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William Crump
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Jim Hunt: Please excuse the delay in replying. I asked the question of Neven because I value his opinion and the various models for the projection of future arctic sea ice conditions is a moving target and changes over time. I thought Neven might be more current on the models than I am and was hoping he would identify the models in which he places the most trust. You also appear to have a great deal of knowledge on this subject. Which model or models of future arctic ice projection do you believe are the most accurate? I understand that the models can only be used for general projections and the current conditions at any one point in time reflect weather and not climate so conditions during a particular year can not be used to either validate or to invalidate a particular model. Clearly arctic ice will continue to decline as more CO2 is added to the atmosphere - it is a matter of simple physics and not a matter of opinion - what I am interested in understanding is which model people like Neven and you, who are far better versed in the science than I am, believe represents the best estimate of how quickly this decline will occur. Perhaps due to variability and the difficulty in incorporating all the factors impacting arctic ice there are no models that can be relied upon, but I am interested in your view of the current models strength and weaknesses.
Toggle Commented Nov 23, 2018 on PIOMAS October 2018 at Arctic Sea Ice
Neven Which of the current models do you endorse, if any, as having the most accurate projection of future arctic sea ice?
Toggle Commented Oct 22, 2018 on PIOMAS October 2018 at Arctic Sea Ice
Neven I have been here many years and even kicked money into the pot at one point. I value the site for its science and observations. I have been a critic of simple line drawing projections of future Arctic Sea Ice and projections of a faster disappearance of ice at the September minimum, and premature claims concerning when the arctic will have ice free summers. My criticism has been born out by actual conditions and observations. Any time current ice conditions are low there are comments about this being the year of a new minimum. How accurate are such projections? Based on your comments, it appears that there is no correlation and such comments are not valid. Just go back and look at comments I made in 2011 that predicted that the arctic would not be ice free in the time frame indicated by Wipnius's line projections and others, including Wieslaw Maslowski. There appears to be a database going back to 1979. That is 39 years so I do not understand your contention that there are not sufficient data points to prepare a correlation analysis and that 59-69 years of data are required. Waiting 20-30 years will be too late as there will be many periods far below the minimal standard used by many commentators as to what constitutes "ice free" conditions at the September minimum over the next 30 years. I provided a link to research by Mark C. Serreze and Julienne Stroeve. Are they not considered reputable researchers on Arctic Sea Ice? Serreze is the Director of the NSIDC. Julienne Stroeve is a Senior Research Scientist at NSIDC. I was hoping you had information on the correlation of current ice conditions to the next September minimum as opposed to a statement concerning your lack of surprise as to what future conditions might be regardless of what those conditions might be. If you do not have the information just say so.
Toggle Commented Oct 22, 2018 on PIOMAS October 2018 at Arctic Sea Ice
Neven Of course, but not from AGW. People will adapt. What I was looking for was a measure of whether October ice conditions have any predictive significance with respect to the following year September minimum. Your statement was a rather unscientific guess - how about some data about correlations based on prior year observations and whether October conditions have any correlation to the following September minimum. Anybody can guess.
Toggle Commented Oct 22, 2018 on PIOMAS October 2018 at Arctic Sea Ice
Arctic sea ice trends, variability and implications for seasonal ice forecasting "atmospheric variability provides an inherent limit on sea ice predictability. For example, while 2013 started out with a large fraction of thin, first-year ice following the record minimum of 2012, comparatively benign summer weather conditions enabled a large fraction of that thin ice to survive, which was not foreseen by the forecasting community. Thus, while we expect sea ice extent to continue to decline in response to forcing from atmospheric greenhouse gases, interannual departures from this long-term trend will remain hard to predict." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4455712/
Toggle Commented Oct 21, 2018 on PIOMAS October 2018 at Arctic Sea Ice
This is a weather related phenomena. What are the specific weather related conditions that are causing this particular ice condition? It is clear that arctic sea ice is in a long term decline due to climate forcing caused by increased CO2 and AGW. This particular decline, while part of the general climate pattern, is better described as part of the variability caused by weather for a particular year. The Daily Arctic Temperature graph displayed above showed much higher than normal temperatures for January through March and still ice survived in September of 2018. While tracking current conditions are important, please disclose what the historical observed correlation of October ice conditions are compared to the subsequent September minimum. Please present facts, not guesses or "I wouldn't be surprised" statements. These people claim that: "By using a simple and computationally inexpensive statistical approach, one can anticipate more than 80% of SSIE up to 4 months in advance, based on the antecedent atmospheric and oceanic conditions over stable regions." September Arctic Sea Ice minimum prediction – a new skillful statistical approach https://www.earth-syst-dynam-discuss.net/esd-2018-61/esd-2018-61.pdf A method that can only predict 80% of actual coverage 4 months in advance does not appear to be a particularly useful method, but perhaps others will not see it that way. I do like their honesty when they admit "The predictability of these extreme years poses big challenges for the sea ice prediction community."
