MR. KOJO NNAMDIFrom WAMU 88.5 at American University in Washington, welcome to "The Kojo Nnamdi Show," connecting your neighborhood with the world. Our oceans are constantly on the move. Tides and currents keep the world's bodies of water in constant flux. That water is also largely on the rise, and sea level rise is a growing problem in Virginia. Last year, the Chesapeake Bay rose almost two millimeters, which doesn't sound like a lot.

MR. KOJO NNAMDIBut over the course of decades, millimeters have a way of adding up. And to make matters worse, the ground in Southeastern Virginia is actually sinking. Cities and countries across the globe have been holding advancing oceans back for centuries. But even the most conservative estimates say the next century will bring big changes that come faster than they did in the past. So just how worried should we be, and what can we do about it?

MR. KOJO NNAMDIHere to help us answer that question is Steve Gill. He's an oceanographer who has worked at the National Oceanic and Atmospheric Administration for over three decades. He's currently the chief scientist for NOAA's Center for Operational Oceanographic Products and Services, which monitors tides, currents and sea levels. Steve Gill, thank you so much for joining us.

MR. STEVE GILLHi. Thank you for having me.

NNAMDIAlso with us in studio is Chris Pyke. He is the chair of the Chesapeake Bay Program's Scientific and Technical Advisory Committee. He's also the vice president of research for the U.S. Green Building Council. Chris Pyke, thank you for joining us.

DR. CHRIS PYKEGood to see you.

NNAMDIGood to see you also. And joining us by phone from Gloucester Point, Va., is Carl Hershner, director of the Center for Coastal Resources Management at Virginia Institute of Marine Science, where one of his specialties is policy issues. Carl Hershner, thank you for joining us.

DR. CARL HERSHNERMy pleasure.

NNAMDIThis is a conversation that you, too, can join by calling 800-433-8850. That's 800-433-8850. What questions do you have about sea level rise? Give us a call. Have you noticed changes in the water level in a body of water that you have visited recently? 800-433-8850. You can also go to our website, kojoshow.org. Join the conversation there, send us a tweet, @kojoshow, or email to kojo@wamu.org.

NNAMDISteve, I'll start with you. Sea levels have risen considerably in a number of places around the world and across the country. How are levels measured, and what are they showing us?

GILLWell, my agency works with the water level gauges with the tide stations, and we've accumulated long-term tide gauge records over the years. Some of our longest records are over a century-and-a-half long now. For instance, at San Francisco, many of our major ports have had continuously operating tide stations. So, from those data, we accumulate data and compute sea level trends.

GILLSo we've been computing sea level trends for the last century, accumulating more and more data over time. And we've been able to measure them and provide information to our users on what these trends are. Our tide gauges measure relative sea level change, and that's what is the water level doing relative to the land at each one of those tide station locations. And that's what's more important is what is the water level doing relative to the land over time.

NNAMDIYou use gauges to measure sea levels, but it's my understanding that satellite images also come into play.

GILLThat's right. That's one of the important advances over the last 20 years, is that, since 1993, the world's had a series of satellite altimetry missions. It started with a TOPEX/Poseidon satellite altimeter that covers the global oceans from about 60 degrees north to 60 degrees south. And that offers global coverage as opposed to tide stations, which offers spot coverage, nonuniform coverage, around our coastlines.

NNAMDICarl, do we know what's causing these changes in the sea level?

HERSHNERWe do, we believe. Here in Virginia, there are two primary reasons, which you mentioned at the outset. One is more water in the oceans, which is causing that sea level to rise, what's measured by the satellite altimeters. And then here in Virginia, among other places in the world, the land is actually sinking. And that's a result of both tectonic activities, the movement of the earth's surface. And then also locally, we have subsidence due to -- here, it's removal of groundwater, primarily.

NNAMDICarl, New Orleans is the U.S. city hardest hit by this issue, but the Hampton Roads tidewater region in southeastern Virginia is a close second. What's happening in and around Norfolk?

HERSHNERWell, the most recent sort of evidence of the emerging problem or growing problem is the increased flooding that is found in downtown Norfolk. So what used to require major coastal storms to produce water in the streets, now, your average northeaster can flood neighborhoods that create real problems for the residents that live there, as well as the city managers. So...

NNAMDISteve? Oh, go ahead. Go ahead, Carl. I thought you were done.

HERSHNERWell, in addition to the residents, the -- as you know, the southeastern part of Virginia has very large port facilities, shipbuilding and a lot of our -- our biggest naval base, one of our biggest Air Force bases. And all of those activities occur in some of the lowest areas in this region, and so they are all increasingly experiencing operational difficulties caused by flooding and high water levels.

NNAMDIAnything you'd like to add, Steve Gill?

