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Comments 41951 to 42000:

  1. Models are unreliable

    "Climate trends are weather, averaged out over time - usually 30 years. Trends are important because they eliminate - or "smooth out" - single events that may be extreme, but quite rare."

    So if we look at the past 30 years we should get the climate trend. According to skepticalscience's trend calculator from 1983 to 2013 the earth's temp has increased by 0.17 C per decade (GISTEMP moving average 12 months). Since CO2 has risen at about a linear rate since 1980 (according to: http://www.esrl.noaa.gov/gmd/ccgg/trends/), is it reasonable to predict a best guess rise of 1.7C from decades (1990 - 2000) to (2090 - 2100)? This would point to the low scenario from IPCC 2007, which has a best guess of 1.8C.

  2. Understanding the pre-IPCC Anti-Climate Science Misinformation Blitz

    @rockytom #49:

    As long as the fossil fuel industry exists, Deniersville will exist.  

  3. Understanding the pre-IPCC Anti-Climate Science Misinformation Blitz

    I guess the deniers couldn't find any emails to steal! They do become more strident as their numbers decline.

  4. Public talk explaining our consensus paper & answering critics

    The Monckton quote comes from http://www.youtube.com/watch?v=xZSPOawk698 - around the 2:30 minute mark.

  5. Public talk explaining our consensus paper & answering critics

    Can you please give the provenance of the Monckton quote?

  6. 16  ^  more years of global warming

    The video in the post is "private". A mistake?

  7. Latest myth from the Mail on Sunday on Arctic ice

    The Mail on Sunday's "retraction" yesterday didn't amount to the proverbial hill of beans, so here's our latest report deconstructing the recent "Shock news!" about "And now it’s global COOLING!":

    http://GreatWhiteCon.info/2013/09/santas-secret-summer-swim/

  8. Why is the IPCC AR5 so much more confident in human-caused global warming?
    I'm not sure about the usefulness of the RPCs as they all seem to assume economic growth continuing to the end of the century. That seems like an awfully large assumption given resource depletion and environmental deterioration (not to mention debt levels). However, I suppose the people they are targetting all make the same assumption so maybe it's useful as a way of engaging the unengagable.
  9. Models are unreliable

    Further to Zwiers. Any good scientist is a skeptic - a real one. Fake skeptics are only skeptical about things they disagree with and will swallow any kind of junk uncritically if it supports their notions.

  10. Models are unreliable

    tcflood "wouldn't the effect be to remove the ENSO effects thereby insuring some departures of observation from the models when real ENSOs would occur? "

    Essentially true. See for instance the graph here. Forcing ENSO in model to match what happens is somewhat like Kosaka and Xie did. See discussion here.

    Comment from Mike at RC on Zwiers.

    "[Response: Francis is a top-rate scientist of the highest integrity. I strongly suspect that he has been misquoted and mischaracterized quite a bit lately. -mike]

  11. Secretary of State Kerry and Senator Boxer Remark on the IPCC Report

    It's been interesting to see some of the reader comments on sites like the UK Guardian and PBS Newshour. The climate denier trolls seem to be out in full force. But none of them appears to have actually read the Summary Report for Policymakers. As an American I am embarrassed that someone as ignorant about science as Lamar Smith chairs the House Committee on Science, Space and Technology.

  12. Models are unreliable

    @jsmith.  Thanks for the response. I read somewhere that many of the GCMs actually do produce ENSO episodes but that the timing of their appearance (as in nature) is chaotic. If modeling results are reported as an average of many models, wouldn't the effect be to remove the ENSO effects thereby insuring some departures of observation from the models when real ENSOs would occur? So, hypothetically, if there were some way to trigger an episode at the same time in all the models, the match between models and observation might be much improved. I don't pose this as a realistic modeling strategy, but rather as an accurate and effective counterargument to this common cavil in the denier echo chamber?  

    Also, the denier rant that called my attention to the above-cited paper said Zwiers is a vice chair of the IPCC. I infer from your comment that he is nonetheless a skeptic. The paper certainly reads like he is.   

     

  13. Secretary of State Kerry and Senator Boxer Remark on the IPCC Report

    The BBC carried a series of comments from notable figures including leading UK politicians, environmentalists and scientists (with a few in denial).

    Moderator Response:

    [JH] Thank you.

  14. The Pacific Ocean fills in another piece of the global warming puzzle, and puzzles Curry

    I wanted to chime in with my own SOI analysis inspired by Kevin C and Icarus.

