http://www.giss.nasa.gov/research/briefs/gornitz_09/

The graph shows sea level rise of 120 meters over 18,000 years since the last ice age. The increase was not uniform, but had at least three meltwater pulses (MWP), and possible four, that led to rapid sea level rise.

The interesting point of this graph is that the rate of sea level rise has decreased dramatically in the past 5000 years, rising only 5 meters in that time. The rate of rise is only 1 mm per year.

The takeaway from the graph and accompanying text is that human influence was zero during that entire 23,000 year period, except for the past 150 years at the most. Yet, sea level rose rapidly at times, and held almost constant at times. The concept that humans have any impact at all on polar ice melting, and sea level rise, is ludicrous. Other forces are clearly at work, and their effects are overwhelming when compared to human activity.

Scroll down to Item 3, and click on the film reel icon next to Sea Level Rise Workshop.

http://www.cal-span.org/cgi-bin/archive.php?owner=CCC&date=2009-04-09

Envirofanaticism pursued by intellectual lightweights who remain politically powerful can easily bankrupt or starve billions to no good purpose.

For example, have your studies into the decrease in C13:C12 fraction considered the man-induced loss of billions of tons of naturally sequestered CO2 over the past century or two to soil erosion?

Have they considered the deleterious effect of an increased world price of corn, increased nitrogen pollution of river deltas, increased aldehyde pollution of urban air, increased fuel consumption following decreased mileage creating world recession and financial failure, of increased potable water use and exhausted aquifers, and decreased resources via failure of ethanol plant closures in the enviornmentally friendly pursuit of biofuels?

Your much.too.lame.to.read illiterati at RC are dangerous, not well intentioned and reasonable. Return to your ‘dog’s breakfast’.

Reread my post. I clearly did not say that we are facing “7 or so degrees rise in average global temperatures because of human produced CO2″.

I’m not sure about the latest models, but the IPCC’s AR4 report [beware that’s a big pdf file) concluded that climate scientists believe that if we let greenhouse gasses rise to 1000ppm (in CO2 equivalents) we would face somewhere between 3.5 and 8 degrees rise by the time the climate equilibrium was reached. I hope humanity isn’t that suicidal. They concluded that if we continue on a business as usual emissions scenario we are likely to get between 2.3 and 4.8ºC warming between 2000 and 2100 with 3ºC being the most likely.

Smokey:

“And as always, it must be kept in mind that the current sea level rise is the result of natural climate variability. The theory of natural climate variability has never been falsified. And unless natural climate variability is falsified, the AGW/CO2 hypothesis fails.”

Mate, a straw-man doesn’t compensate for a logically flawed statement. The climate is naturally variable. No one has ever disputed that. We are taking a variable system and forcing it toward a state it is very unlikely to have otherwise have reached and at a far faster rate than is otherwise plausible.

Gary Gulrud,

The various economic analyses I’ve seen suggest that reducing CO2 emissions significantly will have a modest affect on the growth rate of economies, and may even boost them. It’ll certainly be a lot cheaper than wars and unrestrained financial scullduggery. The costs (in both financial and human suffering terms) of adapting to the predicted consequences of our current emissions path are otherwise going to be unimaginably huge.

Fatuous nonsense. No one here cares, we’re overweighted with engineers with virtual or actual minors in math and physics. Only trolls provide links to RC and beg us to visit and mourn Gaia’s defilement.

Here’s a puzzle. If, as you suggest, the predicted warming can not possibly cause significant melting of our ice-caps. How is it that the ice-cap covering a very substantial portion of North America during the last ice age to a depth of several kilometres, melted away with a global increase in average temperature of just 7 or so degrees?

Are you suggesting that we are facing a further 7 or so degrees rise in average global temperatures because of human produced CO2? If so, over what time frame?

If not, what temperature rise are you suggesting will occur because of human produced CO2 and over what timeframe, and what sea-level rise will that cause? What other effects will it have? Please be explicit.

Further, what will it cost to mitigate those problems by reducing CO2 production? What probability do you place on the proposed mitigation actually doing anything usefull? What cost do you place on mitigating the problems using other approaches, like moving people?

I think some of the changes in the graph are the result of an error which was discovered last Summer in the processing algorithms for Jason-1 sea level when they were calibrating the new Jason-2 satellite.

This reduced Jason-1 ’s sea level trend from 3.3 mms per year to 2.4 mms per year and the old years were restated.”

