Another interesting sea ice interaction

Observing Arctic ice-edge plankton blooms from space

False-colour satellite image of ice-edge phytoplankton blooms
False-colour satellite image of ice-edge phytoplankton blooms

Ongoing climate-driven changes to the Arctic sea-ice could have a significant impact on the blooming of tiny planktonic plants (phytoplankton) with important implications for the Arctic ecosystem, according to new research conducted by scientists at the UK’s National Oceanography Centre (NOC).

“Ice-edge phytoplankton blooms in the Arctic Ocean provide food for planktonic animals called zooplankton, which are in turn exploited by animals higher up the food chain such as fish,” explained Dr Andrew Yool, one of the team of NOC researchers.

During the Arctic spring and summer, sea-ice melts and breaks up. Freshwater from melting ice forms a blanket over the denser, saltier water below. This stratification of the water column, along with seasonal sunshine, triggers the appearance of phytoplankton blooms, which often form long but narrow (20–100 km) bands along the receding ice-edge.

Arctic ice-edge blooms have in the past been studied largely during research cruises. These studies have often focused on regions such as the Barents Sea between Norway and the Svalbard Archipelago, and the Bering Shelf bordering Alaska, where blooms are thought to account for 50% or more of biological production.

However, advances in modern satellite technology now offer the opportunity to observe and monitor ice-edge blooms at high spatial resolution over large areas and extended periods of time from space.

“Our aim was to use satellite data to get a synoptic view of ice-edge blooms across the whole Arctic region,” said Dr Yool.

To do this, the research team used daily data from the NASA’s SeaWiFs satellite, which was launched in 1997. SeaWiFs continuously observes ocean colour (sea-ice, cloud and fog cover permitting), sampling the whole globe every two days. To provide an alternative estimate of bloom occurrence, and an independent check on their findings, the researchers also used data from the MODIS satellite.

Ice-edge blooms are identified from the spectral signature of the photosynthetic pigment chlorophyll, after correction for contamination by other coloured organic matter in surface waters.

So as better to understand the relationship between phytoplankton blooms and seasonal changes in sea ice, the researchers also used information on sea ice concentrations obtained from the US National Snow and Ice Data Center (NSIDC). Their study covered the period 1998–2007.

They found that ice-edge blooms occurred in all seasonally ice-covered areas and from spring to late summer. They observed ice-edge blooms in 77–89% of locations for which they had adequate data. The blooms usually peaked within 20 days of ice retreat, sometimes forming long belts along the ice edge (greater than 100 km).

“The bloom peak is most often located close to the ice edge,” said Dr Yool, “We observed blooms propagating in a wave-like fashion behind the receding ice edge over hundreds of kilometres and over several months, while others remained stationary.”

Because of the geography of the Arctic Ocean, sea ice does not always retreat northwards. For example, in Baffin Bay and Davis Strait, west of Greenland, ice shrunk both westward and south-eastward from the north in spring and summer, with phytoplankton blooms propagating along the ice edge as it receded.

“Our findings demonstrate strong biophysical linkage between bloom propagation and sea-ice melt back, which is independent of the actual direction of retreat,” said Dr Yool.

These findings are important because they indicate that future change in Arctic sea- ice resulting from climate change could significantly impact the occurrence of phytoplankton blooms as well as the animals further up the food chain that ultimately depend upon them, including fish.

Ice-edge phytoplankton blooms also play an important role in the Arctic carbon cycle. Through photosynthesis, phytoplankton blooms draw large amounts of carbon dioxide down from the atmosphere, some of which is exported to the deep ocean.

What effects future shrinkage in sea-ice will have on the ecology and biogeochemistry of the Arctic Ocean are still largely unclear, as Dr Yool explained:

“It is quite possible that ongoing climate change will lead to ice-free summers in the Arctic within the next few decades. As the melt season becomes longer, ice-edge blooms may propagate over larger distances, stripping out surface nutrients as they go. However, whether the Arctic becomes more or less productive will ultimately depend on complex factors affecting ocean stratification and mixing, and thus the availability of nutrients in sunlit surface waters.”

Dr Yool and his colleagues hope that their findings will contribute to a better conceptual understanding of the ecology of the Arctic Ocean, which should help computer modellers forecast future changes under global warming.

The researchers are MahéPerrette, Andrew Yool, Graham Quartly and Ekaterina Popova of the National Oceanography Centre.  The research work began as part of MahéPerrette’s Masters degree undertaken within the University of Southampton’s School of Ocean and Earth Sciences.

Publication:

Perrette, M.,Yool, A., Quartly, G. D. & Popova, E. E. Near-ubiquity of ice-edge blooms in the Arctic. Biogeosciences 8, 1–10 (2011). doi:10.5194/bg-8-1-

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62 thoughts on “Another interesting sea ice interaction

  1. Aside from the obligatory references to climate change (funding has a price), this is pretty interesting.

  2. “Dr Yool and his colleagues hope that their findings will contribute to a better conceptual understanding of the ecology of the Arctic Ocean, which should help computer modellers forecast future changes under global warming.”
    =============
    Did Dr. Yool just say he is only giving data to the computer modelers, and is not responsible for their actions??

  3. Through photosynthesis, phytoplankton blooms draw large amounts of carbon dioxide down from the atmosphere, . . .

    Wonder how they do that.
    Newtonian ‘action at a distance’?

  4. Presumably the phytoplankton and the fish survived the shrunken and thin ice back in the fifties as well as other episodes of ice retreat over time…

  5. Indeed Doug in Seattle,

    “Dr Yool and his colleagues hope that their findings will contribute to a better conceptual understanding of the ecology of the Arctic Ocean, which should help computer modellers forecast future changes under global warming.”

    which means, we are proper scientists who use observed data to test hypotheses but we got our Climate Change meme in at the last moment to secure our future funding and stop us being viewed as pariahs by the rest of the “clan”

    Dr Yool is as canny a businessman as any of us.

