Guest post by David Archibald
Successful prediction of levels of solar activity suggests that prediction of other phenomena driven by solar activity might also be successful, and useful. Sea level rise is a concern of some people. President Obama said in June 2008 that his nomination in the Democratic primaries was “the moment when the rise of the oceans began to slow”.
The above graph shows the satellite data from the University of Colorado from late 1992. A change of trend is evident in 2004. Prior to that, sea level was rising at 4.2 mm/annum, and after 2004 at 1.5 mm/annum. 2003 was the recent peak in solar activity in terms of flares, F10.7 flux and proton flux. It is likely that the lower rate of rise post 2004 is due to lower subsequent solar activity.
The CSIRO compiled tide gauge data from 1870. The graph above shows that data with the subsequent satellite data plotted together.
The modern retreat of glaciers began in 1860. Initially sea level rose at 1.0 mm/annum. After 1930, it almost doubled to 1.9 mm/annum. This is a well-defined uptrend, now 80 years long.
Our prediction of a 2° C decline in temperature for the mid-latitudes over Solar Cycles 24 and 25 suggests that sea level will stop rising, and should start falling at some point prior to 2032.
The graph above combines the satellite data with the prior ten years of tide gauge data and shows the bounds of the long term rise at 1.9 mm/annum post 1030. Sea level could remain flat for another ten years before that trend in sea level rise is broken.
Leif Svalgaard,
My freezer is about 32F and is filled with ice. My floor is dry.
I open the door of my freezer and the ice starts to melt. My floor becomes wet.
I close the door of my freezer and the ice melt slows to a stop. My floor is still wet.
Does this help you understand??
Now, consider that the LIA was when the most ice was frozen “recently” and we have generally been on a warm trend since. We would need temps colder for a long time to return that water to the glaciers and ice sheets.
John A says:
December 1, 2010 at 12:25 am (Edit)
I think the correct Latin phrase is “post hoc ergo propter hoc”. And its a fallacy.
on top of that, he cherry picked the metric, cherry picked the index, and disregards other changes in rate.
CRF changes would affect the ionization of molecules in fluids (atmosphere, ocean, and magma). This would cause pressure changes and changes to velocity of some circulation patterns. Changes in magnetic field would affect the movement of polarized molecules.
kuhnkat says:
December 1, 2010 at 9:32 am
We would need temps colder for a long time to return that water to the glaciers and ice sheets.
Tell that to D.A. who advocates ‘solar change’ as the cause of the slope change in 2004.
Steven Mosher says:
December 1, 2010 at 9:37 am
on top of that, he cherry picked the metric, cherry picked the index, and disregards other changes in rate.
D.A. does this all the time, and he is hardly alone in such folly.
Lief, I believe our concern is the derivative, not the absolute level.
How does he support his assumption about temperatures during solar cycle 24 and 25…
Juraj V. says:
December 1, 2010 at 1:29 am
HelmutU says:
Read the article rather than making comments on things you know very little about. The article says 1mm/year from land sources such as land ice and stored water. It says nothing about thermal expansion of the oceans and doesn’t analyze that. Goddard is feeding you incorrect information and it HAS been exposed previously so there’s no need in perpetuating his error.
To David Archibald:
Its one thing to make an observation (and I contest that the observation means very much). It is quite another to suppose that the observation is caused by some other variable without a theory that would demonstrate cause and effect outside of the immediate dataset.
I don’t mind that people do this sort of thing on their own, because we all have conjectures that we would like to see proven. And this is not peerreviewedlitchurchur.
But I remain solidly unconvinced by a post hoc rationalization without theory – it remains for me a conjecture and can be ignored like many other conjectures.
It’s not as bad as Willis’ terrible grasp of greenhouse physics, however.
aaron says:
December 1, 2010 at 10:22 am
Lief, I believe our concern is the derivative, not the absolute level.
