The mom sponsors very the biggest mobile phones are very in a world. System ultimately some stores will work on some more than 3 meter. Were going to make more money there she got to be. Among the water became whole back was 5 meter water. In recent years the global Sea Level Rise has been accelerating this marks the beginning of a trend that could dramatically change much of the worlds coastlines. Maybe it is of Sea Level Rise what does the worst Case Scenario look like. That is dealt. Storm conditions things if they get it wrong the cost could be immense the loss is. Just too close to. How much time do we have left to find a solution. That will be places we wont be able to say much because how can we protect ourselves against this rising danger. Not ensure us all out of see the. Close call but is a prominent physicist who studies the risks associated with rising sea levels his research could help prevent billions of dollars worth of damage in new york city one of the worlds most vulnerable cities. Around the thing you have to solve. Some scientists here in new york got together and they have realized that we have to really raise the Public Awareness of the risks that are coming our way. We chose they should have a 100 year storm coming into the city on the computer model any help the 1st results that they called us and said you have a problem look at this more they got. This it loops. This is hes a killer his heel is that its main artery silicates it underground and. We found out to our surprise that it takes only about 40 minutes for the. Subway system to fly. For a decade the simulation devised by klaus yakov and his colleagues remains little more than scientific speculation. 2012 Hurricane Sandy showed that the apocalyptic scenario modeled by the scientists was uncomfortably close to reality. Take a look at the water that it is in new york city sandy killed 44 people 100000 homes were flooded and millions of residents were left without electricity for weeks the damage to the city was estimated at 19000000000. 00 the city was up to its neck in water. Until recently such extreme weather was regarded as a once in a century of event but that has changed. Believes that even a slight rise in sea levels could trigger a significant rise in flooding. Yeah so why yourself as much as 90. 3 me those are your eyes by the end of the century and thats extremely scary. Around the World Population growth and urbanization in coastal regions is outstripping demographic developments further inland yet coastal populations are far more vulnerable to the impact of rising sea levels there are 136 coastal cities with people. The population of birds so those cities with about 400000000 people about 14000000 of those people actually live in the coastal flood playing with current see the bulls. In many places coastlines have been fairly stable and coastal flooding largely limited to storm surges which are around the world. Extreme water levels are recovering with growing frequency scientists believe this is the 1st phase in a long term process which is also gaining momentum. To go off to tom and then lets me what weve seen along germanys coast over the last few decades is that extreme water levels have been rising more quickly than the Mean Sea Level. Scientists are investigating what rising sea levels would mean for the impact of waves of the coastlines. Soon could down and off simulates east changes in a way for tank as a wave travels from deep to Shallow Water which is met by a rising sea bed the friction dissipates the energy of the wave and it breaks normally that happens before it reaches the coast. And also before then i mean an increase in sea levels would mean that many waves that now break long before the dike would instead approach the dike with a far greater mass of water of course. Those waves would put more pressure on the dike and possibly wash over a loss from shastri and indigestion over bush here and can. Highest sea levels amplify the power of waves the waves break later and hit the coast with far greater force. Even a modest rise in water levels can have a dramatic impact on a wave power. Thats. Today here the sea level and here comes a storm along so it floods everything that this elevation or below but now we have. Sea level here so we need only a smaller storm to flood the same area or we get the same storm its much higher. An average Sea Level Rise of just a few decimeters a few tens of centimeters could make once in a century flood events become commonplace in relatively low lying coastal cities like new york the critical point to be reached at about a one meter rise in sea level is. The big apple submerged is this just a scenario out of the Science Fiction film or is it a preview of all future. On a geological time scale the last extreme rise in sea levels happened just a fraction of a 2nd ago but stone age humans were already living in settled communities archaeologists have found traces of abandoned settlements at the bottom of the baltic sea along the coast of present day gemini. The archaeological remnants discovered taya were abandoned some 7000 years ago the settlement was on the banks of a huge freshwater lake at the end of the last ice age sea levels began to rise a channel of water from the north sea swept over a land bridge washing away the prehistoric settlement but its traces remained. Before we found the items have a depth of almost 2 metres this is an x. Made from antlers. Dust and these are typical tools used by hunter gatherers who lived here they caught fish and hunted seals. The people who lived in the stone age settlements were forced to retreat from the rising sea. Absent still around 6500 b. C. E. The sea level was around minus 20 meters from the end of your problem over the next 2000 years it rose by 20 meters. Sponsors the entire later basin was transformed into a marine marginal seniors from the. Fish bones found in the area around researches to estimate how quickly the freshwater lake was consumed by the baltic sea within