Paul Dennis

Thanks for the R^2.

I used the rate graph because it was handy. It saved me a lot of aggravation trying the derive rates from Jevryjeva et al on a tablet in Stansted airport.. Perhaps you would try deriving rates for the same periods yourself for comparison with those I used.

Latimer Alder asked for a hindcast, so that is what I tried. We had been discussing the relation between CO2 forcing and sea level and he wondered if my hypothesis could hindcast. Its taken me a couple of weeks to find the time.

Harold W

If you want raw data, go to NOAA or CSIRO. Try producing graphs yourself, probably the best way of testing its validity. Remember what I like to do. I am not duplicating the full analysis done by the professionals, I am trying to find simple ways to cross check that analysis.

I wanted to get away from temperature. It oversimplifies what is going on.

Regardless of temperature changes in sea level are driven by deviations from equilibrium. If there is a net input of energy a sea level rise would be expected (eg. early Holocene). If there is a net output, sea level should drop (eg late Eemian). At equilibrium there should be no change ( eg 1850)

This should apply whether you are in a hothouse Earth 5C warmer than today or a glacial period 5C cooler.

The problem is to quantify it, something I'll come back to.

My graph and the forcing data both show one oddity I keep encountering in climate data. There are three points above expectations around 2.0, 0.6 and another three below expectation around 0.5, 0.4.

Go back to the rate data and you see high rate of sea level rise with a low rate of sueface temperature rise in the early 1900s, 1940-1970 and the 2000s. High temperature rise and low sea level rise go together in 1910-1940 and 1970-2000.

Together they point to a 60 year cycle in which energy oscillates between going into the ocean bulk or staying at the surface. The same thing shows in temperature/year grabs for the period from 1880 to the present. I am becoming more convinced of its existance in the last 130 years, though not earlier.

The lowest point I calculated was 0.5, 0 from 1880. That is not where I derived the origin. For some time before 1870 there was a period with stable sea level and stable CO2. I regarded this as an equilibrium state, ie 0,0, and used that as my origin.

Martin A

Aren't you getting rather OCD about minor details? This is a social chat, not a formal paper.

Radical Rodent

Science is fun, and puzzles like sea level rise even more so. :-)

In science correlation is a signpost telling you where causation might be found if you look further. It is not certain, but often a good bet.

For an old man like Al Gore or myself a seafront property would be a short term investment, which we could afford to lose. I am surprised that sceptics are not busily buying them as investments, since you are the ones who think they are safe.

How about a deal? You invest in a seafront property for me to rent until my death. If I am right it will then soon becomes worthless but that won't matter to me since I'll be dead. If you are right it will still be there and you can sell it at a profit.

Martin A
Or done to wind you (and others with a scientific background which EM claims) up?

HaroldW

The graph came from here . Look at Figure 3. The sea level data came from Church and White 2006, the temperature data from GISS and the original graph was from Rahmsdorf 2006 (link available in the label under Figure 3).

Think of sea level and temperature as proxies for the oceans' total energy content. If that is constant, sea level with remain constant.

Changes in energy content change temperature/ocean volume/sea level, not the other way round. Thus the chain of causation is : Forcing(aka energy imbalance) changes system energy content, which changes temperature/ocean volume/sea level.

By looking at forcing I am trying to get at the original causes for change, rather than fiddling with proxies. I've been hoping for someone to make a proper energy based scientific case for the low sea level rise possibility. Perhaps you could point me towards something.

Radical Rodent

Why should either be a cause?

Birmingham has a Labour council, likely to fit extra street lights and tolerate homosexuals.

Harold W

Why are you assuming that we will follow RCP6.0? So far emissions have followed RCP8.5, with very little sign that the big producers are in any hurry to change.

HaroldW

From IPCC AR4

"Radiative forcing is a measure of the influence a factor has in altering the balance of incoming and outgoing energy in the Earth-atmosphere system"

As there seems to be life in the old dog yet, is anyone going to look at the important part? That the sea level rise is a 'threat to civilisation'.

It hardly matters if the predicted SLR is a foot or a metre if the consequences are trivial in both cases.

And I'm coming to the same conclusion about pH. If it were to change by 0.1 unit, would anything care? Or even notice?

HaroldW

I suspect we share a basic understanding of the warming process and are arguing over terminology.

I'm not ducking the point, but this is a whole new line of argument. There is a wide range of views on sea level rise.

