## Acceleration in rise of Global Mean Sea Level (Yi, Heki, Qian, from 2017)

Most impressive!

This is Figure 2 of S. Yi, K. Heki, A. Qian, “Acceleration in the global mean sea level rise: 2005-2015”, 2017, Geophysical Research Letters:

Of particular interest to me is their use of a Fan filter in order to, in the authors’ words, “restore the leakage of the land signals to the oceans”.

Yi, Heki, and Qian check on the closure of their fits:

and the robustness of their acceleration estimates:

See https://wordpress.com/view/667-per-cm.net/ Retired data scientist and statistician. Now working projects in quantitative ecology and, specifically, phenology of Bryophyta and technical methods for their study.
This entry was posted in anomaly detection, attribution, carbon dioxide, climate change, climate data, climate disruption, geophysics, global warming, ocean warming, oceanography, oceans, sea level rise. Bookmark the permalink.

### 21 Responses to Acceleration in rise of Global Mean Sea Level (Yi, Heki, Qian, from 2017)

1. Jan, I gave you kudos on your comment on ATTP but the moderator apparently felt I was “piling on” and eventually deleted it. This is it rescued from the RSS feed.

2. ecoquant says:

If all you do is cite your own work, it isn’t Science. You need a community of knowledgeable and mutually criticizing people to agree with you. Whether Science, or Mathematics, or Statistics, without community, there is no knowledge. That’s because there is no way, then, to tell if something is right or wrong.

Quoting,

This is primarily a technical blog. While friendly discussion and humor is welcome, positions and proclamations or arguments are expected to be accompanied by evidence or citations of evidence, whether as links or as figures or equations. \LaTeX is available. Authors of long derivations or similar contributions might want to consider using Overleaf/ShareLaTeX for their pieces.

In the end, I reserve the right to determine what’s appropriate here or not. This is my blog. I pay for it. There is no subsidy or advertising that helps pay for it.

3. ecoquant says:

Not 500, just 413.. There’s no carbon in N2O. The only significant CO2 production from breakdown products of other gases is from CH4 (methane). It’s currently at 1.86 ppmv, and when that CH4 oxidizes it’ll produce 1.86 ppmv CO2.

N2O is a centennial scale greenhouse gas with, arguably, a stronger GWP than CO2. Surely, CH4 is CO2 in waiting, even if it’s free in atmosphere.

No, the oceans won’t net outgas CO2 until levels are below about 300 ppmv. The thing is, all that CO2 we’ve added to the atmosphere has had a big effect on CO2 levels in the atmosphere, but only a very small effect on CO2 levels in the ocean. Per Henry’s Law the oceans will continue to absorb CO2 from the atmosphere until equilibrium is reached, which we are far, far above.

The Skeptical Science reference is not a reference. You are quoting yourself since that is where the link goes, and this is intellectually dishonest. Try again. Do it again and you’re banned. I won’t waste readers time or, worse, distract them from the actual science.

For residence time to be as short as 50 years means take-up rates of CO2 in oceans need to be fast, so equilibrium between oceans and atmosphere are achieved quickly. This also means that whatever the equilibrium level of CO2 in atmosphere is given a pulse of emissions, if it is drawn down, CO2 must necessarily come out of the oceans at the same rate, since it is symmetric. The only slowing that occurs is deep ocean CO2. Once CO2 gets into the deep oceans, then the time constant is very slow. This is why, whether you talk to Glen Peters, or Susan Solomon, or David Archer, or Ray Pierrehumbert, you’ll learn 50% of CO2 will come out of atrmosphere after cessation of emissions, but the other 50% takes a long time.

• daveburton says:

I wrote, “Many other scientists have also done that exercise, or something similar, and found approximately the same result.
Here’s a lengthy explanation:
https://skepticalscience.com/news.php?n=1851#132574
ecoquant replied, “The Skeptical Science reference is not a reference. You are quoting yourself since that is where the link goes”

Of course it is. That’s where I wrote the “lengthy explanation.” That’s why I linked to it.

ecoquant replied, “, and this is intellectually dishonest.”

You know perfectly well that there’s nothing “dishonest” about me linking to my own lengthy explanation, in answer to the question that you asked.

When you ask a question, and someone answers it for you, the correct response is, “thank you,” not “You’re dishonest.”

ecoquant replied, “Try again. Do it again and you’re banned.”

You’re welcome.

Fair warning: I often link to my own material, both on my web site and on other blogs.

I wrote, “The only significant CO2 production from breakdown products of other gases is from CH4 (methane). It’s currently at 1.86 ppmv, and when that CH4 oxidizes it’ll produce 1.86 ppmv CO2.”
ecoquant replied, “…CH4 is CO2 in waiting”'”

That’s what I said. Each 1 ppmv of CH4 eventually becomes 1 ppmv of CO2. (CH4 residence time is a little over a decade.)
(Note: that link goes to my own web site. If you think that’s “dishonest,” then go ahead and ban me from your site.)

ecoquant continued, “For residence time to be as short as 50 years means take-up rates of CO2 in oceans need to be fast,…”

Oceans and biosphere, not just oceans. It’s the “removal rate,” which, as I just explained in great detail, we know pretty closely.

ecoquant continued, “… so equilibrium between oceans and atmosphere are achieved quickly. This also means that whatever the equilibrium level of CO2 in atmosphere is given a pulse of emissions, if it is drawn down, CO2 must necessarily come out of the oceans at the same rate, since it is symmetric.”

Incorrect. As I told you, it is highly asymmetric. The oceans contain about 50 times as much CO2 as the atmosphere. So when CO2 is removed from the atmosphere by dissolution into the oceans, it is drawn down fast, but the CO2 concentration in the ocean is only slightly affected.

The rate of CO2 flow between ocean and atmosphere is proportional to the difference between actual atmospheric level and what it would be at equilibrium. Perhaps 1/4 of the CO2 we’ve emitted is now in the oceans, and 1/2 remains in the atmosphere. So, if the CO2 in the oceans were well-mixed, you can see that would mean we’ve added only enough CO2 to the oceans to raise the equilibrium atmospheric OO2 level by between 1 and 2 ppmv,

On the face of it that would seem to suggest that, at current temperatures, the oceans would not outgas CO2 until the atmospheric level dropped below 282 ppmv. But, even though currents and calcifying coccolithophores are constantly moving carbon from the surface waters to the depths, a disproportionate amount of the added CO2 is still in surface water, so it’s actually higher than that, though still probably below 300 ppmv. As CO2 levels drop, you’ll get CO2 from the soil and biosphere long before the oceans cease being net carbon sinks.
(Note: that link goes to material on my own web site, where you can find many references. If you think that’s “dishonest,” then go ahead and ban me from your site.)

ecoquant continued, “…you’ll learn 50% of CO2 will come out of atrmosphere after cessation of emissions, but the other 50% takes a long time.”

I guess it depends on what you mean by “long,” but unless you mean only a few decades, 10% is more like it, not 50%.

If CO2 emissions ceased today, atmospheric CO2 levels would be below 350 ppmv within 35 years, below 330 ppmv within 70 years, and below 320 ppmv within a century.

As CO2 levels fell, CO2 emissions from decaying organic matter would slow the decline, but a cooling climate would have the opposite effect, by increasing uptake of CO2 by the oceans.

4. ecoquant says:

Agreed on the equilibration with oceans. However, at present rates, we will not zero emissions before 2030, even possibly not before 2050, even possibly not before then (agriculture).

Also effective present amounts of CO2 in atmosphere is about 500 ppm if CO2 equivalents which haven’t broken down to CO2 yet are included, and things like N2O.

In the third place, the effective residence time (a/k/a “adjustment time”) for CO2 emitted to the atmosphere is only about fifty years.

Please provide citations for this to established literature. (See commenting guidelines.) In particular, I think you’ll find there’s a confusion here between equilibration time with oceans and soils and the idea that CO2 is expunged from the climate system.

Specifically, if some time later 100 units of CO2 are drawn out of atmosphere artificially, after equilibration (again, the 50 years), the net atmospheric drawdown will only be 40 units, because 30 units each will back out of soils and oceans, restoring equilibrium.

• daveburton says:

Oops, I accidentally turned an <a…> tag into an <s…> tag. Sorry about that! Trying again now; please just delete the botched comment.

ecoquant wrote, “…at present rates, we will not zero emissions before 2030, even possibly not before 2050, even possibly not before then (agriculture).”

We won’t see zero CO2 emission rates ever. But if CO2 emission rates fall by 50%, atmospheric CO2 levels will be falling.
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ecoquant wrote, “Also effective present amounts of CO2 in atmosphere is about 500 ppm if CO2 equivalents which haven’t broken down to CO2 yet are included, and things like N2O.”

Not 500, just 413.. There’s no carbon in N2O. The only significant CO2 production from breakdown products of other gases is from CH4 (methane). It’s currently at 1.86 ppmv, and when that CH4 oxidizes it’ll produce 1.86 ppmv CO2.

I wrote, “In the third place, the effective residence time (a/k/a “adjustment time”) for CO2 emitted to the atmosphere is only about fifty years.”
ecoquant replied, “Please provide citations for this to established literature. (See commenting guidelines.)”

It’s a pretty straightforward derivation.

It is trivially true that changes to the average atmospheric CO2 level must be equal to the difference between the processes which add to that level and the processes which subtract from it.

