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Arctic sea ice watch

Filed under: — group @ 10 August 2007

A few people have already remarked on some pretty surprising numbers in Arctic sea ice extent this year (the New York Times has also noticed). The minimum extent is usually in early to mid September, but this year, conditions by Aug 9 had already beaten all previous record minima. Given that there is at least a few more weeks of melting to go, it looks like the record set in 2005 will be unequivocally surpassed. It could be interesting to follow especially in light of model predictions discussed previously.

There are a number of places to go to get Arctic sea ice information. Cryosphere Today has good anomaly plots. The Naval Sea ice center has a few different algorithms (different ways of processing the data) that give some sense of the observational uncertainty, and the National Snow and Ice Data Center give monthly updates. All of them show pretty much the same thing.

Just to give a sense of how dramatic the changes have been over the last 28 years, the figures below show the minimum ice extent in September 1979, and the situation today (Aug 9, 2007).

Sep 05 1979Aug 09 2007

The reduction is around 1.2 million square km of ice, a little bit larger than the size of California and Texas combined.

Update: As noted by Andy Revkin below, some of the discussion is about ice extent and some is about ice area. The Cryosphere Today numbers are for area. The difference is whether you count ‘leads’ (the small amounts of water between ice floes) as being ice or water – for the area calculation they are not included with the ice, for the extent calculation they are.

Update: From the comments: NSIDC will now be tracking this on a weekly basis.


504 Responses to “Arctic sea ice watch”

  1. 151
    Hank Roberts says:

    Well, between your opinion and Dr. Hansen’s, I’ll take Dr. Hansen’s.
    The leap from “not happening” to “too late” is from the denial playbook.
    I refute it thus: http://naturalscience.com/ns/articles/01-16/hansenFigure9.jpg

  2. 152
    Sphere says:

    Re #115: By ‘Forcing’ do I take that figure as representing the yearly change in the increase in the surface energy balance? (Increase because the surface energy balance is increasing — otherwise known as global warming.) If so then any value other than 0 means some sort of geometric growth catastrophe (in the mathematical sense of catastrophe).

    [Response: Forcings are defined at the top of the atmosphere, not the surface. They in no way imply geometric growth catastrophes. - gavin]

  3. 153
    Sphere says:

    Re # 138: “I got it —- a 10-year window of opportunity to take decisive action.”

    Hank, if you want to stick your finger in the dike go ahead, but I’ll vote against building anymore levees surrounding New Orleans.

    I figure civilization has a 50-50 chance of surviving what’s coming, and humanity has a pretty good chance of surviving. I’ll worry about increasing the likelihood of civilization getting through this, and preserving information in case it doesn’t. I’ve given up on the notion of stopping it.

    Besides, from a global perspective this warming trend is minor. It only really matters to us and a few other large land animals.

  4. 154
    Jim Steele says:

    dhogaza wrote: “Why should it warm both poles somewhat equally?”

    Well mixed green house gases like CO2 should theoretically trap heat equally across the globe unless there is a mechanism of heat transport that moves heat unequally from the poles.

    Ocean currents generally speaking move heat from the equator to the poles, so we would need to answer the question how heat is being moved differently to the Arctic and Antarctic. Additionally then you would have to answer why CO2 has not heated the Antarctic proportionately despite the different hea transport mechanism. And if one could then show there was a offsetting change in heat transport, you should then ask if similar changes are happening in the Arctic. Most respected oceanographers will admit it is close to impossible to predict when and where the ocean will release heat trapped from decades, centuries and millenia gone by. There is still much to understand and much to debate.

    [Response: You have an incorrect understanding of the factors involved. Read our 2-year old post "Antarctic Cooling, global warming?". There is no contradiction at all between the predictions of anthropogenic climate change and the observation that inland Antarctica has cooled while the periphery has warmed. In fact, this is what the models predict. This nonetheless remains one of the favorites of the specious contrarian talking points. -mike]

  5. 155
    Nick Gotts says:

    RE #150 [I think the great coal burning of the 1800s had already sealed our fate.]

    On what grounds do you base your opinion, which appears to be contrary to the general expert view? The amounts of anthropogenic CO2 pumped into the atmosphere in the 1900s, and hence the rise in its atmospheric concentration during that period, far exceed that in the 1800s. See AR4 report of WGI, Ch.2, FAQ2.1, figure 1, p.135. The forcing is logarithmic in the rise in atmospheric concentration (so for example each doubling from pre-industrial levels is expected to have roughly the same effect), but I have heard of no scientific argument that the amounts of CO2 added in the 1800s would be sufficient to cause dangerous climate change.

  6. 156
    Sphere says:

    Re 155: “On what grounds do you base your opinion, which appears to be contrary to the general expert view?”