At the optimistic end are Latimer Alder and yourself, who regard the current rate of rise as likely to continue, You expect 2-3ft and,curiously, so do IPCC. This is only a major problem if you are already close to sea level, like Miami Beach.

In the middle as those like Rahmsdorf who expect increased forcng and accelerating sea level rise to match. They are thinking in terms of1-2 metres. This give potential for more serious damage.

The third group regard simple extraolation as inadequate. There are potential tipping points which would change the dynamics of the system by rapidly increasing forcing.The four main ones are Siberian permafrost melt, Greenland ice sheet melt, West Antarctic ice sheet collapse an methane clathrate melting. The potential sea level rise is 10M+.

Latimer Alder

There is a tendency here to assume that I regard sea level rise alone as sufficient to destroy civilisation. This is clearly not the case. I do expect it to be a contributing factor.

Use of metaphor here usually gets me mobbed by yahoos, but consider this. If I fired a machine gun at you, and miss your vital areas, you will still bleed to death from multiple wounds. I expect our current civilisation to collapse into a collection of failed states under the combined effect of overpopulation, resource depletion and climate change, with sea level rise one factor among many.

As to effects, when Fukushima got wet it rendered 1200 square kilometres of Japan uninhabitable. We have nuclear power stations at Sizewell, Heysham and Dungerness vulnerable to a slow motion version of the same inundation. You do not move a nuclear power station as you would rebuild a house. At best, you lose a multi-billion pound investment.

@entropic

You can use as many metaphors as you like. Metaphor away!

But if you want anyone to care about your argument, they'd better be backed up with some real life examples of actual harms, rather than just vague Private Frazer-like warnings that 'were all doomed'.

And if you think back to those long-ago days when you proposed this debate...and before the stress caused your withdrawal, you might recall my remarks:

'A rise of 3 feet in a tsunami over a period of a minute or two would indeed be a disaster (though whether even such a disaster would be truly 'a threat to civilisation' is debatable) .

But SLR according to the predictions is exactly unlike the sudden and unheralded approach. It is a very very very gradual known and predictable encroachment. We know in general terms that its been going on since the Ice Age and it has been so gradual that for all practical purposes we've never really noticed.

And nowadays, with vastly improved monitoring capabilities, it is still difficult to look back over recent (last 100 year) history and find many practical examples where SLR has made much difference to anything. It's hard to find any places that have been inundated and made uninhabitable. The Maldives have been the poster child for such fears, but even they have so little actual fear of it happening that they are building a new airport for the purpose of importing more tourists...not for evacuating the existing population.

SLR will be such a gradual process that it will be 'no surprises'. A rise of three feet per century is the same depth as a single housebrick (4 inches) every 8 or so years. We have plenty of time to prepare and take action if the more alarmist predictions are seen to be coming true. Or to do less if they don't (as seems currently to be the case).'

Your highlighted example - Fukushima - was the result of an earthquake triggering a tsunami. It was not the result of very gradual, very predictable sea level rise. And even if were to lose (in some may decades time) the three nuclear stations you mention, it would be unfortunate and annoying.

But not a threat to civilisation. Your specific point fails.

EM Dec 30, 2014 at 7:33 PM says

If there is a net input of energy a sea level rise would be expected (eg. early Holocene). If there is a net output, sea level should drop (eg late Eemian). At equilibrium there should be no change ( eg 1850)

This statement required some conditions. Heat water from 0C to 4C and it will contract. Above that it expands but different rate. I have create a graph of raising the temperature of a 100 metre column of water by 0.1C. For instance, if the water is a 5C, a 0.1C rise will expand the column by 0.16mm. If 10C, by 0.88mm and 25C by 2.57mm.
The average temperature of the oceans is 3.9C. It is only if the water is heated near the surface outside of the polar regions that there will be expansion. So heat disappearing into deep oceans (Trenberth's missing heat), or being transported to the Arctic on currents (a more reasonable assumption for the decline in sea ice extent than warmer surface air temperatures) will not contribute to sea level rise. The patterns of ocean temperature changes are complex, so even with the most sophisticated models estimating sea level rises from thermal expansion are mostly guesswork.

Latimer Alder

You may remember that I started this thread for two purposes. One was to discuss sea level. The other was a challenge to you personally to demonstrate that you could function in a scientific debate.

I just went back over the debate and counted the number of pieces of scientific evidence you used in support of your side of the debate. The answer? NONE, not a single paper.

HaroldW has the right idea, using evidence to support his view as a scientist would.

Latimer Alder does not argue like a chemist, he argues like a politician. You are a charlatan, sir.