Bill, the first recalculate graph appears in 2006, the next one in 2007.
So that can’t be what you mention.

I see no obvious differences in the 2008 and 2009 graphs, just 2 measurements in 2002 that have been retroactively corrected.
I’d love to see the corrected graph. If the trend goes down from 3.3 to 2.4 mm/year, that must might the sea level has been decreasing a bit.

Robin I can’t understand the data at all. It seems to be manipulated to achieve a desired effect. The starting point for 60 day smoothing has shifted from -14 in the ‘04 graph to -26 in the 2009 graph.This would give a consistent upward trend to the smoothing line.
However, the graph for 2006 seems totally inconsistent with the others. What is actually happening?”

Ian, the zero has been moved 3 times on the vertical axis.
2004 60-day smoothing starts at -14
2005 60-day smoothing starts at -14
2006 0 goes 12 units down, 60-day smoothing line starts at -2
2007 0 goes 30 units up, 60-day smoothing line starts at -32
2008 0 goes another 6 units down again, smoothing line starts at -26
2009-1 smoothing line starts at -26
2009-2 smoothing line starts at -26

But that doesn’t change the shape of the graph. As you can see when you compare graph 2004 and 2005 with graph 2008. Exactly the same graph with the zero in a different place.
Of course the 2008 graph is horizontally compressed to get more years in the same space, but it is easy to see that it is the same graph as 2004 and 2005.

Now compare graph 2008 with the 2 graphs of 2009.
The zero is in exactly the same place, the 60-day smoothing line starts in all graphs with -26, but the graphs themselves are very different.
And it’s not just some recalculation of the smoothing line, because the individual measures points that hover around the smoothing line are also in differently positions.
They have changed\corrected the measurements.
Why?!

And the weirdest thing: they had already done that in 2007. Compare the 2007 graph with 2009 and you’ll see that it’s identical.
Then why in 2008 did they go back to the 20004/5 graph?

Not to mention that the 2006 graph is different in shape from all the others.

I’m not sure how providing a photo of the Port Arthur historic sea level mark without any context helps you. But if others are interested, here is an explanation of its relevance. Remember it is a single location, and so can’t be considered a proxy for the entire ocean.

You first said that because the temperature in Antarctica is below 50ºF a few degrees warming can in no way affect the ice. Then, when I demonstrated that that is a misleading assertion, you said that temperature doesn’t affect glacier flow. Interesting theory; I suggest you do a little more reading on that.

Here’s a puzzle. If, as you suggest, the predicted warming can not possibly cause significant melting of our ice-caps. How is it that the ice-cap covering a very substantial portion of North America during the last ice age to a depth of several kilometres, melted away with a global increase in average temperature of just 7 or so degrees?

Here is an article from NASA that you may be interested to read Snowmelt In Antarctica Creeping Inland, Based On 20 Year Of NASA Data

I’m sorry if the RealClimate people hurt your feelings. I’ve observed that they welcomes skeptical posters, but get cranky if writers don’t make sense, try to misrepresent data, are abusive, use dodgy rhetorical tricks to advance their case, or refuse advance their understanding of the science. They do the same if folks who believe global warming is real try the same tactic. Scientists are very strict on people talking gobbldegook.

OK, I have to ask – what satellite measurement drift? As far as I know there is none, and it would not be linear. There is no drift in the position or timing (GPS based with RF link radiometric measurements used to provide independent tracking).

I would have to look at the payload designs again but there is no ‘drift’ in their performance.

Will check your link but that sounds like a lot of CU BS to me.

AJStrata

This reduced Jason-1 ‘s sea level trend from 3.3 mms per year to 2.4 mms per year and the old years were restated.

What is very interesting is that the Jason-2 calibrations were completed early in the Fall and operation of the satellite was turned over to JPL.

But, no data has been released from Jason-2 yet.

“I’m surprised than no one (especially those of you with a geology background) has raised this issue of subsidence here.”

Chuck you may have missed my post at (21:18:59).

More than just subsidence due to sediment loading, is isostatic adjustment of oceanic crust as it cools down. Cooler things are more dense, and as oceanic crust cools and moves away from the spreading axis, it cools down, becomes more dense and “sinks” lower in the mantle.

So we have some crust sinking due to sediment loading, other sinking because of isostasy, and some crust (continental) rising due to isostatic rebound that has been occurring since the glaciers melt.

The whole deal makes for an interesting mess when trying to measure rates of change with respect to sea level.