Figure 2 purports to show an ‘uptrend now 80 years long’. That is in the absolute level. Also shown is an ‘inflection point’. So what the graph shows [or alleges] that there is a discontinuous jump in the slope from 1.o to 1.9 mm/yr in 1930, not a progressive uptrend. This is the misleading aspect of the graph and the ‘discussion’ of it. So either D.A. is talking about the absolute level and there is an ‘uptrend’ or he is discussing the derivative and there is no 80-yr long trend, but a jump in 1930. Or he is just being inconsistent and sloppy or ‘political’ without having the ‘facts’ straight. I took the generous interpretation.
JS says:
December 1, 2010 at 5:34 am (Edit)
Don’t know where the setelites have ever measured 4mm/year sea rise but it certainly wasn’t at the seashore. E.g. see data from tidegauges around UK.
http://www.pol.ac.uk/ntslf/pdf/annual_reports/2008/2008report_gps.pdf
It’s 1mm/year. Looks like Albion is pretty safe from the Armagedon.
Ostensibly David has used the same data as I have. For the 1992-2003.7 decade my calc using the builtin linear regression function of open office calc shows 3.37mm/year. David’s graph shows a pasted on figure of 4mm. My calc for the 2003.7-2010 period is 2.17mm/year his pasted figure is 1.5mm/year.
I don’t know what is responsible for the discrepancies. I asked him if he used the No inverted Barometer non-seasonally adjusted dataset, but in his response to me he didn’t address this question. It shouldn’t matter much which of the four Colorado datasets is used, they shouldn’t show a 0.6mm/year discrepancy.
What I do know is that the forcing required to warm the ocean enough to cause the thermal expansion necessary, on top of the rise due to ice melt is around 4W/m^2. This is substantially more than the IPCC claim for the co2 forcing, and is likely due to diminished cloud cover as empirically measured by the ISCCP cloud project with the weather satellites.
Leif Svalgaard says:
December 1, 2010 at 7:04 am
Solar activity is now what it was 108 years ago. SC23 was much like SC13, yet ‘sea level’ now is at 125 mm and ~1900 it was -50 mm. doesn’t seem to have anything to do with solar activity.
The oceans can accumulate and lose solar energy on long timescales, as evidenced by much warmer deep ocean temperatures during the permian and triassic eras. The tide gauge graph David Archibald provides shows a decline in sea level from the 1800’s to ~1930 and a rise since.
The integration of sunspot number as values departing from the long term average sunspot number and approximate ocean equilibrium value also fall to ~1930 and rise afterwards. The sea surface temperature to and from ~1930 taken on longer term averages also shows the same signature. All three seem to be a reasonable proxy for ocean heat content.
I’ve covered the method in more detail here:
http://tallbloke.wordpress.com/2010/07/21/nailing-the-solar-activity-global-temperature-divergence-lie/
I know you don’t like it, but the evidence is getting stronger, and David’s tide gauge graph, if correct, lends further support to my hypothesis which I’m grateful to him for.
tallbloke
4W/m^2 ? How did you end up with that fantastic number? Sounds about 10 times too high.
tallbloke says:
December 1, 2010 at 12:40 pm
The tide gauge graph David Archibald provides shows a decline in sea level from the 1800′s to ~1930 and a rise since.
Again, because of David’s sloppiness, confusion is all over the map. The graph shows according to David, an increase of of sea level at a rate of 1.0 mm/yr, followed by an even bigger increase of 1.9 mm/yr from 1930 on. Regardless of the facts, apparently people see what they want…
lgl says:
December 1, 2010 at 12:45 pm (Edit)
tallbloke
4W/m^2 ? How did you end up with that fantastic number? Sounds about 10 times too high.
This is for 1993-2003 decade only, should have mentioned that.
I used IPCC figures for the ratio of melt to steric rise. Leif checked my calcs as far as getting the number of Joules added to the ocean heat content. I converted that to W/m^2 later. It’s always possible I messed that calc up, but I don’t think I did.
IPCC says the extra solar forcing from lowered cloud albedo was 2.5W/m^2, but they got to this by subtracting an inflated figure for the co2 forcing from the total.