    Plot of SOI variability
    I took a monotonic warming and laid the scaled SOI on top of it, comparing to the GISS temperature record. Then I added in the major volcanic disturbances using the BEST data. The lower panel is the SOI-corrected signal, which shows no evidence of a pause.

    Since the SOI reverts to the mean, it is virtually impossible for the pause to continue considering its past historical trend.

  15. Secretary of State Kerry and Senator Boxer Remark on the IPCC Report

    William@12

    No. Kerry was never a member of the GOP or Republican Party. His first campaign for national office was in 1972. He ran as a Democrat and lost to Paul W. Cronin, the Republican candidate.

    You may be thinking of Robert Gates, President Obama's first Secretary of Defense, a hold-over from the Bush presidency.

  16. Understanding the pre-IPCC Anti-Climate Science Misinformation Blitz

    @RobertF #45. (On-topic) Because `a sub-beginner`, `denier friend` and  `What am I missing?` I suggest tentatively you might be missing `the big picture`. I started 6 months ago (I had assumed it was a simple, boring slam-dunk in prior years) with a few hours of getting physical quantities - sun, earth`s ecosystem, mostly oceans of course with 97.3% of all the ecosystem heat being there and the other 2.5% being water that`ll return to oceans one day, then fossil fuel reserves & consumption weights & measures. I concluded `global warming` is heat entering the oceans, it cannot be anything else. Surface & air temperatures are important to us, a fairish proxy and needed to rise eventually to stop the global warming. So, the actual question is how many ZettaJoules of heat are going into the oceans. There`s information everywhere to study and make your personal decision from, I`m going with the 13 ZJ per year. Your 'denier friend' must be going with less or he`d be an `alarmist`. After you have studied and formed your own opinion, you need to ask him for his estimate in ZettaJoules of heat per year that are going into the oceans (he must provide you with a ZJ number and accuracy range for you to ponder) and what he bases that on. Suggest you look at what`s available regarding ocean temperature measurements, XBT, ARGO floats, the prior rubber buckets, and the various numbers. Sure, surface & air temperatures are important for a few reasons but it`s all about quantifying heat change in the oceans.

  17. Latest myth from the Mail on Sunday on Arctic ice

    AnotherBee - We covered that point here.  We are continuing to pursue that issue and many others with both the Mail and the PCC.

    In case it's of some interest, here's our latest video report, hot off the presses, which covers the Mail's recent "revision" and also touches on the mismatched dates issue:


    Moderator Response:

    [DB] Reduced Video Player width to 450.

  18. Secretary of State Kerry and Senator Boxer Remark on the IPCC Report

    And yet, with a stroke of the pen, the politicians could have a profound effect on the problem.  Simply put in Hansen's Tax and Dividend.  The economics will take care of the rest.  What is so hard for them to understand here.  Wasn't Kerry a member of the GOP before Obama hired him.  Perhaps he should go and talk with his former colegues.

    Moderator Response:

    [JH] John Kerry was indeed a Senator from Massachusetts. He was also the Democrat's nominee for President in 2003, when George W. Bush won re-election. You can rest assurred that Kerry has communicated and will continue to communicate with his former Senate colleagues on a wide variety of subjects including what to do about climate change.  

  19. Understanding the pre-IPCC Anti-Climate Science Misinformation Blitz

    @scaddenp #43 I'm harping on this a bit but it's important because it's the basics and "denier" comments on web sites don't grasp it (the paid and mischief makers pretend not to grasp it) and you said "...CIMP models...". Yes, I`m sure the "models" would do an excellent job but I`m talking reality, not simulation, and it`s simple. It needs 5.5 ZettaJoules to raise average air temperatutre 1 degree Celsius (I got from Dr. Randall lecture + simple math) and ORAS4 reanalysis says oceans took up 250 ZJ the last many decades. Add 8% estimate for ice melt & miscellaneous and this would have today raised air temperature by 49 degrees Celsius. No simulation "models" needed just simple math & logic. The "models" are good for projecting what will happen with various emissions scenarios but whenever a simple concept can be described without reference to these simulation "models", it should be.

  20. Secretary of State Kerry and Senator Boxer Remark on the IPCC Report

    @ClimateChangeExtremist #7 You have quantity mistake. Total current CO2 in air 400 ppmv = 3,120 gigatonnes, which is 390 Gt above 350 ppmv. 

