Much importance has been ascribed to tracking the change in Arctic sea ice, but what about the global trend? That doesn’t seem to get much press. However there is some important information that needs to be presented related to the global trend of sea ice as measured by satellite since 1979. The results are surprising. – Anthony
Source: NASA’s Aqua satellite – click for larger image
A guest post by Jeff Id, from The Air Vent
2nd Update 12/24/08 It turns out that an error in documentation at NSIDC is the cause, see this new post for a full explanation.
Update and correction:
To my readers, Anthony Watts received a comment from our friend Tamino on the ice data I used for the area analysis. Unfortunately for me he is right this time. It appears that a correction to the data is required prior to 1987 which will create an approximate negative trend of 0.88 million sq kilometers per 30 years. It is a fairly small trend in the scheme of a 20million sq kilometer signal, but understand this mistake is entirely mine and is unrelated to Anthony Watts excellent blog.
Unfortunately the change makes the Area signal difficult to determine prior to 1988 because the percent fill is unknown. Anthony cannot check every detail of a post which took me days of research and he simply requested if he could copy it here.
The link to my corrections is:
http://noconsensus.wordpress.com/2008/12/16/sea-ice-decreases-despite-the-air-vent/
My apologies.
Jeff Id
I calculated a true global sea ice anomaly in this post using the National Snow Ice Data Center data. What would you say if I told you that over the last 30 years the sea ice area has stayed flat or even trended — Up!!!???
This isn’t a small deal. We have been told, well screamed at really, that CO2 is causing unprecedented rise of temperature on a global scale. We hear constantly that the ice is melting and the result will be dramatic flooding of the earth; movies have even been made. Those of us who pay attention to the scientists have heard that the most significant warming will be at the poles (according to the computer models). We also hear that the Antarctic has added ice during the same time the Arctic lost sea ice. This is explained in that the Antarctic ice increase is a local situation and the Arctic ice loss is a result of global warming. A unique form of cherry picking but should be treated with an open mind.
If you’ve been paying attention, you have heard that the net ice level is going down. The Antarctic gain cannot compensate for the Arctic loss. Well, I set out to see how bad the situation is.
First, anthropogenic global warming scientists use two measures, extent and area.
Extent looks at all the square Kilometers (Km^2) with more than 15% ice in them and adds them up.
Area looks at all the square Kilometers (Km^2) with more than 15% ice in them and adds them up but multiplies the Km^2 by the amount of ice in the square kilometer. i.e -(if you have 1 Km^2 of sea filled 15%, ice- extent counts it as 1Km^2 while area counts it as 15% of 1Km^2 or 0.15Km^2)
This post deals with the amount of sea ice so I used Area. In the future Iwill do it with extent. The NSIDC uses two algorithms for calculation of sea ice, nasateam and bootstrap. We will look at both here.
Without modification the NSIDC data for bootstrap runs from 1978-Dec. 2006 and the nasateam runs from 1978-Dec 2007, these near 30 year trends comply close enough with current science which states (conveniently) that climate requires a 30 year trend to see the result.
This is a graph of the global sea ice area from the nasateam algorithm.
The red line is the slope of the global sea ice data from nasateam in its raw format. The slope is negative by only 6803 Km^2/year and the mean is 18,290,000 km^2.
We should look at sea ice anomaly to be the most accurate for trend. To calculate sea ice anomaly I took the average shape of the annual signal and subtracted it from the curve above.
The average ice variation globally looks like this on an annual basis.
I subtracted this curve above to get the sea ice anomaly.
The downward slope of this graph is more extreme but the scale is highly magnified. The net downslope in 30 years of global warming is – 10173Km^2/year. Over 29 years of data this means that we have lost 302025 Km^2 of ice. This is a 1.65 percent drop in global ice level in 30 years. Remember though that this data ended on an extraordinary high melt year of 2007, the ice level can be seen recovering in dec 07 leading into 2008. This shows as a slight change in slope of the very tip of the first graph (a subtle, difficult to see effect).
Well NSIDC recommends using the Bootstrap algorithm for research instead of Nasateam because of certain errors which have been corrected for.
The bootstrap algorithm plot for global data looks like this.
The red line is slope again, and this time it is positive, indicating an increase in ice level from 1978-Dec 2006. The slope of the red line is plus 6341 km^2 per year indicating that the earth in 28 years has added 177,000 sq kilometers of ice with a mean ice level of 20.42 million Km^2.
The anomaly is better for calculating trends because it cleans up the end points making the slope insensitive to the start and stop point of the annual cycle.
The up trend for the anomaly in sea ice from 1978 to end 2006 is 804Km^2 per year. Which in our timeframe the preferred bootstrap algorithm says the earth ADDED 22,000 Km^2 of ice area!!
Here are the anomalies rescaled to actual by adding the mean of the original data back in.