    First, I didn’t know there were experts on the question of what would have happened had greenhouse gas emission stopped about 1900.

    Second, the experts, your, and my opinions don’t really matter. The “decision” will be made by “mother nature”. What we have to do is decide what action we will take. I happen to be interested in the rather esoteric problem of defeating entropy; which implies a preference for assuming the worst and hoping for the best.

    In line with my interests, I’d propose taking some action to try to stop global warming, but assuming it to be largely unstoppable short run I’d put the bulk of effort into surviving the event as best we can. I wouldn’t waste effort trying to hold onto that which is most likely lost.

    Third, experts such as Christina Hulb have come about to my view — she was rather annoyed by the collapse of Larsen B and the rapid outflow of glaciers following that event. I didn’t really predict Larsen B, but I did predict that the shelves were holding back the glaciers.

  7. 157
    Timothy Chase says:

    Hank Roberts (#151) wrote:

    Well, between your opinion and Dr. Hansen’s, I’ll take Dr. Hansen’s.
    The leap from “not happening” to “too late” is from the denial playbook.
    I refute it thus: http://naturalscience.com/ns/articles/01-16/hansenFigure9.jpg

    Looking at the article that the chart belongs to, I find it incredible how well the runs from the models fit the data. Of course, for someone who doesn’t know how the models work, someone who assumes that they are constructed by fitting the models to the data rather than being grounded in physics, it is all too easy to conclude that scientists merely tinkered with the formula until things fit. Afterall, this is just one chart. But there are so many charts, and the models are integrated such that if one tinkered with one part in order to make things fit a particular curve the other curves would take on bizarre forms which in no way fit the other curves.

    Looking at an article recently, which I am having some difficulty looking up, it stated that we had doubled the vertical resolution of the models both with respect to the atmosphere (from 20 to 40) and with respect the ocean (5 to 10, if I remember correctly), and then changed the horizontal resolution from 1.25 degrees to 1 degree, which means that the cross-sectional resolution has more than doubled. This is more or less standard nowadays. And that is since the 1990s, I believe. Likewise, a recent Hadley calculation involved an ensemble of over a thousand runs. Hansen’s 1988 was just a single run.

    Anyway, I will see if I can find the links – I believe I saved them somewhere.

  8. 158
    Jim Steele says:

    Chris S Says: Isn’t there a large carbon sink in the southern hemisphere that was recently studied and deemed “completely saturated of Co2″? Maybe that’s the reason.

    Perhaps Chris you could show me a link where “atmospheric CO2” concentrations are not well mixed, especially around Antarctica? The sink notion is meaningless in this context if the atmospheric concentrations of CO2 are equally distributed.

    You mention the difference may have to do with polluting populations in the northern hemisphere but again you are assuming atmospheric CO2 concentration are NOT equally mixed. I believe the answers have more to do with natural cycles and processes that are being minimized in this debate. Likewise for ozone holes. You would expect bigger ozone holes in the northern hemisphere near the polluting centers. However just the opposite is the case and it is the Antarctic not Arctic that gets ozone holes.

    Chris S Says: “This is the first I’m hearing of this. Last time I checked, it was melting, much quicker then expected. Didn’t the Laresn B Ice shelf colopase some decades ealier then expected? “
    Read the following by researchers who wrote much of the IPCC’s information on polar climates.
    A synthesis of Antarctic temperatures
    by William L. Chapman and John E. Walsh
    http://igloo.atmos.uiuc.edu/Antarctic.paper.chapwalsh.2005.pdf
    They conclude, “Trends computed using these analyses show considerable sensitivity to start and end dates with starting dates before 1965 producing overall warming and starting dates from 1966-1982 produce cooling rates over the region.”
    So if we start from 1966, isn’t it odd that during such a period of “dramatic warming” in the last 4 decades that Antarctica is cooling!?! Most CO2 advocates like to use before 1965 trends to dismiss this theoretical problem and so contend there is still a warming trend. I find that to be more spin than good scientific inquiry!

    And it is true that we lost the Larsen B ice shelf and any measure of melting in Antarctica is founds only in the this area of western Antarctica and represents about a tenth of the Antarctic ice. The eastern Antarctica show no such melting by most measures.

    There are several studies showing sea ice is generally expanding in area and extent in most of the Antarctic but with a decrease in the western area. Overall the sea ice is increasing.
    Here is a link to the abstract of a 2004 paper “Interpretation of recent Antarctic sea ice variability”
    http://www.agu.org/pubs/crossref/2004/2003GL018732.shtml
    And here is a link to a map showing that while the atmosphere was cooling globally, the area of the Larsen B ice shelf was still warming. This strongly suggests that ocean currents and stored heat may be more responsible than atmospheric warming and CO2.

    http://en.wikipedia.org/wiki/Image:Global_Cooling_Map.png

    Chris S Says: “Where is that coming from? You mean the “Artic sea level?” or worldwide sea level. That question isn’t very clear.”

