Guest Post by Willis Eschenbach
Following on from Anthony’s article, here are my thoughts about the phytoplankton paper “Global phytoplankton decline over the past century”, by Daniel G. Boyce, Marlon R. Lewis & Boris Worm.
I started to write about this earlier, but I decided to wait until I had the actual paper. The paper in question is behind a paywall at Nature Magazine, but through my sub-oceanic channels (h/t to WS) I have obtained a copy. The paper makes two main claims, that: a) the numbers of phytoplankton have been cut by more than half since 1900, and b) the general warming of the global oceans is the reason for the declining numbers of phytoplankton.
First, what are phytoplankton when they are at home, and where is their home? Plankton are the ubiquitous soup of microscopic life in the ocean. Phytoplankon are the plant-like members of the plankton, the ones that contain chlorophyll and feed on sunshine. Phytoplankton are to the ocean what plant life is to the land. Almost all oceanic life depends on phytoplankton. Other than a thin strip of seaweeds and sea grasses along the coasts, phytoplankton are the microscopic plants that are the foundation of the vast entire oceanic food chain. Without phytoplankton there would be no deep water oceanic life to speak of. Figure 1 shows where you find phytoplankton:
Figure 1. Global distribution of phytoplankton. Lowest concentration is purple and blue, middle concentration is green, highest concentration is yellow and red. Source http://www.nasa.gov/vision/earth/environment/0702_planktoncloud.html
So where did the Nature paper go wrong?
The short answer is that I don’t know … but I don’t believe their results. The paper is very detailed, in particular the Supplementary Online Information (SOI). It all seems well thought out and investigated … but I don’t believe their results. They have noted and discussed various sources of error. They have compared the use of Secchi disks as a proxy, and covered most of the ground clearly … and I still don’t believe their results. Here’s exactly why I don’t believe them.
This is their abstract (emphasis mine):
In the oceans, ubiquitous microscopic phototrophs (phytoplankton) account for approximately half the production of organic matter on Earth. Analyses of satellite-derived phytoplankton concentration (available since 1979) have suggested decadal-scale fluctuations linked to climate forcing, but the length of this record is insufficient to resolve longer-term trends.
Here we combine available ocean transparency measurements and in situ chlorophyll observations to estimate the time dependence of phytoplankton biomass at local, regional and global scales since 1899. We observe declines in eight out of ten ocean regions, and estimate a global rate of decline of ~1% of the global median per year. Our analyses further reveal interannual to decadal phytoplankton fluctuations superimposed on long-term trends. These fluctuations are strongly correlated with basin-scale climate indices, whereas long-term declining trends are related to increasing sea surface temperatures. We conclude that global phytoplankton concentration has declined over the past century; this decline will need to be considered in future studies of marine ecosystems, geochemical cycling, ocean circulation and fisheries.
The first clue to where they went wrong is visible in Fig. 1. Although as you can see there is more phytoplankton in the cooler regions of the north, the same is not true in the corresponding regions in the south despite the ocean temperatures being very similar. In addition, there are many places where the ocean is warm (e.g. tropical coasts) that have lots of phytoplankton, while in other warm areas there is very little phytoplankton.
The rude truth of phytoplankton is this: phytoplankton growth is generally not limited by temperature. Instead, it is limited by nutrients. Where nutrients are plentiful, the phytoplankton grow regardless of temperature. Nutrients are more common along the coastline, where sub-oceanic currents come to the surface bringing nutrients from the deep ocean floor, and rivers bring nutrients from inland. For example, in Fig. 1 you can see the nutrients from the Amazon river causing the red area at the river mouth (north-east South American coast).
Indeed, the fact that phytoplankton are generally nutrient limited rather than temperature limited has been demonstrated in the “ocean fertilization” experiments using rust. If you spread a shipload of rust (iron oxide) out into the tropical ocean, you generally get an immediate bloom of phytoplankton. Temperature is not the problem.