The figures aren’t exact, but are in the ballpark.
tallbloke says:
December 1, 2010 at 1:05 pm
I used IPCC figures for the ratio of melt to steric rise. Leif checked my calcs as far as getting the number of Joules added to the ocean heat content. I converted that to W/m^2 later.
The heat content [Joules] is for the ocean column and cannot be converted to W/m^2.
The 1930 inflection point looks reasonable… the 2004 inflection point, eh, not so much. I mean, granted, it looks like an inflection point graphed on that scale. It seems to me, however, before declairing any significance to it, one would have to run throught the entire 1870-2010 graph looking for any and every roughly 15 year period that also shows an inflection point, since the 2004 inflection point is based on roughly 15 years of data. If one does this, then just roughly eyeballing it from the graph provided, it looks to me as if there are probably inflection points at roughly 1900, 1915, (1945?), 1955, 1970, 1985… add 1930 & 2004 in, and from just the eyeball vantage it looks like approx. 15 year regular cycles from inflection point to inflection point.
Then, for every inflection point found, one would have to see if there is any major solar change such as those being correlated to the 1930 and 2004 inflection points, and if the direction of solar change also matches the direction of rate changes for 1930 and 2004. If there isn’t…. well, it would certainly decrease the likelihood of the inflection points being related to, or at least primarily caused by, solar changes.
Tallbloke,
“What I do know is that the forcing required to warm the ocean enough to cause the thermal expansion necessary, on top of the rise due to ice melt is around 4W/m^2. ”
I don’t think this is correct. If the melt contribution was ~1.8 mm/yr (before 2003) and the total was ~3.3mm/yr, then about 1.5 mm/yr was due to thermal expansion. The global imbalance (all of the Earth’s area) needed to generate this much expansion is about 0.62 watt per square meter, not 4 watts per square meter, assuming you are warming up water that averages 15C (and assuming I have done my math right). The current rate of rise that is likely due to thermal expansion is much less… about 0.2 mm/year or less, so that makes the current global imbalance about 0.083 watt/M^2, once again assuming that you are warming water that averages 15C.
The complication is that expansion of deeper water (which is much colder) is less per watt added, so it is hard to place a solid number on the imbalance based on rise assigned to warming, unless you also know where the warming has taken place. But we do know that the current imbalance is quite low in any case.
Here’s the graph of tropical cloud cover vs temperature from the ISCCP data:
http://tallbloke.files.wordpress.com/2010/11/isccp-temp.jpg
I believe Roy Spencer had a ballpark figure for the solar forcing increase per 1% drop in cloud cover, but I can’t recall it. Anyone?
re post by: Leif Svalgaard says: December 1, 2010 at 7:04 am
I don’t think that logic quite works. With 108 intervening years of “not like SC13 & SC23” solar conditions, ocean levels kept creeping up – almost certainly including from causes that weren’t directly related to solar cycles. Once sea levels reached the pre-SC23 level, one can’t expect it to exhibit a massive step change taking it back to 1900 levels essentially overnight, even if solar levels are now roughly equivalent to those 108 years ago. That they have failed to exhibit a massive step change of that nature doesn’t negate an equivalent solar effect on ocean sea levels, it seems to me.
Leif Svalgaard says:
December 1, 2010 at 12:59 pm
tallbloke says:
December 1, 2010 at 12:40 pm
The tide gauge graph David Archibald provides shows a decline in sea level from the 1800′s to ~1930 and a rise since.
Again, because of David’s sloppiness, confusion is all over the map. The graph shows according to David, an increase of of sea level at a rate of 1.0 mm/yr, followed by an even bigger increase of 1.9 mm/yr from 1930 on. Regardless of the facts, apparently people see what they want…
Leif, apologies, my mind was racing ahead and my words were too elliptical. I’m considering the steric component of sea level rise, not the overll rise including melt. So I should have said a drop in the steric component to 1930, not a drop in the overall rise. Tricky to work out the relative magnitudes in pre-satellite era, so there is still some educated guesswork involved.
