Southern Ocean, Antarctica, Totten Glacier discussed on The Science Show



What happens to the surrounding oceans. And that's what's motivating our work at the moment going on the field. Yes exactly what's happening to Arctic. Ice Sheet is something that for a long time. It's been the largest uncertainty in terms of future sea level rise but satellite data shows us. That not only is Antarctica. Losing mass overall therefore raising sea level but the rate which is losing masses accelerating. And so we see that in west Antarctica and just recently. We've done some work. In fact on the voyage H we took the Aurora Australis to place ship. It never been before the front of the totten glacier. The glacier is important because this single glacier holds enough ice nice to increase equivalent to three and a half meters of global sea level rise about half a greenland in this one Antarctic glacier satellite data hits told us that it was thinning. But it didn't didn't fit the pattern. Warm water wasn't supposed to get there and so on that voyage The ship was reaching the front of the totten glacier and we found that actually there is warm water reaching that part of East Tactica. That's important because most of the ice more than ninety percent of the Antarctic ice sheet is in the eastern part of Antarctica. So if that's also exposed to warm ocean moderns debts are concerned. It means that we need to take that contribution to sea level rise into account as well have you told skomer my doors open and we're doing everything we can. Maybe use doors closed to communicate the scientists effectively as we can but sometimes it is a challenge whose moods so Merz. Let's was part of the famous Australian Arctic Explorer Douglas Mawson's expedition down to Commonwealth Bay and one of his colleagues who was a particularly skilled skier And so he took Murzyn on his trip west to explore west of Commonwealth Bay famous story. I'm sure all of you know it but it didn't didn't go so well so new. NFL Crevasse with most of their food Murzyn and Mawson continued on. They didn't realize at the time that eating dog liver was not a good idea. You and Mertz died and so eventually got back to the base just in time to see the ship. Sailing away and spent another winter is famous. That's Australian Antarctic Story. So much somewhere down. The glossier and Mitch is on the move again. I understand stand. That's right so in two thousand ten long extension of the Mertz Glacier broke off in a forum to a massive iceberg about eighty kilometers long and Benoi. Ny Legacy one of my colleagues. It's IRO works on. Glaciers did a calculation of where merged body would have been at the time of the glacier calving and it looks likely that he's he's on the move and floating along with this massive icebergs. See Twenty eight which is making its way westward and so much is on the move again on the move again now I mentioned William Hewlett before Cambridge invented the word scientist in a question from Coleridge. The poet actually heating thirty three and the other word that he mentioned. You mentioned a number of words in signs many many of them and the the one I'm very fond of is conciliates because that's to do with a number of different elements of evidence. You have to make a case that something is so and when you come to climate change here you have in Antarctica and the southern ocean and all of what you're measuring yourself and your colleagues so many elements and you add those all the other ones they've got for example in San Diego the keeling curve killing he went up the mountain. The measured calm dockside. First Time no one knew why and he told this graph going up and up and up and up and up and anyway these numbers of evidence you got fifty one hundred. Two eight hundred. The evidence is staggering. Isn't it that we have a problem. The evidence now is completely clear that climate it is changing. It's changing more rapidly with time and that human actions are responsible so that the scientific evidence for that is clear the the scientific evidence is also clear that we were humanity was blessed in a way by getting delivered a fat wallet full of Carbon To get it through the lifetime of humanity but the temperature of the earth depends on how much of that carbon we spend. It's a very clear almost linear relationship and so forth nightly pay packet and you blow it all in the first. Tonight's IT'S GONNA be tough to eat later on and that's basically what we're doing with our carbon budget. If we WANNA keep carbon below level at which the consequences will be manageable. We need to rein in the rate at which we're using up the carbon that we were blessed with in the analogy is not so distant not so far fetched in the sense that we will literally find it more difficult to feed ourselves and to find shelter as levels rise and the other consequences of climate. Change come through unless we change our behavior one of the things. I WANNA come back to the notion about what you see if I go into a conference. Mm Front in North America in February gigantic snow into these huge cold winters and people come and say well. Where's with global warming gone? Tom and here is a case. Of in fact it's suggested took the wind up. North a wobbling and bringing down these Turkey Nicole streams of air and similarly. Do you get wobbles with the current in the Southern Ocean or do you get some changes to the currents that way we get wobbles in the current but also wobbles in wins over the Southern