So to start with, the idea that increasing temperature automatically leads to decreasing phytoplankton is not generally true. There are vast areas of the ocean where higher temperatures are correlated with more phytoplankton. For example, the warmer deep tropics generally have more phytoplankton than the cooler adjacent subtropics.
The paper’s most unbelievable claim, however, is their calculation that since 1899, the density of phytoplankon has been decreasing annually by 0.006 milligrams per cubic metre (mg m-3). They give the current global density of phytoplankton as being 0.56 mg m-3. Thus they are claiming that globally the concentration of phytoplankton has dropped by more than 50% over the last century.
Now, a half century ago I learned to sail on San Francisco Bay. Since then I’ve spent a good chunk of my lifetime at sea, as a commercial fisherman from California to the Bering Sea, as a sailboat delivery crewman, as a commercial and sport diver, and as a surfer. And call me crazy, but I simply don’t believe that the sea only has half the phytoplankton that it had in 1900. If that were true, it would not take satellites and complex mathematical analysis to show it. People would have noticed it many years ago.
I say this because phytoplankton are the base of almost the entire mass of oceanic life. They are what almost all other life in the ocean ultimately feeds on, predators and prey as well. The authors of the study do not seem to realize that if the total amount of phytoplankton were cut by more than half as they claim, the total mass of almost all living creatures in the open ocean would be cut about in half as well. No way around it, every farmer knows the equation. Half the feed means half the weight of the animals.
And I see no evidence of that having happened over the last century. It certainly does not accord with my own extensive practical experience of the ocean. And I see no one else making the claim that we only have half the total mass of deep-water oceanic life that we had a century ago..
The other thing that makes their claimed temperature/phytoplankton link very doubtful is that according to the HadISST dataset, the global ocean surface temperature has only increased by four tenths of a degree C in the last hundred years.
Four tenths of a degree … an almost un-noticeable amount. Yet their paper says (emphasis mine):
Our analyses further reveal interannual to decadal phytoplankton fluctuations superimposed on long-term trends. These fluctuations are strongly correlated with basin-scale climate indices, whereas long-term declining trends are related to increasing sea surface temperatures.
These kinds of claims drive me nuts. Is there anyone out there that truly believes that a change of global average ocean temperature of four tenths of a degree C over the last hundred years has cut the total mass of phytoplankton, and thus the total mass of all oceanic creatures, in half? Really?
So that’s why I say I don’t know where their math went wrong, but I don’t believe their results. I don’t believe we’ve lost about half the total mass of all oceanic creatures. Half the planet’s open ocean dwellers? Where is the evidence to support that outrageous claim? And I don’t believe that an ocean temperature change of four tenths of a degree over a century has made much difference to phytoplankton levels, as they grow at all temperatures.
Why don’t I know where their math went wrong? Unfortunately, they have not posted up the data that they actually used. Nor have they shown any of their data in the form of graphs or tables. Instead, they have shown model results, and merely pointed to general websites where a variety of datasets are maintained. So we don’t know, for example, whether they used the 1° grid version or the 2.5° grid version of a given dataset. Nor have they posted the computer code that they used in the analysis. Plus, the very first link in their paper to the first and most important data source is dead.
Grrrr … but dead link or not, pointing to a website as the data source in their kind of paper is meaningless. To do the analysis, they must have created a database of all of the observations, with the meta data, and the details for the type etc. for each observation. If they would include that database and their code in the SOI, then someone might be able to figure out where their math went wrong … my guess is that it may be due to overfitting or misfitting of their GAM model, but that’s just a wild guess.
It is a shame that they did not post their data and code, because other than the lack of data and code it is a fascinating analysis of a very interesting dataset. I don’t accept their analysis of the data because it doesn’t pass the “reasonableness” test, but that doesn’t mean that the dataset does not contain valuable information.
[Update] An alert reader noted that the image in Figure 1 was of a particular month and not a yearly average. So I’ve made a short movie of the variations in plankton over the year.
