Hi C.Steele,

Three times ? No, not really: I asked about a two-inch rise in sixty years, and the data in Jayb's article seems to indicate a four-inch rise in a century from thermal expansion and ice-shelf melting, plus a two-inch rise from extra loss of fresh-water from rivers to the sea from human extraction and evaporation from crop-lands, etc.

So yes, a two-inch rise in sixty years from actual human-induced global warming. Okay, 2.4 inches.

Instead of models, from some mob in Sweden or somewhere, is there any chance of actually measuring sea-level rise as it is happening, or as it has happened over the last century or so - let's say, from all the measuring stations around Australia ? Taking land-rise into account along the east coast, and subduction of the Australian Plate under the Pacific Plate (and therefore apparent sea-level rise) in the Torres Strait ?

And what can we do about it ? Unless, that is, you are happy to sit back and whinge ? After all, it's not your fault, is it ? So it's not really your problem, it's ours ?

Cheers,

Joe

Dear Loudmouth,

Thank you, I'm happier with the correction/qualification, and well done with doing it so timely. There are others on this thread who could use some lessons.

You are right though, modelling can be fraught. You will note the study says;

"Together, unsustainable groundwater use, artificial reservoir water impoundment, climate-driven change in terrestrial water storage and the loss of water from closed basins have contributed a sea-level rise of 0.77mm (0.031 inches) per year between 1961 and 2003, about 42 percent of the observed sea-level rise,"

Yet surly impoundment should have a negative contribution to sea level rises.

“By reconstructing the history of water impoundment in the world's artificial reservoirs, we show that a total of approximately 10,800 cubic kilometers of water has been impounded on land to date, reducing the magnitude of global sea level (GSL) rise by -30.0 millimeters, at an average rate of -0.55 millimeters per year during the past half century.”
http://www.ncbi.nlm.nih.gov/pubmed/18339903

Well we could throw all those models away and look at the actual data.

http://en.wikipedia.org/wiki/File:Recent_Sea_Level_Rise.png

This graph taken from data from “the change in annually averaged sea level at 23 geologically stable tide gauge sites with long-term records as selected by Douglas (1997). The thick dark line is a three-year moving average of the instrumental records. This data indicates a sea level rise of ~18.5 cm from 1900-2000.”

You have yet to give me the level at which you would become uncomfortable.

Thank you, C.Steele - at last some data ! 18 cm sea-level rise in 100 years (seven inches), or 0.18-0.2 mm/yr, and - in the side-bar, a one-degree C temperature rise in the same time.

Yes, you make a good point about the empoundment of water in dams and wetlands, etc.

No, I'm not comfortable about any sea-level or temperature rise, but it depends on the amount on the one hand, and what governments can do about it on the other: horses for courses. It may sound a bit Pollyanna-ish, even Micawber-ish, but one degree - taking into account all other possible explanations, including urban-heat-island effects, sun-spots, etc., and seven inches' rise in sea-level - doesn't sound all that much in the first instance, and what governments can do, and what many are doing, gives me some cautious optimism that the problem can be contained, if not overcome.

I've knocked around Indigenous affairs for too long to be all that impressed any more about exaggerations in people's assertions: they tend to immediately make me wary, even turn me off. If your cause is just, if you are genuinely onto something, you don't need to exaggerate. I guess the 'glaciers all melting by 2035' hysteria is what did it for me, coupled with the fraudulent assertions about Bangla Desh being swamped, and the mountains of Fiji disappearing under the waves in a few short years.

On a more personal note, I do recall picking apricots in 46 degrees in about 1980. That was fun, huddling under the apricot trees, nobody getting out on the ladders: the apricots might be green on the outside, but they have boiled on the inside and are all ripe and mushy, useless for drying. I haven't experienced 46 degrees since. When I do, I'll take more notice :)

Cheers,

Joe

Dear Loudmouth,

I am glad to hear you are not comfortable with the rate of sea level rises of 1.8mm/yr over the last century though you did say “it depends on the amount”.

You should know the current rate is actually over 70% higher than that, or 3.1mm/yr, according to satellite data which in theory should remove the vertical movement of gauging sites impacting on the figures.
http://en.wikipedia.org/wiki/File:Global_Mean_Sea_Level.svg

You should also note it is reported that “for the globe as a whole, surface air temperatures over land have risen at about double the ocean rate after 1979 (more than 0.27°C per decade vs. 0.13°C per decade),”
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch3s3-es.html

Quite a few years ago I too had been wavering on the issue, especially given the hype from both sides. I forced myself to sit through over 20 one hour long MIT lectures plus other readings to get a better handle on the mechanics. Even then I was only scratching the surface.

I do have concerns at how often new figures seem to jump the traces so to speak. I am happy to have our government at least seeking to confront the issue even if it wasn't their preferred method.

Yes, C. Steele, as I wrote, " .... I'm not comfortable about any sea-level or temperature rise, but it depends on the amount on the one hand, and what governments can do about it on the other ...." That about wraps it up for me.

Hi Belly,

Two 'highest maximums' and two 'lowest minimums' today. That's how it goes, some days no maximums or minimums at all, other days we're tripping over them.

Maybe that variability is a sure sign of the instability arising from global warming ?

Cheers,

Joe

Dear Loudmouth,

Sorry to pester you on this but I am really curious about your response.

You initially flagged a 5cm per 60 years rate of sea level rise.

You said back then “Is that what we are supposed to be worried about ?”

I have shown the rate of sea level rise is currently well over triple that.

You have expressed I think discomfort over the rate of rises but I'm wondering at what figure might that translate into real concern?

If as you keep signalling 'it depends on the rate' would a figure of 5mm/yr be enough? Or 7? Or 10?

Or to put it another way if the Carbon Tax was the only tool available to us at what rate of sea level rise would you accept its deployment?