Ocean currents respond to those some of those are natural wobbles but some are are caused by human activities and there's not just carbon dioxide but of course the ozone hole is a big issue in the south and so as the ozone hole develops the winds shifted did south and that was a direct response of the system to a human forcing but a different one than the greenhouse gas. And the other thing that really puzzled me is is that with what you described these huge ocean moving so fast down the south unimpeded by quick continents nonetheless. You can take water coming all the way from the Arctic all the way from the north. How do you do that so it is connected? So the the global ocean circulation is fully connected and so the properties ladies that are set when water sinks from the surface in the North Atlantic. Give a parcel of water. At a certain fingerprint that allows us to identify the origin of that water. The reason is so important for climate really is that it plays a big role in driving that global network of ocean currents and it's that global conveyor belt of ocean currents the transports heat and carbon into the oceans when we talk about global warming. It's not so well known that it's really ocean warming that we're talking about more than ninety three percent. Ah of the extra heat energy that's been stored by the planet over. The last fifty years is found in the oceans. The implication of that is if you want to track how climate is changing. We really really need to be using that Planetary Monitor. It is the ocean we need to be measuring the oceans but the oceans also influenced by taking up so far about a third or thirty eighty percent of the carbon dioxide we've emitted into the atmosphere. It's a service. The Ocean is provided in the Southern Ocean is the primary way that heat and carbon dioxide get into the oceans. So that's why it's so crucial that we understand how the southern ocean works now and also how it may change in the future because if it becomes less efficient it picking up carbon dioxide decide that will act as a positive feedback and that will further accelerate the rate of climate change. You think the heat will come out of the ocean instead of being absorbed by it so it does eventually come back out again and how long it takes depends on how deep it goes in. What part of the ocean circulation gets wrapped up in so the changes in those ocean currents are part of how climate change will unfold now? Obviously we've talked about a number of different elements here and you're getting two point. Perhaps perhaps although it seems to me a consistent story that you might find duct members of the public stop giving so many elements. How'd you put them together? What do you you say when they seem to be asking that question you know? What's what's the big story? What's the clear line? And why do you keep having to have more and more evidence adding up. You know I said that. The evidence is clear that climate is changing and what that evidence is is looking for changes in all parts of the system in the atmosphere. The ocean the ice the land and vegetation. We know what to expect in terms of the pattern of change and so when we look across all those different parts of the system. It's all pointing in a consistent direction. It's all changing aging in a way that's consistent with climate change signal. Put another way why you keep having to do more research to find out more things and what are you doing infected among among. We don't need to do more research to show. The climate is changing. We need to know. Exactly how rapidly climate is going to change because that will affect the actions we take and we need to communicate clearly the evidence that we have already obviously because it's important to remember that it's not too late but time is running running out that wallet of carbon that we have it's getting pretty thin and that has to last us for the rest of humanity. The grounds for optimism are that were making and changes to decouple our economy from carbon at a rate faster than we ever have. It's already cheaper to build a renewable energy with storage jdpower plant than it is to build a coal-fired power plant. It's already impossible to get an Australian insurance company to ensure your coal mine. The future is is coming. The problem is it's been a little slow and if we were where we are now thirty years ago we'd be a much better position what it means is we're we're in a race and we've given the other guy very big headstart and so we have to use every tool that we have to try to catch up one thing. The brilliant puzzles me. Everyone it comes back to the dollars and the GRANTHAM institute which is connected to the London School of Economics led by Lord Stern Nicholas. Stern must be by the Lord. They did the crunching the numbers to find out whether it would cost so much to tackle climate change or whether you save money and it turned out that you'd say between one point five. Trillion and two trillion pounds pounds are going down to still Laura Laura money and when you talk to politicians about saving lower our money they say well that's in ten years fifteen years. I'm concerned about next week because people want to have smaller electricity bills. How do you argue with people like that? When they're saying we we won't it now? It's a challenge but I think part of the story that perhaps we haven't told so. Well this is actually the one you've put your finger on which is that. It's actually much more costly