  21. Secretary of State Kerry and Senator Boxer Remark on the IPCC Report

    @Moderator #5 I think it's necessary you clarify whether every Congressperson Lamar Smith opinion is "poppycock" because there's some diverse opinions in it, the obvious being quantiication of "unilateral action by the U.S." as opposed to a global agreement in which the other big coal burners are included.

    Moderator Response:

    [JH] Cong Smith's pontification about the US not proceeding alone tells me that he believes the U.S. should relinquish its role as a world leader. From my perspective as a patriotic American, such a policy is poppycock. 

  22. Secretary of State Kerry and Senator Boxer Remark on the IPCC Report

    Perhaps  Congressperson Lamar Smith can publish  his latest readings in relation to his review of the 'actual scientific assesment of the peer-reviewed literature." 

  23. Secretary of State Kerry and Senator Boxer Remark on the IPCC Report

    We can expect the deniers to still deny and the contrarians to still be contrary to mainstream science.  The fight will go on!  In the U. S. we are seeing the result of our failed education system in not teaching critical thinking.  The republicans are blind to facts and the truth, as they have been for a few generations.  Maybe the AR5 will help.  Let's hope it does.

  24. Secretary of State Kerry and Senator Boxer Remark on the IPCC Report

    Nothing short of a Manhattan style approach to dealing with our CO2 emissions, not just from fossil fuel burning, but land use as well, will do. And it isn’t just a matter of reducing our CO2 emissions; there's the issue of energy requirements - from non-fossil fuels of course - needed sequester several thousand gigatonnes of excess CO2 to get us back down to 350 ppm. Bold statements are all very well; bold action is another matter and the political gridlock in Washington is all but guaranteed to prevent any real action from happening. And unfortunately, if the US doesn’t act, then it's unlikely any of the other major polluters will.

  25. Why is the IPCC AR5 so much more confident in human-caused global warming?

    chriskoz @47 - RCP 3PD and RCP 2.6 are the same.  PD is peak and decline, with the decline being from 3 W/m2 to 2.6.

  26. Secretary of State Kerry and Senator Boxer Remark on the IPCC Report

    (-snip-).

    Smith is Chairman of the House Committee on Science, Space and Technology. 

    Moderator Response:

    [JH] Discussing somone's religion is prohibited.

  27. Latest myth from the Mail on Sunday on Arctic ice

    I heard a garbled newspaper review of today's Mail revision (as highlighted by MA Rodger) above, so I visited the article to see what it actually said.

    In addition to the blaming the NSIDC for the previous error, I noticed an interesting slight of hand with the images that accompany the article.  There are two comparison images, the first captioned "NASA satellite images showing the spread of Arctic sea ice 27th August 2012" and the second captioned "And now, much bigger: The same Nasa image taken in 2013".  Yes, it was an image from 2013, but the image itself bears the date of August 15th.  Now, what do you suppose happens between August 15th and August 27th?

    Take a look at the side-by-side comparisons on the UIUC Cryosphere Today Site.  Here's August 15th and here's August 27th.  Of course they both show a story of greater ice area in 2013, but - especially the 27th comparison - is not the story that Rose tells in the article.

  28. Models are unreliable

    @tcflood it looks like there was indeed less warming over the period 1997-2012 than the models predicted, however, what "skeptics" often fail to mention is that "the surface warming trend from 1993 to 2007 was significantly higher than projections." See here for more information: http://www.abc.net.au/environment/articles/2013/09/27/3857704.htm

  29. Christopher Gyles at 01:40 AM on 30 September 2013
    Secretary of State Kerry and Senator Boxer Remark on the IPCC Report

    Congressperson Lamar Smith (R-Texas) released the following statement.

    Chairman Smith: “Lobbying by several nations to influence the latest IPCC report demonstrates that these reports have become more political than scientific. The ‘summary for policymakers’ released this morning in Stockholm appears to be designed to provide cover for excessive regulations and carbon taxes. There is little doubt the Obama administration will try to use this report to support additional costly regulations. But even the EPA has admitted that unilateral action by the U.S., including its recent energy regulations, will result in negligible changes to our carbon dioxide emissions and will have no discernible impact on the global temperature.“The IPCC also has had to backtrack from previous reports in several important areas. The report backs away from claims about a connection between climate change and severe weather. The report states ‘low confidence’ in any connection between human-driven climate change and increased droughts or hurricanes. Rather than releasing politically-influenced opinions, the IPCC should let the science speak for itself. I look forward to reviewing the actual scientific assessment of the peer-reviewed literature.”

    http://www.spaceref.com/news/viewpr.html?pid=41680

    Moderator Response:

    [JH] Thank you for your contribution. It helps us track the poppycock being spread by climate deniers.