    My apologies I should have specifically said Arctic sea level. Here is a link: http://news.bbc.co.uk/1/hi/sci/tech/5076322.stm

    They found over the past 10 years “Arctic sea level has been falling by a little over 2mm a year“

    Sphere Says: “Um, what about http://www.cdc.noaa.gov/map/images/fnl/sfctmpmer_365b.fnl.html?”

    Umm sphere I am not sure what your link is suppose to tell me. But I am an ignorant naysayer. Please explain. Read the Chapman & Walsh paper I linked to.

  9. 159
    Nick Gotts says:

    Re #153 [Besides, from a global perspective this warming trend is minor. It only really matters to us and a few other large land animals.]

    On what is your opinion based?

    How about coral reefs and all the marine life depending on them, species in tropical forests likely to turn to savannah, marine animals which build shells of calcium carbonate (due to ocean acidification), high-altitude fauna and flora?

    According to Thomas, Cameron et al “Extinction risk from climate change” (NATURE |VOL 427:145-8, 8 JANUARY 2004 http://www.gbltrends.com/doc/nature02121.pdf) somewhere between 15% and 37% of a broadly distributed sample of species will be “committed to extinction” due to climate change by 2050, but prompt action can make the higher part of that range less likely.

    Another recent study (Climate simulation of the latest Permian: Implications for mass extinction JT Kiehl, CA Shields – Geology,33;9;p. 757-760 2005), the greatest known mass extinction in Earth history was probably caused by CO2-induced global warming (in this case due to massive volcanic eruptions), of about 6C. This amount of warming is within the range of possibilities if (but according to expert opinion only if) we do not take serious action to reduce greenhouse gas emissions.

  10. 160
    Timothy Chase says:

    PS to #156

    The resolution comparisons are:
    Verical was 19 levels of atmosphere, now 38 levels, the ocean was calculated as 20 levels and now as 40 levels for the first 5 km, the horizontal resolution was 1.25 degrees by 1.25 degrees but is now 1 by 1. And that is the advance from the 1990s to present.

    See:

    Models ‘key to climate forecasts’
    By Dr Vicky Pope
    UK Met Office’s Hadley Centre
    http://news.bbc.co.uk/1/hi/sci/tech/6320515.stm

  11. 161
    Sphere says:

    Re 159:

    “Re #153 [Besides, from a global perspective this warming trend is minor. It only really matters to us and a few other large land animals.]

    On what is your opinion based?”

    My opinion.

    “How about coral reefs and all the marine life depending on them, species in tropical forests likely to turn to savannah, marine animals which build shells of calcium carbonate (due to ocean acidification), high-altitude fauna and flora?”

    Tropical coral reefs have had to move in the past, and I’m sure will have to move in the future. We’re just an annoyance.

    “According to Thomas, Cameron et al “Extinction risk from climate change” (NATURE |VOL 427:145-8, 8 JANUARY 2004 http://www.gbltrends.com/doc/nature02121.pdf) somewhere between 15% and 37% of a broadly distributed sample of species will be “committed to extinction” due to climate change by 2050, but prompt action can make the higher part of that range less likely.”

    The higher range seems believable. I’m not at all convinced about the “prompt action” part. I’m inclined to think that the best we can do is make the mess we’ve created slightly better.

    “Another recent study (Climate simulation of the latest Permian: Implications for mass extinction JT Kiehl, CA Shields – Geology,33;9;p. 757-760 2005), the greatest known mass extinction in Earth history was probably caused by CO2-induced global warming (in this case due to massive volcanic eruptions), of about 6C. This amount of warming is within the range of possibilities if (but according to expert opinion only if) we do not take serious action to reduce greenhouse gas emissions.”

    Interesting….

  12. 162
    Nick Gotts says:

    Re #161 [Re 159:

    “Re #153 [Besides, from a global perspective this warming trend is minor. It only really matters to us and a few other large land animals.]

    On what is your opinion based?”

    My opinion.]

    I think that probably tells us all we need to know about whether we need to take anything you say seriously.

  13. 163

    Re #152 and Gavin’s response that forcings are defined at the top of the atmosphere.

    Is it any wonder that the scientists have got the melting of the Arctic sea ice completely wrong? They are measuring the forcing at the top of the atmosphere (TOA) when the sea ice that is melting is at an altitude of 0 m (0 feet) ASL (above sea level.) i.e. the bottom of the atmosphere (BOT)!

    It is fairly obvious to anyone that the melting is due to the increase in CO2, which is raising the snowline and causing the Alps to melt. See Alps host mass naked photo shoot. The snowline has now risen to at least 10 m (30 feet) at the poles. That means the end of the Arctic sea ice, but not the ice at the South Pole where the altitude is 2,835 m (9,300 feet.)

