Climate Catastrophe: A Superstorm for Global Warming Research

By Marco Evers, Olaf Stampf and Gerald Traufetter

Part 5: The Reality of Rising Sea Levels

Photo Gallery: Climate of Fear Photos
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They could have been scenes from a horror film: New York's skyscrapers jutted out of the ocean like reefs, while cities like Hamburg and Hong Kong, London and Naples had been flooded long ago. Entire countries had been swallowed up in other places. Denmark, the Netherlands and Bangladesh had ceased to exist.

A quarter of a century ago, climatologists grabbed the public's attention with such horrific visions. At the time, the experts calculated that the sea level would rise by more than 60 meters (197 feet) if the greenhouse effect caused all of the Earth's ice to melt.

No one talks about such nightmare scenarios today. None of the current simulations involves the complete melting of the Antarctic ice sheet. On the other hand, hardly any glaciologists doubt that sea levels will be significantly higher along coastlines by the end of the century. But how much higher, exactly? Estimates range from 18 centimeters (7 inches) to 1.90 meters (6' 3").

Hard to Calculate

"Of course, this isn't a satisfactory statement for coastal planners and politicians," admits Peter Lemke, chief climatologist at the Alfred Wegener Institute for Polar and Marine Research in the northern German port city of Bremerhaven. "But we can't sell something as certainty if we don't know exactly what it will be."

The current IPCC report mentions a relatively conservative range of 18 to 59 centimeters. "Most experts consider this estimate to be too small," says Lemke.

Two factors influence the sea level. The first one affects it directly: When water heats, it expands. This warming effect, which can be calculated with relative precision, is expected to cause the sea level to rise by about 22 centimeters by 2100.

Another effect that is not as easy to calculate is the melting of mountain glaciers and inland ice in Greenland and Antarctica. Most of the melting today is happening in mountain glaciers, from the Andes to the Himalayas. According to IPCC calculations, this melting activity contributes 0.8 millimeters a year to the rise in sea level. Greenland and Antarctica each contribute another 0.2 millimeters.

Quicker Melting

Meanwhile, satellite observations indicate that the rate at which the ice is melting has increased. Glaciologists speculate that parts of the Western Antarctic and, to a greater extent, Greenland, are melting more quickly than initially assumed.

But many scientists are reluctant to make new predictions, because the inner processes in the gigantic ice caps remain insufficiently understood. Reliable data on the behavior of calving glaciers has only existed for about 10 years. Greenland's glaciers are currently spitting a particularly large amount of ice into the ocean. After such a phase, however, many ice flows become dormant again for a longer period of time.

Lemke, like most of his fellow scientists, expects the sea level to rise by somewhere between half a meter and one meter.

Build dikes or get out of the way -- this is the principle coastal residents have applied for years to defend themselves against the forces of nature. In Hamburg in northern Germany, storm surges are now more than half a meter higher than in the 1960s. This is not the result of climate change, however, but of the narrowing of the Elbe River. Nevertheless, the port city is not as threatened as it once was, thanks to improved flood protection.

But storm surges aren't just caused by rising sea levels. Another factor that is at least as important is the wind, which pushes large amounts of water against coastlines.

Can we truly expect to see stormier times in a greenhouse climate?

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1. Will humans, for once, be sensible?
plotinus 04/01/2010
I constantly point out, and people constantly ignore, that, in the absence of countervailing forces, if you pour carbon dioxide and other greenhouse gases into the atmosphere, the atmosphere _*must*_ warm up. This is just basic physics, and is as certain as the Law of Gravity. Of course there are possible mitigating factors, such as changes in cloud cover and the injection of certain types of dust into the atmosphere; but these factors are, as yet, far more problematical than the raw fact of global warming. The Earth has already become warmer and sea levels have already risen. These facts are clearly visible in what is happening to low island nations and to the arctic regions. The Spiegel article is calmer and more reasonable than those in many other popular journals, but I would fault it for not mentioning that changes in the arctic must necessarily increase heat absorption in those regions, and for not mentioning the release of greenhouse gases as polar permafrost melts. Also, it is important to point out that it is not relevant that humans and other life forms survived even greater changes in climate in the past. Those changes almost always were very slow, occurring over many hundreds and thousands of years. There was time to adjust. The global warming which we are creating will, from the point of view of Earth history, occur in the blink of an eye. The effects on life on the planet will be incalculable and much more serious than those that occurred in the past. We must tune out the noise created by zealots, self-interested moneyed interests, and political and religious ideologies. For once in the life of the human species, let us be careful and rational.
2. Climate catastrophe?
StSwithin 04/01/2010
An excellent article which presented a balanced view of the current situation. One fact, which is often ignored, is that sceptics like McIntyre actually believe that global warming is taking place. They just do not believe all the forecasts of tipping points and imminent catastrophe. One of the weaknesses of the IPCC stance is that they only present selected data. When you look at longer term data it is clear that claims such as "the rate of temperature rise is accelerating" are just not true. Temperature rose just as fast from 1910 to 1945 as they did at the end of the last century. For a balanced review of the data see: www.climatedata.info
3.
vespasian678 04/03/2010
---Quote (Originally by plotinus)--- Also, it is important to point out that it is not relevant that humans and other life forms survived even greater changes in climate in the past. Those changes almost always were very slow, occurring over many hundreds and thousands of years. There was time to adjust. The global warming which we are creating will, from the point of view of Earth history, occur in the blink of an eye. The effects on life on the planet will be incalculable and much more serious than those that occurred in the past. ---End Quote--- I am an archaeologist who works with Holocene climate records on a regular basis (part of our project involves the palaeoecology of our region). The statement above is incorrect. The Younger Dryas, for instance, saw abrupt changes of perhaps 5 degrees Celsius in the mid-latitudes and 10 degrees in high latitudes over the course of a few decades (at most; cf. http://www.ldeo.columbia.edu/res/pi/arch/examples.shtml). Mid-latitude precipitation also changed rapidly and dramatically, at least in Europe (contrary to popular belief, as temperatures warm it tends to get wetter, at least on a large scale - there may of course be regions of decreasing precipitation). Although I think energy policy should be managed as if global warming was imminent (more nuclear and other non-CO2 emitting generation, incentives for conservation, internalising the externality of CO2 emissions through taxation, etc. - call it the "Pascal's Wager" approach to AGW) It seems to me that the "skeptics" in this debate hardly have a monopoly on "zealots, self-interested moneyed interests, and political and religious ideologies".
4. An excellent article which presented a balanced view?
jensmacha 04/03/2010
Obviously,there are other opinions out there! First of all: Jones was rehabilitated. Secondly there seems to be a certain climate bashing around. I recommend: http://www.wissenslogs.de/wblogs/blog/klimalounge/medien-check/2010-04-01/klimaforscher-bashing-beim-spiegel http://blogs.ajc.com/kyle-wingfield/2010/04/02/climate-er-change-a-papers-sober-look-at-the-science/
5. CO2 GH effect is logarithmic, no linear
tomfp 04/03/2010
[quote=plotinus;108476]...if you pour carbon dioxide and other greenhouse gases into the atmosphere, the atmosphere _*must*_ warm up. False. The GH effect of CO2 is logarithmic, not linear. At some point, therefore, rises in concentration MUST cease to produce a significant rise in GH effect. Much reputable opinion holds that at present concentrations it is already at that stage. You can find a good discussion of this flaw in the "basic science" of AGW alarmism here: http://wattsupwiththat.com/2010/03/08/the-logarithmic-effect-of-carbon-dioxide/
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