just a few centuries freshwater fish were replaced by salt water species the landscape had been flooded by the encroaching sea water. The size 35th dimension People Living here would have observed the rising sea levels and understood that the sea was creeping closer and claiming more and more land is that. The threat of being displaced by rising sea levels is something people in europe have not faced for several 1000 years thats too to an unusual period of stability which began after the last ice age. So 20000 years ago sea there was about minus 120 meters below todays values and then as the world war sea levels rose about for me to per century sometimes a bit faster but thats the average rate in the capital going all the way up until about 7000 years ago when sea levels then were constant and that is the period when civilizations have moved. Around the world over thousands of years a coastal infrastructure has taken shape cities were built right by the sea and opportunities for trade business in prospect. Flourished there would have this was dependent on the comparative stability of sea levels. Human civilization is very much product of stable sea levels. Or systems of thinking also truth is a constant. Mean sea level is a day too so it starts to change that makes what we do about it start to get messed up so. We are moving into a new epoch where were going to have to change some of our thinking. So when did this new park begin satellites began tracking sea levels only a few decades ago to more fully map this trend oceanographers and could down and off embarked on a search for old data. As merely the 1st sea level measurements dates back to the 17th century and. Since the mid 1800 there have been around 70 or 80 tide gauges around the world that allow us to assess the change in sea levels. One is these cages is on heligoland off the northern coast of gemini since 885. 00 the tide gauge there has been taking continuous measurements that wealth of data is held in a special archive in the town of turning in nose in germany. 2 for research as such tropes of data are of the only way to determine whether the recent rise in Mean Sea Levels is simply a natural fluctuation all part of a longer term trend that data is clear means sea levels have been rising since the 19th century and more recently the pace has changed. So i knew this point in sea level started rising more quickly at the end of the 19th century. And then surely by around the one millimeter per year. After the 960. 00 s. And seventys that trend accelerated reaching the current 3 millimeters per year i mean to meet up with. I. Mean sea levels have risen by almost 20 centimeters into the time of the 20th century. But that is a global mean which can vary widely from region to region in new york city for example sea levels rose 30 centimeters during that same time frame. In. Many miranshah remember the sea levels do not rise evenly like when i feel this paddling pool. Water masses are distributed around the world by ocean circulation winds blow the water from one side to another and redistribute it as a result the sea levels rise on one side but are lower on the other the miracle should be up there on them so that the ocean currents and wind pushed masses of water against the coasts causing variations in sea levels and the earth itself is also moving under our feet some coastlines are rising while others a sinking new york city for example is located in an area that sinking that contributes another one millimeter a year to the rise in sea levels in sweden meanwhile the landmass is rising by almost one centimeter per year. On all of these processes mean that regional sea levels can differ significantly from the global mean operation from. That its the global Mean Sea Level that forms the Reference Point to assess the changes across time and place. And as live a man studies the impact of Climate Change on the worlds oceans hes a coauthor of the Intergovernmental Panel on Climate Change or i. P. C. C. Reports the Gold Standard survey of Climate Science issued every 5 years. Weve only recently begun projecting the rise in sea levels. A long time we couldnt say how much it was increasing by. Predicting sea levels is one of the key challenges facing scientists today projections a few chip Global Warming have grown increasingly sophisticated but when it comes to sea levels this kind of modeling is still in its infancy for towns and cities on the coasts reliable predictions are a matter of 5 klim potence in the next in the last report was the 1st to include projections for the rising sea levels expert we said we cant provide a worst Case Scenario only the most likely scenario which leaves a lot of scope for uncertainty just. One of the factors explaining the rise in sea levels is comparatively easy to quantify water expands as it warms a process called thermal expansion the 2nd factor could soon become the driving force the loss of ice. For researches melting ice is a confounding factor as more ice melts they have to revise their projections upwards the i. P. C. C. Is most pessimistic estimate predicts a rise of 110. 00 centimeters by the end of the century but even that projection has been called into doubt. The reasons in the we dont really know what the worst Case Scenario might look like a tsunami all seen that. Happen. Most people dont realize. The laws the characters. Journey. So if you look at hiring a new port to make honey mass similar to most mass what youll see has we start off by in the middle lower the sides and the honey from the middle is falling to the edges so that the honey in the middle is deforming under what we call a gravitational driving stress and the honey is trying to float. The ice is flow velocity will decide the fate of the ice sheet covering greenland the more that velocity increases the more of greenlands ice mass will be lost to the ocean. Greenlands ice cap is gigantic. Taken together it encompasses about 2700000 gigatons of ice until 1990 the ice mass was fairly stable. But in the past 20 years greenland has lost an average of 266. 