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  • You've likely heard about the effects climate change is having on our planet and specifically in the Arctic

  • which is warming twice as fast. But what would actually happen

  • if all the ice melted on Earth.

  • Bill: I can help with that! When you and I drink water

  • We drink non-salty water, we drink fresh water

  • Of all the water in the world most of it is salty, just 3% is not salty

  • Now of that 3%, you can't get to most of that because 70% of that 3%

  • is FROZEN - thirty million cubic kilometers of frozen water!

  • It's so much frozen water, so much ice that if you put a layer of it

  • a thousand meters thick, it would cover North America

  • That's a lot of frozen water people!

  • On land frozen water forms glaciers, icesheets, permafrost and snow

  • but the Arctic is largely ocean so there it takes the form

  • of floating sea ice like icebergs and because it's in direct contact with warming waters

  • Sea ice will be the first to melt as global temperatures rise

  • In fact this year NASA reported that the extent of Arctic sea ice was the lowest ever recorded for

  • for January, February, April, May and June 2016

  • Bill: So the world is getting warmer and the ice is melting

  • Pretty soon you'll be able to drive your ship from Europe to Russia,

  • right over the North Pole, with no ice in the way.

  • That's good for certain shipping companies maybe, but for the marine species: the polar bears, the walruses,

  • the seals! They don't have their own habitats. They're all going away, they're melting out from under them.

  • And ocean dwelling animals like bowhead whales and narwhals aren't immune to these changes either.

  • As sea ice melts energy and oil companies are taking it as an opportunity to search

  • further north for untapped resources using a process known as seismic blasting

  • they shoot air explosions into the water in an effort to map the ocean floor

  • and find oil. Of course, this has detrimental effects on the whole ecosystem of the Arctic ocean

  • while also causing physical trauma and habitat relocation in whales.

  • In terms of sea levels, melting sea ice won't have much of an effect.

  • This is because the floating ice already displaces roughly the same amount of water

  • as it would produce when it melts, so that effect would be negligible.

  • Furthermore, of the majority of Earth's ice, more than 95% is land-based

  • and contained mostly in enormous ice sheets that cover Greenland and Antartica

  • where there are entire mountain ranges almost as big as the alps, completely buried in ice

  • So, what if all the ice on land melts?

  • Bill: If all this ice melts, the ocean's gonna have more water in it

  • So the sea levels, as measured from the coasts, is gonna go up.

  • It's gonna go up 70 meters. That's a long way people. Half the world's citizens

  • live on sea coasts. That's where the, uh, commerce action is.

  • So they're gonna have to move! Where are they gonna go? And...

  • who's gonna pay for it?

  • Tokyo, New York, Sao Paulo, Mumbai, Shanghai and Jakarta are all coastal

  • and happen to be some of the world's biggest cities.

  • Even a small sea level rise of only a couple feet could cause up to a trillion dollars worth of flood damage

  • per year. A rise of 10 meters would displace more than 630 million people

  • nearly 10% of the world's population.

  • At 25 meters, 1.4 billion people, roughly 20% of humanity is left homeless

  • and to visualise the full 70 meters, the rising seas would drown out most

  • of the US Eastern seaboard, much of the West coast,

  • the entire state of Florida, huge areas of Asia including Bangladesh

  • and much of Northern China and create a new inland sea in Australia.

  • At the North and South pole of the Earth we have a lot of ice. Ice is white.

  • Ice reflects sunlight into space.

  • But there's a feedback mechanism, one thing leading to another. As the world gets warmer

  • the ice melts. As the ice melts it's reflecting less sunlight into space

  • which lets the world get warmer still. The sunlight is absorbed

  • by the dark , liquid ocean. So as the ice melts

  • the world gets warmer. And the sea gets fresher.

  • Currently the world's oceans are crisscrossed by a set of currents that act as a giant conveyer belt.

  • And these currents are powered in part by the differences in the saltiness

  • between one part of the ocean and another.

  • So, if a melting ice sheet in Greenland dumps a whole bunch of non-salty, fresh water into the North Atlantic

  • it's possible that it could disrupt the currents.

  • Bill: So the conveyer belt takes chemicals, takes nutrients around the world,

  • which feed plankton,

  • which feed fish,

  • which feed us.

  • Half of the oxygen you breathe is made by plants in the ocean.

  • So you don't wanna mess with this.

  • Furthermore, as that sea surface gets warmer,

  • off of Greenland, the Gulf Stream will probably shift a little bit,

  • and if that shifts, what keeps Europe warm right now,

  • May not keep Europe as warm. So the crops are gonna have to be grown elsewhere

  • and who's gonna grow them and who's gonna ship them around and who's gonna feed each other

  • and what's going on?! This is serious business! When you go melting the ice.

  • We actually went up to the Arctic to see the current state of things first hand

  • while documenting it all and were absolutely shocked by what we found.

  • Click here to watch our documentary, The End of the Arctic,

  • where we learn about an Inuit communities fight to defend their human rights

  • against oil companies and the Canadian government

  • all while trying to save the Arctic from the drastic effects of climate change

  • and seismic blasting.

  • You can help spread awareness by sharing the video and signing our petition

  • to put pressure on the governement to prevent seismic blasting in the Arctic

  • which would have detrimental, long-lasting effects on the wildlife

  • and the Inuit people living in Northern Canada.

  • Check out the links in the description

  • and join the movement to stand up for the Arctic, and our Planet.

  • And subscribe for more weekly science videos.

You've likely heard about the effects climate change is having on our planet and specifically in the Arctic

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B1 US arctic sea sea ice ocean water melting

What If All The Ice Melted On Earth? ft. Bill Nye

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    韓澐 posted on 2016/09/27
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