  6. I’m not qualified to comment but UK Sceptic has a valid point. What happened in the 50s? and every other time the summer ice disappeared or is this unprecedented as is every other natural occurrence of late?

  7. I want to be snarky (“It is quite possible that ongoing climate change will lead to ice-free summers in the Arctic within the next few decades….” … then again, maybe not!) but feel I should first read the whole article (pdf).

    For example, ummm, under section

    6 Conclusions and perspectives

    … Of points becoming durably ice-free only ∼50% have at least 3 observations in the succeeding 20 days….

    But no time to digest it tonight.

  8. It’s a blooming Yool tide – he’ll be there till Christmas :)

    I’ll get my parka….

  9. Phytoplankton blooms at the ice edge should not be a surprise. It is their first sight of the sun for 3 months or so and so start to grow again. There is also a lot of phytoplankton entrapped in the ice and are now melting out.

  10. They have omitted to say that ice-edge phytoplankton blooms may well in large part originate from that fraction which had been frozen within the sea ice and then released during the thaw. Some years ago in the Antarctic, Dr John Bunt (don’t know year) showed that sea-ice incorporated phytoplankton survived being frozen until the summer thaw, when this fraction helped initiate a bloom – nutrients are in plentiful supply in the Antarctic. In fact, it was this discovery that helped to explain the rapid growth of phytoplankton biomass through the thaw, despite the very low Antarctic surface water temperatures, even in summer (around minus 0.5 degrees C).

  11. Here is one of my favourite satellite photos of a plankton bloom.

    You could fit every human being on the planet an arms length apart on that island (Nunivak) off the coast of Alaska. Kind of puts things into perspective.

  12. Ref – Doug in Seattle says:
    March 4, 2011 at 10:48 pm
    “Aside from the obligatory references to climate change (funding has a price), this is pretty interesting.”

    DITTO!!!
    (500+ years ago, “scientists” had to get a bishop’s Imprimator, today it’s a curtsy to the Lord’s Of Global Warming. Nothing ever really changes. There’s always going to be someone to tell everyone else how to genuflect.)

  13. Satellite photo from paulhan very interesting. You would think commercial fisherman would use such images to their benefit.

  14. You could fill a library with the stuff that I don’t know about melting/freezing water.

    IIRC, when water freezes slowly, the H2O freezes selectively, concentrating what was previously dissolved, in the remaining volume.

    Assuming that there are already sufficient nutrients in the salt water; and the right nutrients, the fresh melt-water would provide a more-varied range of concentration of such for the plankton. There would be greater opportunity for optimum conditions for plankton growth, should it be sensitive to concentrations of various dissolved substances; nutrient and otherwise.

    And then there is the assumption that there is already enough dissolved in the salt water for optimum growth of plankton; and that the waters that flow into the oceans from the ice don’t contain substances which’d improve metabolism.

    You’d have to build another 3 libraries to hold what I don’t know about biology.

  15. Fred H. Haynie says:
    March 5, 2011 at 5:32 am

    This is another bit of evidence that the freeze/thaw cycle is the factor that controls the annual atmospheric CO2 cycle, rather than trees in the mid latitudes. Will someone quantify which consumes the most CO2 and when? As to an ice free summer, I’m betting it will never happen. http://www.kidswincom.net/arcticseaice.pdf.

    Except that phytoplankton is part of the biosphere, even if it is in the oceans, not on land. And less is left if the ice is shrinking, thus less CO2 uptake. That is the opposite of what you assumed.

  16. What a bunch of morons……

    the ice really is “dirty”, dust, pollen, etc, that’s why there’s plankton around it, it’s food

    What about that other study showing plankton has decreased 40%? /sarc

  17. See recent publications by Odd Helge Otterå showing associations of Arctic & global changes with the Atlantic Multidecadal Oscillation.

    Atlantic Multidecadal Oscillation as seen in models, observations and paleo data
    Odd Helge Otterå, et al., G.C. Rieber Climate Institute, NERSC, Bergen & Bjerknes Centre for Climate Research, Bergen

    “Suggest that 69% of recent upward trend is due to changes in aerosols (volcanic=46%, dust=23%) Evan et al 2009″

    AMOC linked to the rate of change of AMO (AMO ROC) ->
    atmosphere link?
    Overall it seems like the natural forcing act as a pacemaker for the
    multidecadal variability in BCM

    External forcing as a metronome for Atlantic multidecadal variability
    Odd Helge Otterå, Mats Bentsen Helge Drange and Lingling Suo, Nature Geoscience Letters 12 SEPTEMBER 2010 | DOI: 10.1038/NGEO955

    Here we use a coupled ocean–atmosphere general circulation model to show that the phasing of the multidecadal fluctuations in the North Atlantic during the past 600 years is, to a large degree, governed by changes in the external solar and volcanic forcings. We find that volcanoes play a particularly important part in the phasing of the multidecadal variability through their direct influence on tropical sea-surface temperatures, on the leading mode of northern-hemisphere atmosphere circulation and on the Atlantic thermohaline circulation.

  18. Ferdinand,
    “Except that phytoplankton is part of the biosphere, even if it is in the oceans, not on land. And less is left if the ice is shrinking, thus less CO2 uptake. That is the opposite of what you assumed.”

    That’s my point. It is another strong sink mechanism in the Arctic that I believe is stronger that the mid-latitude tree mechanism.
    I don’t see how you can expect CO2 uptake to decrease in summer as a result of more melting. Those buggers thrive in relatively fresh water with a ready supply of sunlight and CO2. The bloom will more likely grow as more fresher water is produced.

  19. Wouldn’t this be good news, since prior to this we were warned about the dangers of global warming causing a decline in phytoplankton?

