Environment

NASA teleconference on sea level change warns of rising oceans

NASA teleconference on sea lev...
Image showing sea level rise based on satellite data
Image showing sea level rise based on satellite data
View 4 Images
Global sea level measurements from 1993 - 2013
1/4
Global sea level measurements from 1993 - 2013
Observations of ice mass loss from NASA's GRACE satellite
2/4
Observations of ice mass loss from NASA's GRACE satellite
Measurements from the TOPEX/Jason satellites displaying sea level change in the short-term (top) and longer-term (bottom)
3/4
Measurements from the TOPEX/Jason satellites displaying sea level change in the short-term (top) and longer-term (bottom)
Image showing sea level rise based on satellite data
4/4
Image showing sea level rise based on satellite data

On Aug. 26, NASA held a media teleconference regarding current predictions on sea level rise, highlighting the risks to coastal populations in low-lying areas, and the inherent problems in creating reliable global models. A panel of experts from NASA's recently-founded Sea Level Change Team tells us that ocean levels are inexorably on the rise, but gaps in our understanding and ability to survey risk regions mean we don't know just how fast the change will take place.

"People need to beprepared for sea level rise, we're going to continue to have sealevel rise for decades and probably centuries, it's not going tostop, the question is how fast is it going to be?" states JoshWillis, climate scientist at NASA’s Jet Propulsion Laboratory (JPL)in Pasadena, California. "If you live on a coastline, or youhave some economic dependence on a coastline, we have to be preparedfor rising seas, it's not a question of how much, but rather when."

The board stated thatthe rise in ocean levels is coming from three distinct sources. Thefirst is thermal expansion, in which ocean water expands as itis heated, taking up more volume and causing sea levels to rise. Thiseffect has been exacerbated by greenhouse gas emissions, of which theocean absorbs over 90 percent of the resultant heat.

Global sea level measurements from 1993 - 2013
Global sea level measurements from 1993 - 2013

The second source isice loss from the Greenland and Antarctic ice sheets, while the finalthird is from melting mountain glaciers. Ice sheets and glaciers canbe lost from contact with warmer air, the creation of icebergs, orfrom interaction with warm sea water. It is estimated that theGreenland ice sheet alone has lost around 303 gigatons of mass peryear for the last decade.

We are aware of thisthanks to a number of scientific instruments wielded by NASA and itspartners. A notable contributor to our knowledge has been the Jason 1& 2 and TOPEX/Poseiden satellites, whose altimeters have allowedfor incredibly precise measurements. Simultaneously NASA's GRACEsatellite has been observing Earth's gravitational field, takingaccurate measurements in order to determine by how much ice sheetsand glaciers are shrinking.

Data from thesesatellite missions and other resources tell us that our oceans haverisen by about 8 inches (203 mm) since the onset of the 20thcentury, and that we may be facing a rise in excess of 3 ft (0.9m) before the centuryis out. A visual representation of the phenomenon is presentedin the video below (starting at the 40-second mark), which draws on data from 23 years of satelliteobservations, the result of a collaboration between NASA and theFrench space agency Centre National d'Études Spatiales.

Watching Rising Seas From Space

The visualrepresentation shows us that water is not rising at a global standardrate. Instead there are significant levels of variation and in someisolated pockets, the water level is actually subsiding, as evidencedby the rare blue patches. It is however worth noting that thesediscrepancies are due to identifiable ocean mechanics.

"Sea level along thewest coast of the United States has actually fallen over the past 20years because long-term natural cycles there are hiding the impact ofglobal warming," explains Willis. "However, there are signs thispattern is changing. We can expect accelerated rates of sea levelrise along this coast over the next decade as the region recoversfrom its temporary sea level 'deficit.'"

Other variables that can affect the height of water in blue zonesinclude the strength of the Gulf Stream, and other pre-identifiednatural phenomenon such as the Pacific Decadal Oscillation.

Measurements from the TOPEX/Jason satellites displaying sea level change in the short-term (top) and longer-term (bottom)
Measurements from the TOPEX/Jason satellites displaying sea level change in the short-term (top) and longer-term (bottom)

During theteleconference, the panel of experts was keen to point out a majorflaw in our ability to create accurate models of sea level rise –our lack of understanding regarding the role that the degradation ofEast Antarctica's leviathan ice sheet has on rising sea levels. Thisis due to the fact that many of the changes taking place with the icesheets occur under the water line, making it very difficult toobserve them from space.