GILLWell, I think it's also important to -- as he said, the increased flooding aspect of it is even without any climatologically driven change and increased frequency and duration of storms, what we're seeing is -- even under normal conditions, a normal year, normal storm patterns that we -- that happen to occur and high tides that happen to occur, from astronomic considerations, you get higher increases of flooding.

NNAMDIWe're talking about sea levels rising and its impact in this area, inviting your calls at 800-433-8850. Is your neighborhood more likely to flood during a storm than it was, say, a decade ago? Call us, 800-433-8850, or send us a tweet, @kojoshow. Chris Pyke, while the focus is often on Hampton Roads and the Virginia Peninsula, we do see the effects in Northern Virginia, Maryland and in D.C., too. You say a spring trip to Roosevelt Island is helped to drive that fact home to you.

PYKEWell, we are somewhat isolated in the sense of -- in comparison to what's going on in Hampton Roads. However, we can look in our immediate environment and look at areas that are sensitive to rising waters. And the instance you were mentioning is that we were looking at, you know, how we think that our infrastructure is robust to the amounts of water that come through. But just this spring, folks were very exposed to these high water levels that were coming through, leaving, in a sense, only a tiny bit of freeboard between the bridge over to Roosevelt Island and the water.

PYKEAnd it's -- that's not an instance in itself of global sea level rise, but there are a bunch of factors working together that create vulnerabilities that we might not otherwise expect. And then we can look around our community and see other instances like that where the combination of rain and sea level rise -- and we'll be talk about a storm surge -- combined to create vulnerabilities and things that we can address.

NNAMDICarl, when people think about the military, the word progressive may not be the first one that comes to mind. But, when it comes to dealing with sea level rise, the military has been just that. What's at stake for the Navy in particular?

HERSHNERWell, their naval base in Norfolk, one of the obvious or observable sort of changes that they have to make is that they have raised the elevation of most of the piers that serve the fleet when it's in port. And that was done, in part, to get all of the electrical service that hangs under those piers up above the normal tide and storm surge levels. They also have operational difficulties with very high tides because the interior of the base, having been constructed many decades ago with much of the service infrastructure installed back then, creates real problems for their electrical service and switching stations.

HERSHNERSo they have been -- they've actually been among the most progressive groups here in the region in terms of trying to adapt to the changes we know are coming.

NNAMDIChris, care to comment on that?

PYKEYeah, I think that the -- there is an instance. We don't think of our federal agencies as the most progressive. But, in this instance, they recognize that they're going to be using that asset, those facilities for decades into the future, and it has to do -- and it affects their mission. And so they've been leading the way in asking how will they continue to meet their operational requirements with -- under changing conditions.

PYKEOther folks have been -- haven't had the mandate or the reason to fully incorporate that in their decision-making, but I think that's -- it's a sign of things to come for other -- for the 95 percent of other folks in the region who -- 95 percent of the land area in the region that isn't managed that way.

NNAMDIWe've been talking Navy, but, Steve, it's my understanding that the U.S. Army Corps of Engineers is also using NOAA's data.

GILLRight. I've been impressed with their progressive -- excuse me -- activity. I've been working with them for the past few years.

NNAMDIWhat kind of information have you been providing?

GILLWell, providing our baseline information from our tide gauges, and they're interested in using that information to develop engineering guidance documents. They've come out with a series and working on a series of guidance information so that the corps of engineers can use this information in their planning and designs, so they can proactively take into account projected sea level change in their engineering design, which they design, you know, out from 50 to 100 years kind of lifetime for their designs.

GILLSo they're very concerned about making sure they take into account sea level change appropriately.

NNAMDISteve Gill is oceanographer who has worked at the National Oceanic and Atmospheric Administration for over three decades. He joins us in studio, along with Chris Pyke, chair of the Chesapeake Bay Program's Scientific and Technical Advisory Committee. And joining us by phone from Gloucester Point, Va., is Carl Hershner, director of the Center for Coastal Resources Management at the Virginia Institute of Marine Science. One of his specialties is policy issues.

NNAMDIWe're talking about sea level rise and how it might affect the way we live today and in the future and what we can do about it, taking your calls at 800-433-8850. If you've lived in a coastal area where sea level rise was an issue, how was it handled there? 800-433-8850. Carl Hershner, the military may be on board, but despite mounting evidence on sea level rise, some people are still, well, skeptical.

NNAMDIA recent Washington Post article highlighted a group of residents in Gloucester County, Va. who are pushing back against planners' efforts to address the issue. What are you making of this pushback?