Finally, some facts on this issue:
“Cancun climate change summit: small island states in danger of ‘extinction’
Protect us from becoming an ‘endangered species’ say small island states as UN report shows devastation from sea level rise.”
http://www.telegraph.co.uk/earth/environment/climatechange/8170075/Cancun-climate-change-summit-small-island-states-in-danger-of-extinction.html
Note: this article was fully peer reviewed by this author’s peers, while on the beach at Cancun monitoring sea level rise.
Leif Svalgaard says:
December 1, 2010 at 1:08 pm
tallbloke says:
December 1, 2010 at 1:05 pm
I used IPCC figures for the ratio of melt to steric rise. Leif checked my calcs as far as getting the number of Joules added to the ocean heat content. I converted that to W/m^2 later.
The heat content [Joules] is for the ocean column and cannot be converted to W/m^2.
Nonetheless it’s not too difficult to work out what the additional W/m^2 forcing at the surface must have been to cause that many extra Joules to be in the ocean. So , not a direct conversion, but an equivalent.
Rational Debate says:
December 1, 2010 at 1:37 pm
I don’t think that logic quite works. With 108 intervening years of “not like SC13 & SC23″ solar conditions, ocean levels kept creeping up – almost certainly including from causes that weren’t directly related to solar cycles.
Solar activity was highest mid-20th century [solar cycle 19], so went up and then went down, not overnight. The solar magnetic field is often used as an indicator of solar irradiance. It is possible to measure that field using the Earth itself as the instrument. Our best reconstruction of the magnetic field [and hence solar activity in general] is perhaps shown in Figure 10 of http://www.leif.org/research/2009JA015069.pdf
In the 1830-70s solar activity was a high as in the latter half of the 20th century. There seems to little relationship between solar activity and sea level ‘change’.
tallbloke says:
December 1, 2010 at 2:07 pm
Leif, apologies, my mind was racing ahead and my words were too elliptical. I’m considering the steric component of sea level rise, not the overall rise including melt.
You were directly using David’s graph as mounting ‘evidence’…
tallbloke says:
December 1, 2010 at 2:10 pm
Nonetheless it’s not too difficult to work out what the additional W/m^2 forcing at the surface must have been to cause that many extra Joules to be in the ocean. So , not a direct conversion, but an equivalent.
That is very difficult as you don’t know what depth [perhaps not even constant] to use and what the circulation was doing and what the time scales are [and were]. Just too much guess work thrown around and taken as ‘evidence’.
Steve Fitzpatrick says:
December 1, 2010 at 1:15 pm (Edit)
Tallbloke,
“What I do know is that the forcing required to warm the ocean enough to cause the thermal expansion necessary, on top of the rise due to ice melt is around 4W/m^2. ”
I don’t think this is correct. If the melt contribution was ~1.8 mm/yr (before 2003) and the total was ~3.3mm/yr, then about 1.5 mm/yr was due to thermal expansion. The global imbalance (all of the Earth’s area) needed to generate this much expansion is about 0.62 watt per square meter, not 4 watts per square meter, assuming you are warming up water that averages 15C (and assuming I have done my math right). The current rate of rise that is likely due to thermal expansion is much less… about 0.2 mm/year or less, so that makes the current global imbalance about 0.083 watt/M^2, once again assuming that you are warming water that averages 15C.
The complication is that expansion of deeper water (which is much colder) is less per watt added, so it is hard to place a solid number on the imbalance based on rise assigned to warming, unless you also know where the warming has taken place. But we do know that the current imbalance is quite low in any case.
Hi Steve and thanks for this. Since both you and lgl think my figure is well out I’m going to find my notes and go through it again to see where I goofed.
The profile of the temperature falloff to the thermocline is well known, and pretty much linear below the well mixed layer. If i recall correctly (no guarantee-I was in a bad crash a few years ago) the figure I got to was 0.15C increase of the top 700 metres of ocean, giving a rise of 0.3C at the surface, which agreed well with the observed SST record. The Joules figure was in the region of 8×10^23J to heat the top 700m of the worlds oceans 0.15C. I’m trying to remember off the top of my head how I figured the W/m^2 equivalent and I’ll come back on this.
I’m really pleased others are interested in working on this stuff so thanks again.