Toggle Commented Oct 21, 2018 on PIOMAS October 2018 at Arctic Sea Ice
gkoehler September Arctic sea ice is now declining at a rate of 12.8 percent per decade, relative to the 1981 to 2010 average. https://climate.nasa.gov/vital-signs/arctic-sea-ice/ Current State of the Sea Ice Cover https://neptune.gsfc.nasa.gov/csb/index.php?section=234 Climate Change: Minimum Arctic Sea Ice Extent https://www.climate.gov/news-features/understanding-climate/climate-change-minimum-arctic-sea-ice-extent Polar Ice Is Disappearing, Setting Off Climate Alarms https://insideclimatenews.org/news/27122017/arctic-antarctic-sea-ice-sheets-2017-year-review-glaciers-disappearing-polar-records Here’s what vanishing sea ice in the Arctic means for you https://www.theverge.com/2018/5/10/17339046/arctic-sea-ice-decline-albedo-effect-climate-change-global-warming gkoehler You need to isolate which existing "solutions" are economically practical if you want to gather political support. Tax credits will work better than imposing direct costs as it results in the most economically efficient methods being applied rather than a particular person's "favorite solution." The "solution" these people propose costs more per ton of CO2 removed than carbon capture at the source and is therefore impractical. http://www.climeworks.com/ "Climeworks says that its direct air capture (DAC) process – a form of negative emissions often considered too expensive to be taken seriously – costs $600 per tonne of CO2 today." This is a ridiculously expensive method of carbon capture. https://www.carbonbrief.org/swiss-company-hoping-capture-1-global-co2-emissions-2025 These people focus on producing energy without using carbon sources, however, no one suggests this is a practical method to operate the entire electrical grid. Carbon Capture And Storage: An Expensive Option For Reducing U.S. CO2 Emissions "Our analysis shows coal plants equipped with CCS are nearly three times more expensive than onshore wind power and more than twice as expensive as solar photovoltaics (PV). Although these costs will decline with research and development, the potential for cost improvement is limited. Coal with CCS will always need significant subsidies to complete economically with wind and solar." https://www.forbes.com/sites/energyinnovation/2017/05/03/carbon-capture-and-storage-an-expensive-option-for-reducing-u-s-co2-emissions/#6c0ec35f6482 The estimated cost of carbon capture is about $60 per metric ton for coal-fired plants and around $70 for natural-gas plants, according to a 2015 report from the Office of Fossil Energy. Another $11 goes to transporting and storing the carbon dioxide." This article suggests using tax credits to support carbon capture. https://www.technologyreview.com/s/610296/the-carbon-capture-era-may-finally-be-starting/ This article explains the impact of current tax credits to assist carbon capture. Funded by new tax credits, US carbon-capture network could double global CO2 headed underground. Note: this legislation was passed with bipartisan support under the Trump Administration. "The authors propose in the Proceedings of the National Academy of Sciences a pipeline network that would transfer carbon dioxide waste from ethanol refineries in the American Midwest—where grains are fermented to produce the alcohol-based fuel—to oilfields in West Texas. The captured carbon would then be pumped into near-depleted oil fields through a technique known as enhanced oil recovery, where the carbon dioxide helps recover residual oil while ultimately being trapped underground." "The authors were motivated by a tax credit passed by Congress in the 2018 Bipartisan Budget Act to encourage investment in carbon capture and storage." https://phys.org/news/2018-09-funded-tax-credits-carbon-capture-network.html Here is an idea for carbon capture at natural gas power plants. https://www.technologyreview.com/s/608755/potential-carbon-capture-game-changer-nears-completion/ gkoehler, I could manage a $.02 cost per kilowatt hour of electrical production. These people think that is possible. They are looking at carbon capture at the source for power plants using integrated coal gasification combined cycles (IGCC), pulverized coal-fired simple cycles (PC), and natural gas-fired combined cycles (NGCC) They claim "based on the studies analyzed, there is a consensus that using today’s capture technology would add 1.5-2¢/kWh to the busbar cost of electricity for an IGCC or NGCC power plant. For a PC plant, the incremental cost of electricity would be over 3¢/kWh. The strongest opportunities for lowering the capture costs in the future were identified as gains in heat rates and reductions in the amount of energy required by the separation. New technologies like coal gasification show the most long-term promise, with incremental costs for CO2 sequestration at IGCC power plants being potentially reduced to about 1¢/kWh in the next decade." https://sequestration.mit.edu/pdf/David_and_Herzog.pdf gkoehler: I agree the time to act has long since passed and action is required, but please do not kill me with your solution.
Sorry to all for mentioning the border wall. gkoehler I agree with your statements and yes we are all in this together and that was not the point of my post. My point is that people can accept AGW is real, which I most certainly do, and accept the mantra that we are all in this together, but choose to deal with problems as they arise rather than take preemptive action. You can label this irrational. It is clearly not the best choice, but it is a choice. I understand there is a threat. I have no additional resources and outside the few personal efforts I engage in, I am not willing to do more. If you come up with solutions that require no expenditures on my part or changes to my rather minimal lifestyle you have my full support, but that is not the reality. The facts are that there are no such solutions that would not materially affect my survival. Your solutions would essentially slowly kill me the same way people on low lying islands are going to succumb to rising sea levels. They can move, moving will not prevent me from being overwhelmed by the solutions you would advocate to mitigate AGW. Solutions are not free. Doing nothing entails costs, but I can survive doing nothing, I will not survive if your solutions are implemented. Who are you going to get to pay for the mitigation efforts? Why shouldn't people who choose to look down the gun barrel of AGW by living in coastal areas that will be most affected by rising sea levels and more severe hurricanes bear the brunt of any remediation costs? Why should I pay to support their poor decision? People with large families make AGW worse - it is a matter of numbers. Why should I with one child and no grandchildren be forced to pay so their profligate propagation habits can be supported? I am already forced to pay for their wanton reproduction through property taxes supporting public schools. Enough already! Tax people based on their reproduction habits to support your AGW mitigation costs and I am all in. Good luck getting a politician to go against a group of people who hold the most votes.
Perhaps America needs to be more concerned about building sea walls to protect coastal properties from storm surges rather than worrying about building a wall on the border with Mexico.
gkoehler What if the public decides AGW is a real threat but they decide to pass the buck to the next generation to fix the problem or they choose to deal with problems as they occur in order to keep the economy growing? A foolish choice perhaps, but a choice nevertheless. Politicians understand that if you do not have a job now or if the economy grows too slowly you will vote them out of office today. What if I am on high ground 300 feet above sea level, why should I pay for people who foolishly build on sand on the coast and barrier islands or live in designated flood plains? The threat is a slow moving threat. Coastal areas get hit with more powerful hurricanes - why isn't this a problem for the people living on the coast to deal with by constructing homes more able to handle the storms, increasing shore protection with higher sand dunes or simply abandoning housing on barrier islands that were built on sand that would shift location even in the absence of AGW, although perhaps not as fast? People put homes in New Orleans in locations below sea level, did not spend the money to build a proper levy system despite decades of warning. They still do not have a system sufficient to meet existing threats even after seeing the threat first hand from Katrina. https://www.nola.com/expo/erry-2018/05/df6c9a722a7295/new_orleans_area_levees_under.html Why is their failure my problem? People in Houston built homes in the designated flood areas designed to be flooded during a heavy storm - why is that my problem? https://www.houstonchronicle.com/local/gray-matters/article/houston-buyouts-floodplains-greenways-13100637.php The hurricanes do not occur every year and there is a certain randomness in where they hit and how much damage results. Chicago in 1995 got hit with a heat wave that resulted in many deaths - solution, get air conditioning and increase programs to check on or assist people in homes without a/c the next time a heat wave hits. http://www.chicagotribune.com/news/ct-chicago-heat-wave-20-years-later-met-20150715-story.html A similar heat wave has not struck Chicago since 1995. What politician in their right mind is going to endorse a tax that substantially increases the cost of gasoline at the pump or substantially increases (double or triple) utility bills so carbon capture at the source is included in the cost of utilities? People will vote a politician out of office if they support a $.25 a gallon tax even if the funds are used to eliminate potholes and gridlock. How are you going to get them to pay substantially more now for mitigation that helps 12 years from now? In the U.S. we are going to run a TRILLION DOLLAR Federal deficit with none of those funds going for climate mitigation. This also represents a threat to our children but we go merrily on our way. Arctic ice melts to nothing in September and new shipping routes open up. More northern latitudes become warmer and more habitable. Look at the temperatures in the Southwest US like Phoenix AZ. People manage to live in that heat, they will manage in other localities as temperatures rise. The ponds of my youth do not refreeze sufficiently for ice skating these days so I pay to skate at an indoor rink. Slow changes in climate will shift where crops are grown and they may become more expensive. That will be the "tax" paid for not dealing with AGW, but people will carry on just as they always have done. People who rely on glacial runoff for water will adapt. In the U.S. we are pumping underground water out of an aquifer faster than it is being replaced. People do nothing about this well documented slow moving threat over which there is no scientific doubt in the mind of the public. https://water.usgs.gov/edu/gwdepletion.html This is cruel, but people in countries with sea level issues and no high ground will have to move or die. I am being purposefully harsh, and I do respect your view that something needs to be done, but AGW is not the only environmental disaster we need to address and based on how little humans are reacting to existing well accepted threats I hold a dim view that people will address AGW. Best of luck though. I will not be here to see the damage in 2050 and you will likely not be here in 2100 and none of us will be here for the big stuff in 2300. That still leaves 280 years to do something. I accept the IPCC report that we have less time to "fix" the problem. I am on a fixed income and can make ends meet, but if your solutions are implemented I will not be able to do that. How are you going to convince me who fully buys the dangers of AGW to vote for a significant diminishment of my well being to help someone I will never meet. PS. I have no grandchildren, but if I did I would be more concerned about their healthcare and affording college than AGW.
Sam Intuitively the idea that first year ice (FYI) will melt more slowly does not feel correct. I am speculating that this could reflect a difference in where the FYI is found. I do not think the article is saying that (FYI) in regions outside the central arctic basin (CAB) is melting more slowly as warmer temperatures in these regions and the near complete disappearance of ice each year in these regions clearly contradicts such a finding. The result of FYI melting more slowly may be related to FYI replacing MYI in the CAB. With colder temperatures in the CAB, FYI has a greater survivability in the CAB than it does in other regions. This could result in data that shows FYI melting more slowly in total arctic data when what it is actually measuring is an increase in the mix of FYI in the CAB. It is intuitive that FYI in the CAB melts slower than FYI outside the CAB. Sam - is it possible that this change in mix in the CAB could be producing what you are calling a "statistical happenstance in a random data set"? I do not know the answer, but if this is what is behind the data, it does not mean the melting process has ended, it only means that the rate has slowed in comparison to previous data that included a higher percentage of MYI and ice outside of the CAB. If the prior data was based on arctic wide data that included regions which have reached a state of complete melting by the September minimum this would introduce a bias in extrapolations using this data. The decline of ice in these regions has reached the point that these regions can not contribute to decline statistics because there is no such thing as negative ice. Is it possible that this is what the article is measuring?