Figure 2. Monthly movie of plankton concentrations. Click on image to see animation.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
Richard S Courtney says:
August 1, 2010 at 4:57 am
But the LCPD remains and continues to harm energy policies.
Why hasn’t the UK Government challenged the EU in court? Are they too Lib-Dim?
Had fun crunching their numbers
Nasa says that:
“‘Every day, more than 100 million tons of carbon dioxide are drawn from the atmosphere into the ocean by billions of microscopic ocean plants called phytoplankton during photosynthesis.””
That would be +36 billion tons a year. (100 million X 365)
If plankton is reduced by 50% in the past 100 years, then prior to 100 years ago, the oceans would have taken up +/-72 billion tons a year.
So there’s a net gain of +/-36 billion tons a year from lazy plankton.
NASA also says:
“”Between 1751 and 2003, 306-626 billion tons of carbon were added to the atmosphere as carbon dioxide, mostly through fossil fuel combustion””
That’s 252 years.
If you divide their high number – 626 billion – by 252 years, you come up with only about 2.5 billion tons added to the atmosphere each year from burning fossil fuels.
So lazy plankton explains 100% of the increase in atmospheric CO2 levels.
Guys, temp has nothing to do with it. There were massive volcano eruptions prior to 1900 that put dust and iron in the atmosphere. Fertlizer for phytoplankton. They started their measurements at 1900, the height of a plankton bloom.
Here’s the volcano dust index for that time period:
http://rankexploits.com/musings/wp-content/uploads/2008/01/histvolcanoerup.jpg
Billy Liar says:
August 1, 2010 at 11:44 am
Richard S Courtney says:
August 1, 2010 at 4:57 am
But the LCPD remains and continues to harm energy policies.
Why hasn’t the UK Government challenged the EU in court? Are they too Lib-Dim?
________________________________________________________________
For the same reason the USA did not get rid of all the regulations on childcare centers when it was found the criminal trials were based on “evidence” from Social Services brainwashed kids and many innocent people spent years (or died) in jail. The real target are the laws, the lies are used to get the public to accept the laws they would not accept otherwise. Once the laws are in place they are cast in stone and the next step in stripping the masses of their freedom is initiated.
Two steps forward never any steps back. Money and Power are the goals of politicians that we have to always guard against.
“Eternal vigilance is the price of liberty.” — Wendell Phillips, (1811-1884)
I don’t believe I would give these boys their phds.
Re oxygen depletion — would we be able to see the oxygen depletion in our atmosphere if phytoplankton have declined 40% since 1950?
You will certainly get less oxygen in the atmosphere, over time, if the creatures that produce half or more of it decline in number by 40% or more.
Whether you would notice much of a change in a few decades depends upon the cycling rate of oxygen out of the atmosphere, though.
It it were to take 2,000 years for oxygen to disappear from the air if it were not replenished, then we should see an approximate 10% drop in 200 years, a 1% drop in 20 years, and thus a 3% in 60 years. If phytoplankton produce half the oxygen, and if they have declined 40% in 60 years (since 1950), then we would have a fraction of the 3% decline in 60 years which would occur if all sources of oxygen replenishment disappeared. The reduction would be 0.4 times 0.5, or 0.2, e.g., a 20% reduction in replenishment, vs. the hypothesized 100% reduction.
So you can calculate 1/5th of the 3% oxygen depletion that would occur over 60 years, or 0.6% reduction. It is a tiny figure, but with our expertise in detecting things, we might be able to find such a reduction, I would guess, if it has in fact occurred.
The 2,000 year life is taken from an article by Wally Broecker. I THINK I read it correctly, but I’m not a climatologist.
Comments??
Lucy Skywalker says:
August 1, 2010 at 1:12 am
Thank you again Willis.
It’s wonderful to have your fresh wind of commonsense and observation, blowing out the cobwebs of the current stagnation, myopia, and plain idiocy in climate science.
Willis, I look forward to the publication of your book.
