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0:07
in less than 30 years scientist description of the ocean has completely changed we realized that the ocean was filled with well pools it was a turbulent fluid with no current running straight it revolutionized the way we saw the ocean [Music]
0:30
in fact the currents determine the geography of life in the [Music] oceans a burning question today is what impact will melting ice fields and therefore a change in the quantity of fresh water have on the Deep thermohaline circulation the ocean plays a vital role in exchanges with the atmosphere particularly the absorption of carbon dioxide so the ocean plays a key role in
1:04
the ocean is the most important part of our Global Climate system and that's why the research is so intense right now to understand what happens in the oceans we'd need to be able to monitor a drop of water through the heart of the oceanic machine and try to decipher the processes that occur
1:43
[Music] for a long time the sea remained a relatively obscure World a large fish tank that we'd cross without worrying too much about its internal functioning and even less about its role in the existence of Life at the end of the 1980s we knew more about space than about the oceans which nonetheless cover a cool 70% of our planet a planet which was showing worrying signs of warming up [Music]
2:30
analyzing the mechanisms at work in this upheaval became a matter of urgency so the scientific Community turned to the
2:47
oceans today we realize that the ocean is a very complex Machinery with several engines multiple gears and we can see that everything is connected this system connects all the planet's Waters and all its basins everything is linked and interconnected Bruno Blanc is one of the oceanographers who wondered about the movements of water masses about their Journeys all around the world he sensed there might be a trail to be followed that would reveal the secrets of the ocean
3:26
machine in fact to properly understand what happens in the oceans you'd have to take a single drop of water and be able to follow its sea Journey it might fall for instance into the ocean in one of the branches of the Gulf Stream off iseland and we'd follow it to the center of the ocean machine and use it to decipher the mechanisms that occur
4:00
this idea isn't Just a Dream Bruno Blanc has in fact modeled the path of a drop of water carried by the Sea
4:11
currents the results confirmed the researcher's intuition the water droplet will Transit through all the oceans on the planet before returning several centuries later to its starting [Music] point a huge circuit which which passes through the most remarkable phenomena the oceans have to offer all of which are now the subject of scientists research we will tell the story of that
4:44
Voyage the drop of water heads North carried by a succession of surface currents which cool in contact with the atmosphere cold water which is denser will tend to sink into the ocean and when it arrives in the polar Seas other processes will contribute to making it dive deeper The Voyage leads without further Ado to the heart of a phenomenon which influences global climate in its entirety this happens in the cold season under the ice flow the ice formed by the freezing sea
5:18
water throughout the winter expels via gravitation the salt it contains this produces a heavy cold brine which sinks to the de deps dragging with it huge quantities of water at more than 10 times the flow rate of all the rivers in the world this gigantic undersea waterfall acts just like an engine 2,000 M further down it generates a wide conveyor belt of salty cold water which spreads southwards this migration is offset on the surface by warmer Waters which are pulled
5:56
northwards thus the thermohaline circulation is created Thermo for temperature and haline for salinity a vast Circuit of currents responsible for transporting heat and therefore for the climatic balance of the planet in short our [Music]
6:24
thermostat and it's this Arctic engine indispensable to temperature regulation which is is now worrying the
6:34
scientists for the last 20 years or so Louis forer has carried out a good many field missions attracting the attention of policy makers to the ongoing transformations in the polar environment the Arctic Ocean is a very small ocean accounting for barely 4% of all the ocean's surface area but it has a role disproportionate to its size because it hugely influences the currents of the North Atlantic and indeed the whole Northern Hemisphere but over the last few decades the major
7:04
discoveries in the Arctic are obviously the rapid disappearance of the polar ice cap as well as the acceleration in the Greenland glaciers melting so right now with the ice flow melting the surface waters reaching the Greenland sea and the labrador sea are less and less salty and will be less and less dense when the ice Fields form we fear this will result in a gradual slowing of the deep water thermohaline circulation can fresh water really hinder the workings of the Arctic engine
7:37
and what consequences would that have for the climate in actual fact the phenomenon did occur some 13,000 years ago at the end of the last ice
