Sea Level May Rise 40 Percent Higher

Prokomenos · 12-16-2006, 08:35 PM

Sea Level May Rise 40 Percent Higher Than Predicted, Study Says

December 14, 2006

Global warming could push sea levels about 40 percent higher than current models predict, according to a study that takes a new approach to the calculation.
Most sea level models predict changes based on what we know about how ice sheets melt and warmer waters expand

These models suggest that by 2100 sea level will be between 4 and 35 inches (9 and 88 centimeters) higher than it was in 1990.

But the physics of how ice sheets melt and how the oceans will expand in a warmer world is still poorly understood.

So Stefan Rahmstorf, an ocean physicist at Potsdam University in Germany, took a different approach: He used studied actual observations of changes in sea level collected in the 20th century to make predictions for the 21st century.
Current models don't jibe with actual sea level rise during recent decades, Rahmstorf says. So he crafted a formula based on a relationship between global temperature and sea level seen during the past hundred years.

"The more the temperature rises, the faster the sea level rises," he said.
In a paper published today in the online advance edition of the journal Science, Rahmstorf applied his formula to 21st-century warming scenarios from the Intergovernmental Panel on Climate Change (IPCC).
His results predict that by the end of the century sea level will rise between 20 and 55 inches (50 and 140 centimeters) above 1990 levels.

"We have much larger uncertainty than we previously thought about the sea level," Rahmstorf said.

Unforeseen Factors Rahmstorf added that the actual range of uncertainty is probably larger than his calculations suggest.

The IPCC numbers are based on an older assumption that the ice sheets over Greenland and Antarctica will melt by a steady amount over time.
Recent research suggests, however, that ice sheets are melting faster.

"If something dramatically new happens—something we haven't foreseen—then of course the whole approach [of using observations to make predictions] breaks down," Rhamstorf said.

"We may end up with more sea level rise."
Konrad Steffen is a professor of geography at the University of Colorado at Boulder who studies how melting ice sheets and glaciers contribute to sea level.

He said one wild card that could impact predictions is the so-called dynamic response of the ice sheets to warming. In the last five to eight years, he noted, the speed at which Greenland's glaciers move toward the sea has sped up dramatically.

Scientists think that meltwater, which pools up on the ice, funnels down to the glacier bed. There, the water acts as a lubricant, allowing the ice to slip seaward more quickly.

The process may last five or ten years, or it may last decades, Steffen said.
"We have hypotheses on what is happening, but we can't model it for the future," he said. "That is where [Rahmstorf] is correct."

High Water Risk
Study author Rahmstorf notes in Science that a sea level rise of 39 inches (1 meter) is plausible if the 20th-century relationship between temperature and sea level holds true in the 21st century.

That much sea level rise would expose major coastal cities such as London and New York to greater storm surges, threatening life and property.
Reducing greenhouse gas emissions can impact such sea level rise, he noted.
"By implementing effective climate policy," he said, "we can stay below the lower end of my range [around 20 inches, or 50 centimeters]."

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Hephaestion · 12-16-2006, 09:54 PM

We should all be very concerned about this.

Megale · 12-17-2006, 01:33 AM

This enviornmental talk has been going on for many years now. People should be concerned about the enviornmnet because it affects THEM and not the Earth. Concern of the Earth is self-rightous vlakies. The Earth will STILL be here and we won't, no matter how much we spoil the planet.

Ellinas · 12-17-2006, 06:09 AM

The air-conditioners are doing most of the damage right now regarding the ozone hole. The spray stuff are a myth. Take Greece as an example. The climate change since the use of the air-conditioners started is evident.

The situation is serious, however only time will show what will happen. Studies can't predict something securely.

Prokomenos · 12-17-2006, 07:28 AM

Quote:

Originally Posted by Ellinas
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The air-conditioners are doing most of the damage right now regarding the ozone hole. The spray stuff are a myth. Take Greece as an example. The climate change since the use of the air-conditioners started is evident.

The situation is serious, however only time will show what will happen. Studies can't predict something securely.

It cant but they can assume by conducting their tests and most of the time their tests are pretty close. I believe we will see dramatic changes in the next 30-50 years possibly. Thats what I keep seeing on the Science channels. Well the fact is even here in NY its the end of December and we have 50 degrees temperature which is definately not normal.

Megale · 12-17-2006, 10:21 AM

Wierd its around 50 degrees where I'm at too. But January and Feburary are the coldest months, so if its 50 degrees then, then I'll join everyone else in worry.

Prokomenos · 02-07-2007, 05:58 AM

This whole week its been in the teens and with the wind chills its like zero. This is the normal weather that we should of been having.

Megale · 02-07-2007, 07:48 AM

Quote:

Originally Posted by Prokomenos
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This whole week its been in the teens and with the wind chills its like zero. This is the normal weather that we should of been having.

The past week its been the "Ice Age." Winter has been slow coming but when it hits, its hit! I'm still not feeling the global warming thing.

Hellenika · 02-07-2007, 01:56 PM

I think the whole thing is ridiculous. I mean, it's not like we have records showing what the temperatures were going back to antiquity.

Didn't all this record keeping begin like 100 years ago? How can they make these conclusions on 100 some years worth of data for a planet that has been around for millions of years. People are acting as if the planet just came into existence.

Prokomenos · 02-07-2007, 02:04 PM

Quote:

Originally Posted by Hellenika
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I think the whole thing is ridiculous. I mean, it's not like we have records showing what the temperatures were going back to antiquity.

Didn't all this record keeping begin like 100 years ago? How can they make these conclusions on 100 some years worth of data for a planet that has been around for millions of years. People are acting as if the planet just came into existence.

I though it did? :err: