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daveburton at 15:36 PM on 13 July 2023How big is the “carbon fertilization effect”?
Rob wrote elsewhere, "greening is now turning into 'browning.' ... fertilization [has now been] overwhelmed by other effects... In other words, the greening has now stopped," and here, "You were making the claim that natural sinks were removing more of our emissions, and that is not the case by any stretch of the imagination.""
Here's AR6 WG1 Table 5.1, which shows how natural CO2 removals are accelerating:
https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter_05.pdf#page=48Here it is with the relevant bits highlighted:
https://sealevel.info/AR6_WG1_Table_5.1.png
Or, more concisely:
https://sealevel.info/AR6_WG1_Table_5.1_annot1_partial_carbon_flux_comparison_760x398.png
(Note: 1 PgC = 0.46962 ppmv = 3.66419 Gt CO2.)As you can see, as atmospheric CO2 levels have risen, the natural CO2 removal rate has sharply accelerated. (That's a strong negative/stabilizing climate feedback.)
AR6 FAQ 5.1 also shows how both terrestrial and marine carbon sinks have accelerated, here:
https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter05.pdf#page=99Here's the key graph; I added the orange box, to highlight the (small) portion of the graph which supports your contention that, "greening is now turning into 'browning.' ... fertilization [has now been] overwhelmed by other effects... In other words, the greening has now stopped."
https://sealevel.info/AR6_FAQ_5p1_Fig_1b_final2.png
Here's the caption, explicitly saying that natural removal of carbon from the atmosphere is NOT weakening:
The authors did PREDICT a "decline" in the FUTURE, "if" emissions "continue to increase." But it hasn't happened yet.
What's more, the "decline" which they predicted was NOT for the rate of natural CO2 removals by greening and marine sinks, anyhow. Rather, if you read it carefully, you'll see that that hypothetical decline was predicted for the ratio of natural removals to emissions.
What's more, their prediction is conditional, depending on what happens with future emissions ("if CO2 emissions continue to increase").
Well, predictions are cheap. My prediction is that natural removals of CO2 from the atmosphere will continue to accelerate, for as long as CO2 levels rise.
The "fraction" which they predict might decline, someday, doesn't represent anything physical, anyhow. (It is one minus the equally unphysical "airborne fraction.") Our emission rate is currently about twice the natural removal rate, so if emissions were halved, the removal "fraction" would be 100%, and the atmospheric CO2 level would plateau. If emissions were cut by more than half then the removal "fraction" would be more than 100%, and the CO2 level would be falling.
I wrote elsewhere, "This recent study quantifies the effect for several major crops. Their results are toward the high end, but their qualitative conclusion is consistent with many, many other studies. They reported, "We consistently find a large CO2 fertilization effect: a 1 ppm increase in CO2 equates to a 0.4%, 0.6%, 1% yield increase for corn, soybeans, and wheat, respectively.""
If you recall that mankind has raised the average atmospheric CO2 level by 140 ppmv, you'll recognize that those crop yield improvements are enormous!
Rob replied, "If you actually read more than just the abstract of that study you find this on page 3: 'Complicating matters further, a decline in the global carbon fertilization effect over time has been documented, likely attributable to changes in nutrient and water availability (Wang et al. 2020).'"
Rob, I already addressed Wang et al (2020), but you might not have seen it, because the mods deemed it off-topic and deleted it. Here's what I wrote:
Rob, it's possible that your confusion on the greening/browning point was due to a widely publicized paper, with an unfortunately misleading title:
Wang et al (2020), "Recent global decline of CO2 fertilization effects on vegetation photosynthesis." Science, 11 Dec 2020, Vol 370, Issue 6522, pp. 1295-1300, doi:10.1126/science.abb7772
Many people were misled by it. You can be forgiven for thinking, based on that title, that greening due to CO2 fertilization had peaked, and is now declining.
But that's not what it meant. What it actually meant was that the rate at which plants remove CO2 from the atmosphere has continued to accelerate, but that its recent acceleration was less than expected. (You can't glean that fact from the abstract; would you like me to email you a copy of the paper?)
What's more, if you read the "Comment on" papers responding to Wang, you'll learn that even that conclusion was dubious:
Sang et al (2021), "Comment on 'Recent global decline of CO2 fertilization effects on vegetation photosynthesis'." Science 373, eabg4420. doi:10.1126/science.abg4420
Frankenberg et al (2021), "Comment on 'Recent global decline of CO2 fertilization effects on vegetation photosynthesis'." Science 373, eabg2947. doi:10.1126/science.abg2947
Agronomists have studied every important crop, and they all benefit from elevated CO2, and experiments show that the benefits continue to increase as CO2 levels rise to far above what we could ever hope to reach outdoors. Perhaps surprisingly, even the most important C4 crops, corn (maize) and sugarcane, benefit dramatically from additional CO2. C3 plants (including most crops, and all carbon-sequestering trees) benefit even more.
Rob also quoted the study saying, "While CO2 enrichment experiments have generated important insights into the physiological channels of the fertilization effect and its environmental interactions, they are limited in the extent to which they reflect real-world growing conditions in commercial farms across a large geographic scale."
That's a reference to the well-known fact that Free Air Carbon Enrichment (FACE) studies are less accurate than greenhouse and OTC (open top container) studies, because in FACE studies wind fluctuations unavoidably cause unnaturally rapid variations in CO2 levels. So FACE studies consistently underestimate the benefits of elevated CO2. Here's a paper about that:
Bunce, J.A. (2012). Responses of cotton and wheat photosynthesis and growth to cyclic variation in carbon dioxide concentration. Photosynthetica 50, 395–400. doi:10.1007/s11099-012-0041-7
The issue is also explained by Prof. George Hendrey, here:
"Plant responses to CO2 enrichment: Much of what is known about global ecosystem responses to future increases in atmospheric CO2 has been gained through Free-Air CO2 Enrichment (FACE) experiments of my design. All FACE experiments exhibit rapid variations in CO2 concentrations on the order of seconds to minutes. I have shown that long-term photosynthesis can be reduced as a consequence of this variability. Because of this, all FACE experiments tend to underestimate ecosystem net primary production (NPP) associated with a presumed increased concentration of CO2."
Rob wrote, "It does seem that you're claiming CO2 uptake falls with increasing temperature.""
That is correct for uptake by water. Or, rather, it would be correct, were it not for the fact that the small reduction in CO2 uptake due to the temperature dependence of Henry's Law is dwarfed by the large increase in CO2 uptake due to the increase in pCO2.
Rob wrote, "But it's unclear to me how you think this plays into the conclusion that CO2 levels would 'quickly normalize' over the course of 35 years" and also, "You also claimed CO2 concentrations would quickly come down (normalize) once we stop emitting it. This is also not correct unless you're using 'normalize' to mean 'stabilize at a new higher level'."
Perhaps you've confused me with someone else. I said nothing about CO2 levels "normalizing."
I did point out that the effective half-life for additional CO2 which we add to the atmosphere is only about 35 years. I wrote:
The commonly heard claim that "the change in CO2 concentration will persist for centuries and millennia to come" is based on the "long tail" of a hypothetical CO2 concentration decay curve, for a scenario in which anthropogenic CO2 emissions go to zero, CO2 level drops toward 300 ppmv, and carbon begins slowly migrating back out of the deep oceans and terrestrial biosphere into the atmosphere. It's true in the sense that if CO2 emissions were to cease, it would be millennia before the CO2 level would drop below 300 ppmv. But the first half-life for the modeled CO2 level decay curve is only about 35 years, corresponding to an e-folding "adjustment time" of about fifty years. That's the "effective atmospheric lifetime" of our current CO2 emissions.
Rob wrote, "Dave... The fundamental fact that you disputed is that oceans take up about half of our emissions."
That reflects two points of confusion, Rob.
In the first place, our emissions are currently around 11 PgC/year (per the GCP). The oceans remove CO2 from the atmosphere at a current rate of a little over 2.5 PgC/year. That's only about 1/4 of the rate of our emissions, not half.
More fundamentally, the oceans are not removing some fixed fraction of our emissions. None of the natural CO2 removal processes do. All of them remove CO2 from the bulk atmosphere, at rates which largely depend on the atmospheric CO2 concentration, not on our emission rate. If we halved our CO2 emission rate, natural CO2 removals would continue at their current rate.
Because human CO2 emissions are currently faster than natural CO2 removals, we've increased the atmospheric CO2 level by about 50% (140 ppmv), but we've increased the amount of carbon in the oceans by less than 0.5%, as you can see in AR5 WG1 Fig. 6-1.
Sorry, this got kind of long. I hope I addressed all your concerns.
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Rob Honeycutt at 11:23 AM on 13 July 2023How big is the “carbon fertilization effect”?
Dave... The fundamental fact that you disputed is that oceans take up about half of our emissions. It's a fact that has been clearly stated in the citations both of us have presented.
You also claimed CO2 concentrations would quickly come down (normalize) once we stop emitting it. This is also not correct unless you're using "normalize" to mean "stabilize at a new higher level". But they're not going to stabilize back to 300ppm.
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daveburton at 08:56 AM on 13 July 2023How big is the “carbon fertilization effect”?
Rob, in answer to your first question, Bob is correct: they use different units.
Both the graph and the "plug in suitable values" calculation (above) are for freshwater, but that hardly matters. CO2 is noticeably less soluble in saltwater, but the effect of temperature on CO2 solubility is nearly identical. Here's the same calculation with salinity 35 (typical seawater), for a 1° temperature increase (from 288K to 289K):
Bob is also correct that ocean chemistry is more complicated than that, in part because most of the dissolved CO2 immediately dissosiates into various ions. Here's a good resource on ocean chemistry:
http://www.molecularmodels.eu/cap11.pdfWhat's more, in the oceans, biology generally trumps chemistry, and that is certainly true for CO2 uptake. Some people think that the capacity of the oceans to take up CO2 is limited to surface water by ocean stratification. But that's incorrect, beause the "biological carbon pump" rapidly moves CO2 from surface waters into the ocean depths, in the form of "marine snow."
The higher CO2 levels go, the faster that "pump" works. Here's a paper about it:
https://www.science.org/doi/reader/10.1126/science.aaa8026Once carbon has migrated from the ocean surface to the depths, most of it remains sequestered for a very long time. Some of it settles on the ocean floor, but even dissolved carbon is sequestered for a long time. For instance, it is estimated that the AMOC takes about 1000 years to move carbon-rich water from high latitudes to the tropics, where it can reemerge. That is obviously far longer than the anthropogenic CO2 emission spike will last.
Due to the temperature dependence of Henry's Law, a 1°C increase in temperature slows CO2 uptake by the oceans by about 3%. That's a slight positive feedback: more CO2 in the air increases water temperatures, which slows ocean uptake of CO2. But it is very minor, because a 50% (140 ppmv) rise in atmospheric CO2 concentration accelerates CO2 uptake by the oceans by 50%, which obviously dwarfs 3%. That's the main reason that ocean uptake of CO2 continues to accelerate despite the temperature dependence of Hanry's Law.
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Rob Honeycutt at 04:47 AM on 13 July 2023How big is the “carbon fertilization effect”?
Dave... Going back to read what you previously wrote. (sigh)
You stated, "Some people point to that little orange box and say that greening has ceased."
No, I don't think anyone is pointing to your little orange box, nor are they using the original graph to make such a determination. This was a predicted result long before that graph existed. The determination of whether it's occurring is based on other observations related, I believe, primarily related to ongoing deforestation, changes in land use, etc.
You also stated, "This recent study quantifies the effect for several major crops. Their results are toward the high end...[etc]"
If you actually read more than just the abstract of that study you find this on page 3:
Complicating matters further, a decline in the global carbon fertilization effect over time has been documented, likely attributable to changes in nutrient and water availability (Wang et al. 2020). While CO2 enrichment experiments have generated important insights into the physiological channels of the fertilization effect and its environmental interactions, they are limited in the extent to which they reflect real-world growing conditions in commercial farms across a large geographic scale.
That directly confirms for you what I've been saying. (You really do need to read the full papers.)
It does seem that you're claiming CO2 uptake falls with increasing temperature. But it's unclear to me how you think this plays into the conclusion that CO2 levels would "quickly normalize" over the course of 35 years. Research tells us that's not the case.
Persistence of climate changes due to a range of greenhouse gases
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Bob Loblaw at 04:13 AM on 13 July 2023How big is the “carbon fertilization effect”?
Rob @ 16:
daveburton's graph is using different units from the Pro-ocean one - g/100g, rather than mole/kg-atm.
Before going down this Henry's Law rabbit hole, note that the uptake of CO2 in water is not solely related to the solubility of CO2 in water. The CO2 rapidly dissociates into ions that combine with the calcium carbonate present in sea water.
There is an excellent series here on ocean acidification:
OA Not OK part zero lists all the individual posts.
Part 15 mentions how solubility of CO2 depends on the presence of other ions.
...but there are many parts to the series. Each individual part is small, so going through them is worthwhile.
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Rob Honeycutt at 01:41 AM on 13 July 2023How big is the “carbon fertilization effect”?
Dave... Perhaps also think about what this chart represents. It's saying the solubility of CO2 falls as temperature increases. That means when temperature rises more CO2 remains in the atmosphere leading to more warming.
I believe this is the same effect that amplifies warming from orbital patterns to produce glacial-interglacial events.
If I'm correctly interpreting what you're claiming, it seems you're saying that warming oceans will take up more CO2, which would be inverse to the actual effect of CO2 solubility.
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Rob Honeycutt at 01:21 AM on 13 July 2023How big is the “carbon fertilization effect”?
Before we dig into your equation, can I ask why your Y-axis is an order of magnitude greater than the Pro-ocean graph?
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daveburton at 00:59 AM on 13 July 2023How big is the “carbon fertilization effect”?
I wrote elsewhere, "Due to the temperature dependence of Henry's Law, a 1°C increase in temperature slows CO2 uptake by the oceans by about 3%."
In reply, Rob asked, "Where do you come up with this 3% figure?"
From Weiss (1974), an approximate relationship is (as summarized by Pro-Oceanus):
The equilibrated ratio of partial pressure to dissolved concentration is governed by solubility:
pCO2 = Kₒ [CO2 (aq)]
where pCO2 is the partial pressure of CO2 in the gas phase, Kₒ is a solubility coefficient, and CO2 (aq) is the concentration of CO2 dissolved in the water.
The solubility of CO2 in water is a function of both the temperature and the salinity of the water, one relationship from Weiss (1974):
ln (Kₒ) = -60.2409 + 93.4517(100/T) + 23.3585(ln(T/100)) + S(0.023517-0.023656(T/100)+0.0047036(T/100)²)
where the solubility coefficient (Kₒ) has the units of mol kg⁻¹ atm⁻¹, temperature (T) is Kelvin, and salinity (S) is in parts per thousand (approximately equal to PSU).
Note that for non-saline waters, the second term of the equation becomes zero, leading to
ln (Kₒ) = -60.2409+93.4517(100/T)+23.3585 ln (T/100)
To get the "3%" figure, you can plug in suitable values, or you can look at a graph, like this one:
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daveburton at 22:26 PM on 12 July 2023Hansen predicted the West Side Highway would be underwater
One of the "BL"s here wrote, "[Major snip] Response: [BL] All of this is off-topic for this thread."
And that is why SkS is not on my list of recommended climate change blogs.
You left Rob Honeycutt's accusations, but deleted my response to them.
You left Bob Loblaw's speculation about my identity, but deleted my response.
If this is not the right thread for the replies to those comments, then how can it be the right thread for them to make those comments, BL?
Moderator Response:[BL] Moderation complaints snipped.
Please note that posting comments here at SkS is a privilege, not a right. This privilege can and will be rescinded if the posting individual continues to treat adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.
Moderating this site is a tiresome chore, particularly when commentators repeatedly submit offensive or off-topic posts. We really appreciate people's cooperation in abiding by the Comments Policy, which is largely responsible for the quality of this site.
Finally, please understand that moderation policies are not open for discussion. If you find yourself incapable of abiding by these common set of rules that everyone else observes, then a change of venues is in the offing.Please take the time to review the policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.
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daveburton at 21:53 PM on 12 July 2023Hansen predicted the West Side Highway would be underwater
Bob Ludlow wrote
[Contents snipped]
"You have no objective criteria to declare that The Battery and Honolulu are "the best" at representing anything other than local effects..."
The Battery has 1825 months of sea-level measurements. No other NOAA Atlantic site has that much. Only San Francisco has more, but it has only 1404 months of measurements since the 1906 earthquake. The downside to The Battery's measurement record is its high (atypical) rate of subsidence, which roughly doubles the local ("relative") sea-level trend there.
There are some European sites with longer, better Atlantic / North Sea / Baltic measurement records, and Australia has an excellent Pacific measurement record, but there are substantial delays getting data for those locations. My sealevel.info stie pulls data from NOAA frequently, so it's much more up-to-date.
Some of the European sites, have recorded a slight acceleration; it was most noticeable at Brest, which saw a 0.0 mm/year trend in the19th century, but a 1.6 mm/year trend since then, though there are substantial gaps in ther record.
Several German sites have particularly excellent measurement records; here's one of them:
In the Pacific, Honolulu has 1421 months (>118 years) of continuous sea-level measurements, without even a single missing month. Just as importantly, Honolulu is a near-ideal measurement site, near the middle of the world's largest ocean, on an "old" island with near-zero vertical land motion, small tides, and (unlike most places!) almost no seasonal cycle. What's more, its mid-Pacific location is near the pivot point of the east-west Pacific "teeter-totter," so it is little affected by ENSO "slosh." That is, El Niño and La Niña don’t affect sea-level there much at all. It really is a superb dataset.
Bob continued, "Just because they have long records does not mean that they accurately reflect regional or global trends."
That's true. As I've mentioned, NYC's sea-level trend is atypical, because of the high rate of subsidence there.
However, if subsidence / uplift are due to very long term processes, like PGR, there's reason to hope that they are fairly consistent over the duration of the measurement record. In that case, even if the linear trend is greatly affected by uplift or subsidence, the acceleration won't be. (Of course, that doesn't work in places, like Manila, where changing local factors, like groundwater pumping, cause varying subsidence.)So it should not surprise you that, even though The Battery and Honolulu have seen quite different linear trends over the last century, the measured acceleration in both places is very similar (negligible).
Bob wrote, "You are clearly picking locations to try to tell the story you want to tell."
That's a false accusation. You just find the data surprising, so you make baseless accusations, without evidence. That is not conducive to constructive dialogue, nor to learning.
If you think I chose unrepresentative sites, or sites with inferior quality measurement data, then YOU tell me what sites YOU think are better, and why.
Bob wrote, "As for your quadratic fits: it has been pointed out to you over the past 10 years that quadratic fits mean nothing when the underlying data does not resemble a quadratic relationship."
Nobody competent makes that claim in the context of sea-level analysis.
If there were a step-change in some climate system input, then you could look for a step-acceleration as a consequence. But there's been nothing like that. The radiative forcing trend from CO2 has been very gradual, and strikingly linear (just barely more than linear) for the last forty years. It's been quite gradual for much longer than that.
Quadratic regression is the cannonical way of detecting gradual acceleration. It's how Church & White did it, and how every competent sea-level analyst since then has done it. When Hogarth reported that, "sea level acceleration from extended tide gauge data converges on 0.01 mm/yr²," that's what he was talking about.
Moderator Response:[BL} I see that reading comprehension is not one of your strong points.
Assuming that "Bob Ludlow" is supposed to mean "Bob Loblaw", you will also note that I said:
This discussion is also getting off topic for this rebuttal of Hansen's statement. If you want to continue to discuss sea level, there are better places here at SkS. Here are two SkS posts that provide some of the material from Tamino that I referred to earlier.
The next off-topic post be be deleted in its entirety.
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bobhisey at 21:30 PM on 12 July 2023CO2 effect is saturated
My arguement is not against global warming, but in falsely ascribing it to CO2.
A full discussion can be seen in "Carbon Dioxide - Not Guilty" on kindle for 99c.
Moderator Response:[BL] repetition of previous points made on other threads snipped.
You have been down this road before, (here, and here) and you have been warned before.
Please note that posting comments here at SkS is a privilege, not a right. This privilege can be rescinded if the posting individual treats adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.
Please take the time to review the policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.
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Philippe Chantreau at 08:02 AM on 12 July 2023Hansen predicted the West Side Highway would be underwater
I have had many other things to do, certainly more important. I have a full time job and a life. I will respond in time. Perusing through the references presented, I was not very impressed.
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Doug Bostrom at 06:41 AM on 12 July 2023Skeptical Science New Research for Week #27 2023
Apologies for belated reply regarding the above item. This could be due to a local software fault or a transient problem with Unpaywall. As with "my bank statement balance is wrong," probably the former.
Open access articles are identified via API calls to Unpaywall; likely we have local problem with interpreting UP's response. A clue is that the "open access" link for this paper doesn't have a url behind it, meaning that UP did not supply such because it doesn't exist.
Thank you for the heads up and triggering debugging. :-)
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One Planet Only Forever at 06:19 AM on 12 July 20237 TV meteorologists discuss their coverage of climate change and weather
An update regarding a couple of the passionate helpful meteorologists covered in this article:
- Eric Sorenson won his 2022 run to be a House of Congress representative for Illinois. (Eric Sorenson's Congress.gov webpage)
- Chris Gloninger has quit his TV job due to the threats he received. But he has moved to a potentially more 'annoying to the science denial troop' role with Woods Hole Group. (USA Today "An Iowa meteorologist's climate change coverage led to a death threat. He's now resigning.")
Nasty 'learning resistant people' will always be around. But it is very important, and very challenging, to keep on disappointing them no matter how angry they get ... as long as others are also being communicated to and can see how harmfully incorrect the 'learning resistant people', and their preferred type of leaders, are.
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Rob Honeycutt at 11:17 AM on 11 July 2023How big is the “carbon fertilization effect”?
Dave... Your reference to the inset on FAQ 5.1 is comical at best.
It states exactly what I'm telling you, as did the other bits I posted.
FAQ 5.1: Is natural removal of carbon
from the atmosphere weakening?
No, natural carbon sinks have taken up a near constant fraction of our carbon dioxide (CO2) emissions over the last six decades.You were making the claim that natural sinks were removing more of our emissions, and that is not the case by any stretch of the imagination. And the caption you posted goes on to say...
However, this fraction is expected to decline in the future if CO2 emissions continue to increase.
How can you not understand this? Take note that AR6, though it's the most current IPCC report, came out nearly two years ago, and the report is relying on data and research that was completed well before even that.
The most recent papers are saying that, yes, that CO2 fertilization effect is now waning.
Tropical Forests’ Carbon Sink Is Rapidly Weakening – Crucial for Stabilizing Earth’s Climate
Once again, in your own citation the language is clear.
FAQ 5.1 | Is the Natural Removal of Carbon From the Atmosphere Weakening?
For decades, about half of the carbon dioxide (CO2) that human activities have emitted to the atmosphere has been taken up by natural carbon sinks in vegetation, soils and oceans. These natural sinks of CO2 have thus roughly halved the rate at which atmospheric CO2 concentrations have increased, and therefore slowed down global warming. However, observations show that the processes underlying this uptake are beginning to respond to increasing CO2 in the atmosphere and climate change in a way that will weaken nature’s capacity to take up CO2 in the future. Understanding of the magnitude of this change is essential for projecting how the climate system will respond to future emissions and emissions reduction efforts.The "observations show" means they are already seeing this happening, and that is based on research that's at least half a decade old.
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Rob Honeycutt at 10:50 AM on 11 July 2023Hansen predicted the West Side Highway would be underwater
Dave... Some abbreviate response is posted on THIS thread. Please go there if you wish to further discuss CO2 fertilization.
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daveburton at 06:58 AM on 11 July 2023Hansen predicted the West Side Highway would be underwater
Philippe Chantreau wrote, "I will respond to Dave Burton on the CO2 fertilization thread on the part of this latest post regarding that subject."
Will you please provide a link to your comment to me, Philippe?
[Major snip]
Rob Honeycutt wrote, "1) That is not an image that appears in AR6, not with the added orange box. Thus you're co-opting their work to infer conclusions they do not make."
That's incorrect.
Since we're onto the next page of comments now, here's the image again:
https://sealevel.info/AR6_FAQ_5p1_Fig_1b_final2.pngIf you enlarge it you can see, in fine print, the URL that will take you to where you can find it in chapter 5 of AR6:
https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter05.pdf#page=99I added the orange box to highlight the (small) part of the image which supports your contention that, "greening is now turning into 'browning.' ... fertilization [has now been] overwhelmed by other effects... In other words, the greening has now stopped."
AR6 directly contradicts your contention, Rob. In fact, it does so in the caption on that very figure:
They could not have been clearer in stating that natural removal of carbon from the atmosphere is NOT weakening.
The authors did PREDICT a "decline" in the FUTURE, "if" emissions "continue to increase." But that hasn't happened yet, and the "decline" which they predicted was NOT for the rate of natural CO2 removals by greening and marine sinks, anyhow. Rather, that hypothetical decline was predicted for the ratio of natural removals to emissions, and their prediction is conditional, depending on what happens with future emissions ("if CO2 emissions continue to increase").
Well, predictions are cheap. My prediction is that natural removals of CO2 from the atmosphere will continue to accelerate, for as long as CO2 levels rise.
The "fraction" which they predict might decline, someday, doesn't represent anything physical, anyhow. (It is one minus the equally unphysical "airborne fraction.") Our emission rate is currently about twice the natural removal rate, so if emissions were halved, the removal "fraction" would be 100%, and the atmospheric CO2 level would plateau. If emissions were cut by more than half then the removal "fraction" would be more than 100%, and the CO2 level would be falling.
Rob, it's possible that your confusion on the greening/browning point was due to a widely publicized paper, with an unfortunately misleading title:
Wang et al (2020), "Recent global decline of CO2 fertilization effects on vegetation photosynthesis." Science, 11 Dec 2020, Vol 370, Issue 6522, pp. 1295-1300, doi:10.1126/science.abb7772
Many people were misled by it. You can be forgiven for thinking, based on that title, that greening due to CO2 fertilization had peaked, and is now declining.
But that's not what it meant. What it actually meant was that the rate at which plants remove CO2 from the atmosphere has continued to accelerate, but that its recent acceleration was less than expected. (You can't glean that fact from the abstract; would you like me to email you a copy of the paper?)
What's more, if you read the "Comment on" papers responding to Wang, you'll learn that even that conclusion was very dubious:
Sang et al (2021), "Comment on 'Recent global decline of CO2 fertilization effects on vegetation photosynthesis'." Science 373, eabg4420. doi:10.1126/science.abg4420
Frankenberg et al (2021), "Comment on 'Recent global decline of CO2 fertilization effects on vegetation photosynthesis'." Science 373, eabg2947. doi:10.1126/science.abg2947
Agronomists have studied every important crop, and they all benefit from elevated CO2, and experiments show that the benefits continue to increase as CO2 levels rise to far above what we could ever hope to reach outdoors. Perhaps surprisingly, even the most important C4 crops, corn (maize) and sugarcane, benefit dramatically from additional CO2. C3 plants (including most crops, and all carbon-sequestering trees) benefit even more.
Bob Loblaw wrote, "...I have no way of knowing whether our daveburton is the same Dave Burton seen in the discussions at Tamino's... The other Dave Burton's name shows up quite a few times, although he does not comment."
Yes, I'm the Dave Burton who Tamino intermittently criticizes. Unfortunately, when I try to comment on his blog, he nearly always deletes my comments, so I stopped trying. Suffice to say, if you like being misled, you should enjoy his blog. (Example.)
Moderator Response:[BL] All of this is off-topic for this thread.
Use the search function to find appropriate threads. You have already been pointed to several options.
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BaerbelW at 17:47 PM on 9 July 2023There's no empirical evidence
Please note: the basic version of this rebuttal has been updated on July 9, 2023 and now includes an "at a glance“ section at the top. To learn more about these updates and how you can help with evaluating their effectiveness, please check out the accompanying blog post @ https://sks.to/at-a-glance
Thanks - the Skeptical Science Team.
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Bob Loblaw at 05:54 AM on 8 July 2023Skeptical Science New Research for Week #27 2023
I get only "Access through your institution" and "Buy or subscribe" options, too.
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wilddouglascounty at 22:59 PM on 7 July 2023Skeptical Science New Research for Week #27 2023
Thanks for this ongoing treasure-trove of information sources: I'm amazed that you can maintain this! I just scratch the surface of your list, but noticed that one article:
Expanding range and role change, Armarego-Marriott, Nature Climate Change 10.1038/s41558-023-01675-8
...is listed as Open Access, but when I open the link, it's not. Thought you might want to correct the designation.
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Bob Loblaw at 22:34 PM on 7 July 2023Hansen predicted the West Side Highway would be underwater
daveburton @ 29:
You seem to be under some serious delusions as to what the words "best", and "accurate" really mean.
You have no objective criteria to declare that The Battery and Honolulu are "the best" at representing anything other than local effects. Just because they have long records does not mean that they accurately reflect regional or global trends. You also state:
Beware of "global" sea-level analyses which use varying mixes of measurement locations. As you can see from the striking difference between Oahu and New York, sea-level trends vary considerably from one location to another.
So, you admit that single locations do not provide global trends - yet you seem to be arguing that the "best" way to get global trends is to ignore most of the other data.
You are clearly picking locations to try to tell the story you want to tell. That is not "accurate".
As for your quadratic fits: it has been pointed out to you over the past 10 years that quadratic fits mean nothing when the underlying data does not resemble a quadratic relationship. It does not matter if you "accurately" calculated the quadratic fit when the underlying physics says "not quadratic".
This discussion is also getting off topic for this rebuttal of Hansen's statement. If you want to continue to discuss sea level, there are better places here at SkS. Here are two SkS posts that provide some of the material from Tamino that I referred to earlier.
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michael sweet at 21:19 PM on 7 July 2023Hansen predicted the West Side Highway would be underwater
DaveBurton:
You are wastiing our time here with your obvious, deliberately incorrect graphs. I note that Tamino specifically addressed your deliberate mistakes as long as a decade ago. You have been wrong for over a decade and you are not informed enough to realize it. You have no excuse for your false claims. Neutral observers wonder why you persist in your obviously false claims for so long.
No-one here will give your garbage a second consideration. You will not convince anyone with your absurd claims. You need to go back to WUWT where they do not care about being lied to.
Every scientist who studiies sea level rise states that sea level rise has accelerated substantially. When you are alone claiming something and everyone who studies the topic professionally states that you are wrong you need to realize that you are not Galileo, you are simply wrong. Look at the pictures of fish in the streets all over the world.
You should go away. You contaminate a scientific site with pretend analysis.
Moderator Response:[BL] Please tone down the accusations a bit.
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Rob Honeycutt at 11:11 AM on 7 July 2023Hansen predicted the West Side Highway would be underwater
Dave @29... Here you're playing the classic science denier game of cherry picking facts that support the conclusion you prefer. Your graphs are technically correct but intentionally misleading because you're using them outside of the full context of the issue at hand.
If, on the absurd chance, you actually believe what you're presenting is compelling evidence then it is encumbent upon you to publish your findings in a legitimate science journal and convince a panel of experts that your findings are significant.
Given you've been doing this for something over a decade now I would have expected your position to become more substantive and nuanced. But it's not. You're regurgitating the same junk you've been posting all over the internet this entire time.
This leads me to believe you're not genuinely interested in facts or science. You're merely promoting an ideological position and you think this is an interesting way to do that.
Once again, this is not ad hom. Lots of people do exactly what you're doing and they (and you) have every right to do so. All any of us are doing is pointing out how weak your position is.
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Eclectic at 09:10 AM on 7 July 2023Hansen predicted the West Side Highway would be underwater
Indeed, Daveburton, the sea level is a complex subject. I applaud the detailed work you have done on some aspects of it.
Nevertheless, Dave, you have taken a relatively short-term look at some trees ~ while entirely failing to look at the forest. And failing to take a commonsense look at the underlying physics : the causes of long-term changes.
I am fairly sure you are not the Flat-Earth Scientist who completely discounts the role of CO2 in climate & consequent sea level changes (despite you consciously /subconsciously "trailing your coat" at the start of post #29 ).
My worry (for you) is that you have been "captured" by Motivated Reasoning . . . and that for a number of years now, you have not climbed out of the rabbit-hole.
So . . . good luck for self-examining your inner emotions & motivations. A scientific thinker must rise above his inner bias.
As OnePlanet says, it is the half-truths which are the danger [to one's own self, especially].
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daveburton at 07:21 AM on 7 July 2023Hansen predicted the West Side Highway would be underwater
Michael wrote, "the last time Carbon dioxide was over 400 ppm the sea level was more than 20 meters higher than current sea level."
Yes, many things were different 4.5 million years ago. They weren't all caused by CO2.
For example, the highest-quality Pacific sea-level measurement record is from Honolulu, on Oahu. But it would be difficult to say anything meaningful about how sea-level there has changed since CO2 levels were last this high, because Oahu (and the Big Island) didn't exist 4 million years ago!
Michael wrote, "Your sea level graphs are obviously flawed."I guarantee that they are not flawed.
They are accurate plots of sea-level measurements at those two sites, which are the best long NOAA Atlantic sea-level measurement record (The Battery, NYC), and the best long NOAA Pacific sea-level measurement record (Honolulu, HI). The linear and quadratic regressions are accurately calculated from the most recent 100 years of data at each site, shown with deep blue traces. Earlier data (not included in the regressions) is shown in light blue.
If you click the links, you can adjust the measurement periods over which the regressions are calculated, and see the effect of those adjustments. You can also smooth the plots, and choose whether to plot linear and/or quadratic fits, as well as confidence and/or prediction intervals. At the top of each graph you'll also find links to the corresponding NOAA and PSMSL web pages for those sites. You can also do the same analyses for other NOAA measurement sites, and for over 1000 sites with data available from PSMSL (though the PSMSL data aren't as up-to-date as the NOAA data).
Michael wrote, "you have cherry picked two single locations to do your calculations without justifying your choice."They aren't "cherry-picked," I told you why I chose them: they are "the best long U.S. Atlantic and Pacific sea-level measurement records, respectively."
The analysis period of 100 years is arbitrary, of course, but if you click the links which I provided you can easily change it:
https://sealevel.info/MSL_graph.php?id=Battery&c_date=1923/6-2023/5
https://sealevel.info/MSL_graph.php?id=Honolulu&c_date=1923/6-2023/5I also reported the conclusion of a comprehensive study: "Hogarth studied many long measurement records, and concluded, 'Sea level acceleration from extended tide gauge data converges on 0.01 mm/yr²'" (That's negligible, BTW.)
Beware of "global" sea-level analyses which use varying mixes of measurement locations. As you can see from the striking difference between Oahu and New York, sea-level trends vary considerably from one location to another. So if you use a different mix of measurement locations for the left and right ends of a plot, you can easily create the illusion of a sharp acceleration or deceleration which is not evident in the individual measurement records.
Also, beware of the fact that there are also regional effects, in some places. For example, ENSO causes changes in low-latitude easterly Pacific trade winds. During El Niños easterly Pacific equatorial trade winds diminish, so the Pacific ocean sloshes east, raising sea-level in the eastern Pacific, and lowering it in the western Pacific. This is very striking when you compare the sea-level measurement records of Kwajalein (in the western Pacific) and San Diego (in the eastern Pacific). They are almost perfect mirror images!
https://sealevel.info/1820000_Kwajalein_San_Diego_2016-04_vs_ENSO_annot4.png
(One of the nice things about Honolulu is that it is near the ENSO "teeter-totter pivot point," so, unlike other long Pacific sea-level measurement records, Honolulu's is scarcely affected by ENSO.)
Another example of regional effects is the southeastern United States, where Gulf Stream variations are apparently the cause of well-known multi-decadal fluctuations in sea-level trends. For a discussion see Zervas (2009), NOAA Technical Report NOS CO-OPS 053, Sea Level Variations of the United States, 1854-2006. Here's a relevant excerpt:
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One Planet Only Forever at 01:16 AM on 7 July 2023Hansen predicted the West Side Highway would be underwater
Eclectic @26,
Indeed it can be hoped that people will turn over a new leaf if they developed a liking for and acted on a "...ratio of disinformation to information...".
it is important to appreciate that it is unacceptable for any presentation of misunderstanding to be paired with a lack evidence of a passion to learn to be corrected and evidence of significant interest and effort to limit and repair damage done by the incorrect belief and sharing of the misunderstanding.
Note that the seed for effective disinformation is a kernel of truth. No matter how much truth is part of a presentation of disinformation (a deliberate creation and sharing of misunderstanding) the presentation is still 'harmful disinformation'.
PR and marketing experts are well aware of the knowledge that "The Whole Truth and Nothing but the Truth" has a significant disadvantage in competitions for popularity or profit.
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Bob Loblaw at 00:59 AM on 7 July 2023Hansen predicted the West Side Highway would be underwater
Rob @ 25, Eclectic @ 26.
Oh, I think it is almost certain that our daveburton and "the other Dave Burton" are one and the same, but Tamino's posts give extensive detail that applies to daveburton's arguments whether it is the same person or not.
Tamino's posts also give considerable detail on the background of the other Dave Burton that give a pretty good idea of where the other Dave Burton's biases might originate. The other Dave Burton has peddled his wares at other blogs that I have seen - RealClimate, and And Then There's Physics.
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Eclectic at 16:01 PM on 6 July 2023Hansen predicted the West Side Highway would be underwater
Rob Honeycutt @25 ,
thanks for that info. I did come across a Dave Burton and his SeaLevel website a couple of years back (via the illustrious WUWT, iirc). But I soon gave up on his "sealevel" site, because the ratio of disinformation to information was excessively high.
Perhaps he is in the process of turning over a new leaf ~ and will now provide some useful scientific info & analysis. Hope springs eternal, eh.
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Rob Honeycutt at 12:48 PM on 6 July 2023Hansen predicted the West Side Highway would be underwater
I'm reasonably certain this is the same Dave Burton, Bob. I've come across him many times over the years. He operates the sealevel.info website. He's making the exact same claims. He's an IT guy who fancies himself an expert on sea level rise.
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prove we are smart at 11:31 AM on 6 July 2023The melting Arctic is a crime scene. The microbes I study have long warned us of this catastrophe – but they are also driving it
Interesting and informative, I really enjoyed this one. Another example of what our flawed human nature is causing.. How to give the "Overview Effect" to the people who can change things? I wish I knew.en.wikipedia.org/wiki/Overview_effect
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Rob Honeycutt at 10:50 AM on 6 July 2023How big is the “carbon fertilization effect”?
Here's a graph for the Henry's Law Constant.
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Bob Loblaw at 10:50 AM on 6 July 2023Hansen predicted the West Side Highway would be underwater
Oh, my. Commenter daveburton is certainly sending a lot of information our way. I am going to focus on his sea level acceleration claims in comment #10. In that comment, he links to two US locations (The Battery, in the NYC area, and Honolulu) for tide/sea level data, and gives us some quadratic equations to make a claim that sea level rise is negligible, and not much of a worry for the future.
Most regular readers here will also be familiar with Tamino's blog. Although Tamino has not been particularly active recently, over the years he has done a number of posts on analysis of sea level data. It turns out that a lot of those posts have the name "Dave Burton" showing up in them, either as a source of information that Tamino is debunking, or (on a few) as a commenter.
Now, I have no way of knowing whether our daveburton is the same Dave Burton seen in the discussions at Tamino's, but there is a similarity: they both like using The Battery and Honolulu stations as examples, and they both like fitting quadratic equations and arguing that there is little or no evidence for acceleration in sea level rise. To avoid confusion, I'll refer to the Dave Burton that is discussed at Tamino's as "the other Dave Burton".
I don't have the space or time to try to re-write everything that Tamino has written, so I'll just link to a few of his posts on the matter (well, nine) and provide very brief summaries.
The first Tamino post is from 2012, titled Unnatural Hazards. The other Dave Burton's name shows up quite a few times, although he does not comment. Tamino looks at The Battery data, plus a global sea level data set, and demonstrates why a quadratic fit is unsuitable. He also shows clear acceleration in the data. To provide a little graphic input for this comment, I'll included two of Tamino's figures:
A graph of the seasonally-detrended sea level at The Battery:
And a graph showing the rate of sea level change:
I"ll let you decide if you think this shows acceleration. Read Tamino's post for further details.
The next Tamino post isn't until October 2019. He had five posts from October to December, covering the following:
- Sea Level Rise. This post looks at acceleration in several global data sets, finding it present. The other Dave Burton comments extensively, and claims that "Honolulu is a nearly ideal place for sea-level measurement". He uses a quadratic equation to look for acceleration (and basically says it isn't significant).
- The next Tamino post is on Sea Level Acceleration. This post was prompted by the comments from the other Dave Burton on the previous post. Tamino looks at San Diego, Key West, Boston, St. Petersburg (FL), and Honolulu. Honolulu is the only one without acceleration. Tamino uses changepoint analysis to look for changes in linear trend. (Spoiler alert: he finds changes.)
- Further comments from the other Dave Burton lead to Tamino's next post, on Sea Level Accleration Denial. Tamino goes into more detail on the folly of the other Dave Burton's quadratic analysis, and explains more aspects of statistical testing for acceleration.
- Tamino's final October post is on Sea Level: Eastern North America. This post only has a passing mention of the other Dave Burton, but it is another excellent analysis along the entire east coast from the Caribbean to Canada.
- In December, we see another post on A Century and More of Sea Level Acceleration. Also only a passing mention of the other Dave Burton, but this post looks at several different sea level data sets, and includes more acceleration analysis.
It isn't until November 2021 that we see another Tamino post where the other Dave Burton is mentioned. This one is titled North Carolina Sea Level Rise: Problem Not Solved. (The other Dave Burton first came on the scene, arguing against forcing North Carolina developers to include future rapid rising sea levels in their planning.) Tamino quickly followed the first November post with another, titled Sea Level at Wilmington, NC (and other places). This adds another North Carolina station to the analysis.
And finally, in February 2022, Tamino posted on Sea Level Denial, where the other Dave Burton's name comes up again. This post has further looks at Wilmington, Cedar Key, Pensacola, and Key West.
Again, our daveburton posting here may not be the same as the other Dave Burton, but the arguments are much the same - and rife with the same errors. Let's hope that our daveburton can read Tamino's posts and learn from them The other Dave Burton certainly did not.
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Rob Honeycutt at 10:46 AM on 6 July 2023Hansen predicted the West Side Highway would be underwater
Dave... "Due to the temperature dependence of Henry's Law, a 1°C increase in temperature slows CO2 uptake by the oceans by about 3%."
Moving this to an appropriate thread.
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Rob Honeycutt at 10:45 AM on 6 July 2023How big is the “carbon fertilization effect”?
Moved from another thread.
Dave... "Due to the temperature dependence of Henry's Law, a 1°C increase in temperature slows CO2 uptake by the oceans by about 3%."
Where do you come up with this 3% figure?
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Rob Honeycutt at 10:06 AM on 6 July 2023Hansen predicted the West Side Highway would be underwater
Dave @19... "Rob wrote, "that greening is now turning into 'browning.'" Well, here's what AR6 shows:"
This is absolutely classic.
1) That is not an image that appears in AR6, not with the added orange box. Thus you're co-opting their work to infer conclusions they do not make.
2) The caption for FAQ 5.1 is stating exactly what I've been explaining to you:
For decades, about half of the carbon dioxide (CO2) that human activities have emitted to the atmosphere has been taken up by natural carbon sinks in vegetation, soils and oceans. These natural sinks of CO2 have thus roughly halved the rate at which atmospheric CO2 concentrations have increased, and therefore slowed down global warming. However, observations show that the processes underlying this uptake are beginning to respond to increasing CO2 in the atmosphere and climate change in a way that will weaken nature’s capacity to take up CO2 in the future. Understanding of the magnitude of this change is essential for projecting how the climate system will respond to future emissions and emissions reduction efforts. [emphasis added]
Therefore, quite clearly, you are using this graph completely out of context and using without understanding any of the underlying physics or research on the issue.
You are merely crafting tidbits to confirm your personal biases.
And, Dave, pointing out that you don't have the requisit training in this subject is not ad hominem. I don't have the training either, but I'm not making statements that directly contradict what the leading researchers in the field are saying.
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Philippe Chantreau at 10:00 AM on 6 July 2023Hansen predicted the West Side Highway would be underwater
I will respond to Dave Burton on the CO2 fertilization thread on the part of this latest post regarding that subject.