7:50
age then the Arctic Ocean was a huge immobile block of ice frozen stiff by the intense cold nothing moved until the the atmosphere warmed
8:07
again in a few hundred years the landscape was totally altered glaciers melted the ice Fields disintegrated making way for currents which dragged icebergs in their wake the Arctic Ocean began to function more or less as it does today but at the same time it found itself confront Ed by Massive quantities of fresh water from the melting flows so what happened the answer is found in these core tubes of sediment sampled from the bottom of the ocean they're made up of
8:43
various strata of materials deposited by currents and drifting ice over time here we begin to see deglaciation with intervals marked by sediment Which is far lighter a light brown here if I had to date the interval between this and that I'd say that around here we're at 11,000 to 12,000 years before the present day CL Marcel has made a speciality out of reading and interpreting these mysterious sedimentary cryptograms here he gleans a possible pointer to the disruption threatening the
9:22
planet the sediment here is essentially coarse grains it's therefore probable as their millimeters in diameter that it's the kind of material usually carried by floating ice or icebergs this gives a picture of an ocean in which the sea ice has begun to move around again and the melted water from this sea ice will penetrate the northern seas and other words the Norwegian sea the Greenland sea and then towards the basins of the North Atlantic and will lessen the salinity of those
9:53
basins and slow the formation of deep water in the North Atlantic
10:02
when the flow rate of the great undersea waterfall slows the oceanic conveyor belt weakens less cold water is sent to the depth less warm water is pulled northwards to the surface the thermostat goes wrong we'll suddenly have a huge coal snap in the North Atlantic so for around a thousand years almost Ice Age conditions will set in the ice front in the North Atlantic will sh shft around 1500 km South following this episode which is entirely caused by the
10:40
Artic the consequence of this kind of observation is a realization that if in the future a lot of fresh water arrives in the Arctic it can significantly disturb the overall Oceanic circulation
10:57
[Music]
11:12
so now we're heading south our water droplet will cross the Atlantic Ocean from north to south following a deep water current at a depth of around 2,000 M on the western side of the Atlantic Basin a current that results from the formation of dense water in the Arctic
11:37
ocean once we get to the southern hemisphere we come to a strategic place for the global climate the Southern Ocean an ocean whose importance has long been underestimated because it's hard to access and therefore poorly measured in fact it's a particularly inhospitable region
12:03
the Southern Ocean a vast mass of tumultuous Waters in circling the Antarctic continent located at the far reaches of the world it's the least accessible and the most dangerous of all the planet's
12:20
oceans a challenge for whoever would explore it and understand the way it works here there is no land to slow the world's most violent winds in their unceasing round nothing either to reduce the strength of the circumpolar current a monster which whips the waters into a dizzying ride around the Antarctic continent it's the most powerful current on the planet in places 2,000 km wide capable of reaching as far down as 4,000 m in depth but through a lack of observations
12:55
and data in situ the Southern Ocean and its terrible current have long been sidelined in the models built by the
13:09
scientists Sabrina spes is a researcher who sensed an urgent need to know more about this ocean with the bad reputation in 2004 she organized one of the first large-scale programs devoted to studying Antarctic
13:27
Waters in the 19 '90s we realized that this ocean was supplying Waters that were very important to the global Oceanic circulation and as these campaigns were very rare we needed to understand a lot
13:48
more in this type of campaign the aim is to measure the variables which give an identity to what is called a water mass in other words the temperature the salinity the pressure in terms of physics and chemical elements Like Oxygen to obtain time series that show us both how we can recreate the movements of water masses in this region and therefore understand the exchanges to the south of Africa between the various Oceanic basins and also how these Waters can change with
14:22
time there's the notion of variability like the weather varies in the atmosphere the circulation can vary from one year to the next in the ocean thanks partly to campaigns led by Saina spe scientists have managed to identify the route taken by the massive volumes of water which circulate around the Antarctic
14:48
continent we have thus discovered the way in which the three great oceans on the planet are
14:57
connected in fact everything revolves around the circumpolar current which acts as a transmission belt in its ceaseless round it captures the Deep cold Waters from the three major Oceanic basins that is the Atlantic the Pacific and the Indian it slowly brings these Waters towards the surface and redistributes them from one ocean to the