    Can I just point out that Gavin is wrong anyway. The forcing is not measured at the TOA. It is measured at the tropopause. See the glossary in the latest IPCC assessment report (AR4) where it states:

    Radiative forcing is the change in the net, downward minus upward, irradiance (expressed in W m–2) at the tropopause due to a change in an external driver of climate change, such as, for example, a change in the concentration of carbon dioxide or the output of the Sun.

    Had I made such an elementary mistake I am sure Gavin would have been down on me like a sack of coals, just as he was when I suggested that the sudden drop in CO2 concentration above 80 km is due to the CO2 molecule being heavier than other air molecules.

    The point is that just because science is correct does not mean that scientists are correct. Science is what the scientists got right – not what they believed, such as the existence of phlogiston and aether, or their disbelief in ice ages, meteoric and cometary impacts,and continental drift. Even the Croall-Milankovitch theory of astronomy induced ices ages was long held in doubt.

    You don’t have to be a Galileo to have your correct ideas doubted.

    I rest my case :-)

    [Response: If you want to be picky, then forcing is best defined as the adjusted change in forcing once the stratospheric temperatures have adjusted. At that point, there is no net flux divergence in the stratosphere (since it is neither cooling nor warming) and therefore the forcing at the tropopause is identical to that of the TOA. The tropopause/TOA distinction is only important for the instantaneous forcings. - gavin]

  14. 164
    Nick Gotts says:

    Re #156 [First, I didn’t know there were experts on the question of what would have happened had greenhouse gas emission stopped about 1900.] There are reasonable well-founded estimates of the sensitivity of the climate system to GHG levels in the atmosphere, frequently discussed on this site. If these are anywhere near right, the amount put into the atmosphere before 1900 would not have caused dangerous climate change.

    [Third, experts such as Christina Hulb have come about to my view — she was rather annoyed by the collapse of Larsen B and the rapid outflow of glaciers following that event.]

    I assume you mean Christina Hulbe. In what sense has she come about to your view? Do you mean she agrees with you AGW sufficient to make the collapse of civilisation likely is almost certainly unstoppable?
    Here’s something she posted on 11th May 2007 (http://www.theleftcoaster.com/archives/010309.php#010309) – she’s summarising the IPCC report, but gives no indication she disagrees with it:
    “First, technologies already exist to accomplish meaningful greenhouse gas (GHG) stabilization goals. Second, the costs of mitigation are manageable (estimates range from small gains in GDP to costs in the few percent of GDP range). Third, there are significant co-benefits to mitigation, including economic growth in some sectors, public health, and energy & food security.”

    [I did predict that the shelves were holding back the glaciers.]
    When and where?

  15. 165

    [[Re 147″ “disintegration of the Ross Ice Shelf ”

    That would be Larsen B. http://nsidc.org/iceshelves/larsenb2002/

    If the Ross goes then most likely the West Antarctic would quickly follow.]]

    Oops. Sphere got that right and I got it wrong. My bad.

  16. 166

    Hank — Please don’t call me a denialist. I’m nothing of the sort. I fully intend to support and work for efforts to conserve energy and develop renewable energy sources and, if it will help, carbon sequestration. I’m just saying that I expect to lose.

  17. 167

    Re #166 where Barton writes:

    I fully intend to support and work for efforts to conserve energy and develop renewable energy sources and, if it will help, carbon sequestration. I’m just saying that I expect to lose.

    Barton,

    If only Hank, Gavin, and everyone else would face up to how serious the situation really is then perhaps we would not lose. But while scientists like Gavin find it more fun to argue with ignorant denialists about 1934 than to confront the real issues of life after Arctic Ice, then there is little hope for the planet.

  18. 168
    David Price says:

    One thing I have noticed from the map is that the North West Passage is now open. Will there be a lot of ships sailing through it in Summer now? Will this cause further loss of ice?

  19. 169
    J. Steele says:

    Mike a moderator said “You have an incorrect understanding of the factors involved. Read our 2-year old post “Antarctic Cooling, global warming?”. There is no contradiction at all between the predictions of anthropogenic climate change and the observation that inland Antarctica has cooled while the periphery has warmed. In fact, this is what the models predict. This nonetheless remains one of the favorites of the specious contrarian talking points. -mike]”

    [edited] I did read your site’s explanation for Antarctica cooling and I found it somewhat vague and wanting. First of all using the global mean average does nothing to support or deny the effects of CO2 warming. Averages can obscure causal relationships. Your explanation mentions winds, oceans and stratosphere and various heat transport mechanisms as possible explanations as to why the Antarctic is cooling. I certainly agree they all play critical a role. My point is that those same heat transport mechanisms may also play a role in the warming of the Arctic. And those mechanisms may have easily caused the Arctic to warm to a greater degree than the Antarctic that we witness a net gain in average temperature. We see unequal development of polar ozone holes due to natural factors, why not warming. Using the average temperature explains nothing but allows you to mire your analysis in circular thinking.