Obviously people cannot make the claim that sea ice is being lost. It isn’t. The data shows that our trend is basically flat during this time of unprecedented temperatures. It’s clear that there has been no significant change in sea ice area.
This is almost enough to make me turn in my Skeptic union card, but increased CO2 warming the earth makes some sense to me, the magnitude is in question. The fact that polar sea ice not melting is not an insignificant point. It is also important to realize that the changes are too small to fit with IPCC statements about the trend. Unlike trees, ice does make a good thermometer. I can’t say this strongly enough— This is a strong indication of substantial errors in the computer models and temperature data which needs to be addressed before we throw what’s left of our global economy to the wind. How would Earth’s total sea ice ignore such substantial warming? It’s a good question which deserves an answer.
I will update this when new data becomes available and will also attempt to demonstrate that the net slopes we see are within the margin of error for the measurement in a future post. In the meantime, lets let the world know the truth. We aren’t going to drown any time soon!
————————
I had a request for description of the difference between the bootstrap and nasateam algorithms. It is a bit complex but it seems well documented on the NSIDC here are a few links and descriptions from that site. From FAQ section.
2. What is the difference between the NASA Team algorithm and the Bootstrap algorithm?
For general analyses or creation of simple images, either algorithm will suffice. The Bootstrap sea ice concentration data set is believed to be more useful for modeling and process studies in the polar regions because it is generally free of residual errors that could not be removed by conventional techniques. A temporally more consistent time series of sea ice concentrations is provided, offering improved accuracy over the ice concentration maps created from the original Bootstrap algorithm.
More interesting to me was the table provided which shows the strenghts and weaknesses of each process. The original table is at the link above.
For more details and complete descriptions NSIDC provides two links Bootstrap and Nasateam
HERE is a link to the R code to make the above graphs.
Data sources:
ftp://sidads.colorado.edu/pub/DATASETS/seaice/polar-stereo/
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The key to that story, Richard Hegerty, is the statement ‘in the satellite age’.
How can you say that the ice conditions today are unique when you’ve only got about 30 years of data?
There’s various stories that in the 1880s, 1920s that ice levels were much, much lower than a few years previous. From Norwegians.
I’d wait a while yet before being so unequivocal. And I really would scour historical records for evidence that this has happened before.
Because my hunch is that is has.
That story is a classic: ‘Give us a lot of grant money otherwise you might all die!’
You’ll see similar ones about ‘curing cancer’ when they’ve identified a new protein that MIGHT be a drug target, against which drugs MIGHT be developed, which MIGHT or MIGHT NOT be better than current drugs and which will only come to market in 15 years.
Rhys Jaggar (04:38:38) :
Science has never operated in “wait until we understand everything before publishing” mode. By reporting the small steps along the way, that gives other people direction in their own research. It allows people to replicate the results and report back if they are unable to.
Human medical research moves at an especially slow pace. Something about lawyers loving it when a human trial (or post trial) goes wrong. We don’t yet have good design tools to create drugs or enzymes that bind to these new proteins, but we do have some computer software that can test potential drugs’s fit with new proteins. I don’t know how well they work, but it is another step along the path.
One of the differences between science and engineering is that you’re never quite sure where the science is heading. Fix that and then your concerns could be addressed.
To David Hagen and other commentors on the Raiswell- Fe/Iceberg/Plankton study
My understanding of this work is that a negative feedback loop is put into effect by the bio-available Fe providing an essential ingredient for stimulating the growth of plankton.
See http://www.cesm.gatech.edu/faculty/fernandez/index.php
Study of the Biogeochemical Cycling of Fe: Plankton plays a crucial role in the Earth’s life dynamics; this tiny organisms lie at the bottom of the aquatic food chain, and its fate is thus thought to have deep implications in global climate change. Iron, among other trace metals, is an indispensable nutrient for the production of plankton, the most abundant marine organism. Because iron is extremely scarce in surface seawater, it is thought to occur almost exclusively bound to complex ligands of biological origin.
Also
From the Planktos Institute
“Fortunately the utility and efficacy of iron micro-nutrient ocean eco-restoration is near to hand and has benefitted from 20 years and $200 million in public research funds. Just a few weeks ago the Chief Scientist of the largest and best ocean iron micro-nutrient replenishment study performed aboard the German Alfred Wedgner Institutes research ship Polarstern announced that in their experiment they observed the following results. Within 30 days of adding iron (Fe) to enrich a patch of iron deplete Southern Ocean water to approximately 100 parts per trillion Fe a plankton bloom had fixed 50,000 tonnes of carbon (C) for each tonne of Fe applied. Given that biomass C was derived from CO2 that is a Fe:CO2 ratio of ~1:186,000 fixation. Further that scientist reported that 50% of that fixed carbon had sunk to or below the permanent thermocline in the same 30 day time frame.”