The letter by Ronald Kwok in the link below provides an excellent explanation of why the volume and area coverage of Arctic Sea Ice are expected to slow. This is the proposition that I have been unable to properly articulate in my prior posts. I encourage the various commenters on this site to post comments concerning the conclusion reached in this article. http://iopscience.iop.org/article/10.1088/1748-9326/aae3ec
Keep up the great work Neven. With Thick Ice Gone, Arctic Sea Ice Changes More Slowly https://www.jpl.nasa.gov/news/news.php?feature=7258 The entire letter can be read at the link below as it is open access. Arctic sea ice thickness, volume, and multiyear ice coverage: losses and coupled variability (1958–2018) Abstract Large-scale changes in Arctic sea ice thickness, volume and multiyear sea ice (MYI) coverage with available measurements from submarine sonars, satellite altimeters (ICESat and CryoSat-2), and satellite scatterometers are summarized. The submarine record spans the period between 1958 and 2000, the satellite altimeter records between 2003 and 2018, and the scatterometer records between 1999 and 2017. Regional changes in ice thickness (since 1958) and within the data release area of the Arctic Ocean, previously reported by Kwok and Rothrock (2009 Geophys. Res. Lett. 36 L15501), have been updated to include the 8 years of CryoSat-2 (CS-2) retrievals. Between the pre-1990 submarine period (1958–1976) and the CS-2 period (2011–2018) the average thickness near the end of the melt season, in six regions, decreased by 2.0 m or some 66% over six decades. Within the data release area (~38% of the Arctic Ocean) of submarine ice draft, the thinning of ~1.75 m in winter since 1980 (maximum thickness of 3.64 m in the regression analysis) has not changed significantly; the mean thickness over the CS-2 period is ~2 m. The 15 year satellite record depicts losses in sea ice volume at 2870 km3/decade and 5130 km3/decade in winter (February–March) and fall (October–November), respectively: more moderate trends compared to the sharp decreases over the ICESat period, where the losses were weighted by record-setting melt in 2007. Over the scatterometer record (1999–2017), the Arctic has lost more than 2 × 106 km2 of MYI—a decrease of more than 50%; MYI now covers less than one-third of the Arctic Ocean. Independent MYI coverage and volume records co-vary in time, the MYI area anomalies explain ~85% of the variance in the anomalies in Arctic sea ice volume. If losses of MYI continue, Arctic thickness/volume will be controlled by seasonal ice, suggesting that the thickness/volume trends will be more moderate (as seen here) but more sensitive to climate forcing. http://iopscience.iop.org/article/10.1088/1748-9326/aae3ec
Global average sea-level could rise by nearly 8 feet by 2100 and 50 feet by 2300 if greenhouse gas emissions remain high and humanity proves unlucky, according to a review of sea-level change and projections. https://www.sciencedaily.com/releases/2018/10/181008083456.htm
D-Penquin There are some existing mitigating solutions. Increase use of solar and wind. There are also plenty of ways individuals can reduce their carbon footprint and the web has many sites that list examples. You could also try to tax automobiles based on their CO2 efficiency. Use of electric cars. - This is expected to have an impact on the electrical grid as it will create a battery reserve for power as excess power is currently wasted. https://www.forbes.com/sites/constancedouris/2017/10/05/how-electric-cars-could-help-the-power-grid-become-more-efficient-less-expensive/#180b9b47121e Having price differentials for time of use of electrical power consumption. https://corporate.findlaw.com/law-library/time-of-use-electricity-pricing-should-be-mandated-as-a-public.html I understand that these measures are unlikely to get the reductions necessary to meet the IPCC targets. Carbon capture at the source for coal power and other fossil fuel power plants is a solution that I recommend advocating. https://www.technologyreview.com/s/610296/the-carbon-capture-era-may-finally-be-starting/ Another solution is to use biologicals like genetically modified blue-green algae to produce fuel, but this is likely too expensive and at best you may only get this source added as part of the mix with fossil fuel sources. http://www.greenbuzz.gatech.edu/news/promise-blue-green-algae-environmentally-friendly-source-producing-biofuels-and-other-products One concern I have with any solution is that the economics of the solution must be within a range to make it practical. We are addicted to receiving cheap power from fossil fuel sources. A marketing campaign is unlikely to change this. I have seen a number of schemes for carbon capture directly from the atmosphere. These solutions do not appear as economical as capturing carbon at the source at a power generation facility. https://www.sciencedirect.com/science/article/abs/pii/S1750583617300014 Recent studies conclude that the first CCS projects in the power sector are likely to cost between €60 – 90 per tonne of carbon dioxide abated although these costs are expected to decline signifi­cantly reaching €35 – 50 in the early 2020s primarily as a result of cost reductions for carbon dioxide