This is a snapshot from The Inconvenient Truth, depicting the apocalyptic flooding of The Netherlands. The picture is scanned from the front page of todays dutch newspaper NRC Next. (headline translation: "No, it won't go that fast"), but the flooding speed is not what I want to highlight here.

As the journalist Karel Knip pointed out in NRC there is something strange about the dry area: The dry patch on the left is the Alblasserwaard, one of the lowest areas in The Netherlands, famously known for this view:

Now, why would de Alblasserwaard be saved from flooding?

Here is the solution:

The creators of the flooding image misgeoreferenced the satellite image (red) and the elevation data (green), as is indicated by the ice pushed ridges Utrechtse heuvelrug (left) and de Veluwe (right).

Makes you wonder how well the other science was represented.  

You may be right, but can you explain more clearly why - I dont understand you annotation of the image

here is the most accurate elevation map of the netherlands, the two hilly areas in the center are covered with forest on the sattelite image

full res:

http://www.ahn.nl/demo/ahn-nederland1.jpg

http://www.astro.rug.nl/~vdkruit/jea3/homepage/Netherlands.gif

Coollhans.

I doubt VERY much that the two datasets used were incorrectly georegistered - I use the satellite imagery shown (Landsat 7 ETM+ Geocover200 scenes and the global digital elevation dataset (probably SRTM3 - 3 arcsecond resolution) all the time and have not encountered any abnormal positional discepancies. In both datasets the geopositioning is encoded in the data. SRTM3 data is delivered in a set of x, y, z coordinates where x and y are longitude and latitude WGS84 datum. Geocover is delivered as Geotiffs in the local UTM projection  WGS84 datum, pixel positional accuracy in somewhere like Netherlands is likley to of the order of signiifcantly less than 50m north or south of actual.

I suspect it is an in advertant consequence of the GIS algorithm used to show a rising of sea level - a selection mask has probably been used to select pixels in the DEM that correspong to areas of the modern oceans. To depict the effect of rising sea level, pixels of the DEM outside the selection mask, but immediately adjacement to it, were successively coloured to depict sea, as modelled sea level was raised in increments. If the low lying area you refer to is surrounded by dykes, pixels covering it would not have been coloured by this procedure.

The alternative to the above would have been to incrementally colour to show sea, all pixels of the DEM with z values below the level of forecast level rise. However, if this were done to the global dataset, as shown in AIT, this would have caused low lying regions such as the Dead Sea and Caspian Basin to be coloured too, which would not be accurate since these areas below modern sea level are isolated from oceans by high ground.

What ever the casue of this error it does not alter the message.

You don't know how the georeferencing was done, You assume proper used georeferenced data was used as input. The image proves the opposite. I am convinced that a non georeferenced sattelite image was used. No model that calculates a 7 m sea level rise can leave de Alblasserwaard dry.

Here is the netherlands without dikes (dark blue is area flooded by rivers):

indeed the message of Al Gore is loud and clear "Repent, the end is nigh!"

With respect you are wrong.

I think i know the precision of the datasets I work with daily. The issue you raise has absolutely nothing to do with georeferencng of the datasets used. I believe I am right in thinking, based on the documentary credits, that the simulation was produced by Earth Satellite Corporation Inc., who created the Global Landsat imagery mosaic used (Geocover). Earthsat Inc is probably the foremost remote sensing imagery providers in the world, they know what they are doing. The digital elevation dataset probably used is also very accurate postionally.

As I explained to you in great detail, I suspect the error is almost certainly a consequence of the automated sea level rise flooding algorithm used.

Martin North - 12/10/2006 11:19

Village - 12/10/2006 10:59 I am beginning to wonder wwhether the ACC message is simply a modern form of religion that we should all live our lives by or go to hell as the world implodes. Its just a replacement for the old style religion because nobody goes to church anymore on a Sunday.

This is veering dangerously off topic. Please keep to the inconvenience of the error...

[rofl]

1) you don't know which datasets were used to create the flooding image, You assume it is of the same quality as the datasets you work with. My take is that a flooding calculation map  was incorrectly merged with a sattelite image, the scaling and location errors are evident.

2) I worked at the Alblasserwaard waterboard, I loaded the digital elevation data of the dikes into their computer system. There is no way this area kan stay dry with a sea level rise of 7 meters.

Science including the science of climate change ia about as far from religion as is possible to get.

Religion is dogma. People are asked to have blind faith in things and supernatural beings for which there is no evidence, that in some cases defy understanding, the known laws of physics etc. The believers are discouraged from questioning the basis of their belief, but are instead are expected to accept unquestioningly the word of a few who claim to be represent supernatural beings, as fact.

I contrast science is about posing questions, formulating hypotheses, making predictions and testing them via performing experiments and collection of evidence. Those hypotheses that are supported by evidence are useful, an are accepted. Those that do not are not useful and are rejected. Scientific understanding evolves, it is not fixed.

If any group active in the climate change debate, has religious ideas it is anthropogenic climate change denialists and to a lesser degree sceptics. They believe that human activities cannot cause climate change, now matter what or how much evidence is presented to indicate it is occuring and why, despite all and the increasing mountain of the evidence to the contrary. Such unchanging views constitute religious dogma.

Climate change anthropogenic or natural, has alarming implications for this increasingly populated and environmentally pressured world and the media communicates this. The conspiracy to deny the facts and the issue that a tiny minority are attempting to perpetrate and hoodwink the rest, makes the issue highly political and emotive. To be corncerned or alarmed by predictions of the future climate of the world and its consequences is facing up to the reality of the problem. In contrast climate change sceptics and denialists are either hopelessly optimistic, ignorant of the subject about which they profess to underatand or have their heads buried in the sand about the issue. It seems this delusion often has it basis in the fact that to accept that recent climate change is anthropogenic, would be require their acceptance that they are partly responsible and thus, to accept their moral obligations to the rest of society, to change their lifestyles.

I get very angry when the equation between science nad religion is made. It shows the profound ignorance of those making it.

There are is only one public domain global elevation dataset and there is only one global landsat image mosaic and both are postionally accurate to within 50m, and i recognise the processing of the latter to produce the image shown. The way simulated sea level rise is shown is to set the colour of pixels in the DEM to whatever colour you wish to use to show the sea. In this instance those pixels of the DEM depicting land are shown as transparent, so you can see the satellite image underneath. Using a modern geographic information system this is mere a matter of selecting a few menu options. There is no overlay of flood images on a satellite image being performed.

I dont doubt Alblasserwaard would flood if there was a large rise in sea level. I never suggested otherwise. I said, that the reason it was not shown as flooded in the simulation, was because of a flaw in the algorithm used to show simulated sea-level rise. I dont think I can be clearer than that.

This is in keeping with your political agenda to discredit all climate change science that condudes that ACC is occuring or is responsible for a particular environmental change.Your crticism is equivalent to shooting the messenger. It does not invalidate the conclusions or the message.

I said that on the basis that Earth Sat Corp. (MDA Federal as it is now) was credited, so I thought they might have produced the simulation, not that they definitiely did. So dont be surprised if they say they did not. There are many companies that could have also produced the simulation