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Comments 24051 to 24100:

24051. Ken in Oz at 13:38 PM on 4 June 2016
       Study Helps Explain Sea Ice Differences at Earth's Poles
       

       Whilst this provides some understanding of the dynamics of Antarctic sea ice formation, I'm not clear on how it would explain growth of winter sea ice extent.

       I have thought land ice melt and salinity were likely to be playing a significant part; are measurements of salinity of ocean water around Antarctica being taken and are they being related to land ice melt and sea ice? It seems reasonable to me that outflow of fresh water, which is less dense than saline sea water, would tend to concentrate near the surface and, having a warmer freezing point, would freeze more readily but empirical evidence would be very welcome.

24052. John Hartz at 13:21 PM on 4 June 2016
       Donald Trump wants to build a wall – to save his golf course from global warming
       

       Donald Trump makes people across the U.S. political spectrum quite nervous — and with good cause.

       For example...

       Donald J. Trump’s blustery attacks on the press, complaints about the judicial system and bold claims of presidential power collectively sketch out a constitutional worldview that shows contempt for the First Amendment, the separation of powers and the rule of law, legal experts across the political spectrum say.

       Even as much of the Republican political establishment lines up behind its presumptive nominee, many conservative and libertarian legal scholars warn that electing Mr. Trump is a recipe for a constitutional crisis.

       “Who knows what Donald Trump with a pen and phone would do?” asked Ilya Shapiro, a lawyer with the libertarian Cato Institute.

       With five months to go before Election Day, Mr. Trump has already said he would “loosen” libel laws to make it easier to sue news organizations. He has threatened to sic federal regulators on his critics. He has encouraged rough treatment of demonstrators.

       His proposal to bar Muslims from entry into the country tests the Constitution’s guarantees of religious freedom, due process and equal protection.

       And, in what was a tipping point for some, he attacked Judge Gonzalo P. Curiel of the Federal District Court in San Diego, who is overseeing two class actions against Trump University.

       Mr. Trump accused the judge of bias, falsely said he was Mexican and seemed to issue a threat.

       “They ought to look into Judge Curiel, because what Judge Curiel is doing is a total disgrace,” Mr. Trump said. “O.K.? But we will come back in November. Wouldn’t that be wild if I am president and come back and do a civil case?”

       Donald Trump Could Threaten U.S. Rule of Law, Scholars Say, Adam Liptak, New York Times, June 3, 2016

24053. chriskoz at 10:58 AM on 4 June 2016
       Scientists debate experimenting with climate hacking to prevent catastrophe
       

       funglestrumpet@7,

       Your "sober" approach that considers the "extinction the human species" and ignores everything else is akin to destroying the entire global civilisation - all 7b individuals - leaving just a few thousand hunters-gatherers - all that is required to maintain our species. You probably don't realise the meaning of your post overwise you would not have posted it. Please try to realise next time.

       Reading, needless to say arguing with such nonsense is a waste of everybody's time.

24054. chriskoz at 09:49 AM on 4 June 2016
       Donald Trump wants to build a wall – to save his golf course from global warming
       

       John@4

       Let's also remember that US president signs all decisions of Congress into law. And he can refuse to sign anything that he does not like. that's a lot of power, even though Congree can subsequently overrule his refusal under some conditions. E.g. let's keep in mind that Obama famouly stopped KXL pipeline using that very power and Congress did not have enough numbers to overrule him. Had Trump been a president at the time, he would hapilly have signed it, and we would have KXL flowing full steam now.

24055. Tom Curtis at 09:36 AM on 4 June 2016
       Donald Trump wants to build a wall – to save his golf course from global warming
       

       John Hartz @14, much as I despise Donald Trump, I do not think he is literally insane.  Therefore I do not think he would use the nuclear option.  

       What he is likely to do, if elected, is to trash the system of alliances that the US has built up since WW2 and which contribute to it being so dominant a global power.  He will alienate allies, and trash the USA's chances of significant international cooperation on any point.  He may also involve the US in conventional wars on, essentially, a whim.

       Of greater concern is what he is likely to do the US economy.  The reforms he will push, and which will likely gain support in a Republican dominated congress, will distort the economy in favour of the wealthy at the expense of the middle class, workers, and the poor.  He may bring back some manufacturing by trashing NAFTA and bullying Mexico, but the real manufacturing deficit of the US is relative to the Asian giants (particularly China and Japan) who hold a significant portion of US foreign debt.  If he pushes too hard, they may decide to retaliate by closing of the easy credit the US currently relies on, forcing a US depression worse than that of 1927.  I don't think it will come to that, but if follows that Trump will not revive US manufacturing as he claims he will.

       Trump cannot make America great again, as it still is great.  He can certainly impoverish and weaken the US relative to Russia and China, and that is the most likely outcome of his policies.

24056. Tom Curtis at 09:20 AM on 4 June 2016
       Most of the last 10,000 years were warmer
       

       Mike Hillis @63, point by point:

       1)  The quote by Monckton at the head of the article is simply an example of the myth being propogated.  It is not, as you suggest, part of an evidentiary chain other than to the point that the myth exists, and is propogated by at least some climate change deniers.  What is more, by claiming that it is a fabrication that "the "myth" ... is based on a comment made by Monkton", you imply that Monckton has been misquoted.  Following the link for the quote and scrolling down to the second box on page three proves that to not be the case.  Monckton was not misquoted.  He has used the myth.  But the article made no claim that Monckton is the only denier to use the myth, or that he was the primary person to propogate the myth, contrary to your suggestion.