    From the article, “It is quite possible that ongoing climate change will lead to ice-free summers in the Arctic within the next few decades. As the melt season becomes longer, ice-edge blooms may propagate over larger distances, stripping out surface nutrients as they go…”

    Am I reading this wrong or is the reference to “stripping out surface nutrients” implying a negative consequence of phytoplankton blooms in the Arctic?

  20. Elizabeth says, Am I reading this wrong or is the reference to “stripping out surface nutrients” implying a negative consequence of phytoplankton blooms in the Arctic?

    As the sea ice melts it produces fresh water which encourages phytoplankton to grow thus starting the great and wonderful food chain process. Phytoplankton is food for small creatures such as krill, small bait fish eat the krill and propagate by the millions, larger fish eat the bait fish such as tuna, salmon and cod. Fisherman catch the fish and thus provide food for us all. This is one of the wonders of nature, we should appreciate it, but scientist instead tend to see gloom and doom in everything they observe.

  21. Sounds to me like, depending upon the shape as well as extent of the sea ice that some “retreat” could actually increase the plankton and fish populations along with everything else up the food chain.

  22. I’m with Jim G! Intuitively the further the ice retreats in the summer the wider the area that would be treated to the blooms. Even if the Arctic were to become ice free at the end of the summer it would remain so for a very short time. Have studies been done yet to see if bloom intensities can be seen in sediment deposits?

  23. Fred H. Haynie says:
    March 5, 2011 at 5:32 am
    This is another bit of evidence that the freeze/thaw cycle is the factor that controls the annual atmospheric CO2 cycle, rather than trees in the mid latitudes. Will someone quantify which consumes the most CO2 and when?>>>

    I will defer to Ferdinand Englebeen since he’s following this thread, but I’d think you’ve asked the wrong question by assuming the biggest factor is one bio process or the other bio process.

    The biggest driver is ocean circulation. Cold water absorbs far more CO2 than does warm water. So the arctic regions are CO2 sinks, absorbing from the air, rain, snow and as ocean currents bring that water toward the equator, it warms, can’t hold as much CO2, and so CO2 is outgassed.

    My guess is the amount of CO2 circulated in that manner would make how much plankton or rainforest remove fairly insignificant in any given year or cylce. you would have to add up their net effect over decades to measure a meaningfull trend compared to annual uptake and outgas from the oceans.

  24. RE: UK Sceptic and Lawrie Ayres

    Pardon my ignorance, but what evidence do you have that there was less sea ice in the 1950s than there is now? And don’t dredge up those tired shots of submarines surfacing through leads in the sea ice as anecdotal proof. Submarines could surface in the high Arctic in the dead of winter if they wanted to, provided they found a lead like those subs did. If you watch satellite images of the Arctic during the winter, you’d know those leads are not hard to find. The best hard data we have suggests that there was significantly MORE sea ice in the Arctic back in the 1950s than there is now.

    http://nsidc.org/sotc/sea_ice.html

  25. Travis,

    This post by the late, great John Daly has plenty of info regarding your question.

    If it’s too much information, at least read the Conclusion.

  26. Fred H. Haynie says:
    March 5, 2011 at 8:14 am

    I don’t see how you can expect CO2 uptake to decrease in summer as a result of more melting. Those buggers thrive in relatively fresh water with a ready supply of sunlight and CO2. The bloom will more likely grow as more fresher water is produced.

    It was your idea that expanding/melting ice sheets are the cause of the seasonal variations in CO2. But that doesn’t hold:
    – Sea ice expands and melts at least with the same quantities in Antarctica as in the Arctic. Same response from phytoplankton there (there is a recent alarming investigation from the Peninsula, not the rest of Antarctica), but only a very small seasonal amplitude is observed in the SH.
    – The plankton growth and the leaves growth of land plants in spring are similtaneous. Both are lumped together as the biogenic response to temperature. In contrast, the direct sink of CO2 into the oceans is opposite in sign for quantity and quite different in amplitude for d13C compared to the biogenic response.
    – The oceans are net sinks in winter, despite expanding ice cover, because the mid-latitudes up to the ice sheets are absorbing CO2. Only the amount absorbed at the THC sink place, going into the deep oceans, might be influenced by the ice sheet expansion. In contrast, algal blooms are only small sources in winter (about 6 GtC total mass), as the mass is small, be it with a huge turnover in summer (most is feed for the rest of the food chain which returns it into CO2). But land vegetation is a huge source in winter (about 60 GtC land vegetation decay).
    – The maximum bloom is some 20 days after ice retreat and then is reducing, depending of the availability of nutritients. Thus CO2 aborbing also depends of how much more ice is melting, which diminishes over time until late summer. More important is how much ice in total melts. I suppose that will decrease together with the decrease of total summer/winter area.

    For more background, see the (somewhat outdated) NASA diagram:

  27. I’m with others in thinking that this is just another example of the net positive effects of natural global warming. I cant see the alarmists liking this story much. But then again, I tend to view things in a very straight forward way. Unlike the warmists, who through a convoluted and elaborate narrative believe everything is caused by CO2.

    Cheers!

  28. Why do we think it is cute or acceptable that researchers make even token obeisance to any motley CRU or deity other than Science?

    Every scientist who bends over for prejudice and bias diminishes the credibility of their work.

  29. RE: Smokey

    I’ve seen Daly’s work, and it is partially to what I refer. He, in fact, confirms that there was more ice in the Arctic during the 1950s then there is today, and when it comes down to it, he concludes there “Unfortunately there is no comprehensive ice data from the 1930s” which leads me to repeat my question, perhaps modified now that I’m reminded that Daly established that the extent was greater than today in the 1950s: what hard evidence is there that sea ice extent in the 1930s was less than (or comparable to what) it is today?

    Daly’s analysis relied on an extrapolation of Arctic temperature data that is shakier than what goes on at GISS, as well as his interpretation of a series of climate patterns whose interrelationships are frankly much more complex than he admitted in his analysis (or perhaps than he knew at the time).