capture. http://www.ccsassociation.org/why-ccs/affordability/ Pulling carbon dioxide (CO2) from the air and using it to make synthetic fuel seems like the ultimate solution to climate change. But such technology is prohibitively expensive—about $600 per ton of CO2, by one recent estimate. Perhaps that cost could drop below $100 per ton — which this article claims, but there are doubts this is achievable. http://www.sciencemag.org/news/2018/06/cost-plunges-capturing-carbon-dioxide-air Even $100 per ton is not a practical economic solution, besides, who is going to pay for this? There is no magic bullet solution. It will likely take an approach integrating multiple types of solutions. I would caution you that the idea of using carbon capture directly from the atmosphere appears the least viable solution economically. Using this solution removes the burden from the individual to practice carbon conservation. Having CCS at a power source has the advantage of encouraging individual conservation due to the increased cost of electricity. However, no amount of marketing is going to convince people that paying more for their electricity bill is a solution and no politician would be so stupid as to advocate legislation implementing such a plan and if they did, I assure you they would be quickly voted out of office. We can't get people to agree to an increase in a gasoline tax of 10 cents a gallon for use to improve roads. How are you going to convince them to double or triple their utility or gasoline cost for something as esoteric as AGW? I do wish you luck but keep in mind who is going to pay for your solution. Sadly, people may be more willing to accept the costs of AGW and have the costs assessed against the most vulnerable people rather than directly pay the cost for the mitigation of AGW. Remember the example of the person on high ground, why should they pay to help the coastal dweller?
D-Penquin Thank you for reading my post. I am in agreement with the recent special report by the Sixth Assessment Cycle of the IPCC. I do appreciate the hard work that goes into monitoring current sea ice conditions and support the purpose of this web site. I respectfully disagree that we need to focus on technical solutions - there are plenty of proposals and technical solutions. I would suggest that the focus be on obtaining the political cooperation that will be needed to mitigate the problems of AGW. I am pessimistic about obtaining such cooperation and optimistic that technical solutions are already available. The problem is not a lack of solutions, as there are plenty to be found. The issue is whether humans have the ability and political will to address the problem and implement mitigation. What are people going to agree to give up in order to meet this crisis? It is simple human nature that we deal with immediate threats first. Putting food on the table, having a roof over our head, and being financially able to send children to college - these things take precedence over the threat of AGW, not because AGW does not deserve our attention, but because we are hardwired to deal with these immediate needs. As you note, AGW is a slow moving crisis and humans are not very good at processing its dangers, in spite of the work of the good people at the IPCC, until it is too late. The need to gain the cooperation of people across the globe in addressing the problem is a far more pressing issue than finding solutions. It will be easy to gain the cooperation of people who see their island domains being swallowed by rising sea levels. However, in other areas cooperation is more difficult. How do you get a person who lives far from rising seas to join in rather than see the solution as moving people in coastal areas inland. I am jealous of people who have the money to have ocean front homes. For a person on high ground, rising sea levels are the coastal dweller's problem and not something that people on high ground feel they need to incur costs to solve. And yes, I know the problem is more complex that just sea level, but disappearing ice and rising sea levels are easier to process as a problem than a gradual temperature change of a few degrees and shifts in weather patterns. People in countries with developing economies will look suspiciously on developed economy solutions as an attempt to keep them economically disadvantaged. People in colder climates may welcome the changes AGW brings. Gaining political cooperation appears to be a far more difficult proposition than finding technical solutions, and I agree with you that this is a major reason we are in such a mess. I no longer have an automobile, and I have looked into putting solar cells on my roof, but the economics are such that I can not afford to do this with my limited resources. At the same time, on a hot day, you damned well better leave your hands off my air conditioner. The power company already has specific days that I have agreed to let them shut down the compressor for short periods of time - to save money - and it is miserable when they do so. I have no doubt I could do more, I could change my diet to eat less meat, but I like meat and it is relatively inexpensive. How do you propose that we find the means to obtain the political consensus to implement technical solutions?