       Monckton also explicitly ties his opinion to the GISP 2 record in another document (PDF) where he produces this graph:

       

       He captions it, "Warmer than today: most of the period since the end of the last Ice Age has been
       warmer than the present by several degrees Celsius" and writes:

       "Seen in the geological perspective of the last 17,000 years, the 300 years of recent warming, nearly all of which must have been natural, for we could not have had any significant influence except in the past 25 years, are manifestly insignificant."

       The comment about the 300 years shows clearly that he is treating the terminal period of the graph, which actually ends in 1855, as ending in approximately 1995.

       As a side note, he (not unusually) mislabels the source of the data, which is Cuffey and Clow (1997).

       2)  You also dispute that Monckton got the idea from Easterbrook, but Easterbrook propogated the idea in 2008 (PDF), where he produced this graph the below graph, saying:

       "The global warming experienced during the past century pales into insignificance when compared to the magnitude of at least ten sudden, profound climate reversals over the past 15,000 years (Figure 5)"

        

       Again, the graph is claimed to depict "global warming during the past century" even though the last data point on the graph in fact occurs in 1855.

       Easterbrook even predates Monckton on the "some 9,100 of the past 10,500 years were warmer" meme, with an article on WUWT in December, 2010 claiming that:

       "So where do the 1934/1998/2010 warm years rank in the long-term list of warm years? Of the past 10,500 years, 9,100 were warmer than 1934/1998/2010. Thus, regardless of which year ( 1934, 1998, or 2010) turns out to be the warmest of the past century, that year will rank number 9,099 in the long-term list."

       As a side note, I am puzzled as to how he determines that ranking.  Using the GISP 2 temperature data cached by Alley, from 8,905 to 8,915 of the 10,500 years BP in that record are warmer than the terminal data point.  For Easterbrook to gain his ranking, he must conclude that 2010 was significantly cooler than the year he considered to be 1905.

       As a further side note, the 2010 article by Easterbrook is the one discusses by Gareth Renowden above.

       3)  No claim is made in the OP that Easterbrook came to his conclusion as the result of just one study.  The claim that he did so is false, but the only fabrication involved is your attribution of that claim to the OP.

       4)  You claim it is absurd that Easterbrook, as a geologist, did not know that Before Present refers to before 1950 unless otherwise specified, but in the 2010 article, his reproduction of the Alley data clearly labels the x axis "Years before present (2000 AD)", thereby indicating that he took "present" in this data to refer to 2000, not 1950.  So far as I am aware, he still does so.

       5)  Regardless of his reasons, the paper trail clearly shows Easterbrook labeling the data that terminated in 1855 as "present global warming" thereby indicating the tail of that graph to be the warming during the 20th century (see graph above).  Later he clearly labelled that data on an axis for years BP, glossed as being 2000 with a final data point at 95 years BP, ie, 1905 according to his axis.

       To summarize, the purported fabrications are easilly proved to be true from the paper trail, except for two cases where the "fabrication" consists entirely in your misrepresenting the OP.

       Your record on "the facts" is equally poor.  It is true that, but entirely irrelevant, that the Holocene was labelled long before Easterbrook was born.  The studies of Holocene temperatures that lead to the "spaghetti graphs", however, are all recent (last thirty years or so), and the spaghetti graph you used does not come from a peer reviewed paper, and was originally produced in 2005.  Easterbrook has in fact used that graph, as you would know if you followed the links to the original version of the article, and back to prior history.  However, he first used the current version of the graph (produced on the 19th of July, 2010, less than a week before he used it, but only after considerable editing to make it look like this:

       

       Compared to the original, you will note that he has removed the "spaghetti".  More importantly, he has also removed the indication of the 2004 temperature, the inset showing recent proxies, together with the rapidly rising instrumental record.  That is, he has removed any indication that modern temperatures are in fact higher than those shown.  He does not note that the zero point on the axis is "mid 20th century average temperature", but instead inserts a line approximately 0.3 C below the mid 20th century average which he deceptively labels "Present day temperature".  In all, his treatment of this graph is much worse than his treatment of the Alley 2000 data, and cannot be construed as anything other than a deliberate attempt to deceive his audience.

       It is, however, extraordinarily unlikely that Easterbrook, who obtained his graduate degree in 1958, saw any spaghetti graph of Holocene temperatures in highschool (none having existed back then).

       Finally, the graph you cite clearly shows even mid 20th century temperatures to have been warmer than the bulk of the Holocene, while late 20th century temperatures were warmer than the multidecadal average over the entire Holocene.

       In short, your "facts" are fictions.  In some cases ridiculous fictions you invented without basis.  In others, fictions you invented in direct contradiction to known evidence - indeed, evidence presented in the OP in one case.  Skeptical Science is not a form where you are permited to just spin tissues of fabrication.  You are expected to support your claims with facts, something you have signally failed to do at any point in this discussion.  It is also hoped (though not required) that you change your views if fae moderators take a dim view of any further unsupported claims, or gish gallops by you.

24057. John Hartz at 08:03 AM on 4 June 2016
       Donald Trump wants to build a wall – to save his golf course from global warming
       

       Glenn Tamblyn:

       You wrote: A President alone can actually do diddly-squat!  

       I repectfully disagree.

       First and foremost, the U.S. President can at any time push the button to launch missles with nuclear warheads. 

       Given Trump's unstable personality, the thought of him having this power should send shivers up and down one's spin.

24058. william5331 at 06:16 AM on 4 June 2016
       Scientists compare climate change impacts at 1.5C and 2C
       

       These predictions ignore mass changes just as early estimates of ice sheet melting ignored the side effects of faster ice flows into the sea and only considered thermodynamics.  If the Arctic Ocean becomes an area of prevailing rising air as the ocean warms, it should reverse the Polar Hadley cell and suck climate zones northward rather suddenly.  In such an eventuality, all bets are off and we have sudden extensive crop failures in the Northern Hemisphere.  Have you noticed that in the Mana Loa Carbon dioxide web site that CO2 from April 2015to April2016 is 4ppm.  While this may be an effect of El Nino and the line on the graph will revert to the steady 2 to 2.5 yearly increase, it could also signal that one or more carbon sinks is shutting down.  If so, the outlook makes redundant all studies such as this.

24059. funglestrumpet at 06:07 AM on 4 June 2016
       Scientists debate experimenting with climate hacking to prevent catastrophe
       

       Perhaps the moment has come when we (more precisely, those scientists in the relevant disciplines - including  Guy McSpherson and Paul Beckwith -  should collectively disband the IPCC and tell the world leaders to their face what a useless bunch of tosspots they really are. Having done that I  suggest that a sober investigation into just how far away from extinction the human species really is would be really nice to know and if it is avoidable or not.

       I cannot think of any other course of action that stands a chance of bringing them to their senses.

24060. Firgoose at 03:28 AM on 4 June 2016
       Greenland’s Melt Season Started Nearly Two Months Early
       

       I'm puzzled as to why this article has been posted. This article of Brian Kahn's was posted on April 12th and the Greenland situation since then has been spectacularly underwhelming compared to the drama in the Arctic, where the sea ice is quite likely to show a record-setting decline this year.

       The early spike that occured in Greenland dropped to nothing and melting extent remained quiet for a while until another spike occurred in May. But that also dropped to nothing. There's very little story unless June sees the graph shoot way up from the current minimal levels. In fact the story could be how little melting there is, in comparison with the rapid disappeances of Actic snow and sea ice.

       NSIDC's "Greenland Today"

       

24061. ClintonCallahan at 22:37 PM on 3 June 2016
       Scientists compare climate change impacts at 1.5C and 2C
       

       Further distinctions between a 1.5C and 2.0C future are essential, especially regarding the 100x more powerful greenhouse gas methane which has been naively excluded from IPCC prediction models. Thank you.

24062. Dcrickett at 08:51 AM on 3 June 2016
       Scientists debate experimenting with climate hacking to prevent catastrophe
       

       "…we can only solve the [ocean acidification] problem by cutting carbon pollution OR by removing it from the atmosphere."

            The "OR" should be "AND" — the task of preserving the oceans calls for far more than "Go thou and sin no more." To preserve the oceans, we must preserve the climate.

24063. william5331 at 07:02 AM on 3 June 2016
       Scientists debate experimenting with climate hacking to prevent catastrophe
       

       I shudder to think of us controling the heating of the atmosphere by some engineering feat while still spewing Carbon dioxide into the atmosphere,  The funds run out or some other factor stops the ongoing injection of sulphur into the stratosphere.  Mean time we are up at 500 or 600 ppm Carbon dioxide.  The longer before the brown stuff hits the wind pusher the worse the situation would be.  As fast as the changes are at present that we  observe, the rate of change in such a scenario would be devestating.

24064. r.pauli at 05:58 AM on 3 June 2016
       Scientists debate experimenting with climate hacking to prevent catastrophe
       

       Looking back, somewhere in the 1980's, this would have been very exciting.   Now it could be ironic epitaph.  Kids, you will have great struggles ahead. 

24065. KR at 05:13 AM on 3 June 2016
       Donald Trump wants to build a wall – to save his golf course from global warming
       

       dalesmith - Under the current conditions, any third party candidate could only act as a spoiler for the mainstream candidate they are closest to in outlook. And at this point I don't see any possibility of a late third party candidate drumming up enough support to split things enough to have a contested election. 

       If they somehow did, given the current makeup of the House of Representatives and the outsized influence of Tea-Party Republicans, I would consider that outcome nothing short of disaster for the US.

       The only possible third-party candidate I might consider strong enough to invoke that disaster is Sanders - and I suspect he's intelligent enough to know what a mess that would cause. 

24066. jja at 01:23 AM on 3 June 2016
       Scientists debate experimenting with climate hacking to prevent catastrophe
       

       I think it is just great that we need to have comic actors do psa's because our political leadership are bought off and will only gently push the envelope from behind the scenes if they are aware of the scientific reality at all. I wish that I could transport back to us today scenes of this planet 30 years from now when the Arctic sea ice melts out in mid August, and perpetual drought, hunger, migrations, sea level rise and mass human and animal die-offs are the norm. It wouldn't be so F_ing funny then.

24067. Glenn Tamblyn at 23:24 PM on 2 June 2016
       Donald Trump wants to build a wall – to save his golf course from global warming
       

       dalesmith
       
       Irrespective of the arcana of the US presidential electoral system (and it does seem to an outsider to be extremely arcane), surely the issue is less the Presidency, and more the make-up of the Congress. A President alone can actually do diddly-squat!

24068. MA Rodger at 21:16 PM on 2 June 2016
       Temp record is unreliable
       

       dvaytw @358.

       Your 'guy' is quoting from AR5 SPM which does refer you to Sections 2.4 & 5.3 of the full report. His quote also sits cheek-by-jowl with Figure SPM-01a, the lower panel of which does show the confidence intervals for decadal measurements. Figure 2-19 also shows these for HadCRUT & also the differences between temperature series.