    Daly’s analysis is at least 7 years old, going on 8. How much have we learned about Earth’s climate since his death? How much have we discovered about how the Arctic climate system works and how it is impacted by other global and regional climate cycles? Our understanding of what drives changes in the Arctic, while light years from complete, is far better now than it was in 2004. Sooner or later, it will be time to put that website to rest.

  30. davidmhoffer,

    I agree that the Arctic sea ice freeze/thaw is the pump driving that circulation and is a major part of earth’s thermastat. Ferdinand and I disagree as to what is controlling the annual cycle in atmospheric CO2. I have observed that the concentration in the arctic has a very strong statistical relationship with the freeze/thaw cycle. Ferdinand believes the annual cycle is controlled by land based vegitation in the mid latitudes as proposed by Keeling years ago.

  31. Ferdinand,

    As you know, the Arctic is water surrounded by land and the Antarctic is land surrounded by water. In the Arctic, when the ice freezes, the area of exposed cold water decreases and shifts the sink further south. In the Antarctic, when the ice freezes the sink is shifted north and area of the sink increases. Surface currents flow into the Arctic through relatively narrow passages. Surface currents flow around Antarctica and are restricted to some degree by the West Antarctica Peninsula.

  32. The subject matter s interesting, but the article seems to just use state of the art satellite and image analysis technology to state the obvious and describe methodologies. It reads more like a grant application than a research paper. What did it find? That plankton blooms happen in spring? Wow!

    “The bloom peak is most often located close to the ice edge,” said Dr Yool

    Well its not exactly going to occur in the solid ice. Since the melt speed is related to spring-summer insolation, a close relation between blooms and the melting edge is not surprising either. As Alan Mitchell pointed out, defrosted phytoplankton from ice melt can aparently revive and return to growth; this would have been something interesting to talk about, it would be a good explanation for the prompt bloom at the melt edge. But it was probably either not known by the authors or judged to distract from the climate change epilogue (too much interesting genuine science can distract from the political message). BTW it should be possible to so how experimentally if phytoplankton frozen in ice can revive on thawing – that would be a worthwhile project.

  33. Travis writes,
    “Pardon my ignorance, but what evidence do you have that there was less sea ice in the 1950s than there is now?”

    As you suspect, all the evidence we have points in the opposite direction — there was substantially greater Arctic ice cover during the 1950s. A recent study by Kwok & Rothrock (GRL, 2009) did in fact use data from Cold War submarine observations. They conclude that
    “This combined analysis shows a long-term trend of sea ice thinning over submarine and ICESat records that span five decades.”

    For example, mean submarine-observed ice thickness at the North Pole over 1958-75 was more than 3.5 meters. By 2007, the best estimates are closer to 1 meter. There’s much more in the article, which for the scientifically-inclined should put to rest the legend that submarine-in-an-ice-lead photos prove there was less Arctic ice in the 50s.

    As Travis also notes, leads could open up near the North Pole then and now. They’re not what scientists mean when they discuss a “seasonally ice-free central Arctic.”

  34. Gneiss says:
    March 5, 2011 at 2:13 pm

    Has it been so long ago that one forgets exactly what was being tossed about as proof of Arctic Doomsday Melt?
    The images of the submarines surfacing at the North Pole in 1959 were my idea, I am the one who did that. I just had help in locating them by posters in here. They were in direct address of the panic-stricken claims of open waters in the Arctic as proof of impending AGW calamity. They are normal, and the thickness of the ice varies from year to year, as the images of 1959 and 1961 attest:

    http://www.robertb.darkhorizons.org/WhatGlobalWarming.htm

    and note the date of March 17 and the open water before the sun has returned to melt (a la Gore’s tipping point of no return).
    There is nothing going on in the Arctic right now that is cause for yelling Fire on a Crowded Planet.
    Neither is the Antartic going anywhere soon, as was claimed 35 years ago. Instead, it recovered from it’s low point and went to record high ice extents/areas.
    So what if Global Sea Ice is down 1 M km2? Well within natural variances.

  35. RE: Fred H. Haynie

    I have a number of questions about that analysis, too. Foremost among them is about the supposed 309-year and the 19-year cycle. What physical processes are those supposed to model? It may have a high R-Squared value, but if the model does not adhere to any known physical process, then either it has come up with something scientifically noteworthy, or it’s completely and utterly useless for prediction.

    Another question: can I assume that the discrepancy between the number of observations (386) and the degrees of freedom (375) is due to the rejection of the 10 outliers? If so, was that taken into account when the standard errors were calculated? If not, what accounts for the difference? Was the analysis on every parameter done with the same significance level?

    The proof is in the pudding, of course, but I highly doubt the conclusion that we’re likely to see a new summer minimum only once every 19 years. Time will tell.

  36. Travis,

    This is a statistical model of observations. I have yet to check cause and effect. I suspect the 19 year cycle is related to the multi-decadal changes in equatorial SSTs.
    The 309 year cycle may be associated with changes in the deep oceanic currents.
    A degree of freedom is used each time you fix a value (coefficients or constants). Four coefficients are produced in the regression analysis. The other degrees of freedom were fixed in finding the constants in the cyclic functions. The spreadsheet program does not consider these constants in calculating the error, but there are enough remaining degrees of freedom that it makes little difference. The extreme values were adjusted to model values and not disregarded. The number of values was not reduced.
    I’m not sure how this would effect the error statistics. It improves the fit.

