How Ice A Half A World Away Affects Southern California Sea Levels
Speaker 1: 00:00 The southern California coast is facing some potentially drastic changes as the level of the ocean rises in coming decades from a climate change desk. KPBS environment report at Eric Anderson, fines that are warming climate is already affecting change and San Diego's ocean waters as researchers have found at the end of script's pier. Speaker 2: 00:24 Yeah, Speaker 3: 00:24 once a day for more than a hundred years. Someone on this day, Sean Bruise has come here, opened the door and dropped us sample tube. So right now we collect two samples into the water below you take a sea surface sample and a bottom sample temperatures taken here last summer where the highest ever recorded an oceanographer. Melissa Carter says that isn't just a seasonal elaboration. What we've found is since 2004 we've actually had quite a bit of warming. A warming ocean is changing the underwater environment. Some species that used to thrive here are having a tougher time and Scripps Institution of Oceanography Researcher Helen Fricker says it's also one of three main causes of sea level rise. Speaker 4: 01:09 The temperature of the ocean, the average temperature of the ocean is increasing. And because of that, the entire ocean volume is expanding and there's only one way for that to go because the basins are all fixed and so it just rises up. Speaker 3: 01:23 Water from melting glaciers in the world's highest mountain ranges is another source pushing up sea levels and sea levels are going up because two great reservoirs of ice in Greenland and Antarctica are melting. Fricker has studied the Antarctica ice for 25 years and she surprised at what's happening there. Now Speaker 4: 01:42 the changes that we're seeing in, um, in the untaught take and Greenland ice sheets have really kicked in in the last decade or two. We are now seeing signals that appear to be starting to accelerate. We're getting an increase in the amount of mass coming off the ice sheets Speaker 3: 01:59 and the potential impact is massive. The frozen continent holds enough eyes to push up worldwide sea levels by about 180 feet. Think of the kissing statue sculpture near the USS Midway, seven of them stacked on top of each other are just under 180 feet. Add the ice on Greenland and sea levels could rise another 20 feet. Scripts or researcher [inaudible] Studies, Greenland, which is much warmer than the southern continent. Speaker 1: 02:27 Greenland is changing faster right now and target accounts are about 10% of global sea level rise. Greenland is about twice step 20% but in terms of potential longterm contribution and tired Tikka holds about 10 times as much ice or water. Speaker 3: 02:47 Strange. No. Says the pace of change is a surprise for researchers. Glacial change no longer means very long time scales and that has scientists in a race to catch up. She says tracking and those changes can be dangerous work. Speaker 1: 03:01 What we really need is measurements as close as we can get to where the ice meets the ocean, but that's probably one of the most challenging places where to get observations on the planet. The edge of these glaciers that flow into the ocean is a really dramatic place. Big icebergs breaking off. Speaker 5: 03:21 Let me take the cap off. Yeah. Okay. Speaker 3: 03:24 Stray. No, and Fricker and scientists around the world are working to understand the changing conditions and the pace of change. They want to know how warmer air and warmer ocean temperatures are contributing to the situation. Speaker 4: 03:38 That's the big sort of holy grail question about both of these ice sheets. It's how much ice are we going to lose and how fast or how quickly are we going to lose that ice? Because when you start to think about half a meter, one meter of sea level rise over the next several decades, it really matters how many decades we're talking about and how many sort of tens of centimeters we're talking about. Because if you think about cities and planning and people living near the ocean, um, it's going to affect a lot of communities and we need to know for planning purposes how quickly we need to start making these changes. Speaker 3: 04:13 Fricker says even a change of a few feet can have significant economic impacts. Coastal properties can be swamped and low lying airports in San Diego, Los Angeles, and San Francisco, all face threats from rising ocean levels. Erik Anderson, KPBS news, Speaker 1: 04:32 joining me now is Fiamma Australia, the Scripps Institution of oceanography researcher who is studying the ice sheets in Greenland. Thanks for joining us. Fiamma thank you for having me. So we heard you say in Eric story that Greenland holds less of the ice. It could potentially lift sea levels, uh, than the Antarctic does, but then it's warmer so it's melting faster. Why is it warmer up there? Uh, so two reasons. One, the atmosphere, the air temperatures over Greenland are warmer, uh, in part and, and, and the ocean waters around Greenland or warmer, it's just because of the layout of the continent and how they would set pathway for