       

       However, the main reason for there being doubt as to the interval 1983-2012 being the hottest 30-years in 1,400 years is dealt with in 5.3.5.1 Recent Warming in the Context of New Reconstructions on page 410-11 IPCC AR5 Chaper 5  which states:-

       "NH reconstructions covering part or all of the first millennium suggest that some earlier 50-year periods might have been as warm as the 1963–2012 mean instrumental temperature, but the higher temperature of the last 30 years appear to be at least likely the warmest 30-year period in all reconstructions (Table 5.4). However, the confidence in this finding is lower prior to 1200, because the evidence is less reliable and there are fewer independent lines of evidence. There are fewer proxy records, thus yielding less independence among the reconstructions while making them more susceptible to errors in individual proxy records. The published uncertainty ranges do not include all sources of error (Section 5.3.5.2), and some proxy records and uncertainty estimates do not fully represent variations on time scales as short as the 30 years considered in Table 5.4. Considering these caveats, there is medium confidence that the last 30 years were likely the warmest 30-year period of the last 1400 years."

24069. dalesmith at 20:22 PM on 2 June 2016
       Donald Trump wants to build a wall – to save his golf course from global warming
       

       Many are buying in to a false dichotomy. There will be more than two choices for President.

       This election may be the best chance for a third-party candidate to win. Hundreds of thousands of Republican voters have registered with the Libertarian Party since Trump became the presumptive nominee. There are hundreds of thousands of Democrats who have stated that they will not vote for Clinton.

       If a third-party candidate can win a few states and get a few electoral votes then possibly no candidate will get the required 270 to win election. If that happens, due to an obscure constitutional mandate the House will have to pick the President from amongst the top three electoral vote getters.

       With the current political climate, the Republican-controlled House might not pick Trump because most don't like him. They definitely wouldn't pick Clinton. So, they could pick the third choice (Gary Johnson?) as a compromise.

24070. BBHY at 20:22 PM on 2 June 2016
       Scientists debate experimenting with climate hacking to prevent catastrophe
       

       I think what we really need is to hack our political system.

       Or rather un-hack it. It has already been hacked by the fossil fuel industries and their friends, preventing us from taking the proper steps to reduce CO2 emissions.

24071. scaddenp at 14:05 PM on 2 June 2016
       Temp record is unreliable
       

       The first thing to note is that this is based on comparing one measurement with another. No measurement is perfect, especially the measurement of NH atmosphere over 1400 years. This results in error bars on the measurement which, depending on methodology, can be expressed in probability terms. ie considering the spread of all sources of error in estimating temperature, we would say temp at time x is Tx and can estimate 66% or 95% error bars on that measurement. The IPCC claim is that error range on the modern 30year temp average is highe than the 66% error limit on past temperature (but not higher than the 95% limit).

       Determining error bars is not a simple process. You would need to look in detail at the source papers to determine how that was done. If you look up monte carlo methods to estimating error propogation, you will see one way of doing.

       I suspect you are arguing against wilful ignorance however. Good luck on that.

24072. sauerj at 13:09 PM on 2 June 2016
       Ten years on: how Al Gore's An Inconvenient Truth made its mark
       

       chriskoz @1, I thought your comment was extremely profound. Yes, for SkS to be born out of AIT really does make the evolutionary legacy of AIT quite monumental. Thank you for highlighting this point.

24073. sauerj at 12:58 PM on 2 June 2016
       Ten years on: how Al Gore's An Inconvenient Truth made its mark
       

       Thanks Knaugle for clarification. I was just asking to be super clear on the @3 text so that a denialist couldn't undermine credibility and feed doubt. I am in strong agreement (as I said in @4) that we will be ice free at the summer minimum by ~2030 and agree, as you say, that by then (or shortly thereafter, certainly by 2040) we will instead be measuring the duration of being ice free. Thanks again!

24074. Glenn Tamblyn at 09:38 AM on 2 June 2016
       Ten years on: how Al Gore's An Inconvenient Truth made its mark
       

       knaugle
       
       That would be this graph...
       
       
       
       Although some error margins on the earlier years estimates would be good. Those early years are coming from limited documentary sources.

24075. Glenn Tamblyn at 09:09 AM on 2 June 2016
       Most of the last 10,000 years were warmer
       

       Mike Hills
       
       Yoe perhaps need to look at the graph from Wikipedia more closely. Although the graph doesn't give a citation for its source, and in fact the section in Wikipedia on this notes the need for more citations, the results in the graph are broadly in line with the various studies available.
       
       So look at the black line, presumably the average of the several studies. If that line, at the far right, actually reflected today, now, the 21st century, your point might be valid. But it doesn't! As the creator of the graph clearly shows. They include an arrow indicating the temperature in 2004 - close enoughto now. Clearly showing a temperature higher than most of the black line.
       
       And the inset panel also clearly shows what they label 'recent proxies' showing a steep rise since then.

       Were temperatures largely falling during the Holocene? Yes, that is only what is expected.

       Were temperatures at the start of the Holocene, before that fall somewhere around where they are today? Yes possibly, although this graph doesn't specifiy whether it is showing global temperatures, Northern Hemisphere temperatures or regional.

       Were temperatures during the bulk of the Holocene higher than today? No. The very graph you use shows that.

24076. villabolo at 02:44 AM on 2 June 2016
       Scientists debate experimenting with climate hacking to prevent catastrophe
       

       I think that the f bomb was a little overboard. One round would have been enough and that without the child mouthing it.