  30. Christopher Gyles at 01:33 AM on 30 September 2013
    Secretary of State Kerry and Senator Boxer Remark on the IPCC Report

    US Secretary of Energy Ernest Moniz:

    "I believe that the report is a watershed; we have clear evidence from our climate scientists that global warming is happening and that we as humans are playing a critical role, which is the underpinning of the President's Climate Action Plan. The plan places a strong emphasis on mitigating the risks of climate change through further investments in clean technologies aligning with our all-of-the-above energy strategy. The President's plan also brings forward a strong focus on the need to prepare for climate change because we are already experiencing the anticipated impacts of global warming,"

    Source

    Moderator Response:

    [DB] Added source per request.

    [JH] Thank you for your contribution.

  31. Latest myth from the Mail on Sunday on Arctic ice

    The latest enstallment from David Ruse of the Daily Rail complete with 'apology'. I did wonder if his "60% ice loss" story resulted from such a typo (2.38 sq km not 1.38 sq km). He is of course entirely innocent  He blames it all on the evil NSIDC.

    In this latest installment, Rose is very strong on the "It was the Rail wot done it," it being them who exposed the 17-years-without-a-rise and also that the start date was before the El Nino of 1998. You have to ask though - if it was 17 years, how come the Rail only managed to spot it last year?

    And his HadCRUT data, as well as being cherrypicked are also not very accurate. "David, it is 0.405 for June 1997 & 0.514 for July 2013. And your claimed start-date for the pause (January 1997) was 0.204."

    However Rose has reined back on some of his nonsense. Back in March he told us the temperatures were "about to crash out" of the "95%  degree of certainty" zone. Today it is only "very likely that by the end of this year, world average temperatures will have crashed below the ‘90 per cent probability’ range." So who knows. By the end of the year it might be only an outside chance that Rose is within 1 sd of reality.

     

  32. Secretary of State Kerry and Senator Boxer Remark on the IPCC Report

    Prof Sir Brian Hoskins, from Imperial College London, told BBC News: "We are performing a very dangerous experiment with our planet, and I don't want my grandchildren to suffer the consequences of that experiment."

    IPCC climate report: humans 'dominant cause' of warming

    Moderator Response:

    [JH] Thank you for your contribution.

  33. Why is the IPCC AR5 so much more confident in human-caused global warming?

    I've noticed another detail: RPC3PD scenario is not there anymore: looks like it was replaced by RPC2.6. I'm not sure if those two scenarios are the same or if RPC2.6 has been slightly changed. But looking at Figure SPM.10 (the last one) it seems that the emissions are pacing about the same in all scenarios until 2030, then RPC2.6 starts slowing down in 2040 and stops abruptly in 2050 at cumulative ~750GtC, which is way below the suggested 1Tt alowance known from earlier reports.

    RPC2.6 being the only acceptable scenario for those who care about the future of the planet, I'd like to have a feeling how realistic it is compared to the old RPC3PD. Are they realy the same? The emission halt within 2040-2050 seems to be too abrupt. And then, does AR5 still asume that humans start "scrubbing off" CO2 from the atmosphere around 2070? Or the Earth natural sinks (ocean + biosphere) would significantly outweigh the natural sources (permafrost + clathrate methane) helping to realise RPC2.6 scenario?

  34. Why is the IPCC AR5 so much more confident in human-caused global warming?
    Right, got ya! Thanks scaddenp.Yes, I agree that it's a reasonable inference. As dana noted, the report says "The best estimate of the human induced contribution to warming is similar to the observed warming over this period." Now that I've actually seen it (I don't know why I couldn't find it before), along with the figure, I can see that it's a reasonable inference so I'm loathe to quibble further but the summary doesn't actually make the claim mentioned, I think it could be better explained, but perhaps that's nit-picking.Thanks for the replies to sort my mind out!
  35. Why is the IPCC AR5 so much more confident in human-caused global warming?