  37. Fred H. Haynie says:
    March 5, 2011 at 12:56 pm

    davidmhoffer,

    I agree that the Arctic sea ice freeze/thaw is the pump driving that circulation and is a major part of earth’s thermastat. Ferdinand and I disagree as to what is controlling the annual cycle in atmospheric CO2. I have observed that the concentration in the arctic has a very strong statistical relationship with the freeze/thaw cycle. Ferdinand believes the annual cycle is controlled by land based vegitation in the mid latitudes as proposed by Keeling years ago.
    ______

    Why would the cause of annual CO2 cycle have to be just one thing? Certainly it is based on the seasonal vegetation cycle, but could also have some statistical relationship to the freeze/thaw cycle. Point of fact, these two cycles (vegetation and freeze/thaw) are of course statistically related, but as we all know, a statistical relationship only indicates a common connection, not causation. The change of seasons (i.e. increasing or decreasing solar insolation) is the connection, and a direct causation of annual CO2 cycles is the increase or decrease in vegetative activity the seasons come and go.

    Skeptics are betting that the multi-decadal decline in Arctic Sea ice is part of a longer-term natural cycle, and that soon (yes, it must be very soon, as in the next few years, for them to be right) the year-to-year Arctic Sea ice must begin a long-term incline, as this mysterious (PDO, AMO, solar, or what have you) natural cycle swings the other way. Warmists would posit that GCM’s have it generally correct and that we’ll see a seasonally ice free Arctic in this century– all because of the fact that CO2 levels are at their highest levels in at least 800,000 years.

  38. Gates says:

    “Skeptics are betting that the multi-decadal decline in Arctic Sea ice is part of a longer-term natural cycle, and that soon (yes, it must be very soon, as in the next few years, for them to be right) the year-to-year Arctic Sea ice must begin a long-term incline, as this mysterious (PDO, AMO, solar, or what have you) natural cycle swings the other way. Warmists would posit that GCM’s have it generally correct and that we’ll see a seasonally ice free Arctic in this century– all because of the fact that CO2 levels are at their highest levels in at least 800,000 years.”

    There is so much wrong with this comment that it begs debunking. That’s not hard to do with an R Gates post:

    Skeptics are not ‘betting’ anything. The scientific method, ignored by alarmists except for lip service, requires skepticism. Gates doesn’t qualify as being scientific; he’s just spouting opinion.

    Where do skeptics say a ‘longer term cycle’? That’s just a strawman argument. There are many climate cycles, as Gates shows with his comment on the [to him, ‘mysterious’] AMO, PDO, solar, etc. cycles. Rather, Gates attributes the entire 0.7°C warming to CO2. As if.

    What Gates always tries to avoid is the climate null hypothesis, which has never been falsified. He avoids it because it is a cornerstone of the scientific method. Kevin Trenberth is so upset that the null hypothesis falsifies his alternative CAGW hypothesis that he demands that it must be changed to Trenberth’s own cherry-picked “null hypothesis.” That clearly shows how angry Trenberth is that both the real world and the scientific method are not cooperating with his lucrative alarmism. Gates is just repeating the talking points.

    To falsify the null hypothesis the temperature would have to exceed the parameters of the Holocene. It isn’t even close. The current *mild* 0.7°C warming over the past 150 years is entirely consistent with numerous past warming cycles. Actually, it is smaller than most. As anyone can see, it has been considerably warmer many times over the past ten millennia, which means that the Arctic has melted many times prior to the industrial revolution. It’s a natural occurrence.

    Finally, I am still waiting for Gates or anyone else to show us real world evidence of global harm as a result of the increase in the tiny trace gas carbon dioxide. Despite endless predictions of runaway global warming, no one has ever identified global damage resulting from CO2.

    Thus Gates’ presumption, based on ignorance, is that the cause of the entire 0.7° warming is due to CO2, is nothing but a WAG, because there is zero empirical evidence to support it. It is the argumentum ad ignorantium fallacy: “Since I can’t think of anything else that would cause the warming cycle, then it must be due to CO2.” How stupid is that?

    Debunking complete.☺

  39. R. Gates,
    I’m going on what I observe and not on what I think should happen if this is causing that. Place your bets and lets see how it goes. I expect the next 19 year minimum will occur around 2028. A 309 year minimum is expected around 2067. I might not be around for either event, but I could set up a trust for my grand children.

  40. RE: Smokey

    Somkey Says:

    “To falsify the null hypothesis the temperature would have to exceed the parameters of the Holocene. It isn’t even close. The current *mild* 0.7°C warming over the past 150 years is entirely consistent with numerous past warming cycles. Actually, it is smaller than most. As anyone can see, it has been considerably warmer many times over the past ten millennia, which means that the Arctic has melted many times prior to the industrial revolution. It’s a natural occurrence.”

    Your null hypothesis is insufficient. No credible climate scientist would claim that warming episodes have not occurred naturally in the past. But with the existing unknowns in the climate system, a null hypothesis that simply states that the warming is natural is unsatisfactory. The null hypothesis must be that the current warming trend is explained by known natural phenomenon, which any credible “skeptic” must agree is false. It would be a mistake, however, for a skeptic to casually dismiss the alternative that humans are responsible for the current warming. Unless they, too, can come up with a physical process that accurately models recent changes in climate, than their suppositions are just as worthless as they claim “warmist” science to be.

    The mistake of a casual AGW proponent, likewise, would be to assume that the logical alternative hypothesis would be that rising levels of GHGs are the sole cause. The current warming trend is a complex issue involving multiple factors, and necessitates many tests and many observations, many of which are unfortunately not being made.

    If anyone on either side really wants this to come to any firm conclusion, then we need to press for MORE climate research, not less. It pains me to see people disparage science and scientists and jeer about incompetence when an endeavor fails (like the OCO last year and the GLORY satellite this year). Climate is not an issue that can be resolved politically, and public opinion will not affect whether the “skeptics” or the “warmists” are correct. It just makes one of them look bad in the end.

  41. Travis says,

    “The null hypothesis must be that the current warming trend is explained by known natural phenomenon…”

    That isn’t correct at all. It is not necessary to explain the mechanism. Otherwise, all mechanisms would have to be explained. For example, gravity is a fact, but the Higgs boson has still not been found despite tens of $billions expended in the search, and for all we know it could be a model error. The mechanism for climate cycles [PDO, AO, AMO, etc.] are even less certain. But that does not affect the null hypothesis.