24077. MA Rodger at 02:21 AM on 2 June 2016
       Most of the last 10,000 years were warmer
       

       Mike Hillis @63.

       So you claim that "the bulk of the Holocene was warmer than today" and in evidence present a graph of proxy records from Wikithing that shows the bulk of the Holocene was cooler than 2004. And since 2004, 'today' has been subjected to over a decade of AGW. So we should perhaps add in that 2004 temperature. 2015 was 0.28ºC warmer than 2004 and applying that addition, a very small part of the proxy records in the Wikithing graph are presented as being warmer than today, certainly not in any way "the bulk".

       Am I missing something? Or does your claim require a bit more support?

24078. dvaytw at 02:01 AM on 2 June 2016
       Temp record is unreliable
       

       Hi y'all. I'm arguing with this guy who is claiming that AGW is junk-science. Here's one of his points:

       "According to the IPCC:

       The period from 1983 to 2012 was likely the warmest 30-year period of the last 1400 years in the Northern Hemisphere”

       And likely is a 66% to 100% probability.

       Well, it either was the warmest or it wasn’t. Probability zero or probability one. Explain to me how a random series of trials could come up as it being the warmest 66% of the time and not the warmest 34% of the time. What is this supposed to mean? How is it falsified?"

       Now, I've told him that AGW is historical science, not experimental science, so we aren't talking about "trials", and that temperature averages have uncertainties which means that they are ranges; further that we have even more uncertainties with temperature proxies.  I've also said that, although neither he nor I knows how the statistics work to come up with the probability, to state that therefore it is meaningless is just an argument from ignorance.

       However, he persists. In my annoyance, I'm reaching out to ask: can anyone actually explain this in sufficient detail or point me to a clear source on it, to show him how dumb his argument is?

24079. knaugle at 00:44 AM on 2 June 2016
       Ten years on: how Al Gore's An Inconvenient Truth made its mark
       

       Re @5

       Actually the value from the 1960s comes from the Cryosphere Today site, it's older data: Timeseries of annual and seasonal sea ice extent from 1901-2010, and not by drawing the line.

       Cryosphere Today

24080. knaugle at 23:50 PM on 1 June 2016
       Ten years on: how Al Gore's An Inconvenient Truth made its mark
       

       @4

       Actually, the Arctic Summer minimum is declining about 13% a decade according to the NSIDC reports.  At that rate, there should still be some ice cover during the Summer minimum into the 1940s.  However, this assumes there is not some tipping point at which this decline accelerates

       NSIDC 2015 Melt Season in Review

       Simply drawing the line, 50 years ago, the Summer Ice coverage was thought to be a minimum of about 4.3 million square miles, in recent years that has shrunk to less than 2 million square miles.  By 2030 I'd not be surprised to see that just a bit over 1.4 million square miles and with some years in the 750K range, others near 2 million.  That is getting painfully close to ice free.  From there we will be discussing how long ice free lasts, rather than whether or not as we are now.

24081. Mike Hillis at 23:29 PM on 1 June 2016
       Most of the last 10,000 years were warmer
       

       The fabrication of which I speak, is that the "myth" that most of the Holocene was warmer than now, is based on a comment made by Monkton, who based his opinion on one study by Dr. Easterbrook, who based his entire study on one truncated set of Greenland ice core data that ends in 1855, and that Dr. Easterbrook, a geologist, didn't know that the geological present is 1950, and had no access to data that continued beyond 1855, so he had to lie and pretend the ice cores showed more recent data than 1855.

       Now the facts. The Holocene has been known to geologists since before Dr. Easterbrook was born. Hundreds of studies have been done for many decades, using as many methods as can be dreamed of, using every branch of science, history, and literature. The results of dozens of studies have been charted together giving us the spaghetti graphs that Dr Easterbrook probably learned in high school, all showing that the bulk of the Holocene was warmer than today. One such graph is here:

       

       Moderator Response:

       [TD] I hotlinked the wikimedia link. In future please do that yourself.

       [TD] See the explanation of that image you linked to, on the post "The Two Epochs of Marcott and the Wheelchair." And before you criticize that, read "Real Skepticism About the New Marcott 'Hockey Stick'." 
       
       [Rob P] - Image now embedded in comment.

24082. JoeK at 17:55 PM on 1 June 2016
       Study Helps Explain Sea Ice Differences at Earth's Poles
       

       Interesting. Some questions about how to put this in models for anyone who knows. Presumably the seafloor features here need relatively high resolution to see? How close are they to being incorporated in to routinely used GCMs? I guess they are not already there? Would it be a matter of specially adding high resolution for these features, or will overall resolution increase enough to resolve them (e.g. for CMIP6 models)? Is an alternative route to parameterise these effects? Might parameterisation have some advantages over explicit resolution of the topography?

       Another question: are there advances in understanding other parts of the world likely to come from incorporating higher resolution bathymetric data?

24083. bozzza at 15:50 PM on 1 June 2016
       Ten years on: how Al Gore's An Inconvenient Truth made its mark
       

       @4,

        You don't seem to understand the consequences of a so called ice-free arctic aka "THE BIG BLUE EVENT". It means the structural integrity given by the thicker multi-year sea ice is largely gone.

       This, in turn, means the thinner seasonal ice is easier and easier to break up making the arctic less able to deflect solar radiation from the earth making Greenland more liable to melting and, so, potentially shut down the thermohaline cycle that warms Europe.

       Where are the Syrians going to go then?

       This is real politik!!

       This is the negative externality of mixed market failure!!! Some even call it 'picking winners'...