    TonyW - the figures are not inline with the text but at the bottom of the document. While I dont think Dana is making direct quotes, it is certainly the inference from the figure. Also when it says human is "most likely"  in range in 0.5 to 1.3 and natural forcing and internal variability to be" -0.1 to 0.1", then it seems a perfectly reasonable inference to me.

  36. Models are unreliable

    tcflood's source in pdf, in case SkS can't access it by other means.

  37. Why is the IPCC AR5 so much more confident in human-caused global warming?
    Thanks to dana and scaddenp but I'm struggling to find the quoted passages (as mentioned by dana @42) or the figure (mentioned by scaddenp @43). All I can find is the summary for policymakers, as provided in the link in the article above. It has no figures included and doesn't contain the quotes mentioned by dana.If the quoted passages are accurate, I'm still not sure how they result in the claim that "the IPCC says that humans have most likely caused all of the global warming over the past 60 years." One may be able to infer that for one's own opinion but not as a statement of fact.I guess I'll have to wait for the final draft to be made available on-line to check on this.
  38. Why is the IPCC AR5 so much more confident in human-caused global warming?

    TonyW - it would seem to be the logical conclusion to draw from looking at figure SPM-6 in the just released report.

  39. Secretary of State Kerry and Senator Boxer Remark on the IPCC Report

    "... In reaction to the report, [EU] Climate Action Commissioner Connie Hedegaard said: ''The issue is not whether to believe in climate change or not. The issue is whether to follow science or not. The day when all scientists with 100% certainty warn you against climate change, it will be too late. If your doctor was 95% sure you had a serious disease, you would immediately start looking for the cure. Why should we take bigger risks when it's the health of our planet at stake?"..." [source]

    Moderator Response:

    [JH] Thank you for your contribution.

  40. Why is the IPCC AR5 so much more confident in human-caused global warming?

    TonyW @40 - see the quotes from the IPCC report in the Current Global Warming Caused by Greenhouse Gases, Not Nature section above.

  41. Secretary of State Kerry and Senator Boxer Remark on the IPCC Report

    For the record, Dana was kind enough to put together this post while I was busy working on a third edition of this week's News Roundup. It's chocked full of objective articles on the just released IPCC report.

    I invite readers to post any statements made by the world's policy makers on the IPCC report on this thread. Plesase cite source and provide a link. 

  42. Why is the IPCC AR5 so much more confident in human-caused global warming?

    Thanks so much Dana.  I've been an everyday lurker from almost day one on this site.  I've had no science training beyond chemistry 101.  The fact is I’ve learned so more about climate science then I ever wanted too,  but you guys make it the most interesting.

  43. Latest myth from the Mail on Sunday on Arctic ice

    I have some modest success to report at long last. We have contrived to persuade The Mail to retract the most outrageous of the headline numbers concerning Arctic sea ice that they published on September 8th. They have of course endeavoured to blame the NSIDC for their own shortcomings:

    http://GreatWhiteCon.info/2013/09/the-mail-makes-modest-amends/

    Next we'll try and persuade The Telegraph to follow in the Mail's illustrious footsteps. Then of course there's all those other inaccuracies that they both still need to make amends for!

  44. Why is the IPCC AR5 so much more confident in human-caused global warming?
    dana,"it's very likely more than half, most likely 100%."But where does the IPCC summary state this, as you claimed at the start of your post? Is it just your opinion (which I happen to agree with, by the way) or does it come from AR5 somewhere? I think it's important not to give contrarians ammunition when relaying the (very conservative) assessment of the IPCC.
  45. Understanding the pre-IPCC Anti-Climate Science Misinformation Blitz

    RobertF @45, I have responded elsewhere, where the comments will be on topic.

  46. Foster and Rahmstorf Measure the Global Warming Signal

    Elsewhere, RobertF writes:

    "I am a sub-beginner and probably a bit skeptical of both sides. Recently, I saw a graph from Rahmstorf showing a continuing warming. A denier friend informs me that Rahmstorf cooked the books by adjusting for ENSO, in part. The rationale given is that ENSO has no direct global impact and thus surface temperatures cannot be adjusted for what is a local phenomenon. As justification, the denied offered a citation from Trenberth: "Although it is possible to use regression to eliminate the linear portion of the global mean temperature signal associated with ENSO, the processes that contribute regionally to the global mean differ considerably, and the linear approach likely leaves an ENSO residual."

    What am I missing? Thanks in advance!"

    Your "denier friend" is being no friend in feeding you such nonsense.