    The null hypothesis is simply the statistical hypothesis that states that there are no differences between observed and expected data. The purported expected data from the alternative hypothesis is that CO2 will cause runaway global warming [CO2=CAGW]. But there are no differences between the observed data and the historical data. Therefore, CO2=CAGW is falsified. QED

  42. Smokey says:
    March 6, 2011 at 11:43 am

    “Where do skeptics say a ‘longer term cycle’? That’s just a strawman argument.”

    _____
    The much beloved hero of the skeptics, Joe Bastardi (I actually like the guy myself, though disagree with his sea ice analysis) is constantly speaking about the PDO, AMO, and other natural cycles and how we are seeing them shift back to a their cold cycles and this is going to cause the year-to-year Arctic sea ice to begin to expand again as well, so don’t give me this nonsense about a straw-man argument, because it is just that…nonsense.

    Also, in regards to the decline of the Arctic sea ice, and of global warming in general, it is beyond “known” natural variability, and your inability to understand this provides me ample reason to doubt your overall understanding of the topic. I believe that the GCM’s have it generally correct– CO2 is causing both the warming and the decline in sea ice. If they are incorrect, it is one of the most remarkable of coincidences that they could correctly model these general trends and just so happen to have correctly modeled what some unknown natural cycles are causing. The GCM’s represent an Alternative Hypothesis, which of course need not in any way be the opposite of, or negate a null-hypothesis. The GCM’s collectively embody an Alternative Hypothesis and predict the general trends in the the climate that we’ve seen (through back testing) and are continuing to see. In this sense, Trenberth is correct, and the collective Alternative Hypothesis as modeled and thus embodied in the GCM’s (i.e. the 40% increase in CO2 and related feedbacks) now represent a working hypothesis that has predictive power and that some other hypothesis would have to either replace or refute.

  43. Re: Smokey

    “That isn’t correct at all. It is not necessary to explain the mechanism. Otherwise, all mechanisms would have to be explained.”

    That is taking it to the extreme, perhaps, but I’ll concede the point on those grounds. However, your null hypothesis does not even seem to assess the cause of warming. You state:

    “To falsify the null hypothesis the temperature would have to exceed the parameters of the Holocene. It isn’t even close. The current *mild* 0.7°C warming over the past 150 years is entirely consistent with numerous past warming cycles.”

    Can I ask you to put that into words as a formal null hypothesis? What you say here doesn’t seem to even assess the CAUSE of warming, just whether it is happening or not. If you are going to compare it the scope of the entire Holocene, then of course it’s not statistically significant. As I’ve said, no respectable climatologist would claim that warming events have not happened in the past without aid of mankind.

    Yet in that light, what do you mean by saying that the past 150 years of warming is “consistent” with numerous past warming cycles? Do you mean that it’s the same length? The same magnitude? The same cause? All of the above? A null hypothesis means nothing unless it clearly defines the parameters and population being targeted. So let’s not be nebulous. What is your specific claim?

    Suppose we start with “The trend in temperature over the past 150 years is not statistically significant.” I hope we can agree to reject that without argument. I disagree with the premise that since warming has happened before, it necessarily implies that it is entirely due to natural factors now (just as I reject the notion that it is entirely due to mankind’s influence). Climate scientists, in any case, claim to have falsified the null hypothesis that “the current warming trend can be explained solely by known climate cycles and variability” which you seem to dispute in turn, or at least disregard in favor of hypothesized yet heretofore unknown or hypothetical natural factors. Where does that leave us?

  44. Travis says:
    March 6, 2011 at 1:31 pm

    Climate scientists, in any case, claim to have falsified the null hypothesis that “the current warming trend can be explained solely by known climate cycles and variability”

    They claim that the current warming trend can’t be caused by natural variability. But that is solely based on climate models, which are not validated at all. To the contrary, as no climate model has predicted the lack of warming over the past decade (besides the ENSO influence), they clearly underestimate the influence of natural cycles and need scapegoats like human aerosols, which have such an uncertainty, that even the sign is not certain…

  45. RE: Ferdinand Engelbeen

    “…like human aerosols, which have such an uncertainty, that even the sign is not certain….”

    Hence my disappointment that recent satellite launches of the Orbiting Carbon Observatory and GLORY have failed. They would have supplied much-needed data and perhaps put parts of this controversy to rest…or at least moved us forward into another set of questions.

  46. Whatever drives the Arctic ice sheet when it is retreating from 10e6sqm to 8e6sqm is what determines the minimum ice extent. Typically this is when the ice is retreating from Northern Kamchatka across Siberian shore of the Arctic ocean to Finland.

    I think this new idea is plausible as a driver for minimum extent.

  47. Travis,

    You ask reasonable questions. So I’ll try my best to explain the situation, beginning with statistical significance.

    “You say: ‘The trend in temperature over the past 150 years is not statistically significant.’ I hope we can agree to reject that without argument.”

    Sorry, it is either statistically significant or it isn’t. It’s like being pregnant; you either are or you aren’t.

    Phil Jones, of the alarmist inner sanctum, admitted there was no statistically significant warming, “but only just.” That doesn’t matter. There was in fact no statistically significant warming, which blows the GCM predicitions out of the water. They were wrong as usual.

    Further, Phil Jones himself provided Hadley data showing essentially exact replicas of the current temperature trend going back to 1850. Recall that the Little Ice Age began moderating about 1800.

    Neither current trends nor temperatures are outside the parameters of natural variablity during the Holocene. Any so-called climate scientist who claims to have falsified the null hypothesis is lying, plain and simple. If it had been falsified, Trenberth would have been running around crowing about it, instead of trying to replace it with his own bogus, cherry-picked “null hypothesis.”