        

        **^{[Go Greed: why did you have kids again?]}

24084. sauerj at 10:17 AM on 1 June 2016
       Ten years on: how Al Gore's An Inconvenient Truth made its mark
       

       knaugle @3, by 'ice free' you mean 'ice free at the summer minimum' right? ... 2030 does seem a conservatively assured prediction for that to happen.

24085. Tom Curtis at 09:02 AM on 1 June 2016
       Most of the last 10,000 years were warmer
       

       To recap:

       Mike Hillis @51:

       "I read this thread and am shocked by what I'm reading. The data that Richard Alley uses does not end in 1855, nor does it use 1855 as any sort of "present". Nor does the snow have to be compacted into firn and then the firn into ice, in order to date the annual layers, or for these layers to be usable in isotope measurements. ... I can see where Tom Curtis claimed to have emailed Alley and asked him, and got a reply from Dr. Alley, but also find this to be a copy and paste from another person who emailed Alley, which means Mr. Curtis probably never actually emailed Dr. Alley at all. It's astonishing that nobody has corrected this fabrication so far."

       (My emphasis.)

       Mike Hillis @57:

       "I see where the 1855 comes from now. Somebody, I suppose Easterbrook, is using a data set from a 2004 Alley paper about the Younger Dryas, in which he only uses enough data to clarify that event, starting from 95 years BP and going backwards."

       So we are quite clear, Alley (2000) in fact used data only extending to 1855.  Easterbrook has continuously misrepresented that data by first purporting it continued through to 2000, and then (when the date of the most recent sample was pointed out), purporting that it continued through to 1905, despite the well known geological convention (and the confirmation by Richard Alley) that "Before Present" refers to years before 1950.  In other words, the original article by Gareth, and discussion by me in various comments above have been accurate, and are now acknowledged by Mike Hillis as being accurate.

       He has as yet provided no apology for his being "shocked" by the purported misrepresentation of these facts, which he now acknowledges to have been accurately stated.  Even worse, he has made no apology for calling either the accurate statement of these facts (or possibly his invention that I claimed to have emailed Alley) a "fabrication".

       I guess we can be at least grateful that he now understands the essential point of the article.

       He still insists (correctly) that ΔO₁₈ measurements for GISP 2 can be obtained till as recently as 1987 (ie, -37 BP).  The data site he uses to prove that, however, states that "Between 1989 and 1993, the Greenland Ice Sheet Project 2 (GISP2) collected several ice cores from near the summit of the Greenland Ice Sheet"; and that "Above 180m depth the measured samples are from the 1989 B core; below 180m the 1990-1993 D core was used".  From this we learn that there are at least two other cores from GISP 2 whose data is not listed at that site.  Further, he only has evidence for one of those cores (the 1989 Core B) that it continues with data, effectively to the surface.  (It excludes the last two year prior to collection, presumably because of the risk of contamination from setting up the site, or because the snow was insufficiently packed to be preserved in the core.)  From these facts he cannot determine which core was used by Alley (2000), and nor can he determine that that core had data prior to 1855.

       However, regardless of that, there is a reason why the temperature data from Alley (2000) should not include data to the surface, and indeed, not include any data prior to the closure of the firn.  Alley (2000) in fact used the temperature data from Cuffey and Clow (1997).  Cuffey and Clow did not just use ΔO₁₈ measurements to determine temperature, but the estimated elevation changes as well:

       "We can use the elevation histories to infer a history of temperature at constant elevation (the true climatic change), by assuming a constant lapse rate of 6 ^øC km^-1•  [Putnins, 1970]. The resulting correction to temperature of the last glacial maximum is small compared to the aleglacial temperature change; the temperature range is about 1.5 ^øC for 50 km ≥ AL ≤ 200 km.  More interesting is the correction to the early Holocene temperature record. Here the correction shows a more pronounced early Holocene temperature maximum with a net cooling through the Holocene of 2.5 ^ø to 3 ^øC, if the large marginal retreat history is applicable (Figure 3). The net cooling through the Holocene is 2 ^øC  for AL = 50 km, and in this case the early Holocene is about as warm as the late-mid Holocene."

       Cuffey and Clow use a model based on snow accumulation and estimated margin retreat to determine elevation, but note that total gas barometry of the gas included in the ice provides a potential independent check of the elevation history (which they then discuss).  This use of included gas as an independent check on elevation history provides a sufficient reason to only use data from when the firn had closed.

       Please note that I am not saying that it is the reason.  The Cuffey and Clow data may have terminated in 1855 simply because of the actual ice core they used, or for some other stated reason.  However, because of the role of estimates in elevation in determining the temperature history, it cannot be assumed that ice from before the closure of the firn was equally suitable for determining the temperature history.

24086. shoyemore at 04:46 AM on 1 June 2016
       Study Helps Explain Sea Ice Differences at Earth's Poles
       

       

        

       Antarctic Ice seems to be below average this year, and may go below 2-sigma limits. Is that a challenge to the theory?

24087. MA Rodger at 04:36 AM on 1 June 2016
       Most of the last 10,000 years were warmer
       

       Mike Hillis @52-60.

       Back @52 you write that "it's astonishing that nobody has corrected this fabrication so far." Strong stuff but it is not clear to me what you are branding as "fabrication."  Perhaps it would be good if we could begin by establishing what it is that constitutes this "fabrication."

24088. Mike Hillis at 03:59 AM on 1 June 2016
       Most of the last 10,000 years were warmer
       

       The point is, the data from the GISP2 ice cores, as shown on this link, give temperatures from 2 meters deep (1986) to 3040 meters deep (over 110,000 years BP). Your link to a 2004 Alley paper on the Younger Dryas does not contain all the available data.