15:25
other the results of campaigns are not yet all an but what we can say today is that this Global Oceanic circulation is important for heat exchanges for example between different Oceanic basins and in interaction with the atmosphere particularly in the absorption of carbon dioxide so the ocean plays a key role in the global
15:52
climate but the discoveries didn't stop there other observations which magnified the role of the the Southern Ocean today Force scientists to reconsider the models what we can see here along the Antarctic continent close to the continental slope and shelf is the formation of bottom Waters the bottom of the ocean is carpeted by these Waters the densest Waters we find anywhere in the oceanic Basin and which form in a very localized way around this continent only now are
16:28
we beginning to Noti them we've made some observations but we' no idea of the quantity of these Waters that are formed and the process seems to be linked to the poinas that exist around the
16:43
[Music] Antarctic poinas are huge stretches of water that are free from Ice despite the extreme climatic conditions in the Antarctic poenas are formed by very violent winds called cab itic winds which jostle and Fracture the Ice Flow clearing vast zones of free [Music] water these zones then become ice factories where the ice field regularly forms and then
17:16
disintegrates on each of these Cycles it expels the salt it contains in the form of a cold heavy brine which sinks to the bottom in what quantity and in which directions these are the questions David Barber is one of the first to address the phenomenon of poers in order to precisely measure their characteristics he chose to create them artificially they called these ponds poas so people were always interested in these things so they came up with a special term called a pinia
17:48
and uh so these puddles of open water in a place where there should be sea ice were always quite interesting to early Mariners and to people that were you know hunting seals and or whale or whatever and so plenas have become something that have been very important in studying both poles of the planet when you think about climate change and how climate change is affecting things and the reason for that is that this Open Water behaves much different physically than the sea ice around it
18:14
and so to study penas you can do one of two things you can go to the Arctic or the Antarctic where these penas exist and we do do that as our as part of our field programs but what we've done here at the University of Manitoba is to build our own penia [Music] these plena they form deep water throughout the year so even in the middle of winter when it's 40 below zero and even here at the surf facility that ice is causing the ocean water underneath the sink towards the bottom
18:46
of the pool and we're actually measuring that uh continuously as we're doing our experiments here at
18:54
Surf it's really the driver of how this ocean Circ ulation works and the plenas of the planet play a very important role in this overall concept of deep water formation and the oceanic conveyor belt now there are many many penas in the Antarctic they basically occur all the way around the Antarctic they'll change in size from you know tens of meters to hundreds of meters to thousands of meters and then practically speaking they're in the the thousands of kilometer size square area some of them
19:27
can get to be very big several hundred thousand km in
19:33
size the measurements carried out in the laboratory coupled with field observations indicate that at the bottom of the Southern Ocean is a gigantic network of cold waterer Rivers recently the flow rate of one was successfully measured it's equivalent to 60 times that of the
19:55
Amazon thus these discoveries prove the existence at the South Pole of a second real engine that is involved as the one at the North Pole in the global Oceanic circulation two systems connected in a great conveyor belt that moves a whole network of currents around the world the ocean is the most important part of our Global Climate system and it's the poles that are the engine of our Global Climate system because of the influence they have on Ocean circulation and how
20:24
this ocean how this packet moves around the planet when you think of packets of water moving around the
20:36
planet the more we discover about the currents and their effects the more we feel a need to know more in other words to observe them more perceptively more fully on a permanent
20:49
basis but how technically can we monitor a world so vast what tools can we use one of the most ambitious Solutions is to use little submarines stuffed with sensors a veritable Army of spies which constantly monitor temperature and salinity from the surface to a depth of 2,000
21:18
M before being sent on a mission these little robots are trained here under the attentive eye of the engineers in charge of the program to Lo de and the world's oceans have become a vast
21:38