The delayed and slower than average rebuild of ice in the CAB continues based on data from the time series plot from MASIE. Is this due to weather or climate? Since we are dealing with a single time period the correct answer is weather, as noted by Neven in the post above. Climate should be measured by decade or multi-decade averages. Arctic sea ice remains well below historical averages with the melt season trending toward longer periods and later dates for the September minimum. Using decade and multi-decade averages shows that arctic sea ice is in decline. It is not necessary for arctic sea ice to meet a specific prediction of an arbitrarily chosen figure by a specific year like the predictions made by Wieslaw Maslowski or by Peter Wadham. The failure of these predictions only lends weight to those who are attempting to deny the obvious. Arctic sea ice is in decline. The exact year conditions in the Arctic reach an agreed upon standard of ice free may be difficult to predict, but it will surely happen. I continue to be unimpressed with the predictive power of graphs, particularly linear graphs using whole arctic ice data, to predict when this event will occur. The factors that drive a specific year's minimum, which have been well documented by this website, and are far too complex to make an accurate prediction of next year's minimum using such a crude methodology. I appreciate the work of Neven and others on this website who are reporting on current arctic sea ice conditions. My only caution is that conditions for a specific day or month which fit a particular bias or preconceived view should not be used as confirmation of climate changes, as these values may subsequently swing in the opposite direction. Instead, I would advocate using trends from long term averages which are not susceptible to a particular moments weather conditions. Such items may lack the visceral impact of a report on current conditions, but they are more than sufficient to show the declining trend of arctic sea ice. Keep up the good work, Neven.
viddalo: Where is the big melt out in the Central Arctic Basin? 2014, 2015, and 2016 are all 200,000 km2 above 2012 and 2013. If you do a trend analysis based on all available years of MASIE data for the Central Arctic Basin, when would the data indicate that the CAB will be ice free in September? ftp://sidads.colorado.edu/DATASETS/NOAA/G02186/plots/4km/r11_Central_Arctic_ts_4km.png
Toggle Commented Sep 17, 2016 on ASI 2016 update 7: minimum time at Arctic Sea Ice
The PIOMAS volume vs extent graph appears to indicate that the thickness of Arctic ice has stabilized. This is to be expected as most of the thick multi-year ice has disappeared from the Arctic. I believe this chart supports the position that the Central Arctic Basin ice will last longer than extrapolations based on Arctic wide data indicates it will last.
Toggle Commented Sep 3, 2016 on PIOMAS September 2016 at Arctic Sea Ice
viddaloo I like your analysis but why narrow the focus to top 3? Wouldn't a prediction of top 5 have a higher probability of success and be every bit as effective as a prediction of the declining state of the ice? Can someone with far better skills than I have do a graph showing how the five year moving average has changed over the last five years? The focus on single year numbers is weather, not climate. Looking at five or better yet, changes in decade averages is a better measure of a climate trend.
Toggle Commented Sep 3, 2016 on PIOMAS September 2016 at Arctic Sea Ice
Neven: I am in full agreement with AGW - it is simple physics, more CO2 more warming. The only item I am being contentious about is the issue of when the Arctic will be "ice free" and I am suggesting that the data set for making projections should be based solely on the Central Arctic Basin and not Arctic wide data as the temperature above 80 degrees north, as shown on your most recent post Mega-Dipole is clearly cooler than the rest of the Arctic. I am advancing this position because I believe it will provide a more accurate prediction and I agree that the natural variability is sufficient that an individual year may result in an abnormally low result. The problem as I see it is that aggressive projections of an ice free Arctic open the AGW supporters to unwarranted derision from denier groups when these aggressive projections fail. I appreciate the fine and hard work you are doing in putting out this blog.