    I am not claiming [and I never have] that human emissions have zero effect on temperatures. What I am stating is this: The demonization of “carbon” [by which the scientifically illiterate mean carbon dioxide, a very minor trace gas] is happening because it is extremely lucrative, and because the nerdy scientists who succumbed to the rock-star fame of being repeatedly interviewed, with the public swallowing their catstrophic prediction hook, line and sinker, never in their wildest dreams thought they would go from zero to hero simply by lying about climate data.

    Based on my background and following the articles posted here and elsewhere for the past four years, and listening more closely to those scientists who are at the pinnacle of their carreers and thus have nothing to gain by lying or exaggerating [such as Dr Richard Lindzen], I think that the effect of CO2 is insignificant, on the order of a few tenths of a degree per doubling at most. There is no evidence showing otherwise. Thus, the rise in CO2 can be completely disregarded for all practical purposes.

    Next, you asked for a definition of the null hypothesis: The null hypothesis is the statistical hypothesis that states that there are no differences between observed and expected data. The warming over the past century and a half is coincidental with the rise in CO2. If CO2 caused even a large part of the warming, the temperature would closely track the rise in CO2. It doesn’t.

    Finally, you ask about the cause of the current warming. Once again I must explain that the question of cause is entirely separate from the null hypothesis. A reductionist fixation on mechanism can lead to the fallacy, “argumentum ignarus res” or argument in defiance of facts: so much faith is placed in a mechanism [and in the simplicity of the mechanism’s operation in the real world] that an alternative hypothesis is stubbornly believed in spite of substantial evidence to the contrary. CAGW is a prime example of this.

    The null is simply a benchmark. The claim was repeatedly made that rising CO2 will cause runaway global warming [now mendaciously changed to ‘climate change’]. James Hansen has been arm-waving about this since at least 1988. As it turns out, Hansen and every other person that predicted runaway global warming was wrong.

    The null hypothesis is sometimes challenged by alternative hypotheses. If the alternative hypothesis, such as CO2=CAGW is valid, then there must be an observable change from the prior climate. But there has not been any measurable change in trends, temperature, or magnitude. The current climate is completely normal. In fact, the it is is especially benign compared to the extremes of the past 10,000 years.

    Those demonizing “carbon” are self-serving charlatans along with their cognitive dissonance-afflicted true believer followers. As Prof Lindzen puts it:

    Future generations will wonder in bemused amazement that the early 21st century’s developed world went into hysterical panic over a globally averaged temperature increase of a few tenths of a degree, and, on the basis of gross exaggerations of highly uncertain computer projections combined into implausible chains of inference, proceeded to contemplate a roll-back of the industrial age.

    So you can relax. A few tenths of a degree temperature change is completely normal and natural. It would be a different story if the temperature was inexorably rising year after year in line with CO2. But it isn't. The temperature anomaly is now exactly where it was in 1981, 30 years ago. There is simply no empirical evidence – none – that CO2 causes even minuscule warming. It may. But if so, it is insignificant.

    R Gates,

    As I've shown, GCMs have an abysmal prediction record. Not one of them predicted the last decade's cooling. And based on your comments you still have no understanding of the null hypothesis.

    You improbably claimed that atmospheric CO2 is causing the ice caps to melt away. But plenty of glaciers are growing. I have no doubt you will use unbelievable rhetoric to explain how CO2 is causing the melting of ice in one location but not in another.

    Claiming that "…in regards to the decline of the Arctic sea ice, and of global warming in general, it is beyond “known” natural variability, and your inability to understand this…" & etc. That is simply wrong. It is wishful thinking. The Arctic has been ice free many times throughout the Holocene. But we only have instrumental data from the 1950's. You are basing your entire conjecture on a few decades, and your mind is closed to the ice core evidence showing much warmer temperatures throughout the past ten millennia.

    Your preposterous claim that a minor trace gas comprising only 0.00039 of the atmosphere is melting the Arctic is as silly as it sounds. Warmer water under the ice is melting the ice cap. As the great John Daly explained it, "As we can see from recent history, both the extent and thickness of Arctic sea ice is certainly subject to variation. But it would be a mistake to assume that a brief period during which the Arctic is in a thinning cycle is anything more than that – a cycle. We know from past history that it has been subject to earlier retreats as suggested by the opening quote from 1817." [source]

    There is no empirical [real world], testable evidence showing that CO2 is the cause of changes in Arctic ice cover. There are only your baseless claims – and the always-inaccurate computer models that can’t predict their way out of a paper bag. As the great scientist Prof Freeman Dyson explains:

    Here I am opposing the holy brotherhood of climate model experts and the crowd of deluded citizens who believe the numbers predicted by the computer models. Of course, they say, I have no degree in meteorology and I am therefore not qualified to speak. But I have studied the climate models and I know what they can do. The models solve the equations of fluid dynamics, and they do a very good job of describing the fluid motions of the atmosphere and the oceans. They do a very poor job of describing the clouds, the dust, the chemistry and the biology of fields and farms and forests. They do not begin to describe the real world that we live in. The real world is muddy and messy and full of things that we do not yet understand. It is much easier for a scientist to sit in an air-conditioned building and run computer models, than to put on winter clothes and measure what is really happening outside in the swamps and the clouds. That is why the climate model experts end up believing their own models. [source]

    The disreputable alarmist crowd has lately tried to demonize Prof Dyson. Of course he did synthesize and reduce to practice the Feynman/Schwinger/Tomonaga solutions to the renormalization problems of quantum electrodynamics, and Prof Feynman stated that he deserved the Nobel prize in Physics. But it is limited to three recipients [unlike the worthless Nobel “Peace” prize], and Dyson was the fourth member of the team. I prefer to listen to true scientists without an agenda. Prof Lindzen and Prof Dyson are two of the few commenting on climate issues who haven’t sold out for money and fame. You can listen to climate charlatans like Mann, Pachauri, Gore and the rest of their clique. But the truth is not in them.