warm ocean water carried by the Gulf stream and towards the Arctic in Europe to reach pretty close to Greenland. And this, this has an impact both on the air temperature and the ocean temperatures, whereas an tire tech is like its own little island surrounded by very cold waters and, and a system of ocean currents that keeps it cold throughout both the atmosphere and the ocean. Speaker 1: 05:40 Oh, understand sea level doesn't rise uniformly planet wide. What, why is that? And this southern California sea level affected more by Antarctica then Greenland ice melt. So, uh, sea level, it's the regional sea level, the local sea level. The one we really care about off of our coast is a influenced, not just by how much water there is in the ocean and what the volume of the entire ocean is, but also by ocean currents that can cause sea level to rise on one side and lower on the other. Or what's happening now is as we're losing ice from the ice sheets, um, you can picture a nice sheet as a big mass and it attracts water to it, much like the moon attracts a water. And, and uh, we get tides, so it's the ice sheets melt this gravitational attraction that they had on the ocean waters, it's decreasing. Speaker 1: 06:42 And so we're going to see sea level drop near Greenland and near Antarctica as the ice melts. And it tends to produce sea level rise just by changes in the gravitational attraction on the ocean waters in the [inaudible] band, all the way up to the mid latitudes. So these patterns make it such that even if we know how much extra water is going into the ocean or how much the ocean has expanded, there's bulges that are different all over the ocean. In, in response to sea level rise. So should San Diego sons be paying more attention to what's happening in the Antarctic or in Greenland? I think to both because both ice sheets are contributing to sea level rides. Um, but the, the, the way the, the patents of discreditation of attraction are changing and tired to guys likely to have a slightly larger effect on sea level rise off the coast of California, then Greenland, um, but not just the ice sheets. Also, the system of current and the atmospheric patterns, um, are really going to effect exactly where sea level rights happens or how much sea level rise happen. Now the world from Pri has been running radio stories from reporters who traveled to Greenland and the Antarctic, uh, where the ice is melting and we have a piece of sand from Amy Martin who recorded this, a noise of the ice melting by holding a microphone too, Speaker 6: 08:16 provides in the ice sheets in Greenland as listen. That's a pretty ominous kind of a sound. Have you heard that sounds Yama. Speaker 1: 08:27 I, I've seen, I've heard, um, the sound of of ice melting over the ice sheets. I've been on the Greenland ice sheet and especially at its margins and not only are the sounds amazing from the ice melting, but also from the pieces of ice breaking off and, and the sides. It's, it's something, the scale of what is happening, it's difficult for all of us to imagine unless you're actually, and you can put it in perspective, when you see icebergs that are a mile long Rolan break off. Um, it, it sounds like funder, it's, it's incredibly loud. How are you going about measuring the rate of ice melt up there in Greenland? So the measurement of the rates of ice, the rate of ice melt, our best measurements are from satellites that in different ways can tell us either about the change in volume by looking at what, where the surface of the ice sheets or, um, how the gravitational attraction, again, changes in you can reconstruct a, the mass loss. Speaker 1: 09:38 Um, what I do is actually, uh, take ships to the margins of where these glaziers, uh, from the Greenland ice sheet flow into the ocean. And we are studying the impact of warming ocean temperatures on these glade suits. So we're looking at the melt that is happening underneath, below the sea surface, uh, that is driven by the ocean, which we think is one of the drivers of changes both in Greenland and Antarctica. And is it true that even if we take radical steps to reduce carbon emissions and slow global warming, this process you're describing of ice melting will continue for years based on what's already in the atmosphere? That's, that's right. But the warming that the planet has already experience will have an impact on the ice sheets, uh, for a long time. But, but at the same time we see that it's speeding up. Speaker 1: 10:35 So we're seeing sea level rise, the rate at which it's happening, increase over time. And, uh, this is something we should really be worried about in terms of trying to reduce the rate of sea level rise, trying to stay away from feedbacks, positive feedbacks that can really enhance the rate of melt of ice sheets. So it will keep happening for, uh, tens and hundreds of years. But if we do not act to reduce greenhouse gases, we're going to see much greater changes ahead. Fiona, thanks so much for the work that you're doing. Thank you for having me. That's fiamma strong neo of the Scripps Institution of Oceanography. Speaker 7: 11:22 Oh.