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 be prepared for sea level rise, we're going to continue to have sea level rise for decades and probably centuries, it's not going to stop, the question is how fast is it going to be?" states Josh Willis, climate scientist at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. "If you live on a coastline, or you have some economic dependence on a coastline, we have to be prepared for rising seas, it's not a question of how much, but rather when."
The board stated that the rise in ocean levels is coming from three distinct sources. The first is thermal expansion, in which ocean water expands as it is heated, taking up more volume and causing sea levels to rise. This effect has been exacerbated by greenhouse gas emissions, of which the ocean absorbs over 90 percent of the resultant heat.
The second source is ice loss from the Greenland and Antarctic ice sheets, while the final third is from melting mountain glaciers. Ice sheets and glaciers can be lost from contact with warmer air, the creation of icebergs, or from interaction with warm sea water. It is estimated that the Greenland ice sheet alone has lost around 303 gigatons of mass per year for the last decade.
We are aware of this thanks to a number of scientific instruments wielded by NASA and its partners. A notable contributor to our knowledge has been the Jason 1& 2 and TOPEX/Poseiden satellites, whose altimeters have allowed for incredibly precise measurements. Simultaneously NASA's GRACE satellite has been observing Earth's gravitational field, taking accurate measurements in order to determine by how much ice sheets and glaciers are shrinking.
Data from these satellite missions and other resources tell us that our oceans have risen by about 8 inches (203 mm) since the onset of the 20th century, and that we may be facing a rise in excess of 3 ft (0.9m) before the century is out. A visual representation of the phenomenon is presented in the video below (starting at the 40-second mark), which draws on data from 23 years of satellite observations, the result of a collaboration between NASA and the French space agency Centre National d'Études Spatiales.
The visual representation shows us that water is not rising at a global standard rate. Instead there are significant levels of variation and in some isolated pockets, the water level is actually subsiding, as evidenced by the rare blue patches. It is however worth noting that these discrepancies are due to identifiable ocean mechanics.
"Sea level along the west coast of the United States has actually fallen over the past 20 years because long-term natural cycles there are hiding the impact of global warming," explains Willis. "However, there are signs this pattern is changing. We can expect accelerated rates of sea level rise along this coast over the next decade as the region recovers from its temporary sea level 'deficit.'"
Other variables that can affect the height of water in blue zones include the strength of the Gulf Stream, and other pre-identified natural phenomena such as the Pacific Decadal Oscillation.
During the teleconference, the panel of experts was keen to point out a major flaw in our ability to create accurate models of sea level rise – our lack of understanding regarding the role that the degradation of East Antarctica's leviathan ice sheet has on rising sea levels. This is due to the fact that many of the changes taking place with the icesheets occur under the water line, making it very difficult to observe them from space.
"The prevailing view among specialists has been that East Antarctica is stable, but we don’t really know," states Eric Rignot, a glaciologist at the University of California Irvine and JPL. "Some of the signs we see in the satellite data right now are red flags that these glaciers might not be as stable as we once thought. There’s always a lot of attention on the changes we see now, but as scientists our priority needs to be on what the changes could be tomorrow."
Simply put, current equipment must reach a greater level of sophistication, with computer models needing to be run at a higher resolution than the current generation of computers can handle. This summer, in an attempt to increase 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 Greenland ice sheet. By combining satellite imaging with terrestrial based campaigns like OMG, NASA hopes to generate more accurate forecasts.
The teleconference paints a grim picture of what can be expected in the decades and centuries to come, and the question was raised as to how the information can be acted upon now. Eleven of the world's largest cities are situated on coastal regions, and in America alone, around 160 million people live on the country's shores. The danger is not confined to seawater flooding low-lying coastal areas – rising seas could have an effect on extreme weather systems such as hurricanes, which will be able to project their influence ever farther inland.
Source:NASA
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
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.
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.
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.
"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.
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...
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