playground there's an amazing Revolution with this type of Argus program before we go off to observe a phenomenon something very precise the boat would put to Sea for a month or however long but naturally we wouldn't be back until a month or a year after here what we said was we wanted a program to observe the ocean which was large scale Global perennial and permanent the target was to have 3,000 floats out at Sea
22:06
permanently on this screen we can see the movements of the network at first we kept things simple and then gradually as the easy parts were being covered we headed south and we'll see how things evolved here typically we find a ship on a long passage that has sailed all the way down that
22:27
road now we can see that we're heading for the South a little more the north is fine the southern hemisphere was done a little later so we can see that in the extreme South there are still a few gaps the Argos system data available free all over the world are used in particular for feeding mathematical models the challenge is to reproduce the dynamic of the oceans at any spot on the
22:56
globe but the problem is in some zones these little spies can sometimes be muzzled by the environment itself here our drop of water is journeying under the ice which is not a problem to the droplet because of course Marine currents do exist under the Zone which in winter is covered by sea ice however this ice is a major obstacle and unfortunate for the oceanic instruments the profiling floats which are supposed to surface periodically and trans their data to scientists to combat this
23:31
researchers have seized upon another measuring vehicle which is not scared to go swimming under zones covered in sea ice [Music] [Applause]
24:02
the thing is these sea elephants are amazing divers we've put dive sensors on these animals that show they're capable of diving to a depth of Beyond 1500 M we used a new generation of Argos beacons which enabled us on the one hand to follow these animals as they moved around at sea but also to study throughout their Journey the diving behavior of sea elephants and when they dived to measure the temperature and the salinity of the water masses crossed by the Sea elephants and therefore to
24:33
characterize from the oceanographer point of view the habitats and zones where sea elephants concentrate their fishing
24:48
activities to reach these hunting grounds this sea elephant heads South and prepares to explore Waters covered with ice [Music] the information gleaned by our special Envoy means that for the first time the oceanographic conditions associated with the formation of the Ice Flow can be recorded and this rounds out the data needed by scientists for their
25:16
models after several laps around the Antarctic continents our water droplet feels like escaping from the circumpolar current of course there are several possible exit gates but one of the main ones intensity wise is towards the Pacific as you approach the South American continent the waters Branch off to the north and follow the coastline first Chile then Peru that's the humbold current and this humbold current allows us to tackle a key phenomenon in the circulation of water [Music]
25:56
masses but what dides these Waters of the Humbolt current hide for oceanographers climatologists biologists and even a few geneticists to be spreading their Nets
26:14
[Music] here for scientists on the Tara Expedition involved in a huge campaign covering all the Seas on the planet there are Treasures to be found here the subject of their research lives in these Waters and in astronomical
26:43
quantities this greenish soup is in fact teeming with life it contains the very origin of our existence but also that which enables us to live and to breathe on the earth plankton
27:00
Plankton is very interesting for lots of reasons first it's our oxygen producing machine 50% of the oxygen that we breathe is produced by Plankton there are also organisms which hold carbon dioxide in fact 50% of the carbon dioxide that is discharged into the atmosphere is swallowed up by Plankton at the bottom of the oceans the term Plankton covers thousands of different species in in fact both plant and animal but which all have one characteristic in common their
27:34
existence is entirely conditioned by the Marine currents through which they grow and migrate on the Peruvian coast in particular the exceptional abundance of Plankton is due to the upward surge of deep cold water very rich in the nutrients needed for its growth this vertical current of waters called an upwelling is just generated by the winds which here regularly Blow from east to west it pushes the surface waters which are warmer out to sea and forces the colder bottom Waters to rise
28:09
up towards the coast here the upwelling is directly responsible for an amazing abundance of life in all its [Music] forms another important thing about Plankton is that it's obviously the base of the food chain the unicellular alga are eaten by zup plankton which are eaten by the fish by the whales so whenever there's a lot of Plankton like at upwellings there's a lot of Life lots of fish and so there's lots of