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One Planet Only Forever at 08:00 AM on 6 July 2023Hansen predicted the West Side Highway would be underwater
daveburton,
I will try to limit how much I repeat any of the assistance others have provided to increase your awareness and improve your understanding of the issues. I will try to focus on aspects of your response @10 that have not yet been addressed.
I think it may be best to respond in reverse as follows.
Regarding: "Assumption #2: You seem to think that the CO2 level controls sea-level."
That is a misunderstanding of my comment. I am aware of and understand the following Common Sense Consensus knowledge:
Increased CO2 levels will result in a warmer global average surface temperature resulting in the reduction of the amount of water that is stored as ice supported by land (melting of ice supported by water does not change the level - unless the melting of that ice accelerates the flow of land supported ice to the ocean). Most of the water that is no longer "ice supported on land" will drain into the oceans resulting in a higher sea level (and this process will take a long time to reach a balanced state after CO2 levels stop increasing).
In addition to the sea level change due to melted ice, an increased level of CO2 in the atmosphere will result in an increased average temperature of the oceans. And water expands as it warms resulting in a higher average sea level in addition to the melted ice impact.
Regarding: "Assumption #1: You assume that there's such a thing as "a locked-in doubling of CO2.""
I was not assuming anything. I was presenting a hypothetical situation for consideration. That situation is a case where CO2 levels reach 560 ppm and stay at that level due to continued human impacts.
Simply asking what the sea level will be when CO2 levels reach 560 ppm will result in a vast range of answers. There are a diversity of cases where CO2 levels reach 560 ppm that would have significantly different expected maximum sea level rise. They include the following:
- CO2 rapidly reaching 560 ppm and continuing to rapidly increase. That will produce a low amount of sea level increase at the moment that 560 ppm is reached. But it would cause a much higher level in the distant 'balanced condition' of the future that will be established at some significant time after CO2 levels are no longer being increased.
- CO2 levels slowly reaching 560 ppm and continuing to slowly increase. That would result in a higher sea level when 560 ppm is reached that in case 1. But if the same 'maximum ppm level' as in case 1 is reached then the long term sea level rise would likely be comparable to case 1.
- CO2 level increases to 560 ppm then is held steady by continued human impacts (a locked in level of CO2). This is the case I was referring to. Indeed you misunderstood my comment.
- CO2 levels rise to 560 ppm and then are rapidly reduced by human industrial CO2 removal or other human impact changes that result in reduction of CO2 levels rather than a steady level of 560 ppm. This is closer to what an ethical consideration would conclude. The more ethical conclusion is that CO2 levels should not be allowed to reach 560 ppm. And human actions to remove CO2 from the atmosphere are required even though the CO2 levels do not reach 560 ppm.
Finally regarding your opening statement: "...why are you asking me "about the human origins of global warming"? My comment had nothing to do with that."
I was not asking a question. I was pointing out that the information you provided did not affect the conclusion of the OP. Your comment could be considered to be an attempt to use a 'new twist' of the "Hansen got it wrong" claim.
That raises a new question. Why did you make the claim you made @8?
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daveburton at 07:39 AM on 6 July 2023Hansen predicted the West Side Highway would be underwater
Rob wrote, "that greening is now turning into 'browning.'"
Well, here's what AR6 shows:
Some people point to that little orange box and say that greening has ceased. That reminds me of the folks who say that the it's not as warm as the 2015-16 El Nino, so warming has ceased.
Philippe wrote, "There is probably a better thread for this argument,"I agree. I was just trying to address OnePlanet's remark about a "locked in" CO2 level.
Philippe wrote, "There is only one factor that truly controls how green any region can be: water availability."
That's a common misconception. Elevated CO2 levels greatly improve plants' water use efficiency (WUE) and drought resilience. That's why elevated CO2 is especially beneficial for crops when under drought stress. It has been heavily studied by agronomists. Here's a paper about wheat:
Fitzgerald GJ, et al. (2016) Elevated atmospheric [CO2] can dramatically increase wheat yields in semi-arid environments and buffer against heat waves. Glob Chang Biol. 22(6):2269-84. doi:10.1111/gcb.13263.
Philippe wrote, "The experiences that have shown a CO2 fertilization effect were done in very controlled conditions and involved extremely high concentrations (800 ppm and up)."
That's incorrect. All major crops have been studied, and all benefit from elevated CO2. It is true that the greatest benefits accrue at 1000 ppmv or higher, but even modest CO2 increases significantly improve crop yields.
This recent study quantifies the effect for several major crops. Their results are toward the high end, but their qualitative conclusion is consistent with many, many other studies. They reported, "We consistently find a large CO2 fertilization effect: a 1 ppm increase in CO2 equates to a 0.4%, 0.6%, 1% yield increase for corn, soybeans, and wheat, respectively."
This study evaluated pine trees:
Idso, S., & Kimball, B. (1994). Effects of atmospheric CO2 enrichment on biomass accumulation and distribution in Eldarica pine trees. Journal of Experimental Botany, 45, 1669-1672.
As you noted, the effect is greatest with CO2 >800 ppmv, but, as you can see, even a much smaller CO2 increase has a substantial effect.
Rob wrote, "This entire paragraph is patently absurd and completely fabricated."It is 100% factual, Rob. I'm surprised that you didn't already know it.
These figures are from that same AR6 Table 5.1 excerpt which I already showed you:
average CO2 removal rate in the 2010s = 2.7707 ppmv/yr
average CO2 removal rate in teh 2000s = 2.3481 ppmv/yrThese figures are from Mauna Loa:
average CO2 level in the 2010s = 399.91 ppmv
average CO2 level in the 2000s = 378.84 ppmv(399.91-378.84) / (2.7707-2.3481) = 49.86
So a 50 ppmv increase in CO2 level accelerates the natural removal rate by about 1 ppmv/year.
49.86 / 2.1294 = 23.42 ppmv increase yields a +1 PgC removal rate increase.
I encourage you to do the calculations yourself for any other time period of your choice.
If you have the natural removal rate as a function of CO2 level (which we do), it is trivial to simulate the CO2 level decline if emissions were to suddenly cease. I wrote a little Perl program to do it; email me if you want a copy.
Rob wrote, "if true, the oceans would just continue to suck up all the atmospheric CO2 and we'd live on a frozen planet."
That's incorrect. The system progresses toward equilibrium, which is below 300 ppmv, but not zero.
Rob wrote, "rather that starting from a prior where all the published science is getting it wrong, and making stuff up... you don't have the requisite training to fully grasp the topic"
Rob, it's not necessary to resort to ad hominem attacks. I'm happy to document things that are surprising to you. You need but ask. Everything I've written is well-supported.
Rob wrote, "take some time to fully familiarize yourself with Henry's Law."
Due to the temperature dependence of Henry's Law, a 1°C increase in temperature slows CO2 uptake by the oceans by about 3%. But a 50% (140 ppmv) rise in atmospheric CO2 concentration accelerates CO2 uptake by the oceans by 50%. That's the main reason that ocean uptake of CO2 continues to accelerate.
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michael sweet at 07:27 AM on 6 July 2023Hansen predicted the West Side Highway would be underwater
Dave Burton:
I note that the last time Carbon dioxide was over 400 ppm the sea level was more than 20 meters higher than current sea level.
Your sea level graphs are obviously flawed. A simple eye ball look at the data from the Battery in New York shows that at the start of the time period the data is above the fit line and at the end of the time period the data is way above the fit line. That means that the line does not fit the data and some sort of curved line is needed because the rate of sea level rise is increasing over the time period you chose.
In addition, you have cherry picked two single locations to do your calculations without justifying your choice.
Fortunately, Tamino did an analysis of sea level rise before he stopped posting analysis. (Tamino is a professional statistical data analyzer who has published on sea level rise). He analyized "the data for every tide gauge station in region 3 which had at least 360 months’ data (at least 30 years), at least 120 months of which (10 years of which) are since the year 2000 — after all, we do want to know what’s happening now. That leaves 10 stations". Since he used all the available data his data is not cherry picked like yours is.
Here is one of his graphs of the rate of sea level rise on the East coast of the Gulf of Mexico:
We see immediately that sea level rise does not follow a straight line but varies over the 100 year time from of analysis. Of particluar interest is the dramatic increase in sea level rise since 2010.
The dramatic increase in sea level rise observed since 2010 holds true for an analysis of the entire globe. Your analysis using a linear fit is simply incorrect and cherry picked.
I note that the rate of rise since 2010 is more than double all the previous rates.
We would expect that if the carbon dioxide content of the atmosphere remains above 400 ppm that the sea level will rise 20 meters plus. The question is only how fast the sea will rise. We see the rise is rapidly increasing every year now. Your linear fit deliberately hides the observed rise.
I note that the change in CO2 concentration in the atmosphere has rapidly increased over the past 50 years so one would expect the sea level change to rapidly increase over that time period. Including the data back to 1900 with a linear fit just hides the recent rapid increase in sea level rise.
Does anyone know how Tamino is doing?