HERSHNERWell, it's an interesting phenomenon, social phenomena, I guess, and that we are often puzzled -- we appreciate the ongoing debate about the role that man has played in the changes that we're observing in our climate. But there are certain things that we consider to be facts that seem to fly in the face of resistance to planning for change. And all the things that Steve has been talking about, from our perspective, those are documented changes in the system that are undeniable.

HERSHNERAnd so there is clear evidence that water levels are increasing and that the risks for coastal inhabitants is increasing. And what planners are currently addressing and with greater frequency in our region, they are attempting to institute requirements for occupation of low-lying lands and for the design of structures in those areas that will begin to minimize the kind of both private risks and then, as a result, the public expense of trying to accommodate disasters when they do occur and why people are resistant to that kind of fairly well-reasoned planning remains a mystery.

NNAMDIWell, The Washington Post reports that the group Virginia Campaign for Liberty, a the Tea Party affiliate, has started disrupting Middle Peninsula Planning District Commission meetings, alleging that local planners are unwitting agents of Agenda 21, which is a U.N. environmental plan adopted in 1992, that some activists see as a shadowy global conspiracy to grab land and redistribute wealth in the United States. Having said that, Steve and Chris, if someone refuses to believe that sea level rise is an issue, what do say to them? First you, Steve.

GILLWell, when I look at -- if you just look independently at the data, as Carl just mentioned, the fact is that sea level, especially in the Hampton Roads, is rising quite significantly. And even if you say this is our baseline trend going into the next century, without any climate change or any acceleration of sea level rise, there's still going to be increasing risk. Even the baseline tells us that. So that's an important thing to note and that you, at least, need to plan for this baseline if you don't appreciate any acceleration or agree with any acceleration or climate change in the future.

NNAMDIWhat would you say, Chris?

PYKEWell, for me, I understand the problem as an issue of, actually, professional practice as well. We would expect our professionals -- be they be planners, architects, engineers, so forth -- to be taking the best available information about the anticipated conditions over the range of whatever they're doing, planning for a community, building a home, building a pier or a bulkhead. And, right now, the scientific evidence shows us that, as he was saying, we have trend, an empirical trend.

PYKEIt's not like we're making these up with models or something like that. We have some data. And what we're asking is, how is our infrastructure? How are our decisions today going to play out in the decades ahead? And, for me, I want those professionals to be considering the best available scientific information when they make these long-term decisions, which there -- every time you lay down concrete today, you're making a decision with the intent that it's going to play out for decades. That's why we're bringing this forward now.

NNAMDIBut, Carl, it's my understanding that you point out that the rise is invariably or incredibly variable in that that fuels a lot of the debate around it.

HERSHNERWell, it is, I guess. In this region, we see differences in local change -- local relative sea level rise that are generally attributed to the subsidence that's occurring from the extents of groundwater withdrawals. There are a couple of area where very large amounts of water that are being pumped from the aquifer that's about 1,000 feet down, and the overlying sediments are settling more rapidly there than they are in surrounding areas.

HERSHNERAnd -- but the difference in those rates is measured in millimeters a year. And so the observable change, if you will, doesn't really vary that much from spot to spot. One of the cons or one of the complications for sort of the non-scientific interpretation of personal observations is that storm tracks and the storm surge that results from major systems moving over us can vary quite widely.

HERSHNERAnd so the amount of rise in water levels from the south end of the bay to the north end of the bay can be dramatically different, depending on whether a storm track is offshore or onshore. And people tend to take those short-term episodic events as the conclusive evidence or the only evidence that they want to bring to this debate about whether or not climate change is occurring. And, as I'm sure Steve can explain for you, the trends that we are trying to speak to when we talk about climate change are the long-term trends, not the short-term stochastic events.

NNAMDIIndeed. I'll call on Steve to explain that. But first we've got to take a short beak. If you have already called, stay on the line. We will get to your call. If the lines are busy, then you can go to our website, kojoshow.org, and join the conversation there. Or send us a tweet, @kojoshow. I'm Kojo Nnamdi.

NNAMDIWelcome back to our conversation on sea level rise, but before we resume that conversation, it's now being reported that D.C. Councilmember Harry Thomas Jr., has been charged with theft and filling false tax returns. That's a story that WAMU 88.5 News will be following. Harry Thomas Jr., Ward 5 councilmember in the District, has been charged with theft and filling a false tax return. Listen to WAMU 88.5 News throughout the day to hear more on that story.

NNAMDIOur guest in the studio discussing sea level rise, Chris Pyke is the chair of the Chesapeake Bay Program's Scientific and Technical Advisory Committee, he's also the vice president of research for the U.S. Green Building Council, Steve Gill is an oceanographer who has worked with the National Oceanic and Atmospheric Administration for over three decades. He's currently the chief scientist of NOAA's Center for Operational Oceanographic Products and Services, which monitors tides, currents and sea level.