Larry (22:15:03) :
http://news.bbc.co.uk/2/hi/science/nature/7786910.stm
Someone needs to tell them that they left the AC on this year… we’ve had the onset of ‘winter freezing’ in fall when sometimes we didn’t get any at all.
Last night the SF Bay Area had such things as freeze warnings (20F range) and yesterday the nightly news had film of kids playing in snow in Berkeley. (Though I suspect they had to work hard to find someplace upslope from the city to film…)
These events are unusual even in the depths of winter. (In 30+ years here I don’t remember anything like it… but then again 25 yrs ago I wasn’t as interested in weather…)
E.M.Smith said:
Oh pshaw, don’t you know that the behavior of the atmosphere to increasing CO2 is counter intuitive? At first, you get global warming, but after a while you get global cooling and then chaos!
If you go to Cryosphere Today and click on the map that has the regional ice areas, you will see that for most of the Arctic, it is right on average for sea ice. It is only in one or two areas that ice is not forming (along Russia’s boarder). If you head out to the Bering Straight, the ice is actually above the mean. The Arctic ice area really should be examined in terms of smaller regional areas so that a more refined assessment can be done as to the cause of low sea ice production. If it is only in one or two areas and has a melted edge versus a growing jagged edge, a well defined warm water current is likely to blame. Strong wind may also play a factor in keeping sea ice up against an edge as opposed to growing out to sea, especially in the case of a warm current keeping the edge melted and soft.
even more to the point cryosphere today has ice area growing steadily over the past few days and IJIS has it static or declining. What’s up with that!!
Ric Werme in response to my previous post:
1. Yep I’m well aware about how to develop drugs and the computer aids available – it’s been part of my professional life!
2. I’m all for scientists publishing data part of the way along: what I’m less happy with is ridiculous posturing in the media which befuddles non-scientists into unrealistic expectations of cures or, in the case of climate science, armageddon. Scientists should apply the same rigour to press stories they consent to as they do to their research. And sorry, boys and girls: you don’t. You’re like the rest of society: telling a few porkies for the printed word.
3. Is ‘science’ three sets of scientists coming up with totally different predictions for the top amplitude of the next solar cycle? I don’t think so. It’s laying futures bets.
4. It’s advisable to distinguish between ‘science’ and ‘star gazing’. If I read a paper describing changes in ice conditions over 15 years and then finding that miraculously extrapolotated over a century, I say: ‘you need to study the basis of making extrapolations and the likelihood that they are right’. What scientists write in that context is NOT science. It’s fantasising. It’s either going to get hotter or colder. Well big deal. I didn’t need my Govt to spend £1m of taxpayers’ money to tell me that. It’s friggin’ obvious!
Merry Christmas!
Can some one explain what is happening up there in the Arctic?
The increasing recovery of ice has come to an end
Watts up in the arctic?
Well…either it is those socialist-plot-for-increased-reserch-funding-scientists that is manipulating the data to make the situation look worse that it is, IE more warming, you know(matter has been thoroughly examined on this site, I believe)…
or…
…there is wind or current patterns packing the ice. Remember: You do not need any more than 15% concentration of sea ice in a “grid cell” to be counted in the extent value. That will also be the explanation to why the area curve on CryosphereToday is growing, while the extent curve has gone flat: Packing the slush from 15% conc. to, say, 30% or more, would theoretically result in a decrease in “extent” but leave the “area” unaltered, as I understand the difference between those two figures…that leaves me with the conclusion that “area” is a better, more interesting and far more significant figure to put your interest in regarding the state of the sea ice…even more interesting to remember that the area-minimum of this year was equivalent to last year, and even more interesting than that it is to consider the actual volume of the sea ice, wich tells us how much ice there actually is up there, and some of those {snip} “warmers” are actually pointing out that there now actually is a rather small amount of arctic sea ice regarding the volume of the stuff…
Strange, that…
The whole concept of the biosphere as a greenhouse is incorrect to begin with. It does not behave like a greenhouse. It is a flawed idea from the start, at its roots, so all the arguing about whether or not there is global warming due to GHG’s is also flawed and pointless. This is also one reason that the computer models are complete failures – they are based on a false idea. The ONLY greenhouse type of effect occurs as a result of the effects of clouds, especially the large and reflective type which are generally cumulous (low) clouds and to some extent cirrus and stratos, but mostly the low clouds. More CO2 does not mean higher temperatures but only greater thermal “intertia” so that temperature variability is reduced, not temperature changed. As the atmosphere builds in energy content as a result of greater thermal mass it also builds in re-radiation into space as a result of a pretty constant absolute temperature, this increase in re-radiation away from the earth being in direct proportion to the increased energy concentration. If temperature does increase or decrease then energy re-radiation into space also increases or decreases in direct proportion BUT it also increases and decreases in proportion to the TOTAL available energy. Each extra CO2 molecule equates to an extra absorber AND an extra radiator. Putting aside the effects of clouds, the biosphere is not some kind of thermal “diode” that allows energy in but not as much out. If we are to understand the mechanisms behind global climatic temperature variability then it is absolutely essential to look at clouds as being the primary direct controller of variability and therefore we must understand how and why clouds form and what controls them. This is where Henrik Svensmark and his team of honest, non-politically biased work has been of such great importance.