    [edited]

    Your explanation also refers to the southern hemisphere’s ocean’s absorbing the heat. If that hypothesis is true we should see the ocean’s warming. However the Lyman 2006 paper shows that while there are some areas of warming there are at least equally vast areas of the southern oceans that are cooling in particular around Africa. (And that data is not part of the suspect Argo float errors which are mostly in the North Atlantic)

    And perhaps you can site papers and models that explain why the Antarctic peninsula was warming when there was recent global cooling? Otherwise I am inclined to believe that past heat from the ocean is more critical to the ice shelf collapse than atmospheric and CO2 induced warming.

  20. 170
    Hank Roberts says:

    I was replying to Sphere, not to what you posted, Barton.
    I apologize that it seemed I was replying to you.
    I disagree that it is too late to do anything.
    I may agree with you (I think) that history argues against being hopeful.

    But history is mostly about what people thought and did without science to help.

    I remind myself that, in the whole of human life on Earth, only a few tens of thousands of people have been scientists, and those in the last couple of centuries. In that way, science is providing one hell of an effective candle, all of a sudden, after many thousands of years of darkness.

    Almost every human choice has been made without any way of understanding long term trends and indirect effects and external costs. Only the last maybe fifty years have decisions started to be made that _assume_ the need to ask what science can offer. Most of our stories of hope are the ‘first time’ stories — the Broad Street Pump, for example. Anyone who knows even a bit of science will probably know that story. People who don’t —- can learn.

    David Brin says this far better, in quite a few places.

  21. 171
    dhogaza says:

    I assume you mean Christina Hulbe. In what sense has she come about to your view? Do you mean she agrees with you AGW sufficient to make the collapse of civilisation likely is almost certainly unstoppable?

    I’ve never heard her say that, and I drink beer with her [edit] on a fairly regular basis.

    [edit - no personal information about 3rd parties please]

    AFAIK she holds to mainstream scientific views regarding climate issues. The quote you provide from this past May is consistent with everything I’ve heard her say about the subject.

  22. 172
    dhogaza says:

    Chris S Says: Isn’t there a large carbon sink in the southern hemisphere that was recently studied and deemed “completely saturated of Co2″? Maybe that’s the reason.

    Then Jim Steele said:

    Perhaps Chris you could show me a link where “atmospheric CO2” concentrations are not well mixed, especially around Antarctica? The sink notion is meaningless in this context if the atmospheric concentrations of CO2 are equally distributed.

    Jim, you don’t need a link, a map will suffice. All that blue ink you see represents salt water …

  23. 173
    Hank Roberts says:

    > show me a link where “atmospheric CO2” concentrations are not well mixed, especially around Antarctica?
    > The sink notion is meaningless in this context if the atmospheric concentrations of CO2 are equally distributed.

    That doesn’t make sense. It seems like you’re saying it logically can’t happen?
    But nature answers.

    Air circulates and mixes a lot faster than water; we know CO2 is well mixed over a few years’ time in the atmosphere (Mauna Loa can track seasonal variations from particularly strong or weak growing seasons at different places around the globe, when they come ’round over the Pacific long afterwards, before they get mixed in, the Mauna Loa observatory has a description of that).

    The ocean sink is described here, and many other places in the news of the time:
    http://news.bbc.co.uk/2/hi/science/nature/6665147.stm

    The article mentions Dr. Corinne Le Quere, whose work is in this area. I’ve said before I hope RC can get Dr. Le Quere in at some point. I notice that she is talking about improving the climate models by paying specific attention to the different kinds of plankton that create this part of the carbon cycle and how they change — which is going to be very interesting once it’s in the models.

    The same BBC article also quotes Dr. Sus Honjo of WHOI:

    “…. technology now made possible very detailed monitoring of marine carbon sinks, with some data available in real time.
    ‘We have been way behind the modellers, who are hungry for numbers. But now we are starting to catch up because of the new tools and instruments available’…”

    It’s real.

  24. 174
    Jim Steele says:

    Hank Roberts Says:

    > The sink notion is meaningless in this context if the atmospheric concentrations of CO2 are equally distributed.

    “That doesn’t make sense. It seems like you’re saying it logically can’t happen?
    But nature answers.”

    Hank you have cnfused me. Are you arguing that the ocean carbon sinks explains the cooling in Antarctica?

    I do not see why you would think I am arguing that a sink does not exist. Nor was I arguing that short term asymmetries in atmospheric CO2 can not exist. You have taken my points out of context.