1 ppmv CO2 (molecular wt 44.01) has mass 8.053 Gt, of which 12/44-ths or 2.196 Gt is carbon. (Note: I have a hard time remembering such numbers, so I have a crib sheet of such conversion factors on my web site.) We have good economic data for the global production & use of fossil fuels, so we can trivially calculate anthropogenic emissions from those sources.

It is generally acknowledged that fossil fuels are the main source of anthropogenic CO2 emissions. So even if estimates of the other sources (concrete, land use changes, etc.) are badly botched, we still will be “in the ballpark” for our anthropogenic emissions estimates. Those emissions are currently estimated to be a little over 10 Gt carbon per year, equivalent to almost 5 ppmv CO2 per year.

The various processes which remove CO2 from the air (mainly terrestrial greening, and dissolution in seawater) have rates which are governed by many factors, but those factors are dominated by just one: the average atmospheric CO2 level. (Note that simple physics & chemistry cannot possibly govern the removal rate, because the most important factors are probably biological.)

Since we know how much atmospheric CO2 levels have risen each year, and we know how much anthropogenic CO2 has been added each year, it is straightforward to calculate the removal rate, at which those processes remove CO2 from the atmosphere.

As CO2 emission rates have increased, CO2 levels have also unsurprisingly increased, and as CO2 levels have risen, CO2 removal rates have also unsurprisingly risen. (As it happens, the CO2 removal rate has generally been fairly close to half the anthropogenic CO2 emission rate for quite a while, with the result that CO2 levels have increased only about half as fast as would have happened w/o the negative feedbacks that remove CO2 at an accelerating rate.)

Since we know that removal rates are governed primarily by CO2 level, and we know what CO2 levels have been, we can tabulate CO2 removal rates as a function of CO2 levels, based simply on that historical data.

If you do that exercise, you can trivially simulate what will happen to atmospheric CO2 levels if CO2 emissions are halved or zeroed, or anything in-between. I’ve done that exercise, and the result is a half-life of about 35 years, and a residence time of about fifty years.

Many other scientists have also done that exercise, or something similar, and found approximately the same result.

Here’s a lengthy explanation:
https://skepticalscience.com/news.php?n=1851#132574

ecoquant wrote, “In particular, I think you’ll find there’s a confusion here between equilibration time with oceans and soils and the idea that CO2 is expunged from the climate system.”

Carbon is never really “expunged from the climate system,” it is merely exchanged between the atmosphere and other carbon reservoirs, like the oceans, and the biosphere and soils. Note that the oceans are estimated to contain about fifty times as much CO2 as the atmosphere.

ecoquant wrote, Specifically, if some time later 100 units of CO2 are drawn out of atmosphere artificially, after equilibration (again, the 50 years), the net atmospheric drawdown will only be 40 units, because 30 units each will back out of soils and oceans, restoring equilibrium.”

No, the oceans won’t net outgas CO2 until levels are below about 300 ppmv. The thing is, all that CO2 we’ve added to the atmosphere has had a big effect on CO2 levels in the atmosphere, but only a very small effect on CO2 levels in the ocean. Per Henry’s Law the oceans will continue to absorb CO2 from the atmosphere until equilibrium is reached, which we are far, far above.

• ecoquant says:

## Caution to readers of the blog

There is much wrong about the claims made in the above comment. I recommend reading the existing scientific literature listed in my comment below to get correct scientific thinking, both from atmospheric-oceanic chemistry, and oceanography. I am retaining Mr Burton’s comments in place, but he will not appear here again.

I gave him a chance to discuss and present evidence, but he pontificated, and simply pointed at a stash of claims he has collected over the years, claims which are not supported by observational science, and which are not consistent with scientific thinking. Mr Burton is no Guy Callendar.

He did provide a rambling attempt to address the estimates of Yi, Heki, and Qian, but it contained dismissive comments regarding their use of standard satellite data sources, as well as criticisms of the sources themselves. I concluded that Mr Burton is not a serious student of the subject. I don’t know what his motives are, but those don’t really matter. He is basically an effort and time waster, and he kicks up a lot of confusing dust for people. I do not know, but his behavior is aligned with the kinds of Professional Obfuscators we now have evidence that people like the Koch Brothers pay. He might not be.

5. ecoquant says:

Oh, and I’ll comment about your specific points in the comment some time later. Right off, the expectation that sea level responds somehow instantaneously to increases in CO2 is, ahem, scientifically unsophisticated.

• daveburton says:

You must be a geologist. Only a geologist would call a ninety year delay “instantaneous.” 😉

• ecoquant says:

The cooling of the oceans takes 20,000 years, and only 50% of the CO2 in atmosphere is resolved after a thousand years. 90 years looks like chump change to me.

• daveburton says:

Well, in the first place, rates of snowfall, melting, and thermal expansion (the big three factors affecting sea-level) are affected almost immediately when temperatures change. There’s no thousand-year or 90-year delay.