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nigelj at 07:16 AM on 6 July 2023At a glance - Ocean acidification: Global warming's evil twin
From Woods Hole Oceanographic Institution :
One of the most common negative responses Sarah Cooley gets when she speaks to community groups about ocean acidification is, “What do you mean, ocean acidification? The ocean is not acidic! Seawater is never going to get below pH 7—so you must not know what you’re talking about.
That’s partly true, said Cooley, a postdoctoral researcher at Woods Hole Oceanographic Institution. The pH of seawater is near 8, which makes it mildly alkaline, or basic; but any decrease in the pH of a liquid is considered “acidification.”
“It’s a lot easier to say ‘ocean acidification’ than ‘ocean de-alkalinization,” said Cooley.
pH is an index of how many protons, or hydrogen ions (H+) are dissolved and free in a solution. The pH scale goes from 0 to 14. A fluid with a pH of 7 is neutral. Below 7, it is acidic; above 7, it is alkaline.
A small drop in pH means big change in acidity: The pH of seawater is near 8, which makes it mildly alkaline, or basic; but any decrease in the pH of a liquid is considered “acidification.” The key danger factor is an increase in dissolved hydrogen ions.(Woods Hole Oceanographic Institution)
The more below or above 7 a solution is, the more acidic or alkaline it is. The scale is not linear—a drop from pH 8.2 to 8.1 indicates a 30 percent increase in acidity, or concentration of hydrogen ions; a drop from 8.1 to 7.9 indicates a 150 percent increase in acidity. Bottom line: Small-sounding changes in ocean pH are actually quite large and definitely in the direction of becoming less alkaline, which is the same as becoming more acidic.
If you think about it, we use descriptive words like this all the time. A person who stands 5’5” tall and weighs 300 pounds isn’t thin. If he loses 100 pounds, he still won’t be thin, but he will be thinner than he was before he went on the diet. (And we are more likely to comment that he’s looking trimmer than to say he’s not as fat as he used to be.)
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Rob Honeycutt at 04:13 AM on 6 July 2023Hansen predicted the West Side Highway would be underwater
Dave, I think you should take some time to fully familiarize yourself with Henry's Law. Here's a starter teaching video, but don't stop there. Dig deeper and really learn what this means in relation to the ocean/atmosphere relationship for CO2.
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MA Rodger at 04:10 AM on 6 July 2023Increasing CO2 has little to no effect
manuel2001nyc @444,
You are very dedicated. It is a super-human task attempting to learn from the comments in a long comments-thread such as this.I would guess the term "saturation" you used concerns more the saturation as in laser intensity** rather than any climatological/atmospheric consideration. (**That is, an excited CO2 molecule cannot absorb IR until it has returned to its unexcited state. Such consideration doesn't really apply here.)
As other commenters have explained, 15μm IR can be absorbed by CO2 and the resulting excited CO2 molecules would almost always then be in collision with other atmospheric molecules and lose its excitation in that manner. Thus the absorbed IR energy is converted into thermal energy in the atmosphere. This process is because these collisions with molecules in the atmosphere will occur within microseconds while the relaxation period allowing the CO2 to emit IR is on average in the tenths of seconds.
But that does not mean there is little 15μm IR emitted by CO2 or that such emissions are rare. As well as taking-away the excitation from a CO2 molecule, these numerous collisions can also impart excitation into CO2 molecules. Thus the vast majority of the excited CO2 is because of these impacts. And if the Earth's surface is at the same temperature as the local atmosphere, the CO2 will be shooting off the same amount of 15μm IR back down at the surface as the surface is shooting upwards. (Note the surface only shoots upwards while the CO2 will shoot both up and down)So, to answer yor first question.
It is a rough rule in physics that the absorption and emission of photons balance, usually. If they don't there will be a net flow of energy, with more/less emissions cooling/heating the substance and thus reducing/increasing emissions. Thus the absorption-emission balance would be achieved.The 8μm-14μm waveband is often called the Infrared Window because in a dry atmosphere the IR from Earth's surface has a clear path out into space. Clouds would block that clear path and water vapour acts as a weak absorber.
There is other IR absorbtion in the 8μm-14μm waveband. There is a strong ozone absorption band at 9.6μm. Also, if we do let CO2 concentrations rise far enough, CO2 absorption bands will appear close to 10μm, these starting to become significant for CO2 concentrations above 1,000ppm.
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Rob Honeycutt at 04:02 AM on 6 July 2023Hansen predicted the West Side Highway would be underwater
Dave @15... "The commonly heard claim that... [...] That's the "effective atmospheric lifetime" of our current CO2 emissions."
This entire paragraph is patently absurd and completely fabricated. If you had even one legitimate research paper that made such a claim it might be worth evaluating. But the ridiculousness of your claim is made apparent because, if true, the oceans would just continue to suck up all the atmospheric CO2 and we'd live on a frozen planet.
You know, rather that starting from a prior where all the published science is getting it wrong, and making stuff up to justify that position, maybe try stepping back from the issue. Start from the realization that you don't have the requisite training to fully grasp the topic and endeavor to learn what actual experts in the field can teach you.
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daveburton at 03:51 AM on 6 July 2023Hansen predicted the West Side Highway would be underwater
Thanks for fixing those links, Rob. We were obviously typing simultaneously; you beat me to it by 7 minutes.
However, nothing I wrote was misleading. If you "follow the link to the actual IPCC page to read the full" table, you'll see that it shows exactly what I said it shows: as atmospheric CO2 levels have risen, the natural CO2 removal rate has sharply accelerated. (That's a strong negative/stabilizing climate feedback.)
The commonly heard claim that "the change in CO2 concentration will persist for centuries and millennia to come" is based on the "long tail" of a hypothetical CO2 concentration decay curve, for a scenario in which anthropogenic CO2 emissions go to zero, CO2 level drops toward 300 ppmv, and carbon begins slowly migrating back out of the deep oceans and terrestrial biosphere into the atmosphere. It's true in the sense that if CO2 emissions were to cease, it would be millenia before the CO2 level would drop below 300 ppmv. But the first half-life for the modeled CO2 level decay curve is only about 35 years, corresponding to an e-folding "adjustment time" of about fifty years. That's the "effective atmospheric lifetime" of our current CO2 emissions.
Moreover, it is not correct to say that "the ocean takes up about half of our emissions." Our emissions are currently around 11 PgC/year (per the GCP). The oceans remove CO2 from the atmosphere at a current rate of a little over 2.5 PgC/year, but they are not removing some fixed fraction of our emissions. If we halved our emission rate, natural CO2 removals would continue at their current rate.
Because human CO2 emissions are currently faster than natural CO2 removals, we've increased the atmospheric CO2 level by about 50% (140 ppmv), but we've increased the amount of carbon in the oceans by less than 0.5%, as you can see in AR5 WG1 Fig. 6-1. (It's not a problem for "sea dwelling creatures.")
In the oceans, biology generally trumps chemistry, and that is certainly true for CO2 uptake. Some people think that the capacity of the oceans to take up CO2 is limited to surface water by ocean stratification. But that's incorrect, beause the "biological carbon pump" rapidly moves CO2 from surface waters into the ocean depths, in the form of "marine snow."
The higher CO2 levels go, the faster that "pump" works. Here's a paper about it:
https://www.science.org/doi/reader/10.1126/science.aaa8026Once carbon has migrated from the ocean surface to the depths, most of it remains sequestered for a very long time. Some of it settles on the ocean floor, but even dissolved carbon is sequestered for a long time. For instance, it is estimated that the AMOC takes about 1000 years to move carbon-rich water from high latitudes to the tropics, where it can reemerge. That is obviously far longer than the anthropogenic CO2 emission spike will last.
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Philippe Chantreau at 03:33 AM on 6 July 2023Hansen predicted the West Side Highway would be underwater
There is probably a better thread for this argument, but I always feel that I have to interject when the CO2 fertilization argument is mentioned. That is because it is among the most mendacious and inept arguments out there.
There is no place on Earth where the lack of CO2 (as in pre-industrial concentration) can be shown to have prevented vegetation from thriving. There is only one factor that truly controls how green any region can be: water availability. It dwarfs all other factors together. The Hawaiian islands show this in the most obvious way possible, with precipitation variations such that one side can be arid or semi-arid while the other is covered with rainforest.
Everywhere on the planet where water availability allows for it, the richest plant life has thrived and reached the maximum extent possible in term of biomass and biodiversity. The rainforests of Africa often exists on top of extremely poor soil (laterite) but given enough time, they manages to feed themselfves, as the soil's entire top layer is composed of vegetal debris fallen over time. The soil is thin, hence the buttresses evolved by tree species in an environement where they can't grow roots down very deep. Under it is the laterite, something so sterile that it makes for better road covering material than tarmac in these regions: the laterite roads require less maintenance and last longer.
The experiences that have shown a CO2 fertilization effect were done in very controlled conditions and involved extremely high concentrations (800 ppm and up). The so-called greening that has been observed in some regions by satellite or other means can not be ascribed to CO2 fertilization to the exclusion of other factors because all such factors can not be known, neither can their exact contribution to the greening.