    However I am most assuredly arguing against the above suggestion that the existence of a southern ocean carbon sink will create an atmospheric asymmetry that lead to east Antarctica cooling while west Antarctica warms. As a sink will gradually absorbs CO2, the atmospheric CO2 immediately readjusts to the change in partial pressures. Only singular explosive events like a volcanic eruption would cause measurable atmospheric asymmetries. I suppose someone here could call the sink explanation specious.

  25. 175
    Dr Andrew Iles says:

    It seem that the worst thing one can be labelled is as a ‘Climate change denialist’. It is a catch-all, hence when I say that at best I see selective use of particular data to support a particular argument I will be no doubt pilloried. Ignoring the scientific process is counter-productive and dangerous.

  26. 176
    Timothy Chase says:

    Dr Andrew Iles (#175)

    It seem that the worst thing one can be labelled is as a ‘Climate change denialist’. It is a catch-all, hence when I say that at best I see selective use of particular data to support a particular argument I will be no doubt pilloried. Ignoring the scientific process is counter-productive and dangerous.

    Hardly.

    Among those who are particularly active and who consequently have every reason to know its real and to understand its causes, there exist different types with different clusters of motivation. However, motives don’t even enter consideration until one has had the chance to examine the arguments and the evidence. Nothing to worry about assuming your arguments are valid and you have the evidence to marshall, or alternatively that you are willing to abandon your position once it has been shown to be untenable.

  27. 177
    Nick Gotts says:

    Re #175 [when I say that at best I see selective use of particular data to support a particular argument I will be no doubt pilloried.]

    Well, you might at least be asked to specify where you see it, so your claim can be responded to in a useful way.

  28. 178
    dhogaza says:

    when I say that at best I see selective use of particular data to support a particular argument I will be no doubt pilloried.

    You’ll be pilloried for waving your hands and saying “I don’t believe the science” without providing any specifics.

    Ignoring the scientific process is counter-productive and dangerous.

    Then don’t do it.

  29. 179
    Hank Roberts says:

    Er, could you be a bit more specific? Was it something I said?

  30. 180

    Re #179

    Hank,

    I don’t think anyone is criticizing you.

    But if you are really paranoid then ‘could you be a bit more specific?’ What is the number of the post that you think is attacking you?

  31. 181
    John Mashey says:

    re: #175-179:

    EITHER
    “Dr Andrew Iles” is a reasonable person with a real issue, but the post was minimally-contentful and seemed OT. Usually, if ignored, reasonable people will try again without being asked, and perhaps articulate their point well enough that a) It can be seen to be on-topic and b) a reasonable conversation can ensue.

    OR
    DBAT: Drive-By Anonymous Troll … successfully helping clutter a useful discussion with junk & replies to junk.

    Hence, I suggest IGNORE is a productive first-look strategy.

  32. 182
    Hank Roberts says:

    Yup, sorry Alastair, I meant that as a reply to Iles, failed to point to it explicitly. John Mashey has the better reply (at 3:36pm)

  33. 183
    Timothy Chase says:

    Alastai:r McDonald (#180) wrote

    Hank,

    I don’t think anyone is criticizing you.

    But if you are really paranoid then ‘could you be a bit more specific?’ What is the number of the post that you think is attacking you?

    Alastair, I doubt that he was responding to you when Hank Roberts (#179) humorously wrote:

    Er, could you be a bit more specific? Was it something I said?

    In fact, I believe he was responding to the following (#175):

    It seem that the worst thing one can be labelled is as a ‘Climate change denialist’. It is a catch-all, hence when I say that at best I see selective use of particular data to support a particular argument I will be no doubt pilloried. Ignoring the scientific process is counter-productive and dangerous.

    I suspect that I am much more likely to experience a degree of paranoia than Hank, but if I were putting together a descending list, there are others who I would place much closer to the top of it.

  34. 184
    Sphere says:

    http://www.jpl.nasa.gov/news/features.cfm?feature=1315

    It seems that at the moment the only part of the arctic with anything like a ‘normal’ ice extent or area is leeward of Greenland. Is there any reason at all to believe the current over 2 million anomaly in Arctic sea ice area is just normal variation?

    While I’m not ready to declare that 2007 is the transition year, I do think there is every reason to believe it might well be the year. I doubt this winter will support a sufficient recovery to push the “switch” off another year.

    (I do believe in the butterfly catastrophe theory of systems, and do expect that whenever the change happens it will be sudden. That doesn’t mean that I have any idea on when the catastrophic change will occur.)

  35. 185
    Anthony Shafer says:

    re: 138 “10-year window of opportunity to take decisive action.”

    Can someone inform us lurkers exactly what this means? It’s commonly used, yet uncommonly defined.