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fishing among all the species of fish which benefit from the ecosystem the anvy is clearly [Music] dominant their proliferation makes this region the leading fishing grounds in the world volume wise it represents less than 1% of the world's surface but supplies 20% of catches on a global [Music] [Applause] [Music] scale but man isn't the only Predator to benefit from this manner others like sea lions and great birds are Keen to join the feast thus this vast system both
29:24
economic and ecological has been built around the movement of the water the ocean currents here generate not only the food chain upon which men and animals depend they also give it its instability and among all this disturbance the most feared the most spectacular is called el nino [Music]
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[Music]
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this phenomenon occurs irregularly two or three times every 10 years it all begins with a change in the wind patterns the trade winds which caused the upwelling slow down and even reverse this results in the cold Waters that would rise up towards the coast being replaced by warm currents returning from the open [Music] see all this triggers a wave of atmospheric disturbance which mainly affects the tropical zones rainstorms and Cyclones move towards the American continent meanwhile Indonesia and
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Australia are hit by scorching
30:56
droughts but in Peru the consequences are also economic and force scientists to increase their vigilance the better to anticipate the impending
31:11
disaster we know that the humble ecosystem is characterized by Cold Waters the surface temperature of the seawat is between 13 and 20°
31:25
C A change in water temperature a drop in the production of Plankton the entire ecosystem in Peru is turned upside down naturally this affects the species which feed on the phytoplankton and zup Plankton particularly the Peruvian anchy this affects not only its feeding process but also the Ani itself which is used to living in temperatures of 15 or 16° C and when the elino phenomenon comes to the northern zone of temperatures reach between 25 and 28°
32:04
C under pressure from El Nino the anvy is disappearing and with it 99% of all industrial fishing this has huge consequences for the country's
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economy today in Peru they have learn to better predict the phenomenon and its intensity and therefore to manage the stocks of fish [Music] accordingly but beyond the local context El Nino speaks volumes about the power of the link that unites ocean and atmosphere such gigantic climate disturbances around the world can be caused by a simple variation of the currents at one point on the globe
33:12
now our water droplet sets out on a very long journey mainly on the surface layers in other words the first two or 300 meters of the column of water it is pushed by the trade winds so it leaves the American coast and is carried from east to west to oceanana by the southern equator
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[Music]
33:50
as soon as it gets to the western edge of the Pacific our drop of water is captured by the equatorial undercurrent which sends it back towards America it's a unique current because it flows at a depth of 100 m centered on the equator and it flows in the opposite direction to the surface currents and winds so this droplet will be capable of shuttling back and forth several times between the west and the east of the Pacific alternately taking the surface currents and the equatorial
34:19
undercurrent this type of recirculation isn't uncommon in fact in every subbasin there are internal circulation cells which are of course added to the links with other
34:40
basins a great merrygoround which irrigates the oceans with its vital substance plankton for this reason scientists are now seeking a better understanding of the effect of currents on all the microorganisms that enable the planet to breathe and to feed itself but how to visualize this interaction how to connect the circulation of waters and the biological diversity of the oceans this challenge was taken up by Mick follows at the Massachusetts Institute of Technology MIT by modeling
35:17
the behavior of various species of Plankton according to their environment to do this the researcher reproduced the physiological characteristics of these m microorganisms and introduced them into a global model of the ocean okay thus MCS managed to create a virtual world in which the various communities of Plankton live and grow in color according to the currents and the variations in temperature and salinity just as things happen invisibly in [Music] reality so this movie shows you
35:55
something that we can't yet measure efficiently in the ocean or we probably can but we haven't done yet which is the diversity of the phyter Plankton um it's been measured at some local spots but in the model we can ask how many different species are coexisting at any point in time in space and so this is a pattern of the the biodiversity um and we can find that places like the Kur extension here are very uh High diversity there lots of different types of phop Plankton living
36:30