to us. to not act and it's more costly not just economically but it is more costly economically. But it's more costly socially in terms of health off and the environment and so it doesn't really depending on your values and what you're concerned about is a compelling argument that it makes a lot more sense sense for us to take action to slow the pace of climate change than it does to do nothing to trillion pounds huge amounts of money. We could say there are so many efficient things. I have been broadcast in any number of different schemes for improving things getting cheaper energy more Stable energy and on it goes to the question is turning it around the willingness to do it soon. Have you had arguments with decision makers on that yourself. Well alive count except for when directed which does happen. I've had a series of interesting conversations with a a number of Australian parliamentarians including Senator Malcolm Roberts for example. You may know and it's a it's an interesting experience France. What's clear is that people do use values and making decisions and their beliefs and there are those who are disinclined to act on climate change? Come from a number the different positions but many of them are ideological and they would prefer. It wasn't so and so they find arguments to support the idea that it isn't so it's tough to reconcile that point of view with science because none of the science points in that way and so the challenge is optimism is is important and we need to paint a future that is possible and achievable. It gets more difficult the longer we wait but the truth is that it's it's not too late. And if we act soon we can avoid committing ourselves to consequences that we can't undo and I think that's an important part of the story which is sometimes missed. It is the idea of commitment and Arctic. Ice Sheet for large parts of it to melt may take a century a couple of centuries but we may commit ourselves was to that happening within a couple of decades or decade because for some of the glaciers in Antarctica. Once they start to go. There's no way to turn it off. It's a self fulfilling self-reinforcing process and that's just one example. And so I think when I speak to people and they realized yeah well some people say well. It's hundred years from now. I don't care but if you say that the decisions you make in the next ten years to determine whether that happens in one hundred years we're not that changes how people think about it a little bit now some questions. I'm going to come down here and while I'm walking down. The steps are mentioned. Two things that encourage rage optimism. One of them is a book was published just over a year ago called drawdown by Paul Hawkins with two hundred different ways that you can do something constructive either an industry in work or whatever and they're all costed and you have an indication on each two pages of each the example of the state of whatever it is scheme so there are two hundred different suggestions. There's another film actually called twenty forty with a book matched and they're also examples there plenty of them of what we can do what we can do now. Who would like to ask? Question of Steve the Amana Carbon. That goes up into the atmosphere. There's a level of it when it leaves the water or lays the ground goes up. What dissipated to go up into the atmosphere like what level of breath carbon is omitted from the ground to what it gets up at the top and is there any way to actually dilute? What's coming up before it gets to the atmosphere? The the atmosphere is pretty well stirred mixed up the lower part of the atmosphere so as we omitted the surface it tends to get mixed up through the atmosphere and there are natural processes that remove not that we add but the lifetime of co two molecule. Once it's in the atmosphere is I think a one hundred years or more and so so. This is a gas that sticks around for a while once we put it in the atmosphere unless it's ends up in a plant or in the ocean for example in terms of trying to stop it before it gets in the atmosphere there are techniques of scrubbing. Co Two gas out of smokestacks for example before it reaches the atmosphere. None of that has been proven and yet at the scale that we needed to do. And the the intergovernmental panel on climate change recent did a report on the global warming by one and a half degrees which is the target that the countries of the world set for themselves to try to keep warming blow one and a half to two degrees above the pre industrial level. Most of the scenarios that make that possible require something that doesn't exist yet. which is something called negative emissions technologies? These are things that will actually remove co two from from the air. They depend though scenarios. Most of them depend on having that technology sometime. But we're not there yet so it's just one example of where sciences needed what and we might do is actually change policy on knocking down forests. Did you see the front cover of the Economist magazine. If you didn't look it up it shows all the stumps and and talks about the Brazilian death. Wish for the Amazon knocking. The trees down at such a rate to Manhattan's a week. And what we need is is one point two trillion trees which will make a huge difference to that equation question here in key mines to potter. I think we're a little bit blindsided. The federal election to see how few voters.

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