————–
I just want to second everything that Lucy Skywalker said. I’ve been away and mostly WUWTless due to lack of Internet time and access and it’s wonderful to return and find Willis’s pithy critique which as always goes to the heart of the inconsistencies and inadequacies of yet another headline-grabbing but ultimately empty ‘scientific’ alarm story. If only Willis would write a book about how to target and deconstruct scientific nonsense: case studies from his wonderful WUWT articles would of course illustrate how this is done. As I have said before, I’d be first in line to order any book Willis published…(hint, hint).
They survived the last ice age, and they survived previous warmer periods – its frickin obvious they dont care about temperature!
dh7fb says:
August 1, 2010 at 7:56 am
Thanks, dh7fb, for the link to the figure from the study. That Figure was one of my great frustrations. When I saw it I thought “Great, some data to analyze”. But then I noted that the caption says it’s not data at all, viz:
Grrrr, I’ve inadvertently wandered into a data-free zone …
It also strained my belief that there was a 95% error range shown for the South and Equatorial Pacific, yet they claim that we know the amount of chlorophyll in the North Pacific exactly, with no error range at all … and I get a bit nervous when someone cites “95% Bayesian credible limits” without showing the normal 95% confidence intervals as well. While Bayesian statistics are a valuable tool, they can also lead you very wrong.
Phil. says:
August 1, 2010 at 3:20 am
And I see no evidence of that having happened over the last century. It certainly does not accord with my own extensive practical experience of the ocean. And I see no one else making the claim that we only have half the total mass of deep-water oceanic life that we had a century ago..
Well I hold no brief for this paper but concern regarding the decline in major fisheries over the last couple of decades is widespread. Generally this is attributed to fishing pressure but this paper suggests that it isn’t that simple.
Collapse of N Sea fisheries
http://icesjms.oxfordjournals.org/cgi/reprint/53/6/1130.pdf
—————–
Phil,
I went through this paper and the only reason for the decline in all four of the major North Sea fisheries as outlined in the conclusion is overfishing. The discussion is whether the problem is over-high total allowable catches or a by-catch problem (since discarded fish are dead) and in each case, from the demersal fishees to the groundfish to the mackerel and herring the problem is one version of overfishing or another.
Lots of good arguments by W.E., Alan Mitchell and others about the limiting roles of nutrients, the minute degree of actual sea surface temperature increase, and also how observation-taking has changed, making past observations an unreliable standard for recent observation comparisons. I wonder if recent scientists disclose any information about what eyewear they are sporting as they make their secchi-disc observations.
As far as I can tell (apologies if posted before) ocean water chlorophyll a measurements began in 1965. The first announcement of the method was in Carl J Lorenzen “A method for the continuous measurement of in vivo chlorophyll concentrations” Deep Sea Research and Oceanographic Abstracts
Volume 13, Issue 2, April 1966, Pages 223-227
It appears, therefore, that this leaves only one proxy – ocean transparency – for 67 years of the claimed decline. And I doubt that the method spread so rapidly that chlorophyll a measurements were taken extensively around the world as of 1966.
OT – am just reading Vladil Lysenko’s “A Crime Against the World” (1983) – a book by a former Soviet trawler captain which divulged Soviet fisheries policy in the era before the 200-mile EEZs when Russian factory trawlers vacuumed up much of the world’s most valuable fish stocks. He provides a political side that I had never realized: the Soviets overfished not just to meet their own protein needs and because of the system of production targets that was politically dictated in all sectors of the Soviet command economy, but also to actively destroy fish stocks so as to economically damage the industries of capitalist nations. A rivetting read and strongly recommended.
Tom in Texas says:
August 1, 2010 at 11:35 am
“I haven’t read any of the comments yet, so this point may have already been made:
Out of curiosity, I clicked on the Google ad attached to this post (Highest Quality Pure Multi-Strain Phytoplankton (1 Bottle $29.95)) which stated:
”
I gotta get into that plankton business.