Anywhere on the planet where there is not enough water available, plant life will not thrive, no matter how much CO2, nitrogen or phosphate we throw at it. Water availability and rain patterns should be on top of priority list of concerns of anyone looking into solutions to feed 9 billion people. Available means falling regularly in reasonable quantities. Torrential rains spaced at long intervals with nothing between don't do much good without massive engineering projects.
Ii is ironic that some use the argument that the CO2 concentration change is too small to make an effect when it comes to radiative forcing, where it can be calculated with great precision, but then jump on making wild claims about the effect of that change on vegetation, where it can be, at best, observed to have a small effect in controlled conditions, and with concentration changes far greater than what has happened in nature.
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Rob Honeycutt at 01:46 AM on 6 July 2023Hansen predicted the West Side Highway would be underwater
Dave... On the little red notation in your first graphic where is says "greening"... that greening is now turning into "browning." Read up on CO2 fertilization. It was long predicted there would be some fertilization before that process was overwhelmed by other effects. That is now observed. In other words, the greening has now stopped.
But again, similar to the ocean, this effect was a function of the terrestrial uptakes in response to atmospheric increases that are rising at a more rapid pace. Terrestrial sinks can't keep up with the pace of human emissions.
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daveburton at 01:37 AM on 6 July 2023Hansen predicted the West Side Highway would be underwater
Sorry, I didn't realize that bare URLs don't automatically get recognized and turned into links.
Here's AR6 WG1 Table 5.1, which shows how natural CO2 removals are accelerating:
LINKHere it is with the relevant bits highlighted:
https://sealevel.info/AR6_WG1_Table_5.1.png
Or, more concisely:
LINK
(Note: 1 PgC = 0.46962 ppmv = 3.66419 Gt CO2.)Here are the best long U.S. Atlantic and Pacific sea-level measurement records, respectively, with linear and quadratic regressions calculated for the last 100 years (based on monthly mean sea level data from 1923/6 through 2023/5):
https://sealevel.info/MSL_graph.php?id=Battery&c_date=1923/6-2023/5
linear trend = 3.293 ±0.163 mm/yr
acceleration = 0.00641 ±0.01258 mm/yr²https://sealevel.info/MSL_graph.php?id=Honolulu&c_date=1923/6-2023/5
linear trend = 1.534 ±0.236 mm/yr
acceleration = 0.00568 ±0.01825 mm/yr²Moderator Response:[RH] You're also going to want to learn to shorten extra long URL's by changing the display text.
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Rob Honeycutt at 01:30 AM on 6 July 2023Hansen predicted the West Side Highway would be underwater
Dave... So much is wrong in that post. Let's just start with atmospheric CO2 perturbation. No one claims it stays up there forever. But the change in CO2 concentration will persist for centuries and millennia to come.
https://climatehomes.unibe.ch/~joos/papers/joos97eps.pdf
Your sealevel.info snippet is misleading, and I assume you understand that virtually no one is going to follow the link to the actual IPCC page to read the full passage, because it will directly contradict what you're saying.
What you're looking at in those changes is a function of partial pressure. The ocean takes up about half of our emissions (lucky for those of us who live in the atmosphere, not so lucky for sea dwelling creatures). The increases you're demonstrating are merely a function of increased atmospheric concentrations. The oceans, in particular, are not going to continue to take up CO2 beyond what it's capable of doing due to partial pressure.
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rkcannon at 00:19 AM on 6 July 2023Renewables can't provide baseload power
anmin @198, You'd need compressed air to pressurize the water. "Only 10% to 20% of the energy required to generate compressed air ever reaches the point of. use, while the remaining energy is wasted in the form of heat. The over-all efficiency of a typical compressed air. system can be as low as 10%-15%". NH.gov. If you could pump the water up high enough in a tank, you could then use gravity to pressurize the water and run a pump and power a generator, possible the same pump/motor used to pump the water up, but run in reverse. Or on a large scale, a lake is used. From energy.gov,
What is Pumped Storage Hydropower?Pumped storage hydropower (PSH) is a type of hydroelectric energy storage. It is a configuration of two water reservoirs at different elevations that can generate power as water moves down from one to the other (discharge), passing through a turbine. The system also requires power as it pumps water back into the upper reservoir (recharge). PSH acts similarly to a giant battery, because it can store power and then release it when needed. The Department of Energy's "Pumped Storage Hydropower" video explains how pumped storage works.
The first known use cases of PSH were found in Italy and Switzerland in the 1890s, and PSH was first used in the United States in 1930. Now, PSH facilities can be found all around the world! According to the 2021 edition of the Hydropower Market Report, PSH currently accounts for 93% of all utility-scale energy storage in the United States. America currently has 43 PSH plants and has the potential to add enough new PSH plants to more than double its current PSH capacity.
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daveburton at 17:24 PM on 5 July 2023Hansen predicted the West Side Highway would be underwater
One Planet, why are you asking me "about the human origins of global warming"? My comment had nothing to do with that.
As for your first indented question, it appears that you've made two unjustifiable assumptions:
Assumption #1: You assume that there's such a thing as "a locked-in doubling of CO2."
If I understand you correctly, that means you think CO2 added to the atmosphere just stays "locked in" there, forever, and the longer we add CO2 to the air the higher the level will rise. Is that what you think?
If that's what you think, you're mistaken. CO2 doesn't just stay in the atmosphere. Nature is rapidly removing CO2 from the air, into other carbon reservoirs. The only reason the atmospheric CO2 level is nevertheless rising instead of falling is that we're adding CO2 to the air even faster than nature is removing it.
But it's becoming harder and harder to keep up with natural CO2 removals, because they're accelerating. This is an excerpt from AR6 WG1 Table 5.1, showing how the removals are accelerating:
LINK (Note: 1 PgC = 0.46962 ppmv = 3.66419 Gt CO2.)
At the current 420 ppmv level (i.e., 135-140 ppmv above a 280-285 ppmv baseline), those negative feedbacks already remove an average of about 5.5 PgC per year (= about 2.6 ppmv), and for each 20-25 ppmv increase in atmospheric CO2 concentration those removals accelerate by another 1 PgC/year.
With our current emission rate, the CO2 level is only rising by about 5.1 PgC/year (+2.4 ppmv). So it won't take much of a CO2 level increase before natural removals match our current emission rate: just (20 to 25 ppmv/PgC) × 5.1 PgC = (102 to 128) ppmv.
420 + (102 to 128) = 522 to 548 ppmv. That's the "plateau level" beyond which the atmospheric CO2 level cannot rise, unless our emissions increase further. If we were to continue our current anthropogenic emission rate indefinitely (or until the coal runs out), we'd still not quite reach 560 ppmv.
Assumption #2: You seem to think that the CO2 level controls sea-level. But the data do not support that assumption. Most coastal measurement sites have seen negligible acceleration in sea-level trend over the last century, even as the atmospheric CO2 level rose by 115 ppmv.
Here are the best long U.S. Atlantic and Pacific measurement records, respectively:
https://sealevel.info/MSL_graph.php?id=Battery&c_date=1923/6-2024/12
https://sealevel.info/MSL_graph.php?id=Honolulu&c_date=1923/6-2024/12
Both show a statistically insiginficant acceleration of 0.006 mm/yr² (± at least twice that) over the last century.
Hogarth studied many long measurement records, and concluded, "Sea level acceleration from extended tide gauge data converges on 0.01 mm/yr²"That's very, very slight.
To calculate the effect of that acceleration use the following quadradic formula:
y = B + M·x + (A/2)·x²
where:
x is elapsed time
y is position or sea-level after time x
B is initial position or sea-level
M is current rate
A is accelerationSo (choosing some fairly typical values) if:
M = 1.5 mm/yr
A = 0.01 mm/yr²
x = 100 yrsAnd if the trends were to continue:
y = B + 100·1.5 + (0.01/2)·100²
= B + 150 + 0.005·10000
= B + 150 + 50
= 200 mm = 7.9 inches6" of that 8" is from the linear trend, and 2" of that 8" is due to acceleration.
However, there's a subtle twist. When acceleration is estimated by quadratic regression, we're fitting a quadratic curve to the measurement record to date. Extending that curve is the projection. But the curve's slope matches the linear tread at the midpoint, not at the end.
So, to find y (sea-level) 100 years from NOW, we should use x = 100+(L/2), where L is length of the measurement record.
So if we have a 100 year measurement record, to calculate the accumulated effect of the acceleration 100 years from now we should use x=150, not x=100.
Remember our formula:
y = B + M·x + (A/2)·x²
That last term is the effect of acceleration; using x=150 we get:
(A/2)·x² = 0.005·150² = 0.005·22500 = 112.5 mm = 4.4 inches.
So, an acceleration of 0.01 mm/year² is still negligible, but it's a "slightly bigger negligible."
A warming climate is know to have effects which both increase and decrease sea-level. Based on the negligible effect that the last century's CO2 increase and consenquent warming has had on sea-level trends, it is clear that, so far, the effects which increase and decrease sea-level must be similar in magnitude, and roughly cancelling.
So the assumption that a particular CO2 level "locks in" a particular sea-level is not justifiable.Moderator Response:[RH] Dave, you've been on this site many times now. Please learn how to hot link your citations. It's really easy to do.