NNAMDIAnd joining us by phone from Gloucester Point, Va., is Carl Hershner, director of the Center for Coastal Resources Management at the Virginia Institute of Marine Science. I'll go to the phones directly, where we can start with Gina in Washington, D.C. Gina, you're on the air. Go ahead, please.

GINAHi, Kojo. I was just calling in regards to, I guess, future policy as part of plan change -- management and planning. I was wondering -- it's a twofold question. Number, one, is there going to be any policy or looking towards any policy in the future for private sector, you know, insurance companies? 'Cause obviously, a lot of homeowners, especially in Southern Maryland and East Coast to Virginia, have, you know, have areas in which there will be excessive flooding in the future, obviously, if everything that they are saying is coming to fruition.

GINAAnd, I guess, as a concern as a homeowner, are our premiums going to go up? The other question is also, with the Army Corps of Engineers looking at flood plains, are they going to continue to allow contractors and builders building on these flood plains?

NNAMDII don't know. Know anything about this, Chris? I know that I saw a note where President Obama has expanded the flood insurance programs, but I don't know if you can answer more specifically the question.

PYKEWell, just a little bit. I mean, over the past decade -- and I'm sure that the other folks can, too, but just one of the things is that the reinsurance industry -- actually the big folks who insure the insurers have gotten much more interested in climate change as a source of risk because it leads to big correlated loses. Lots of people taking lot of losses in big events, and so those pressures on the insurers to recalibrate the relationship between premiums and risk is a real issue that's happening. I don't know of anything specific on the short term but...

NNAMDIIn late December, President Obama signed legislation that extended the National Flood Insurance Program through May 31. It was set to expire Dec. 23. Anything you can add to that, Carl Hershner?

HERSHNERWell, even within the flood insurance program, the reworking of flood plain maps -- the FIRM maps is causing premiums to rise for people who live in particularly low-lying areas because, as the data comes from Steve's operation and defines where the title benchmarks need to be established, we are finding that, for example, the house I live in, when I moved there 40 years ago, I was about 10 1/2 feet above mean sea level.

HERSHNERAnd I currently exist at about 9 1/2 feet above mean sea level, and so the insurance rate zones are moving ever closer to my house. And as they pass my house, my rates for flood insurance will increase dramatically.

NNAMDII'm glad you got us back to the data coming from Steve's operation, as you call it. This is not a new phenomenon and the information that NOAA puts out on sea level rise is not based on just a year or two of data. You require decades of records before you publish information, don't you?

GILLRight. It's a signal-to-noise problem as what we call it in our world of getting a sea level trend out of the data. You have to treat it accordingly, and you have to perform some analysis of it before you could determine the trend. You have to account for annual sea level trends or annual sea level variations. You have to account from decadal variations. Once you treat the data appropriately, you get a residual analysis that you can determine the trend of the data firm.

GILLSo to do that and to get a trend with a reasonable uncertainty, a reasonable standard error because of the high noise, you need at least 40 years of data, preferably 60 years of data, continuous data, to do these trends. Anything 30 years and shorter, the error of the trend calculation itself is almost as much as the actual magnitude of the trend.

NNAMDIAnd, Gina, thank you very much for your call. We move on to Jim in Fort Belvoir, Va. Jim, your turn.

JIMYeah. It seems pretty hard for me to grasp a lot of the people who are the deniers of environmental change. I'm -- personally, I'm a retired military. I spent quite a bit in my career in the military overseas, as well as here. And one of the things that I really, really observed is that a lot of people who are the deniers, I guess you could say, lived in the developed world, especially in the U.S. And one of the things I've seen is the attitude seems to be that if it's not affecting me, then it's not happening.

JIMBut if you do some observations of Third World countries where people tend to be less fortunate than developed countries, unfortunately, it's kind of like manure which goes downhill. The poor people that can least afford it are the ones who've been affected worse by it than the more developed countries. And myself, I was born and raised right in the backwoods of Oklahoma, and I've seen environmental changes there just in my lifetime that no one would have ever expected to happen.

JIMUnfortunately, as they were saying, there are the deniers out there who want to disrupt the community meetings and the planners and stuff. My recommendation would be to give all of that land that's going to be a detrimental place to those people that wants to deny it.

JIMSo that when the water does come up and they're looking for somebody who was about to come and get them, then say, hey, you did want it before, you ain't going to get it now. That's pretty much it.

NNAMDIJim, thank you very much for your call. Jim, on the less-than-humane manner to deal with this. But I do take your point, Jim. And you, too, can call us at 800-433-8850. We got an email from Kent, who said, "I'm an ecologist and bay historian who has been keeping tide records for 36 years on the lower Patuxent River in Maryland, where I saw the signal of sea level rise after 10 years records. In the last few years corresponding with Carl's colleague Bob Orth at the Virginia Institute for Marine Science, we seem to see a sudden increase in rise rate that's increased us a foot.