there concurrently um and that's because of the Confluence of currents the motion of currents and also the vigorous supply of nutrient resources that happens to coincide in these places and so this gives you some idea of how the biomes of the ocean so if you think about looking at the land and you'll see going from tropical plants to savanas to fur trees on the mountains this is kind of the analogy for the fight planted in the ocean you're seeing the different biomes As you move around
37:05
in the ocean and how they vary with space and [Music]
37:17
time these images of marine life subjected to the interplay of currents are the fruit of the most advanced modeling that exists today a virtual Universe still under construction which for mck follows will eventually enable us to test the various scenarios linked to climate change and we can start to interrogate um uh models like this to understand why uh those boundaries are moving how they might change if the a permanent change in the physics of the ocean for example
37:50
a warming uh shifted those uh intersections around
38:05
our drop of water still carries westwards pushed by the surface equatorial current once past Madagascar the current separates into two branches the northern Branch leads to recirculation in the Indian Basin but to go towards the Atlantic the southern branch is more effective and quicker and our droplet will take the agas current which is the counterpart to the Gulf Stream for the Indian Ocean and that current will lead to the southernmost tip of
38:34
Africa by penetrating the coastal Waters of South Africa the droplet May well come up against the most spectacular migration of sardines observable on our
38:46
planet the phenomenon is linked to the presence of a powerful upwelling here the cold Waters from the Southern Ocean are flowing up along the coasts they form a corridor of water rich in Plankton ritually taken by millions of sardines every year to the Delight of a whole Army of preditors
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[Music]
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the
40:05
though it may escape the shs of sardines the droplet cannot avoid the strange edies of the aulas [Music] current it's moving around a lot our droplet of water is captured by Oceanic Whirlpool this is another phenomenon that has long fascinated scientists but today we're realiz ing their importance to the climate and to ecosystems a Whirlpool but how do you spot them how do you see them in reality such a structure is undetectable from the earth even when you get up high in a
40:44
plane more often than not it will remain
40:49
invisible and yet the vortex is there somewhere loaded with a considerable energy capable of dragging millions of cubic MERS of water with it to determine its existence you have to go much higher
41:15
[Music] what only satellites are capable of spotting and monitoring the movements of these strange Oceanic vortices in particular thanks to the onboard systems that measure the relief of the oceans and can detect deformations generated at the Surface by [Music]
41:43
whirlpools for Marina Ley who studies these structures and their effects on the marine environment the satellite revealed the scope of a long unsuspected phenomenon AO before there were boats which knew very well that there were whirlpools and so they had identified what they called coherent vortices or in particular Gulf Stream rings but it was really with height finding radar that we realized that the ocean was filled with whirlpools it was a turbulent fluid with
42:15
none of its currents running straight it revolutionized our way of looking at the ocean there are thousands of whirlpools in the ocean and all these whirlpools interact with other wh pools some can survive a long time up to 2 or 3 years but they take a few weeks or a few months to form they're also highly energetic and associated with high speeds in both horizontal currents and vertical currents in fact they generate movements of water from the bottom of the ocean to
42:46
the surface and vice versa which are very rapid the fastest vertical movements of water you can have around 20 30 m sometimes sometimes up to 50 or 100 m per day essentially the whirlpools form at the crossroads of marine currents to the south of Africa the clash between the circumpolar current and the aulas current is so violent that it produces whirlpools capable of crossing the Atlantic in a few months taking with them our drop of water but above all this turbulence
43:22
produces intense mixing whose effects on the physical and chemical properties of the ocean we're now discovering these world pools are all about speed horizontal and vertical and they carry heat and as heat Transporters they're important to the climate in addition these well pools play a part in the ocean's carbon capture process by shaking up the waters vertically the world pools activate the production of plankton a major carbon consumer at the same time they drag
43:57
towards the depths Waters in which carbon dioxide from the atmosphere is already diluted thus this long ignored turbulence is revealed to have a real impact on the climate machine so today we're busy trying to understand what quantitively speaking is the role of these well pools on the carbon cycle it's clear that today they cannot be overlooked in our carbon assessments