RE: “The other thing that makes their claimed temperature/phytoplankton link very doubtful is that according to the HadISST dataset, the global ocean surface temperature has only increased by four tenths of a degree C in the last hundred years.”
It might be interesting to conduct a random public opinion telephone poll asking people how much average temperatures have increased over the last 100 years due to ‘global warming.’ My guess is that most activists are assuming something like 6 to 10 deg F. Perhaps the writers of this paper were assuming the same or perhaps they just expected their readers to do so. I cannot imagine anyone getting worked up over a 0.4 deg C increase.
I wonder what a similar poll of members of Congress would yield.
Willis,
>>a change of global average ocean temperature of four tenths of a degree C over the last hundred years
It is not as simple as that, particularly if you consider UNADJUSTED SSTs:
http://climateaudit.org/2005/06/19/19th-century-sst-adjustments/
The unadjusted change from 1860 to the most recent data is virtually zero.
The “adjustments” are big enough to account for almost all the temperature change.
Douglas Cohen says:
August 1, 2010 at 1:29 am
I’ll bet that at the beginning of the twentieth century there was a lot of organic pollution discharged from large cities near the coasts of the developed world. This sort of ocean fertilization probably led to local and large increases in the phytoplankton right off the coast, which may also be where most of the secchi disk
Folks:
The earth’s human population increased about 400% since the late 1900s. The increase in fertilizers on farm fields has been massive in recent years. Human effects on the nitrogen cycle (the limiting nutrient in most marine waters) have been dramatic over the last 30-40 years. Evidently, these effects increasing nutrients in coast waters are easily offset by effects of warming on thermal stratification in open oceans far from continental shelves. I’ve read alot of off the cuff criticism by Willis and bloggers here but from the perspective of a scientist who does research on pelagic food chains, this criticism is naive and off the point.
[reply] population increased 400% since the late 1900’s? Might need to check figures. RT-mod
Richard S Courtney says:
August 1, 2010 at 4:57 am
“Friends:
I have an interest in this.
In the 1980s there was an ‘acid rain’ scare in Northern Europe. It was claimed that sulphurous and nitrogenous emissions from coal-fired power stations (notably in the UK and Germany) were increasing the acidity of rain with resulting waldsterben (i.e. forest death) especially in Scandinavia and Germany.
……………………….
And – like the ‘acid rain’ scare – the ‘global warming’ scare can be expected to harm energy policies for decades after it is forgotten.
Richard”
That’s fascinating. I remember the acid rain scare with TV shows in the 80s. There were shots of very agitated Norwegians complaining about taller smoke stacks in the UK causing their problems ,and evasive ministers apparently blathering on about more research being needed.
It dropped from view and I never came across the resolution. However, we are left with the serious consequences of ill-judged legislation.
I don’t know if it’s been done before, but your observations seem too important to be just a comment on another article.
Depending on the way you feel about it, maybe you should approach Anthony and write this up as a lead post?
Do these people have any common sense?!
For arguments sake let’s say the sea temperature ranges from -2C at the poles to 32C at the equator. They are saying that a change in this range to -1.6C to 32.4C has reduced the phytoplankton by 40%!
They could argue that phytoplankton are unique to each area and so are individually vulnerable, but the seas and oceans are contiguous [and fluid!] so if this were the case then for any change in surface temperature phytoplankton from neighbouring areas would migrate and thrive. In addition the 0.4C global rise in sea temperature is far less than the annual variation so why would it have any significant effect?
As you suggest, this makes no kind of sense whatsoever.
It is easy to think of these kind of people as idiots or amateurs, but really the alarmist case now seems to be almost 100% deliberate propaganda. It does just seem to be another case of Bad Science. I would hope their peers would point at them and snigger!
@BillD
The paper excluded coastal areas where plankton has increased do to increased runoff.
@WE: “So where did the Nature paper go wrong? The short answer is that I don’t know … but I don’t believe their results.”
You should stopped there.