NNAMDI"This has wiped out a tide pond along my shoreline. Is this real? Have others experienced it, too?" Can you speak to that, Carl, or you for that matter, Chris Pyke?

HERSHNERLet's see. I'm not sure that I have seen records that would verify a rate as rapid as being referred to, but there is certainly been increases which are observable in a 10-year time period. And they have specifically affected some of the living resources in the bay, most notably the submerged aquatic vegetation that Bob Orth, the gentlemen who is referred to, is studying in the bay. But Steve can probably speak a little bit more directly...

NNAMDIYeah, Steve, I was saying a foot does seem high, but go ahead, please.

GILLWell, as I mentioned before there is -- the ocean's have a lot of variability at different time scales, and certainly at decadal time scales, there's an awful lot of energy due to the normal oscillations that we observe, the ENSIL, the El Nino, La Nina oscillation, the North Atlantic oscillations. So we see large scale weather-driven oscillations that affect the oceans.

GILLAnd so a lot of the variability that we see quite often is due to this changes in wind stress, in wind patterns offshore, oceanographic circulation changes along shore. Some of the change that we observed with these rapid rises are due to some of these oscillation changes that the drive the ocean water levels.

NNAMDIAnd thank you very much for your email. We move on now to Dan in Eastern Shore, Md. Dan, you're on the air. Go ahead, please.

DANOh, yes, Kojo. I live down here in the Eastern Shore, and as you know we're kind of low. Every time that, you know, we get a good moon tide, storm and everything, we get anywhere from Cave Penelope and all the way down to Cave Charles, all the roads flood over. And once the sea water rise, all the low-lying communities that are on the Chesapeake Bay and on the Eastern Shore here are -- four or six, maybe eight feet above sea level if we're lucky.

DANAnd I was wondering what kind of precautions or anything -- I haven't heard of any that the counties or states are trying to implement to, you know, kind of save us down here. So we are...

NNAMDIWell there are two -- go ahead, please.

DANI'm saying we, you know, we are a giant sandbar over here and we are sinking. I'll take my answer off the answer.

NNAMDIWell -- Dan, thank you very much for your call. There are two aspects of that question. Chris, I'll ask you to address one aspect of it. What can individuals and communities do to prepare for the consequences of sea rise?

PYKEYou know, basically, there is two things that can be done, and, actually, Maryland has really been on the vanguard of this. The state of Maryland government has done a bunch of adaptation planning that they are trying to get implemented at the local level. But when it comes to individuals, you really have a choice. You can adapt or change something you're doing or you can retreat out of that condition, and, you know, unfortunately there are successful examples of both.

PYKEI mean, the Dutch have faced the rising sea for 500 years, and they have successfully advanced in the face of that and had a perfectly fine time of it. On the other hand, you can retreat out of that safety -- as Carl was saying, into those areas that are safer. And, of course, there are situations where you get pinched, and you can't do either. So -- but looking up the sources of vulnerability, and as the caller said, things like low-lying roads and culverts and setbacks and buffers and asking yourself, what can I do here?

PYKECan I provide some active protection in terms of something that I'm doing to actually respond to these changing conditions? Or can I remove my -- remove something from that danger zone? So those are the two things that we have available to us to do and that can happen at the scale of an individual landowner or probably even more effectively at the scale of a community, where they're asking, what should we put in which of these places.

NNAMDIAny suggestions, Carl?

HERSHNERWell, the -- to the efforts the local communities are making, there are some examples. The county that I live in, for example, is -- has very extensive low liners that are well inhabited, and they have done reviews of the roads that regularly flood. And the emergency services have notified residents in those areas about what conditions will allow them to respond and under what conditions they will not be able to provide services.

HERSHNERSo that -- you know, it basically advices or informs the residents of the risks that they are taking by remaining either in their houses under storm events or remaining to -- continuing to live in an area that is going to experience increasing storm events. We have not yet gotten to the point where localities are officially planning to abandon areas or infrastructure that is too expensive to maintain, but there are certainly discussions about that policy underway.

NNAMDISteve, rising sea levels also mean that -- as has been pointed out, flooding gets worse, especially during storms. But when the consequences are not as bad as they could be like with Hurricane Irene this past summer, do you worry that people will start to think, well, they'd been crying wolf and not heed the warnings the next time around?

GILLWell, sure. Whenever you have a quiet time period, whether it's climate or storms or anything, you know, people -- that's often the case, say, even tsunamis. People, you know, don't worry about tsunamis until one occurs, and they don't take precautions even in the areas -- that they live on the coastal areas, to have the proper warning systems in place, the same with coastal storms. So it's a matter of being prepared always and have monitoring systems in place always as part of your infrastructure.