    How decisive must the action be?

    What must be done?

    What is the economic costs (for the average us citizen) for this decisiveness?

    I am sure there are millions of us wanting to help, changing light bulbs etc… but does this really matter?

  36. 186
    J.S. McIntyre says:

    re 148

    Re 147″ “disintegration of the Ross Ice Shelf ”

    That would be Larsen B. http://nsidc.org/iceshelves/larsenb2002/

    If the Ross goes then most likely the West Antarctic would quickly follow.

    ==================

    A general query.

    Larsen is a separate Ice Shelf near the tip of the West Antarctica penninsule. The next closest and adjoining Ice Shelf is the Ronne. The Ross Ice Shelf is about 1,000 kilometers away, across a swath of land separating it from the Ronne.

    http://nsidc.org/data/atlas/

    While the Ross touches both East and West Antarctica, wouldn’t the result be more impactful to East Antarctica?

    And wouldn’t the disintigration of the Larsen Shelf be enough to set off the West?

  37. 187

    Re #185 Sir David King, the UK Government’s chief scientist spelt out what has to be done to the AAAS last month. See http://www.aaas.org/news/releases/2007/0718king.shtml

    In summary he is saying that we need an international agreement on sharing and reducing the use of fossil fuels to be signed by 2009 and effective from 2012.

    Since it seems highly unlikely that George Bush would sign up to such an agreement, then avoidance of catastrophic climate change seems inevitable.

    This will lead to worldwide famine and a collapse of the global economic system, which will throw millions of Americans out of work, roaming the streets, all armed with guns.

    You can read a report prepared for the Pentagon about the consequences of catastrophic climate change here:
    http://www.gbn.com/ArticleDisplayServlet.srv?aid=26231

  38. 188

    [[re: 138 “10-year window of opportunity to take decisive action.”
    Can someone inform us lurkers exactly what this means? It’s commonly used, yet uncommonly defined.
    How decisive must the action be?
    What must be done?
    What is the economic costs (for the average us citizen) for this decisiveness?
    I am sure there are millions of us wanting to help, changing light bulbs etc… but does this really matter
    ]]

    It matters. If we don’t massively change our CO2 output in about a decade, anthropogenic global warming is likely to trip geophysical feedbacks which will amplify it greatly. At that point it will be impossible to stop and humanity will suffer.

    To stop AGW would require a massive shift to conservation, and away from fossil fuels to renewable sources of energy. I don’t think it’s going to happen, although I will work for it right up to the end. I think we’re out of luck just due to the strong tendency of human beings to do nothing about a crisis until the crisis actually hits. Prevention isn’t in our nature.

  39. 189
    Michael says:

    Re 185. Anthony, there is NO ten year window.

    The opportunity to stabilise warming at 1 degree C has been thrown away.

    Taking the study by Baer and coworker as an example,

    http://www.ippr.org.uk/publicationsandreports/publication.asp?id=501

    there is little time left before the opportunity to restrain warming to 2 degree C, to avoid dangerous climate change with its positive feedbacks etc, is lost. Their study (which is representative of recent emission pathway studies) suggests that global C02 emissions should peak by 2010. Measured in days that is about 1000 days to deliver the peak.

    It is instructive to plot out the graphs in the Baer study as they show the ghg emissions turning that must be delivered. If the results of the global endeavour are going to be seen within 1000 days, it requires leaders to have delivered executable emission reductions plans well before then.

    The profiles in the Baer study are doable.

  40. 190
    Hank Roberts says:

    “10 year window” (maybe 9 by now?) means — _have_made_changes_ within the ten years.

    It’s up to the big coal power plant builders, at this point, to do the right thing the smart way fast.

    Remember — there’s no sign of intelligent life in the universe, with the possible exception of Earth. They have the chance to decide, for this planet.

  41. 191
    Michael says:

    There is no 10 year window. There is a window of a few hundred days.

    There is an absolute requirement on leaders to deliver on their Duty of Care. That is a legal Duty. The Duty is not confined to leaders within the coal industry.

  42. 192
    Michael says:

    re 191. erratum. should have written coal-fired power station industrial sector.

  43. 193
    Chris S says:

    Jim S, – I hope you didn’t take the comment about confusing Arctic and Antarctic towards you. That would be the last thing I would imply on THIS site of all of them. It was a simple expression of how uneducated most American’s really are about the world around them. We are so caught up in our daily lives that like many have stated here over and over “humanity does nothing about a crisis until it hits”. That’s so very true, and so very disturbing. That was a real situation I found my self in when arguing with someone about the “existence” of AGW. Yet they still argue with you. I wasn’t speaking on the terms of scientists but everyday people on the issue.