    To begin with, the link between fluctuations in ENSO and changes in mean global surface temperatures is well established - and is the dominant short term (1-2 year) influence on global temperatures.  This has been established by (among many more credible sources), the noted "skeptics", McLean, Carter and DeFreitas, who produced this figure comparing detrended middle atmosphere temperatures with the Southern Oscillation Index (SOI):

    As you can see, except where there is volcanic cooling, the correlation is very close.  Consequently there is no doubt that ENSO is responsible for most of the interannual variability in GMST.  A fact so well established that even leading "skeptical" scientists are publishing on it is hardly one we should disagree with on the word of an anonymous friend.  

    (Note, use of this figure should not be taken as endorsement of McLean et al's ludicrous claim that because they show a correlation with the detrended GMST, therefore ENSO is responsible for the long term trend in GMST.)

    So, given that there is an correlation, what are we to make of Trenberth's claim?  You will note that he does not say there is no correlation, only that "a linear approach is likely to leave a residual".  And if you look closely at the Foster and Rahmstorf adjusted data above, you will see exactly that residual.  It is most obvious in the peak at 1998, and the trough in 2008 corresponding to the 1998 El Nino and the 2008 La Nina respectively.

    "Leaving a residual" does not mean that there is no relation between ENSO and GMST as your friend would have you believe.  It merely means that the effect is not a simple multiple of the strenght of the ENSO signal.  Therefore any approach which treats it as such (including F&R) will leave a small part of the ENSO signal in the data, ie, a residual.  The effect will be that such approaches will understate the effect of ENSO on short term temperature trends.  Had F&R used a more sophisticated approach, they would have shown still stronger long trends over the last two decades than they actually show (although probably within statistical error of the trends they do show).

    Of course, you do not need a sophisticated statistical method such as F&R to see what recent temperature trends would have been without the effect of ENSO.  You merely need to group like with like - El Nino years with El Nino years, La Nina years with La Nina years - and thus determine the trend largely without any ENSO influence.  John Neilson-Gammon has done exactly that:

    As you can see, the trends for different types of years are approximately the same.  Unsurprisingly, that trend, 0.16 C per decade, is very close to that found by F&R.  (The slight difference is partly accounted for in that this method does not account for the recent cooling of the Sun.)  More importantly, recent years fall very close to there respective trend lines.  Therefore there has been very little recent cooling beyond the switch to a La Nina dominated pattern.

    ENSO may not be the whole story in the recent lower trends in GMST.  Scientists, being scientists, explore every possibility.  But clearly ENSO is the dominant factor, and the other factors which scientists are exporing are additional effects - effects without which we would have seen an acceleration in global temperature rise.  "Skeptics" like to drag those other studies across the trail to suggest ENSO is not a clear and dominant factor.  The want to treat the diligence of scientists in exploring every factor as proof that no factor explored by scientists explains the recent lowered trends.  But that is a simple pea and thimble game.  Scientists know that ENSO is a dominant factor in the recent reduced trends.  All that is at issue is how much of an effect it has had, and how much influence (if any) other less certain factors have had.

  47. Why is the IPCC AR5 so much more confident in human-caused global warming?

    Stranger @29 - those people are probably referring to the fact that the IPCC AR5 only provides a range of equilibrium sensitivity estimates (1.5 to 4.5°C for 2xCO2) and not a best estimate.  This is because while paleoclimate and model-based estimates agree (2 to 4.5°C, most likely 3°C), estimates based on using recent observational data in simple models (Otto, Lewis, etc.) arrive at somewhat lower estimates.  So basically two methods agree, one disagrees, so they don't have a consensus best estimate anymore and instead just put the range.

    Were I a betting man, I'd put my money on the former two methods.  Not only is it 2 against 1, but the latter method has large uncertainties, discussed by Andrew Dessler here.

  48. Why is the IPCC AR5 so much more confident in human-caused global warming?

    chriskoz @28 - somewhere in there the IPCC says that roughly half the increased anthro forcing estimate is due to the rise in GHGs over the past 6 years, and roughly half is due to the decreased aerosol negative forcing estimate (decreased meaning smaller in magnitude).

  49. Why is the IPCC AR5 so much more confident in human-caused global warming?

    TonyW @26 - it's very likely more than half, most likely 100%.

  50. Why is the IPCC AR5 so much more confident in human-caused global warming?

    Me #35 I mean ...and I state +137 ZettaJoules in last 10 years....

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