NNAMDI800-433-8850 is the number to call if you have any questions or comments about sea level rise. Have you noticed changes in the water level in a body of water that you visited frequently? Is your neighborhood more likely to flood during a storm during than it was a decade ago? What do you think should be done about that? Do you think the government is, in any way, overstepping its bounds by planning for sea level rise? Or do you think that even more should be done?

NNAMDIWe're going to take a short break. But we'll still be taking your calls, 800-433-8850. Send us a tweet, @kojoshow, email to kojo@wamu.org. Or simply go to our website, kojoshow.org. Join the conversation there. I'm Kojo Nnamdi.

NNAMDIWelcome back. First, with an update on the situation involving D.C. Councilmember Harry Thomas Jr., the Associated Press is reporting that the councilmember has been charged with stealing more than $350,000 in government funds and filing false tax returns. The two felony counts against Thomas are detailed in a criminal information filed in U.S. district court on Thursday. That would be today.

NNAMDIA criminal information is a document that typically indicates a defendant intends to plead guilty. Although the document does not detail what Thomas did with the stolen funds, he had previously been accused of spending them on a luxury S.U.V., travel and rounds of golf. The tax return charge accuses him of failing to report $356,000 in income between 2007 and 2009. He was ordered to forfeit an S.U.V. and a motorcycle that was seized last month by federal agents who raided his home.

NNAMDIYou'll hear more on that situation later from WAMU 88.5 News. Now, back to our conversation on sea level rise where we're talking with Carl Hershner, director of the Center for Coastal Resources Management at the Virginia Institute of Marine Science. Steve Gill is an oceanographer who has worked at the National Oceanic and Atmospheric Administration for over three decades.

NNAMDIAnd Chris Pyke is the chair of the Chesapeake Bay Program Scientific and Technical Advisory Committee and the vice president of research for the U.S. Green Building Council. Back to the phones. Here is Gary in Sterling, Va., speaking of what we can do. Gary, go ahead, please.

GARYThank you. I'd like to say this is poor -- really upsetting because I think a lot of the problem is that people cut their grass too short. And because of that, you can take a look at the Potomac River after -- anytime we have a big rain, it turns red, color of clay, or yellow if it rains up in Maryland. And with short grass, you have short roots. With tall grass, you have long roots, better CO2 consumption, more oxygen production, a better subterranean labyrinth that the water filtration can recharge the aquifers and stop the ground from sinking.

NNAMDIChris, are we cutting our grass too low?

PYKEWell, the decisions we make on our own property are contributing to the greater problems of the bay. And sea level rise -- to take one of those threads out of there is saying sea level rise does have the potential to mobilize more sediments within the bay. And that's one -- 'cause as it -- as rising waters eat away at our shorelines -- and a lot of our decisions kind of come together on this. And so this is one of those places where the caller kind of talking about sediment in the bay, that is essentially a pollutant.

PYKEIt's smothering life in the bay. And sea level rise plays into that by increasing rates of erosion and so forth. And there are things we can do to manage our shorelines in ways that offset that impact as we try to restore it, actually, as part of our broader restoration effort for the bay.

NNAMDIGary, thank you very much for your call. We move on to Paul in Washington, D.C. Paul, you're on the air. Go ahead, please.

PAULHey. Thanks, Kojo. Thanks for the show. I have a question about D.C. and the $3- to $4 billion investment we're making under D.C. Water with ratepayer dollars to fix the sewer -- combined sewer and storm water system that we have in a third of the District.

NNAMDIYes.

PAULDo you know if D.C. Water is using current climate change data? Or are they using the 20-year-old data that was available when they were putting together the plan?

NNAMDIDo you have any idea...

PAUL'Cause if they're not using the current data, we're in trouble in our investments.

NNAMDISteve Gill, do you know?

GILLYeah. I have no idea what their baseline was.

NNAMDIAnd I certainly don't, and that's something that we should be looking into. And we'll make a few calls and see what we can find out, Paul.

PAULCan I ask a broader question, which is...

PYKEPlease do.

PAUL..are governments using current climate data in their planning? Are local governments, really -- you know, you started to address that for ocean level rise. But for, you know, sort of the whole increase in storms and all that stuff here in the District where we (unintelligible).

NNAMDIOne would hope that they are. The NOAA data is just about available to everyone, isn't it, Steve?

GILLYes, it is. It's publicly available. Within NOAA, for instance, our coastal zone management community, that NOAA works closely with, are using the latest climate information and sea level trends to work with the coastal zone management plans.