       The top 2 meters are not in the existing cores because they were the snow pit that I mentioned, which was shoveled out. But the isotopes for the top 2 meters were measured as well, as Alley states in "Two Mile Time Machine".

       Moderator Response:

       [JH] To whom is this comment directed? 

       [RH] How does any of this have any relevance to the main article?

24089. knaugle at 01:31 AM on 1 June 2016
       Ten years on: how Al Gore's An Inconvenient Truth made its mark
       

       I've also seen the most quoted error in AIT is when Al Gore mentioned that most scientists think the Arctic will be ice free sometime after 2030.  However one scientist from the US Naval Academy said it could be as early as 2013.  Since this obviously didn't happen and I haven't heard Dr. Wieslaw Maslowski's views since about 2011 when he revised his prediction to 2016, many deniers stop there.  However the NSIDC report for Arctic Ice cover for today is rather eye opening in that the 2030+ group still looks well on track.

24090. knaugle at 01:22 AM on 1 June 2016
       Ten years on: how Al Gore's An Inconvenient Truth made its mark
       

       AIT also created an interesting lightning rod for deniers.  My experience has been that many simply think they need to take out Al Gore and Michael Mann, and the whole problem simply goes away because 97% of climate scientists, in their view, aren't really sold on AGW.  Al Gore is after all the only "climate scientist" many people can name.

24091. Mike Hillis at 00:49 AM on 1 June 2016
       Most of the last 10,000 years were warmer
       

       On that link, click the tab that says

       "gisp2_measured.txt 664KB Complete GISP2 continuous sample results (2m to 3040m)"

       The dates are given in BP which is 1950. A date of 0 is 1950 and positive numbers are before then, negative numbers are after then. The first datum point is -36.88 which means 1986

       Moderator Response:

       [JH] What's your point?

24092. Mike Hillis at 00:46 AM on 1 June 2016
       Most of the last 10,000 years were warmer
       

       http://depts.washington.edu/qil/datasets/gisp2_main.html

       Moderator Response:

       [JH] Per the SkS Comments Policy:

       • No link or picture only. Any link or picture should be accompanied by text summarizing both the content of the link or picture, and showing how it is relevant to the topic of discussion. Failure to do both of these things will result in the comment being considered off topic.
24093. Mike Hillis at 23:39 PM on 31 May 2016
       Most of the last 10,000 years were warmer
       

       I see where the 1855 comes from now. Somebody, I suppose Easterbrook, is using a data set from a 2004 Alley paper about the Younger Dryas, in which he only uses enough data to clarify that event, starting from 95 years BP and going backwards. I assure you, that the ice cores were measured, not just from 1855 and back, but every single year. Just because that data is not included in this particular 2004 paper doesn't mean it doesn't exist. The GISP2 study painstakingly measured the isotope levels of EVERY year, right up to the fluffy snow on top of the summit.

       Moderator Response:

       [RH] The GISP2 temperature data end 95 years BP, which is 1855. Period.

       Data series here.

24094. Mike Hillis at 23:32 PM on 31 May 2016
       Most of the last 10,000 years were warmer
       

       The point is not random, I'm saying that if they had used deuterium and 1H then nobody would have made the above mistake, because there are no H2 bubbles in the ice. There are O2 bubbles, and I needed to clarify that nobody is measuring the isotopes of O2 gas bubbles, only the O in the ice molecules.

       Moderator Response:

       [RH] First address your error about dating of the GISP2 data. Then we can move on to the isotopic issue.

24095. Mike Hillis at 23:20 PM on 31 May 2016
       Most of the last 10,000 years were warmer
       

       The reason they use O isotopes instead of 1H and 2H (deuterium) is because the chemists who measure the isotope levels transfer the O from the H2O to CO2 molecule, because it's easier for them to deal with CO2 on the mass spectrometer, for reasons I won't get into now. 

       Moderator Response:

       [RH] Rather than making random statements, you're going to need to make a point here.

24096. Mike Hillis at 23:01 PM on 31 May 2016
       Most of the last 10,000 years were warmer
       

       "Finally, snow pack exist up to the present and shows annual layers as you note. However, the holes within the snowpack containing the gas do not become air tight and hence preserve a record of prior atmospheric concentrations until decades after the fall of the snowpack"
       
       The temperature proxy in ice cores is measured using the isotopes of oxygen in the snow molecules themselves, not the gas trapped in it. In other words, some of the O (I call it O here rather than O2 because we are talking about the O in the H2O not the oxygen gas trapped in bubbles) is 16O and some is 18O. There is also 17O but that is not stable. The temperature record is made from the fact that more 18O atoms are found when temperatures are warmer. The proxy is extremely accurate because there is a big difference between O isotope levels in winter and summer snow of the same year, even the current year. It's not necessary to wait for the snow to turn into firn or ice, in fact the calibration is done using fresh snow and present day thermometers. Let me quote from Werner et al 2001:

       "The observed present-day (spatial) relation between d 18O,
       d D, and surface temperatures of polar sampling sites (Dahe et al., 1994; Dansgaard,1964; Johnsen et al., 1989; Lorius et al., 1979)
       are taken as transfer functions to interpret temporal changes of the d-values as changes of surface temperatures at the drill site"

       So, they measure current temperatures and isotopes at various current places (spatial) and use it to interpret temperatures in the ice cores (temporal), and refer to this as a transfer function.