“And call me crazy, but I simply don’t believe that the sea only has half the phytoplankton that it had in 1900. If that were true, it would not take satellites and complex mathematical analysis to show it. People would have noticed it many years ago.”
I refrain from name calling. People, scientists, have noticed regional declines in plankton. But, as the paper points out, there is a great deal of year-to-year and even decadinal fluctuation in plankton. This paper is ground breaking in being to first to study the issue on a global scale over many decades.
“I say this because phytoplankton are the base of almost the entire mass of oceanic life. They are what almost all other life in the ocean ultimately feeds on, predators and prey as well. The authors of the study do not seem to realize that if the total amount of phytoplankton were cut by more than half as they claim, the total mass of almost all living creatures in the open ocean would be cut about in half as well. ”
What is the basis for your claim? Do you know how to measure the zooplankton levels over this period? What about deep sea life? And how do you count fish – over the whole globe? Maybe there are researchers out there that can do these things, but you cannot.
If you don’t want to be crazy try keeping an open mind. Why do you have to decide if this Nature paper is correct now? It seems like a good paper, but obviously much more work will need to be done. If this finding is corroborated we would still need to understand their likely impact.
This study adds weight to the claim that we should take action to limit GHG emissions, but no one result determines where the balance of evidence lies.
The results of the study also strike me as being risible. And when I’m in a humorous mood, it’s very difficult for me to resist the temptation to make an atrocious pun. That said…
Q: Have you heard about the new vegetarian dog food?
A: It’s made from Fidoplankton.
Spector makes an excellent point. Normal body temperature is 37 degrees C. If you had a body temp of 37.4 degrees C you wouldn’t notice it nor would you be considered “febrile”.
Thanks, Willis!! To quote you, “Grrrrrr!” Simply bad science!!
I haven’t read the article yet & will do so, but it doesn’t appear that they addressed toxicity from pollutants, nutrient depravation or other factors into their model. This is simply an old-school “Let’s scare the populace with more bad news about global warming!!” type of schlock.
Since the Arctic ice mass isn’t in a death spiral, the CAGW crowd are getting desperate for proxies of impending doom, and they are now implying the phytoplankton. A more persuasive argument is that acidification at the Arctic is impacting coccolithophorids (using calcium in their morphology), but the data is still not conclusive yet. Temperature has nothing to do with it.
Organisms adapt to their surroundings if they can, and rising temperatures select for extremophilic organisms. I’m presently working with extremophilic algae isolated from hot springs in Wyoming. Depravation of nutrients or influence of toxics (particularly persistent organic pollutants, POPs, from China and India) from airborne sources is another complication.
Temperature? Not so much….
Mike says:
August 1, 2010 at 3:28 pm
“This study adds weight to the claim that we should take action to limit GHG emissions, but no one result determines where the balance of evidence lies.”
What utter nonsense! This study adds weight to the claim that we should dump more taxpayer money into studying phytoplankton, that’s all. I’m sure this study was funded by a grant and I would love to read the grant application. I’d be willing to bet a month’s pay that the grant application mentioned a reference to global warming due to GHGs. Just another example of some lame biologist jumping on the global warming gravy train.
Dr A Burns says:
August 1, 2010 at 2:11 pm
Thanks, Dr. Burns. I suspect you are correct, but I used the “consensus” view of the changes to avoid an unrelated argument that would distract from the main points.
I have posted up a movie I just made of the annual cycle of phytoplankton. It’s at the end of the head post, take a look, interesting variations. Always more to learn …
Please people, read what he Wrote. He didn’t say Phytoplankton levels were down 50%
He said the “MEDIAN” Density of phytoplankton in the “World’s” Oceans has fallen 50%.
His numbers are, quite likely, Correct.
And “Meaningless.”
Well, we’ve known for a long time that they were making this up as they go along.
So the total of phytoplankton has risen, but they excluded coastal areas from the study to arrive at the desired conclusion. This is Potsdam-style science. Bend the numbers anyway you can to arrive at “Growing temperatures create a huge problem”.