Toggle Commented Aug 30, 2016 on PIOMAS August 2016 at Arctic Sea Ice
Here is an ice projection done back in 2009 using Arctic wide data that suggests we should be at 0km2 for September and October by now. https://images.search.yahoo.com/search/images;_ylt=AwrBT9yCx8VXUEcAL8NXNyoA;_ylu=X3oDMTByN2Ruc2MwBGNvbG8DYmYxBHBvcwM0BHZ0aWQDBHNlYwNzYw--?p=Wipneus+Arctic+Ice&fr=mcafee#id=22&iurl=http%3A%2F%2F4.bp.blogspot.com%2F-lZ4BNWYYhMg%2FULQ_AQ49g-I%2FAAAAAAAAG9M%2FEjcv4iMEL2s%2Fs1600%2FFIGURE13.JPG&action=click I think this shows that using Arctic wide data will lead to false projections of when the Arctic will become ice free.
Toggle Commented Aug 30, 2016 on PIOMAS August 2016 at Arctic Sea Ice
Hi Wayne Per MASIE the "drop" is not that large. As of today down to 2.95 km2 ftp://sidads.colorado.edu/DATASETS/NOAA/G02186/plots/4km/r11_Central_Arctic_ts_4km.png Since Neven's most recent post, 2016 Mega-Dipole, shows the temperature starting to drop below 0 Celsius at 80 degrees North the big melt for the CAB is over for 2016, although areas further south may melt some more. http://neven1.typepad.com/.a/6a0133f03a1e37970b01b7c88d75f3970b-pi NSIDC shows that 2016 is above the minimum for 2012 and well below the average. http://nsidc.org/arcticseaicenews/ Satellite is bonkers on Cryosphere today so that source is kaput. JAXA chart show a whopping 1 million km2 more ice than 2012, but still well below the average. http://neven1.typepad.com/.a/6a0133f03a1e37970b01b8d2172da0970c-pi So there are three sources all saying that we are not setting a new low in 2016 compared to the low established in 2012. I find looking at images to be deceptive as personal bias can color perception in a manner that data does not. Neven's page shows Cryosphere Today as above 2012, but not by much. I am certain you guys understand why JAXA is so much higher than CT, but since I am concerned with comparisons within same data sets it does not matter. The point is that we are not going to see the levels viddaloo is predicting with his line drawing. Go back to 2013 and see what the line drawing people predicted for 2016 ice extent. My guess is we are well above the level the line drawers predicted in 2013. If line drawing using Arctic wide data did not work back then, why is it a valid method today for predicting future ice levels in the next three years? Wayne and viddalo, show me a line drawing projection using Central Arctic Ice data - you pick the data set - use volume for the CAB if you can find it - so that eliminates the charge of cherry picking - when does it predict an ice free CAB? viddalo what makes you think the observations I am making do not constitute thinking for my self - who else has advanced this idea of only looking to CAB data for making the ice free prediction? I will try again to get on wunderground, if its not free, at least it is not much to join. viddalo, wayne appears closer to my WAG about ice free conditions than he does to yours.
Toggle Commented Aug 30, 2016 on PIOMAS August 2016 at Arctic Sea Ice
viddaloo After nearly 30 days of high melting, the Central Arctic Basin has the same ice extent as it did at July 25th, 3.08 MILLION KM2 PER MASIE. Why should I follow your line using Arctic wide data when it is clear (of should I say solid) that the Central Arctic Basin shows no signs it will be ice free by 2024 ftp://sidads.colorado.edu/DATASETS/NOAA/G02186/plots/4km/r11_Central_Arctic_ts_4km.png
Toggle Commented Aug 24, 2016 on PIOMAS August 2016 at Arctic Sea Ice
viddaloo I am trying but it wants money before it lets me in. Will try again tomorrow.
Toggle Commented Aug 23, 2016 on PIOMAS August 2016 at Arctic Sea Ice