       Moderator Response:

       [RH] For a previous article I contacted Dr Alley directly and asked him about the "before present" reference used for GISP2 data. He stated to me that "present" is the 1950 standard used for radiocarbon dating. The GISP2 data ends 95 years before present. Thus, 1950 minus 95 years is 1855. 

24097. Ger at 22:53 PM on 31 May 2016
       In-depth: Experts assess the feasibility of ‘negative emissions’
       

       @Snedder #15.

       15.7 million tons is the lower value. Consisting of straw (wheat, barley, rapeseed), maintenance wood (cleared to prevent forest fires; see Canada if you don't), wood scraps from wood working operations and chicken litter (mixed with sawdust). Materials which are now being disposed off at certain costs. For example chicken litter removal costs can varies between Euro 5 to Euro 35 per ton for removal. It is not a very good fertiliser. Of course chicken farms could process the litter themselfs in small CHP units, providing electricity to the grid and heat to the chicken operation. There is little to no transport except for the initial sawdust (bedding) for the chicken and the feed. Both are well established transport mechanisms. 

       Biggest problem for temperate zone countries is the one single harvest period where all should be collected in a time frame of 3 months and stored for the rest of the year. Straw and other easy to bundle and store materials have to be collected. Use of straw (carton) is nowadays limited so most is ploughed under (burning in the field, even cheaper not allowed since 1993), taking considerable amount of fuel, which could just as well be used to bundle and transport the straw. But if their is no demand, (nothing to earn) no one cares what is happening with it.

       Wood, trees are easier to harvest and can be harvested the whole year long (winter preferred, dryer wood), stored in the same fields to dry for a year (moisture content 25%, little extra mechanical drying needed).

       If there is a collection mechanism, like there is for MSW, even small amounts can be collected and bring up the amount to a 35 million tons of (pretty clean) agricultural biomass.

       Logistics, now fueled by fossils, is considered a point. Looks like people (politicians, general) do not catch that up to a 75% of the fuel for logistics is already used (in the form of empty return cargo) and paid for in the form of the food/fuel price.

       On the part of importing 3 million tons of wood pellets from SE America: feedstock price and logistics. Basicly wood fuel pellets are made from wood residues. When request went up and power houses demanded lower prices (or more subsidies), the paper & pulp industry got interested and all production forest wood for paper is diverted to fuel pellet - as long as one can earn more than with just paper making-.

       Torrefaction in one method to enhance energy density, improve storage capabilities and when done close at the source, reducing transport mass with a 20% to 35%.   

24098. Tom Curtis at 14:58 PM on 31 May 2016
       Most of the last 10,000 years were warmer
       

       Mike Hillis @52, perhaps you would be less shocked if you actually read for comprehension.

       Firstly, I have never claimed (nor ever have) emailed Richard Alley.  The person claiming to have emailed Richard Alley is the author of the OP, ie, Gareth.

       Secondly, neither the article, nor any comment by me, claims that Alley used 1855 as the present.  Rather, we have claimed that the fist datum point in the Alley data is at -95 (specifically 0.0951409 thousand years before present), and that the standard age of "the present" in geology used for dating Before Present is 1950.  Combining these two facts, we determine by arithmetic that the first datum in the Alley data is at 1855.  You may have difficulty reading, and be shocked by, arithmatic - but that is your problem, not mine.

       Thirdly, what has been confirmed by Richard Alley in the email to Gareth that when he referred to "years before present" in the data and article with out explicitly stating he was not following the standard custom, he was in fact following the standard custom.  Given that it would have constituted an error in the document to do otherwise, that comes as no surprise.

       Finally, snow pack exist up to the present and shows annual layers as you note.  However, the holes within the snowpack containing the gas do not become air tight and hence preserve a record of prior atmospheric concentrations until decades after the fall of the snowpack.  Indeed, not until they have been sealed by compression of overlying the overlying snowpack.  How long it takes for that to happen depends on the rate of precipitation, which is slow at the GISP 2 sight at the top of the Ice Sheet.

24099. Mike Hillis at 14:31 PM on 31 May 2016
       Most of the last 10,000 years were warmer
       

       I read this thread and am shocked by what I'm reading. The data that Richard Alley uses does not end in 1855, nor does it use 1855 as any sort of "present". Nor does the snow have to be compacted into firn and then the firn into ice, in order to date the annual layers, or for these layers to be usable in isotope measurements. In his books and papers, for example his book "Two Mile Time Machine", Doctor Alley goes into detail about the snow pits, roughly 6 feet deep, that they were digging in the current and previous year's snow, where they could see the first annual layer by eye. The snow was described as being about 2 or 3 feet per year in fresh snow, which packs down to about 1 foot per year in firn/ice. I am very suspicious in the assertion by Tom Curtis that Alley's study ends in 1855, and much of his reasoning for claiming so. I need to see evidence of this. I can see where Tom Curtis claimed to have emailed Alley and asked him, and got a reply from Dr. Alley, but also find this to be a copy and paste from another person who emailed Alley, which means Mr. Curtis probably never actually emailed Dr. Alley at all. It's astonishing that nobody has corrected this fabrication so far.

24100. Mike Hillis at 13:41 PM on 31 May 2016
       We're heading into an ice age
       

       I don't see how the author of this thread can say the next ice age is 10,000 years away. I see from the graph at the top of this thread that the previous interglacials were all very short, and it appears from the green bars on the graph that the Holocene is already longer than any of the past 4 interglacials. What evidence is there that we can expect 10,000 years of Holocene?

       Moderator Response:

       [TD] Read the text. Then click the Intermediate tab and read that text.

        

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