion tons of salt are carried into the ocean just from rivers alone. If

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you keep doing that for the billions of years this planet has been in existence, you can

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imagine how much salt would gather there. Hey, you don’t even need to imagine, I’ll

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tell you right now: 50 quadrillion tons -- that’s 50 followed by 15 zeros! (Go ahead, write

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it out. I’ll wait here for you. Um, no I won’t.) That’s how much salt is in our

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world’s oceans. If you take away all the water, you’d be left with a layer of salt

03:00                                                         (マルガリータのカクテルには塩を入れる)

almost 500 feet thick! Now, just imagine a Margarita glass big enough to use that.

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Ok, so rivers have been adding salt to the ocean for years and years, and years and years

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and years. Does that mean seawater was originally fresh? Eh, maybe. The problem with that theory

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is the fact that the salt composition in rivers and oceans is different. Sea salt derives

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from a hydrochloric acid, while river salts are from carbonic acid. More scientists today

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believe that the oceans have been salty from the start because of volcanic activity. To

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really simplify a highly complex process: the stuff that these early volcanic eruptions

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produced would pour to the Earth in the form of acid rain and react with the rocks that

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would later become the seabed. The result of that reaction was a brackish solution,

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aka: salt!

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Ok, now that you know 97% of all the water on the planet has always been briny, you can

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safely assume that it’s this way for a reason. …And magically pushing a button to make

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it fresh water in this hypothetical situation would be devastating for life on this planet.

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The most obvious consequence is that the innumerable forms of marine life can only exist in briny

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water – they wouldn’t survive in fresh water. Now, we only know about a little over

04:26                                                                                                   =rather

200,000 species of oceanic life, but that’s just a drop in the bucket - albeit a very,

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very big bucket. There could be millions more! So, what would that mean for us humans? Well,

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without them, we’d lose this source of food, which would have a serious impact on not only

04:45 漁業に大きく依存している国だけでなく、

the countries that are highly dependent on their fishery sectors, but also those they

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export to!

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You also must consider the 10,000 known species of underwater algae. Algae are unique as they’re

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both plants and animals. Like animals, algae are capable of feeding on organic material

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in their environment. Like plants, they take part in photosynthesis. They play a huge role

05:10                                                                                    酸素量の低下 二酸化炭素の急増

in sustaining life because of this. Just imagine how severe the drop in oxygen and the spike

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in carbon dioxide levels will be without all this salt-water-loving algae. This means the

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Greenhouse Effect will intensify, and we’re already having enough problems with that as

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it is! In short, the global ecosystem would collapse as all the existing food chains would

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be destroyed.

05:35 しかし、話はそこで終わりません

Oh, but it doesn’t stop there! The oceans play a critical role in shaping the climate.

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More specifically, it’s ocean currents that can really affect the weather even on land!

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Ocean currents exist mainly because of density differences. Remember, as surface water evaporates

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under the hot sun, the salt gets left behind. This saltier water is denser and sinks, causing

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it to be cooler than the less dense water on the surface. This movement of water while

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sinking and rising is one major thing that causes ocean currents. (Of course, other things

06:11                                             それだけで別の動画1本分になってしまう

like wind and landforms play their part too, but that’s a whole other video itself! If

06:17

you’d be interested in seeing something like that, let me know down in the comments!)

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Anyway, these currents influence the climate by transporting heat. They can carry warmed

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or cooled water as far as several thousand miles. The displaced water can then warm or

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cool the air and the land over which this air blows. The Gulf Stream brings warm water

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from the tropical and subtropical Atlantic northward and bathes the shores of Western

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Europe. As a result, the climate there is much warmer than it could be in other parts

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at that latitude. Thus, Glasgow’s climate is a lot milder than, say, Moscow, Russia

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even though they’re both at the same latitude on the globe!

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So, yeah, ocean currents make the climate on earth a lot more tolerable and suitable

07:01 海水の塩分がなくなると海流がなくなり(欧州は寒くなるので)欧州の人は

for living. Take salt from the oceans, and the currents will disappear. And I guess Western

07:07 暖かいロシアのふさふさな帽子を被るかも    don=wear

Europeans would be donning furry Russian hats!

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Salt water has a much lower freezing temperature too. Without the salt, bigger parts of the

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oceans would turn to ice during the winter. Hot climatic zones would get hotter, cold

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ones – colder. Bigger storms would happen more frequently both on land and in the ocean.

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The climate changes would be so drastic that life on Earth for the existing species becomes

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impossible.

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Plus, all that salt would eventually start appearing right back in the oceans! Minerals

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from the Earth’s crust would start dissolving into the sea again, and oceanic floor vents

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would also pump minerals into the water. So perhaps it’s best if we just leave all the

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NaCL in the H2O and look to bright scientific and innovative minds to think up ways to solve

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the world’s freshwater crisis. And, of course, we can all do our part by being a little more

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careful about our consumption. Come on, you don’t need that hour-long shower no matter

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how relaxing it might be!

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Hey, you’re a bright mind! Do you know any ways to get more fresh water? Share your ideas

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down in the comments! If you learned something new from the video, then give it a like, share

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it with a friend, and here are some more cool videos to check out from the Bright Side of life