  48. R. Gates says:
    March 6, 2011 at 1:11 pm

    …., and your inability to understand this provides me ample reason to doubt your overall understanding of the topic.”
    ===
    Hubris defined.

  49. Smokey said:

    “R Gates,

    As I’ve shown, GCMs have an abysmal prediction record. Not one of them predicted the last decade’s cooling. And based on your comments you still have no understanding of the null hypothesis.”

    ____
    I completely understand the null-hypothesis but also completely disagree with your assessment of the facts of global warming as you see them over the past century. We will not therefore, ever agree on any conclusions to follow after those basic disagreements. However, I do not disagree with your assessment of the specific “prediction” record of GCM’s, though they have been quite good at identifying general trends. But all this has nothing at all to do with the general tenets of the greenhouse properties of increasing amounts of CO2, but rather, of the current state of climate science in attempts to make linear type predictions on a complex chaotic system such as the climate. This failure, does not in any way mean that the basic theory of CO2 induced global warming is wrong, but rather, that the specifics related to this warming (including both positive and negative feedbacks) are not able to be completely modeled by the current GCM’s. For a more thorough discussion on this, I would suggest going to the Climate, etc. website and reading:

    http://judithcurry.com/2011/03/05/chaos-ergodicity-and-attractors/#more-2580

  50. R. Gates says:
    March 6, 2011 at 7:17 pm

    This failure, does not in any way mean that the basic theory of CO2 induced global warming is wrong, but rather, that the specifics related to this warming (including both positive and negative feedbacks) are not able to be completely modeled by the current GCM’s.
    ___________________________________

    Well that’s a fancy way of saying the models are full of sh*t.

    Like we didn’t already know.

  51. Smokey,

    I’m afraid you did not understand what I was asking. I was not asking for the definition of a null hypothesis; I am very well aware of what a null hypothesis is an what is required to reject it. My question/request involved you clarifying exactly what YOUR OWN null hypothesis was.

    You continue to have a difficult time narrowing down a time interval. I am not talking about statistically significant warming over the span of the Holocene; any credible climate scientist would have to agree that there were warm intervals in the past, and neither am I arguing the point.

    You also misrepresent Phil Jones’s quote, which was referring to the past 15 years (since 1995), not the last 150. Besides, that was last year. According to Jones, it was just short of statistically significant at the 95% confidence level at the time. I ran a Linear Regression T-Test of the annual UAH temperature anomalies from 1995-2009 and am forced to agree; the P-value is above the significance level. However, if he ran the test again this year including the 2010 data, he would get a P-value of about .044, making it statistically significant. You say it’s either statistically significant or it isn’t. I agree: it wasn’t then. It is now.

    If you run a simple significance test on UAH data for the trend over the entire satellite era, you get a trend that’s easily significant at a 95% confidence level. A similar test on NOAA data going back to the 19th century will result in the same conclusion at a 99% confidence level.

    You need not demonize those pushing carbon taxes or doom and gloom to me. I am making no such claims. I am simply looking for a base on which to build consensus instead of shooting down ridiculous alternatives.

    If we cannot agree that Earth has experienced a statistically significant warming trend in the most recent 150 year interval, then I’m afraid there’s not much use in continuing this conversation. Thank you for your time.

  52. philincalifornia says:
    March 6, 2011 at 8:30 pm

    R. Gates says:
    March 6, 2011 at 7:17 pm

    “This failure, does not in any way mean that the basic theory of CO2 induced global warming is wrong, but rather, that the specifics related to this warming (including both positive and negative feedbacks) are not able to be completely modeled by the current GCM’s.”
    ___________________________________

    “Well that’s a fancy way of saying the models are full of sh*t.”

    _________________________________________

    In other words, the Bull hypothesis.

  53. Now don’t tell me that all this planktonic activity could actually affect the atmospheric CO2 abundance, by turning all the dissolved CO2 into blooming plants; hence leaving a CO2 deficiency which Henry’s law might see fit to correct by dissolving more atmospehric CO2 into the exposed open water; did they actually call this an ice edge phenomenon; fancy that.

    Well it has been stated elsewhere that atmospheric seasonal CO2 changes, notably drops in the “growing season” are the result of plant growth; ain’t those little oceanic buggers plants too ?

  54. George E. Smith says:
    March 7, 2011 at 4:15 pm

    Well it has been stated elsewhere that atmospheric seasonal CO2 changes, notably drops in the “growing season” are the result of plant growth; ain’t those little oceanic buggers plants too ?

    They are included in the overall oxygen balance, which shows that somewhat 60 GtC is exchanged over the seasons (back and forth) of which over 1 GtC per year is net absorbed by the total biosphere (land + sea). There is some 3 GtC in average in the sea surface as living plant organics (600 GtC in land plants), but these have a rapid turnover in the food chain, thus most is returning as CO2 by krill, fish and sea mammals…

    Thus by far most of the exchange is from land plants, not from sea plants.

  55. “””””

    Ferdinand Engelbeen says:
    March 8, 2011 at 3:15 am
    George E. Smith says:
    March 7, 2011 at 4:15 pm

    Well it has been stated elsewhere that atmospheric seasonal CO2 changes, notably drops in the “growing season” are the result of plant growth; ain’t those little oceanic buggers plants too ?

    They are included in the overall oxygen balance, which shows that somewhat 60 GtC is exchanged over the seasons (back and forth) of which over 1 GtC per year is net absorbed by the total biosphere (land + sea). There is some 3 GtC in average in the sea surface as living plant organics (600 GtC in land plants), but these have a rapid turnover in the food chain, thus most is returning as CO2 by krill, fish and sea mammals…

    Thus by far most of the exchange is from land plants, not from sea plants. “””””

    What sort of land plants grow at the North pole, where NOAA reports the seasonal CO2 cycle is 18 ppm p-p; the largest found anywhere on the planet (three times Mauna Loa’s 6 ppm)? (they say)

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