HERSHNERIf I might...

NNAMDIPlease go ahead, Carl.

HERSHNERThe question's an excellent question. The answer at this point is sort of discouraging in that the reality is we have not been very effective at using our emerging understandings in a lot of the design for infrastructure. Here in Virginia, we are -- I think Maryland's ahead of us on this. But in Virginia, we have been increasingly aware of the need to address climate change, and particularly the impacts on a rainfall event, in the design of our storm water facilities.

HERSHNERBut, currently, the guidelines for storm water facilities are looking at practices that create engineered structures that probably would not be able to perform the same water quality improvement functions that they're intended to 50 or more years from now, given what we are anticipating in climate change trends.

NNAMDIChris Pyke.

PYKEI just wanted to add to that, but I think that the caller makes exactly the right question 'cause the question is when we make a big investment like redeveloping our storm water system or a small investment like even a detention pond, classically, what we're doing and what's happening in a majority of cases is we use a historic design storm and say, OK, how much of that are we going to catch? The data that we're showing is that, whether it's sea level rise or precipitation, there -- these are actually trending.

PYKEAnd so, over the life of that thing, whether it's a treatment plant or a storm water pond, it may not do what we want it to do. And the caller is right. We should be demanding that we're asking how is that going to perform based on the best of our understanding about the next couple of decades. And so that's the right question. And I'll underscore what Carl was saying. It's a little depressing on -- by and large, right now, we're not doing that, but it is something, technically, we can change.

NNAMDIAnd here's what underscores the need for using the most up-to-date data, Chris, because people tend to be most concerned about extreme sea level rise, like we're seeing in New Orleans or we're seeing Hampton Rose. But even a small increase in the ocean level can have a big effect, can't it?

PYKEThat's right. And it -- the systems are so intimately tied together. It goes back to that example of erosion because even a few extra millimeters, when this is the basis for additional storm surge, changes patterns of salinity and circulation and so forth. They can really -- they can have additive effects. And so those -- you're right. Even though -- what seems like a small change is part of a system of changes that work together.

NNAMDIPaul, thank you very much for your call. Steve, it's my understanding that there are also a few places in the world where the sea level is actually going down, too. What's going on in Alaska?

GILLWell, that's right. But it's interesting that, you know, sea level is falling relative to the land in Southeast Alaska in the glacial fjords. But it's really climate change-driven, and that's because the glaciers in recent times have been melting. The weight of those glaciers have been taken off the land as they recede, and that land rebounds. It vertically uplifts from those weight of those glaciers.

GILLAnd so, relative to the sea, that land is emerging at about 11 to 15 millimeters per year in areas like Juneau and Skagway, Alaska, and those recent -- that's a phenomenon happening in the Baltic Sea and Scandinavia as well that we see. But it's caused by a climate driven-signal causing the land to move.

NNAMDIBack to the telephones. Here is Dennis in Reston, Va. Dennis, your turn.

DENNISYeah. Hi. I had a question regarding the possible contribution to sea level rise in the Chesapeake Bay area regarding the ancient Chesapeake bolide, which created the Chesapeake Bay basin. And its current rebounding, much like the Great Lakes region, rebounding from being pressed down by bolide -- and by bolide, I mean potential meteor or asteroid or comet which hit there, and I want to say 25 million years ago -- I might be incorrect on that date.

DENNISBut its -- the bottom of Southern Chesapeake Bay is currently rising, and that engulfs some of the islands in lower-lying areas. And I'm curious as to what contribution that might have to the current rising of sea level in Chesapeake Bay.

NNAMDIAny idea at all, Carl?

HERSHNERI'm not sure what the source of the information the caller is citing because it is contrary to my own understanding of the impacts associated with that meteor. And, in fact, while it is not known precisely what the rates of change are resulting from that displacement of sediment and fracturing of the underlying basal rocks, the expectation -- or at least the hypothesis that I'm familiar with -- says that that is actually contributing to enhanced subsidence of the area from settling and compaction of the sediments that were thrown out of the meteor crater.

HERSHNERAnd so, rather than it causing some rise of the land mass, it's actually contributing, or that, the result of that, has actually contributed to the subsidence we're seeing.

DENNISHmm. OK.

NNAMDIDennis, thank you very much for your call.

DENNISThank you.

NNAMDIOn to Derek in Manassas, Va. Derek, you're on the air. Go ahead, please.

DEREKOh, hi. Yeah, thank you. I was wondering if your guest is familiar with the book and the study by Bjorn Lomborg called "Cool It," where he looked -- they looked at data of sea level rise. And since 1860, sea level has risen almost a foot. And they point to a whole bunch of economic factors that it really hasn't had that massive of an effect. And they're only predicting about five or six inches through 2050.