"The prevailing viewamong specialists has been that East Antarctica is stable, but wedon’t really know," states Eric Rignot, a glaciologist at theUniversity of California Irvine and JPL. "Some of the signs we seein the satellite data right now are red flags that these glaciersmight not be as stable as we once thought. There’s always a lot ofattention on the changes we see now, but as scientists our priorityneeds to be on what the changes could be tomorrow."

Observations of ice mass loss from NASA's GRACE satellite
Observations of ice mass loss from NASA's GRACE satellite

Simply put, currentequipment must reach a greater level of sophistication, with computermodels needing to be run at a higher resolution than the currentgeneration of computers can handle. This summer, in an attempt toincrease our understanding of the impact that ice sheets are having,NASA initiated a six-year field campaign, Oceans Melting Greenland(OMG), to study how warmer ocean waters are affecting the Greenlandice sheet. By combining satellite imaging with terrestrial basedcampaigns like OMG, NASA hopes to generate more accurateforecasts.

The teleconferencepaints a grim picture of what can be expected in the decades andcenturies to come, and the question was raised as to how theinformation can be acted upon now. Eleven of the world's largestcities are situated on coastal regions, and in America alone, around160 million people live on the country's shores. The danger is notconfined to seawater flooding low-lying coastal areas – rising seas could have an affect on extreme weather systemssuch as hurricanes, which will be able to project their influenceever farther inland.