More CO2 has no effect on temperature average, only on temperature range (day to day, season to season, etc) just like the effect of atmospheric water. Moreover, the oceans have about 1000 times the thermal capacity of the atmosphere and to think that the atmosphere could so dramatically affect the oceans when it is apparent and obvious that the major portion of sunlight is absorbed by the oceans, the stmosphere being largely transparent to this, and therefore the oceans have the major controlling effect on temperature variability AND absolute temperature of the biosphere when combined with the effects of land on atmospheric temperature (apart from seismic or volcanic or other internal mechanism activity), to think the atmosphere has a major say in temperature control is incredibly scientifically ignorant or just an outright lie. It shows little if any true understanding of heat, temperature, thermal capacities, energy, radiation or any meaningful physical science relating to the subject in question. The main difference between H2O and CO2 (apart from the numerical differences of their specific physical properites such as degree of freedom, thermal capacity, physical mass, etc) in terms of their effects on the atmosphere is that water is capable of condensing into liquid to form clouds and readily and rapidly moves between surface and atmosphere, daily, seasonally, annually and on even greater time scales, but CO2 does not liquify in the biosphere and transfers over mostly long time periods between surface (primarily oceans, seas, etc) and the atmosphere.
If you want to understand climate temperature trends you MUST study clouds, their formation, their causes, their dissipation, how pressure and temperature systems affect them but most importantly what seeds them. Clouds do not just appear when air and therein contained atmospheric water cools down. Every droplet in a cloud must be seeded on a particle of some kind, generally referred to as aerosols. Up until Svensmark’s work, there were inadequate explanations for some of the effects we have seen in terms of cloud variability and especially with its association with solar magnetic activity. I will not go into depth here but for anyone wanting some real and honest science rather than cult faith you should look into the whys and wherefores of clouds, and not just the work of Svensmark but all reputable scientific sources who do not have an agenda of self-interest (usually income or reputation based on past work – pride is a great influence on perception) with regards to the ever variable climate.
Just a further comment – the so-called greenhouse effect is also the effect of temperature being raised as a result of the energy stored in the atmoshpere, due to that thermal resistance of the atmosphere acting on the infra-red emissions from the ground back out. Without an atmosphere the earth’s surface would be about -18 C (255 K) but the mean temperature of the atmosphere at sea level is in fact around +14 C (288 K), so this difference of +32 K is due to that atmospheric thermal resistance preventing the rush of infra-red into space with the heat being stored on its way out in the atmosphere’s thermal capacitance. However, you MUST remember that over 95% of this effect is due entirely to water vapour, and the remainder is due almost entirely to non-GHGs, with CO2 accounting for some tiny fraction of the order of 0.1%, and this is of the 32K difference and NOT the total absolute temperature of 288K. This is not measureable in the thermally noisy atmosphere let alone has it any noticeable effect on the mean temperature, even if all the CO2 were either removed or doubled.
CLOUDS, folks, it’s the CLOUDS!!!!! These cover, typically, over 60% of the earth’s surface, a great fraction of that being low level and highly reflective clouds, this reflection keeping out a lot of sunlight in the day and having a cooling effect on the earth’s surface, especially with regards to the massive thermal storage capacity of the oceans which is about 1000 times that of the atmosphere. A mere 1% increase or decrease in average low cloud coverage will cause at least 0.3% decrease or increase in thermal energy input into the earth’s surface and thus ultimately into the lower troposphere. The cloud coverage changes by much more substantial amounts than a mere 1%. The night-time effect of trapping heat is no different to the same effect in the day-time but that is heat that would not be there in as great a quantity were there more clouds to begin with. More clouds both drastically reduce energy input from the sun and simply slow release of what energy there is trapped in the lower troposphere, but the long term effect would be a fall in average temperature because of the significantly reduced input power but the atmosphere’s ability to cool is aided by air current circulation whereby the warmer air rises above those low clouds and that infra-red is more easily re-emitted into space, whereby the low clouds now block that re-emission from hitting the ground again to any significant degree. The clouds just slow the cooling thus giving us the “balmy night” effect. CLOUDS control the average temperature offset level from the base (no-atmosphere) level of 255K. No clouds would result in drastically greater offset than +32K, all cloudy would result in a drastically lower offset than +32K. Study clouds, how and why they form, and you will be well on the way to understanding any of this recent climate change, and indeed climate change of past millenia.