DEREKAnd the whole premise of those studies is that it's economically -- you know, economic suicide to try to prevent some of this stuff as opposed to just taking amelioratory (sic) actions like they do in Holland and elsewhere and that -- you know, how do you explain the level rise since 1860, you know? And I just want to know if he was familiar with those studies. Again, it's Bjorn Lomborg, L-O-M-B-O-R-G.

NNAMDIChris Pyke?

PYKEYeah. I mean, I'm familiar with the general body of work. I think that the idea -- what we've seen in recent studies is saying, well, first, our choices about climate -- our emissions that are driving climate change do have consequences for sea level rise. And recent peer-reviewed studies have shown that our choices about emissions -- in other words, having -- reducing the drivers of anthropogenic climate change -- can have a -- over the course of decades, have a material difference on how much sea level we have.

PYKEAnd those choices come with lots of co-benefits by reducing emissions into the atmosphere and impacts on human health and well-being in the developing world, as previous caller pointed out. So I think the thing to say is that, yes, definitely some familiarity with the concepts, but I think that, more generally, reject the idea that there's nothing we should be doing now.

PYKEI think there are -- empirically, there's lots of things we can do that reduce the amount of change that we have to deal with while also embracing the fact that there's a trend that we need to begin building into our decision-making today. So it's a both/and. It's a walk and chew gum.

DEREKBut also that same book and study point out that, even on disease and crop and everything like that, it is much more efficient to take other actions than to try to implement things like Kyoto and other things that aren't being implemented and would cost a fortune. And this isn't a right-wing conservative study at all. It's more of a...

NNAMDIOh, no. But I'm thinking that there's a dependence on one book and one study. And one of the points I think you were making earlier, Carl, is that peer review and broad consensus among scientists is hugely important here, isn't it?

HERSHNERAbsolutely. As anyone of us can cite, there are multiple studies with multiple perspectives, and the only way that one can sort of distinguish the understanding from the noise is by looking to the emerging scientific consensus that results from peer review.

NNAMDIThank you very much for your call, Derek. And this email is a little long, but I think it needs to be addressed from Will. "Given the size of the problem that rising seas presents to the Mid-Atlantic, why is no government agency charged with addressing the threat? At this point, it is, at best, a mixed collection of local offices with highly variable expertise based largely on the wealth of the county state program and a cadre of federal programs dealing with this.

NNAMDI"With no one in charge, there's no accountability at any particular level of government. And with current budget woes, the inclination to assume addressing the threat as someone else's threat only grows. For the guests on the show, who should be in charge of a sea level response plan, NOAA, the Corps of Engineers, state planning officers, county planning or zoning officers? Or is everyone on their own, where those who protect themselves and those who are left in harm's way based solely on local economic factors?" I'd like to hear each of you respond to this. First you, Steve.

GILLWell, we have some regional entities -- the Chesapeake Bay Program, Chesapeake Bay Office entities -- that I think my colleagues can speak to more than I. I think some of those regional entities that combine federal and state and local activities would be the answer.

PYKEMy -- this is Chris. My personal answer is saying, yes. Actually, I think that sea level rise -- changing sea level or any kind of climate change is something that's embedded in all those decisions. And so, ultimately, those people who are an expert in each of those decisions need to understand the consequences for them. The question of whether there's an overriding sort of central resource, that's something that could -- that might be very useful to helping those folks.

PYKEBut I don't think it -- actually, I think the greatest opportunity for action is by saying, yes, this is a dimension of all of those responsibilities, and go get it.

NNAMDIAnd the politics of creating a new federal agency in the current political environment, not so good. Care to comment, Carl?

HERSHNERWell, it is almost an intractable problem for all the reasons that have been outlined. My own personal perspective is that the identification of an appropriate responsible entity depends entirely on who you want to turn to when problems arise. And to the extent that we all expect the federal government to be the ultimate savior for us when natural disasters or just natural trends make our current occupational landscape inhospitable or untenable like New Orleans, then perhaps the federal government is the appropriate entity to step in and set some standards.

HERSHNERBut, ultimately, I think we are going to learn -- and insurance companies are already demonstrating this -- that the expenses of failing to adapt appropriately in the ways that Chris...

NNAMDIRunning out of time very quickly.

HERSHNERFailing to adapt is going to end up costing us more than we can possibly afford.

NNAMDICarl Hershner is the director of the Center for Coastal Resources Management at Virginia Institute of Marine Science, Chris Pyke is the chair of the Chesapeake Bay Program's Scientific and Technical Advisory Committee, and Steve Gill is an oceanographer who has worked at the National Oceanic and Atmospheric Administration for three decades. Thank you all for listening. I'm Kojo Nnamdi.