Source:NASA

19 comments
The Hoff
I can already hear the response of minions who have been educated by the Koch oil brothers ripping on the brilliant NASA scientist warning. But will they name any of the pitiful 3% of climate scientist that don't believe we are changing the planets weather? We have the solar and wind technology to get off of oil. Koch brothers are the dead weight holding us back.
Roland Riese
Fort Denison in Sydney has one of the longest running continuous records measuring the seal level, starting in 1886, and finally local councils are realizing that they need to use the local data to plan ahead, not the IPCC’s or also the green lobby at NASA one-size global fear index. For example, measurements at Sydney between 2005 and 2014 show the tide gauge site is sinking at a rate of 0.49mm/yr, leaving just 0.16mm/yr of the overall relative rise as representing global sea-level change. Indeed, the rate of rise at Fort Denison, and globally, has been decreasing for the past 50 years and that is the reality. Because of the Fort Denison sea level records we can ruled out “satellite or model-generated sea-level ESTIMTES until their accuracy is guaranteed”. And then there is Global Warming, what global warming The video below is a very good explanation why non of the computer climate modeling is or can work. -https://www.youtube.com/watch?v=19q1i-wAUpY
christopher
Relative to what? Every bit of land on earth is either rising or falling - yeah, we can stand on it, but it in turn is itself floating (on the molten inner earth). Unfortunately, these satellites are calibrated to a fixed point based on land, which is floating. Regardless of the answer, it's a pointless question: humans build wherever the heck they want - they put houses below sea level, cities on faultlines, towns in storm-prone regions, nuclear reactors beside active volcanoes, nothing you do or say will stop that, whether or not it's true, and whether or not it's 3ft or 3cm of change that takes place.
Synchro
So Roland, you extrapolate the entire global sea level change from a single point, entirely ignoring what the article says. EVERYTHING is an estimate until it happens and can be measured, however, estimates are all we have, though you apparently you prefer to wait until something catastrophic happens rather than actually trying to think about it. The thing about facts is that you don't have to believe in them for them to remain true. That video (incidentally, created by an organisation that (unlike an actual scientific venture) has an explicit anti-GW (note not just AGW) agenda) is certainly interesting, but concentrates on the fact that accurate prediction is hard - which nobody is disputing. However, regardless of what predictions we may make, straightforward measurement of what has happened to date are not really up for debate. The overall argument that because something is hard, we shouldn't even try is a defeatist, head-in-sand approach, and will not get us anywhere. There's nothing we would like better than to have accurate predictions that everything will be just fine whatever we do, however, our best efforts so far show convincingly that this is not the case.
Rumata
Dear Synchro, you totally miss the point. Nobody tells you, that global climate prediction is hard. They tell you, that IT IS IMPOSSIBLE. "The climate system is a coupled non-linear chaotic system, and therefore the long-term prediction of future climate states is not possible." (IPCC:"Advancing our Understanding", page 771.) Let me help you: in the mathematical language the "nonlinear chaotic system" means, that we have no clue, what happens next :-) So, even the biggest liar of MMGW admits, that we can only guess, but never predict the future states of global climate. And true: IPCC couldn't accurately predict even the next year's global average temperature. And the reason is simple: the global climate is basically determined by solar radiation, wind sytems and cloud formation. And we cannot predict them. The CO2 hystery is really stupid. There is ZERO correlation between our yearly CO2 emission and the yearly increase of atmospheric CO2 level. And if the human CO2 emission cannot even affect atmospheric CO2 level, then how could you say, that human CO2 emission can affect global climate? The greenhouse effect is based on the assumption, that there is no heat covection between lower and higher layers of the atmosphere. But in reality, there are large continuous vertical streams in the atmosphere (without them, there were no clouds!), carrying enormous heat from the surface to the upper atmosphere. Hence, greenhouse effect cannot heat up the surface. The temperature of the upper atmosphere is stabilized by the solar radiation. The temperature of the lower atmosphere is stabilized by the adiabatic temperature rise of downstream winds. And the local surface climate is determind basically by wind sytem and cloud formation. That's all we know.
Steve Jones
I'm hoping within the next 85 years, renewable energy will be cheaper than fossil fuels. Nuclear fusion may only be 30 years away (no, really, they mean it this time). I live a mile from the sea and the predicted rise of 0.9m in that period won't even bring the tide up to the top of the beach. Yes, we still have to worry about increased storm damage and localised, occasional flooding. Yes, increased erosion will cause severe problems in a few locations. And yes, there's even a risk that tipping points / positive feedback systems will mean the picture might be worse than this. I'm just bringing some perspective to a story which seems to imply that most coastal regions will soon be permanently inundated by the ocean.
Synchro
DaniTuri, it's good to see you wave your denialist numpty flag so vigorously. Like the video says - we can't know precisely what's going to happen, but we can certainly get a general idea with some degree of certainty based on how things have acted in the past, especially since they have some obvious trends. "The CO2 hystery is really stupid. There is ZERO correlation between our yearly CO2 emission and the yearly increase of atmospheric CO2 level." Apart from all that pesky data that says it does. For example nearly all fossil fuel emissions have a different mix of isotopes to atmospheric CO2 (no C14) and guess what - the observed change correlates with that mix of isotopes too, i.e. much of the change is from fossil fuels. If you add up all the natural emissions, you get a gap that happens to match our fossil fuel emissions too. If you correlate that with the timings of these changes, you also get a profile that matches our changing use of fossil fuels, ie. a rapid increase. In short, the level of atmospheric CO2 is increasing, the additional CO2 is being produced by burning fossil fuels, and that build-up is accelerating. So now that straw man lies in ashes (hey, it's carbon-neutral!), your next assertion has nothing to support it. As for your greenhouse effect assertions - you're just making things up there too, at the same time as implying that you're the only one bright enough to think about these things. Try a better source (to pick one out of thousands): http://geosci.uchicago.edu/~rtp1/papers/PhysTodayRT2011.pdf If there was a real debate about AGW it would be between scientists, just like it is in every other field; but it's not; it's between science and the clueless. There is essentially no dispute between those that are actually working on it. Though I'm sure your own credentials are first rate, bear in mind that there are no national or major scientific institutions anywhere in the world that dispute the theory of anthropogenic climate change. Really. Not a single one.
AllenH
This article is exactly right. We need to act now. After all, just look at how many hundreds of thousands of people have been displaced by rising oceans. Why we have lost over 10,000 square miles of coastland just in the U.S. alone. What? We haven't? What do you mean no one has been displaced and low-lying cities haven't been lost to rising ocean currents? But the global warming advocates...uh, I mean scientists...have told us that the polar ice is virtually gone and that manmade global warming has been occurring for decades and is irreversible. Why would they make this stuff up...other than the fact they were ordered by the Obama administration to make manmade global warming their top priority and also their future funding and jobs all depend on following this directive... Hey, wait a minute...
Phillip Noe
The climate change deniers are everywhere! steve jones above offered a link to a denier that takes compensation from the heartland institute which is largely funded by fossil fuel interests like the koch brothers. (not capitalizing some names is intentional) For some HONEST information about climate change here's where you can find it. Google search... NASA Climate Change Consensus Google search... AAAS Climate Change What We Know
David Earnest
I've lived in proximity of the Pacific Ocean for almost 60 years and the Sea level changes every 12 hours. It's called TIDES. The mean Sea Level hasn't changed at all in my life time. So I'm going to call BS on this ENTIRE story and premise of the NASA "Scientists".