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TEDx Talks
Published: 2016-02-26
Source: https://www.youtube.com/watch?v=8m1X26Auw6Q
do you ever think about how important the oceans are an idealized the oceans cover two thirds of our planet they provide half the oxygen we breathe the moderator climate and they provide jobs and medicine and food including twenty percent of protein to feed the entire world population people used to think that the oceans are so vast that they wouldn't be affected by human activities well today
I'm going to tell you about a serious reality that is changing our oceans called ocean acidification or the evil twin of climate change did you know that the oceans have absorbed twenty five percent of all of the carbon dioxide that we have admitted to the atmosphere now this is just another great service provided by the oceans since carbon dioxide is one of the greenhouse gases that's
causing climate change but as we keep pumping more and more and more carbon dioxide into the atmosphere more is dissolving into the oceans and this is what's changing our ocean chemistry when carbon dioxide dissolved in sea water it undergoes a number of chemical reactions now looking for you I don't have time to get into the details of the chemistry for today but I'll tell you as
more carbon dioxide enters the ocean the sea water PH goes down and this basically means that there is an increase in ocean acidity and this whole process is called ocean acidification and it's happening alongside climate change scientists been monitoring ocean acidification for over two decades bigger is an important time series in Hawaii and the top lines who's a steadily increasing concentrations carbon dioxide or CO two
gas in the atmosphere and this is directly as a result of human activities the line underneath shows the increasing concentrations of carbon dioxide that is dissolved in the surface of the ocean which you can see is increasing at this crime rates as carbon dioxide in the atmosphere since measure measurements began the log lying on the bottom then she was the changing chemistry as more carbon dioxide
is entered the ocean the sea water P. hate has gone down it's basically means there has been an increase in ocean acidity now an island scientists are also monitoring ocean acidification scientists at the marine institute in NY Galway and we too are seeing acidification at the same rate as the thin these main ocean times theory sites around the so what's happening right at our doorstep now
I'd like to give you an example of just how we collect idea that too to monitor a changing ocean well firstly we we collect a lot of our samples in the middle of winter so as you can imagine in the north Atlantic we got hit with some seriously stormy conditions so not for and if you get a little motion sickness we are collecting some very valuable
data so we'd be lower this instrument over the side of the ship and there are sensors that are mounted on the bottom that can tell us information about the surrounding water such as temperature or dissolved oxygen and then we can collect our sea water samples in these large bottles so we start at the bottom which can be over four kilometers deep just offer continental shelf and
we take samples at regular intervals right up to the surface we take the water back on the deck and then we can either analyze them on the ship are back in the bar tree for the different chemical prime but why should we care how is the ocean acidification going to affect all of us well here are the worrying fax there has already been an increase in
ocean acidity of twenty six percent since pre industrial times which is directly due to human activities unless we can start slowing down our carbon dioxide emissions we're expecting an increase in ocean acidity of one hundred and seventy percent by the end of this century I mean this is with in our childrens lifetime this rate of acidification is ten times faster than any acidification in our oceans
for over fifty five million years so our marine life had never ever experienced such a fast rate of change before so we literally could not know how they're going to cope now there was a natural acidification of events millions of years ago which court and which was much slower than what we are seeing today under this coincided with the mass extinction of many marine species so
is that what we're headed for well maybe studies are showing with some species are actually doing quite well would many are showing a negative response this isn't it are one of the big concerns is Ocean City increases the concentration of carbonate ions in sea water decrease at these items are basically there the building blocks for many marine species to make their shells for example craps %HESITATION
muscles oysters another example are Carlos they also need to these carbonate ions in sea water to make their current structure in order to build Carl wreaths as Ocean City increases and the concentration of carbonate ions decrease the species first find it more difficult to make their cells and that even lower levels they can actually begin to dissolve this here is a terracotta it's called a fee
butterfly and it's an important food source in the ocean for many species from cradle to salmon right up to Wales the shell of the terror plot was placed into sea water at a P. H. that we're expecting by the end of this century after only forty five days at this very realistic P. hate you can see shell has almost completely dissolved so ocean acidification could affect
right up through the food chain and right onto our dinner plates I mean who here like selfish or salmon are many other fish species whose food source in the ocean could be affected this example bees are coldwater Carl's and did you know we actually have cooled water car is an Irish waters just off our continental shelf and they support rich biodiversity including some very important fisheries
it's projected that by the end of this century seventy percent of all known coldwater Carlos in the entire ocean would be surrounded by sea water that is dissolving their Carl structure the last example I have are these healthy tropical Carl's they were placed in sea water at a P. H. were expecting by the year two thousand one hundred after six months Karl has almost completely dissolved
now Carl wreaths of support twenty five percent of all marine life in the entire ocean all marine life so you can see ocean acidification is a global threat I have an eight month old baby boy unless we start now slow this down I dread to think what our oceans will look like when he's a grown man we will see acidification we have already put too much
carbon dioxide into the atmosphere but we can slow this down we can prevent the worst case scenario the only way of doing that is by reducing our carbon dioxide emissions this is important for both you and I for industry for governments we need to work together slowed down ocean acidification and then we can slow down global warming slowed down ocean acidification and help to maintain a