44:27
the planet is getting warmer suffocated by the carbon dioxide emitted by man's activity but the ocean is there and it dissolves close to 50% by absorbing the carbon it contains until now this process has slowed down the climate's worrying Evolution but how long can that go on what is the ocean's carbon absorption capacity it's that particular question that the scientific Community is now trying to answer the thing is carbon exchanges Between the Ocean and the
45:01
atmosphere are very complex to quantify and they work in both ways it's an important urgent matter to evaluate this absorption of carbon by the ocean we recently realized that carbon was absorbed chiefly at World poool level poorly sampled by current oceanographic campaigns otherwise it's where deep Waters or bottom Waters form which means mainly in regions of the North Atlantic and in the Southern Ocean but at the same time the carbon loaded deep Waters that come from the
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North Atlantic rise to the surface to the south of the circumpolar current and restore that carbon to the atmosphere and this makes precise evaluation difficult of what carbon is entering the ocean compared to what is
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leaving it's difficult today to establish a Global assessment of carbon absorption however the results of the most recent studies are rather pessimistic they reveal that locally the quantity of carbon absorbed is tending to [Music] decrease the North Atlantic for example absorbs only half what it did 10 years ago in the Southern Ocean it's 10 times less at the same time the concentration of of carbon dioxide in the ocean has greatly increased scientists have calculated
46:32
that by the year 2100 it will triple for the first time in 20 million years the effect of all this is to gradually increase the acidity of the water and threaten the growth of shellfish and coral organisms
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[Music]
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the global ocean has until now played an extremely important role in reabsorbing and holding our excess carbon dioxide from the atmosphere and it's like a reservoir filling up not only will it soon stop recapturing this carbon dioxide but because its chemistry is changing because it's acidifying and warming this Reservoir will start to reject the CO2 it has been storing since the beginning of the Industrial Age and return it to the atmosphere and that is worrying because very suddenly we may
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see concentrations of CO2 in the atmosphere increase by 50% or even double and global warming will [Music]
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accelerate when it comes within range of the South American Coast the world pool has lost most of its energy it disintegrates and releases its content so the drop of water is no longer captive we see it cross the Equator and it is retrieved by the main circulation cellu in the North
48:14
Atlantic the droplets round the world tour will have taken close to 650 years however in line with our new vision of the oceans we will now have to take a very careful look at the path it takes and watch it follow all the twists and turns of the Gulf Stream recently re-baptized the Lord of the Rings by the scientists [Music] themselves by reviewing this trajectory we realize that our drop of water has felt movements at very different scales throughout its Journey we've seen the
48:51
scale of the oceanic Basin with its circulation cell over the North Atlantic there's also the very large scale with our droplet toppling over from one ocean to another and then there's the small scale with a droplet caught up in a Whirlpool so the ocean Dynamic is a complex puzzle which is made up of pieces that are very different in size yet they fit together complement one another and interact so the ideal thing for us today would be for us to represent this whole dynamic digitally
49:24
just one model incorporating every scale at once even though there's still a long way to go to complete the great virtual model of the oceans the scientist's work is already showing significant results and it's forcing us to take a different look at the world which washes our coastlines it's hard not to see beyond the apparent calmness of these Waters the very complex mechanism which underpins our planet's Fitness for habitation it's hard too to out the changes threatening the whole system and
49:59
revealing its
50:04
fragility it has never been as clear that our existence past and future is intimately linked to the movements which Drive the oceans at their very [Music]
50:21
heart our droplet is going back to its Beginnings we see it come back where it started from of course whether in the real ocean or in this Digital model the number of possible trajectories is unlimited nonetheless the oceanic circulation is most definitely a huge circuit and in fact perhaps our droplet has started off on its second lap
50:57
[Music]
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