00 gigatons of ice a year contributing to a rise of 0. 7 millimeters per year before the ice were to melt sea levels would rise by more than 7 meters. William colgan is on the ground tracking developments in greenland if enough snow were to fall further inland losing so much ice to the sea would not be such a problem. If. That is the author. That is healthy starfish if. Greenland has the worlds 2nd largest ice sheet half a century ago measurements taken by scientists in the northwest of the country showed that fresh snow kept adding new layers none of it melted. To assess whether that is changed in recent decades William Colgan and his colleagues are extracting ice cause any changes could have a profound impact on greenlands ice cap the team examines the cause for any signs of dense ice which could only be due to melted snow. The most powerful influence for finding from the ice cores is that when we look at them today we see every year the snow is interrupted by this hard 3rd layer where the snow has melted and weve frozen this hard clear ice. About 25 percent of the fresh snow that had been replenishing the ice for thousands of years is now melting that could set off a feedback loop that would threaten a key aspect of the ice sheet its thickness. So you picture the ice sheet sort of the rest of the ground from here she has this shape hypocenter flow at the sides so as the. Begins to melt. It gets slower and as it gets slower its moving dale into warmer layers of the atmosphere theres cold high or low and you get this feedback because the farther the lower the ice melts to the lower elevation the. The more melts and the more melts lower the columns and you get this feedback. Such feedback loops make it difficult for scientists to make accurate projections the heights of the ice sheets is just one factor im not that its come up. If we think about like this is the issue is surface. Really why so its relatively refractor generally. About 80 percent of the sunshine that hits the snow surface. But through a variety process as the surface becomes darker as the snow angels grows the surface becomes darker. And you go from a surface that used to reflect 80 percent of the sunlight to one that might only reflect now 40 percent of the sunlight and this becomes a feedback because the more sunlight that absorbs the warmer becomes the darker color so the darker warmer darker warmer darker warmer creates this positive feedback we call the video feedback. Asked scientists discover more about the feedback loops that affect the ice they have to widen the parameters of their food costs. But coastal towns and cities need reliable predictions to prepare for rising sea levels. Things easy if they get it wrong if they miscalculate the future rising sea levels and underestimate the risk of flooding and the cost could be immense. For the city of venice the accuracy of the. Projections as a matter of vital importance parts of the city are less than one meter above the water and as the pace of the Sea Level Rise continues to accelerate flooding has grown more common and venice every centimeter counts. In this moment for the next century that means has a solution. In the 1st warning came in 1906 when floodwaters reached a height of nearly 2 meters. Scientists calculated that an extreme event like this would happen only once every 200 years and in venice still decided to take precautions. And. Deal surratt hes drew up a plan that would close off the lagoon in an emergency and the massive flood barrier was called the movie project. And. Most consists of 78 movable gates fixed to the lagoon floor when a high tide. Comes compressed air raises the floodgates. And the city is separated from the sea construction work began in 2003 and still isnt complete but theres a catch might not be high enough to be. Mentioned this system considering the i. P. C. C. Scenarios. And. Late ninetys and we have to consider the worst scenarios 60 centimeters of Sea Level Rise in the next century. And under current projections the sea level is expected to rise more than a meter in this century them smooth. The 5 and a half 1000000000 euro moser project could handle. If. There will be 2 meters of see their eyes will have to. Have to know Something Else not all even is the entire coleslaw in that a meter in the mediterranean. The latest i. P. C. C. Report says this worst Case Scenario is unlikely but not impossible but to meet a rise in sea levels by 2100 cannot be ruled out if Greenhouse Gas emissions are not slashed. If that happens up to 200000000 people could be displaced. Until recently we had no idea that such a swift rise was possible. But now a group of scientists have challenge this is sumption sea levels can change in dynamic fashion at times it can be very sudden. Antarctica and greenland have enough frozen water to raise sea levels by 66 meters. No stimulus really fast the Sea Level Rise after the last ice age took place between 14814400 years ago so if you over 400 years global sea levels rose by approximately 60 meters thats 4 meters percent true and incredibly fast increases in the gun to know the engine. For a long time scientists believed that the Antarctic Ice sheet is more stable than greenlands they thought antarctica was just a slumbering giant that occasionally discharged an iceberg into the sea. Sea currents carried the icebergs along the same bridge through what is called the iceberg alley towards chile as they approach warmer waters they melt. That patton gave polish scientist mike veba an idea if he could count how many icebergs had traveled through this alley in the past he could calculate how much ice antarctica stands to lose. The the how to find a key to unlock the past a past thats not to weigh at the bottom of the Antarctic Ocean at the depths of more than 3000 meters. Icebergs contain debris as they melt this rock and soil fulls to the seabed and forms a layer of sediment the daybreak can be measured in core sampl