    As someone studying to be in this field in the future, the one thing I will never do is say “that can’t be”. There’s PLENTY we don’t know like you bring up some good points. The Antarctic apparently is a mystery, BUT, I don’t find one missing link in the network of data and evidence on AGW and Climate Change strong enough evidence to denounce the cause of AGW. Hey, Maybe 5, 10, 50 years from now there will be some extraordinary discovery that explains all of this. The question is do we want to sit and wait on that discovery, or try to prevent the collapse of modern civilization. I am more then convinced that this is the case, and it has even made me wonder if bringing a child into this world would be worth it!

    You have to remember Jim, there are plenty of corrupt people in the world, many who will use their “power” or “expertise’ for the all mighty dollar. I’m sure your aware of ExxonMobil and those stories of hiring scientists to write papers, etc.

    In my Core required class, Public Speaking, we had to do a debate. This kid and I did it on the “Cause of GW” not so much it’s existence. He didn’t deny that it the earth was warming etc, but on the day of the presentation debate, he must have had about 15 packets of information, all at his disposal. I won the debate, while some even laughed at him throwing out random “causes” such as “Mar’s is warming, so…” . Come to find out his best friends father is vice president of ExxonMobil. Well go figure.

    I don’t know your area of expertise, just out of curiosity because obviously, I have no level, besides knowing the topic very well. lol. I hope I didn’t “offend” you whatsoever, and those questions I asked you were real questions I had.

    Thanks, Chris.

  44. 194
    Anthony Shafer says:

    (185, 191) Thanks for the links Michael, all I have had time for was the conclusion… which is quite frightening. In all reality here- an unscientific question is where does the community feel we’ll peak at Co2?

    Can anyone point me to more of a layman’s scenario per degree? Has there been any attempt to cross reference bio-diversity/social/political/economic/climate ramifications per degree change all in one place?

    Thank you again for all that you do!

  45. 195
    Gareth says:

    Can anyone point me to more of a layman’s scenario per degree?

    Six Degrees, by Mark Lynas (http://www.marklynas.org/sixdegrees)

  46. 196
    Gary says:

    A little off-topic here, but you have been talking up Co2 a bit lately. What is your take on this story?

    “Biofuels switch a mistake, say researchers”

    http://www.guardian.co.uk/environment/2007/aug/17/climatechange.energy

  47. 197
    Michael says:

    194 & 195. The book by Mark Lynas is an excellent book, although does not attempt to describe, for example, the economic implications per degree. The book provides, however, an excellent background with which to assess implications of each degree from various (eg economic, critical infrastructure, biodiversity) perspectives. One way of doing this is to define a Richter scale for an entity/system under consideration and then read through the book, degree by degree, and assess a Richter-level impact corresponding to each degree. Accumulated bundles of temperature-dependent Richter profiles provide insight into mitigation requirements.

  48. 198
    pbview says:

    Chris S Says:
    20 August 2007 at 2:43 PM
    Jim S, – I hope you didn’t take the comment about confusing Artic and Antartic towards you. That would be the last thing I would imply on THIS site of all of them. It was a simple expression of how uneducated most American’s really are about the world around them.

    Chris, I applaud your curiosity. The problem here is that the term debate is political, not scientific. The sciefintic arena on this topic (AWG) has been confused with politics. The duty of a scientist is to examine all information and come to a conclusion of the question asked (hypothesis) no matter where the funding came from. It is the scientists duty to evaluate all information that has been provided and check it against this hypothesis. It makes no difference who funded the scientific study. We have in science reached an area of Kill the messenger because it does not support our position and will therefore impact our funding. From both sides the change has become character assignation – one side more than the other. I implore you to do some research and you will find that at one time All scientists , 2,000, 1700, 600, 300, have agreed that man is responsible for Global Warming, now called Climate Change. It does not take an Einstein to realize that people are playing with numbers to fortify their positions and funding and or their ego.

    As far as procreating – no matter how you choose, your children will live in a different world than you have known.

    Good luck with your endeavors and always look for the truth.

  49. 199
    Sphere says:

    Re #186: “While the Ross touches both East and West Antarctica, wouldn’t the result be more impactful to East Antarctica?”

    The West Antarctic is considered less stable because more of the ice is below sea level. (I think there is also a slope more conductive to ice flow, but am not sure on that.) It is expected that it will require less climatic change for it to collapse.

  50. 200
    Sphere says:

    Re #188: “It matters. If we don’t massively change our CO2 output in about a decade, anthropogenic global warming is likely to trip geophysical feedbacks which will amplify it greatly. At that point it will be impossible to stop and humanity will suffer.”

    Please fit today’s approximately 2 and a quarter million anomaly in the Arctic Ice Area into your timeline. I’ll note first that there has been a growing anomaly for several years in succession, and second that with about a half month to go in the expected ice melt we are currently about 2/3 million below the previous known minimum.


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