It is the total, cumulative effect that takes thousands of years — and that assumes the anthropogenic spike in GHG levels continues for thousands of years, which is impossible, due to resource constraints, and negative feedbacks that are rapidly removing CO2 from the atmosphere. (AR5 estimates that those processes are running over half as fast as current anthropogenic emission rates, which means that if CO2 emissions were merely halved, atmospheric CO2 levels would be falling instead of rising.)

In the second place, deep ocean temperatures are scarcely affected by manmade global warming. There’s a natural “thermostat” operating which prevents heated surface water from staying warm when it sinks to the ocean depths.

Look at a map of the AMOC, and see that it mostly sinks in polar regions, which have variable sea ice coverage:

When the surface water is warmer, sea ice coverage is reduced, and evaporation rates increase, cooling the water.

The difference in heat transfer rates from ice-covered water and open water is huge, by the way. Based on Nimbus-5 observations, Zwally, et al. 1983 reported that:
“…the release of heat to the atmosphere from the open water is up to 100 times greater than the heat conducted through the ice.”

In the third place, the effective residence time (a/k/a “adjustment time”) for CO2 emitted to the atmosphere is only about fifty years. That’s about how long it would take for about 63% (1-(1/e)) of the anthropogenic increment to be removed. That makes the half-life (the time to remove the first half of the anthropogenic increment) about 35 years, not a thousand.

Those very long estimates you’ve seen (Archer, etc.) are based in integrating a very, very “long fat tail” in the decay curve. But that tail represents what happens when atmospheric CO2 levels are down near 300 ppmv, which everyone acknowledges is a harmless level. So the “long fat tail” is irrelevant.

It only matters how long it takes for CO2 levels to fall below about 350 ppmv, and for the purpose of that calculation the half-life is about 35 years, not 1000.

6. ecoquant says:

Well, you are welcome here. At least you argue with charts, graphs, and some semblance of data. Questionable manipulations, perhaps, but, still, these are welcome over mere words.

I would welcome your comments on the papers cited in the post, and, indeed, if this thread is going to go anywhere meaningful, I think it essential you read them and provide specific criticisms.

7. daveburton says:

Jan, you wrote on Tamino’s blog, “@daveburton,
In addition to responding to what Tamino will offer, scientifically speaking, you also need to respond in detail to the results of two additional and recent papers, …”

Jan, there’s no point asking me to respond there, because, after allowing the one comment which you can see, Tamino has now apparently decided to delete all my other comments there.

He’s deleted my last four comments there, including this short one to you, a short one to Jim Java, and long ones to Mike Roberts and bindidon.

When it comes to sea-level measurements, the gold standard is the best >100 year continuous coastal measurement records, from places like Honolulu, Wismar, and Maassluis (Rotterdam):

The satellite altimetry measurements are vastly inferior:

• ecoquant says:

@daveburton,

I’m afraid given my schedule this week, many of my comments are going to be piecemeal.

So, the trouble with tidal gauges is that to be meaningful, the glacial rebound and tectonic isostatic adjustment needs to be backed out of them. I don’t know — and you did not specify — why “Honolulu, Wismar, and Maassluis (Rotterdam)” are “gold standards”, particularly on this important aspect. People have managed to work with tide gauges, however, but it isn’t easy.

Also, there are many satellite measurements, not merely altimetry. There’s also mass which is provided by the GRACE series of satellites. Basically, if there is more water beneath you, the instantaneous gravitational tug will be bigger than if there is less. Accordingly, if the SLR is higher, and you know the distance from gravitational center of Earth of the seafloor, you can back out of the gravitational tug how tall the water column is.

The Yi, Heki, and Qian article cited above uses all these sources.

I think you need to address these potential pitfalls and be more quantitative when you make claims like some data source being “vastly inferior”. In fact, if you want to do science, if you criticize a data source, your job isn’t finished until you identify and explain specifically the experimental mechanism contributing to its deficiency.

• ecoquant says:

Oh, also, you really need to deemphasize time in your analysis:

• daveburton says:

Neither of those graphs have anything to do with sea-level.

I examined the relationship between CO2 and temperature here:
https://sealevel.info/sensitivity.html
There are a few people who dispute the fact that manmade CO2 emissions are responsible for the rise in CO2 levels. They’re wrong. This is the best demolition I know of that error:
http://www.ferdinand-engelbeen.be/klimaat/co2_origin.html

• ecoquant says:

Yes, you are right, they have nothing to do with sea level. My point was to suggest and illustrate a manner of data presentation. If you want to show the relationship between $X(t)$ and $Y(t)$, plotting these both against $t$ is not as as usual as plotting $X$ against $Y$. In the case of sea level, a lag needs to be removed as well, and you might want to plot $X(t + \delta)$ against $Y(t)$ with $t$ implicit for various values of $\delta$.

My interests on this blog tend to the methodological.

• ecoquant says: