IPCC Climate Change Report........

by cantleave 153 Replies latest social current

• 

  Glander

  We all know who the KNOB is! You silly gomer.

  Now we can get down into a scientific high school chop session.
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  JeffT

  That flat line is significant. We need to nail down why that is happening, in order to do more of it (or maybe less of something) so that the trend will continue or even improve.
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  BizzyBee

  That flat line is significant. We need to nail down why that is happening, in order to do more of it (or maybe less of something) so that the trend will continue or even improve.

  Is this what you consider "substantive"? Really? Read it again. Where did you get your B. Sc.? Of course, you realize that you just acknowledged that humans are responsible for climate trends?
• 

  JeffT

  "Of course, you realize that you just acknowledged that humans are responsible for climate trends?"

  I haven't said we aren't. At least not for some time. And yes, that may be a change of position for me. Thinking people change their minds from time to time, unlike unthinking twits.

  Read what again?
• 

  besty

  Unless Betsy has a new source, she is probably referring to the 2009 Doron/Zimmerman survey that came up with the 97% figure.

  <<<<<<--------- *Besty <he>

  Although it is valid to crtiticize methodology, it is also possible to attempt to replicate results. If you have an alternative peer-reviewed paper which shows climate scientists are not in near-unanimous consensus then please share with the group. (Of course the 3% deniers also serve to destroy the conspiracy myth and provide evidence of the scientific method being alive and well - it just so happens they are almost certainly wrong)

  Aside from Doran/Zimmerman finding that 75/77 climate scientists attribute rising temps to human activity there are several other similar studies with similar outcomes analysed here http://en.wikipedia.org/wiki/Surveys_of_scientists'_views_on_climate_change

  1 - A survey of 928 peer-reviewed abstracts on the subject 'global climate change' published between 1993 and 2003 shows that not a single paper rejected the consensus position that global warming is man caused (Oreskes 2004).

  2 - A follow-up study by the Skeptical Science team of over 12,000 peer-reviewed abstracts on the subjects of 'global warming' and 'global climate change' published between 1991 and 2011 found that of the papers taking a position on the cause of global warming, over 97% agreed that humans are causing it (Cook 2013). The scientific authors of the papers were also contacted and asked to rate their own papers, and again over 97% whose papers took a position on the cause said humans are causing global warming.

  I hope that answers your question. Thanks for the opportunity to elaborate.
• 

  cantleave

  Sorry for being absent from this thread yesterday, I spent the day gardening and then had our good friend Amelia Ashton for one nugget's roast dinners - so JWN was ignored. I think Besty has pretty much shown the difference between the scientific and the ignorant on this thread.
• 

  besty

  @SBF

  How do you arrive at the 97% figure? Does it refer to academic articles on the subject, because what gets published in academic journals is notoriously impacted by bias and interest groups.

  See answer above for TT2C - the 97% figure is well established for some time by multiple studies covering multiple decades and has not been refuted. (Nice little attempt to poision the well - noted)

  Have you read Bad Pharma by Ben Goldacre? He explains this phenomenon in relation to medicine. How a dozen studies can be performed on a drug, only one showing that it works, and it's the only one that gets published.

  Have you read Ben Goldacre's recomendation on studying the IPCC website for climate science information - you do know he is an evidence-based writer, don't you? http://www.theguardian.com/commentisfree/2009/dec/12/bad-science-goldacre-climate-change

  A similar thing could be going on in climate science.

  Pointless speculation - evidence please, and not a view held by Ben Goldacre - see link above for his views on climate science.

  Plus scientists who believe in climate change are naturally drawn to the field, and publish their work. Others who find the evidence less compelling may pursue other topics and hence never publish on the subject of climate change. So there may be selection bias both at the level of what gets published and who enters the field in the first place.

  You are speculating SBF - this is ridiculous, and denies the scientific method. This is not a local book club we are talking about. Every major oil and gas company accepts the science of climate change. To do otherwise is akin to creationsim or flat-earthism. This theory would have been in the trash by now if money and influence could have put it there - it's not - deal with it.

  It is my strong suspicion that the coming decades will confound the climate change narrative, that is if humanity does not destroy itself with nuclear weapons before then.

  The last bastion of the denier - future events will prove me right, even when all previous facts show me to be wrong.
• 

  bohm

  SBF:It is my strong suspicion that the coming decades will confound the climate change narrative

  Or to put it directly, you are aware the current data contradict what you hope to be true, but your bias is so strong you simply believe the data must be in error and at some unknown future point the world will align with your current bias. You are correct, you are not a scientist; what you dont realize is you are doing the opposite of scientific thinking.

  "we are living in the last days since 1914, and jesus said we would see an increase in earthquakes. I know this has not happened, but you know what? i believe the coming decades will proove I am correct so what does the last 100 years of data mean?".
• 

  cantleave

  I apologise for the cut and paste from Live Science. Seems to indicate the deniers are the ones changing their story!

  http://www.livescience.com/39957-climate-change-deniers-must-stop-distorting-the-evidence.html

  Michael Mann is Distinguished Professor of Meteorology at Penn State University and was recognized in 2007, with other IPCC authors, for contributing to the award of the 2007 Nobel Peace Prize for his work as a lead author on the "Observed Climate Variability and Change"chapter of the Intergovernmental Panel on Climate Change (IPCC) Third Scientific Assessment Report. Mann contributed this article to LiveScience's Expert Voices: Op-Ed & Insights.

  It happens every six years or so: The Intergovernmental Panel on Climate Change (IPCC) publishes its assessment of the current state of scientific understanding regarding human-caused climate change. That assessment is based on contributions from thousands of experts around the world through an exhaustive review of the peer-reviewed scientific literature and a rigorous, several-years-long review process. Meanwhile, in the lead-up to publication, fossil-fuel industry front groups and their paid advocates gear up to attack and malign the report, and to mislead and confuse the public about its sobering message.

  So in the weeks leading up to the release of the IPCC Fifth Assessment scientific report, professional climate-change deniers and their willing abettors and enablers have done their best to distort what the report actually says about the genuine scientific evidence and the reality of the climate-change threat. [FAQ: IPCC's Upcoming Climate Change Report Explained]

  This time, however, climate-change deniers seem divided in their preferred contrarian narrative. Some would have us believe that the IPCC has downgraded the strength of the evidence and the degree of threat. Career fossil-fuel-industry apologist Bjorn Lomborg, in Rupert Murdoch's "The Australian," wrote on Sept. 16: "UN's mild climate change message will be lost in alarmist translation." On the other hand, serial climate disinformer Judith Curry, in a commentary for the same outlet five days later, announced, "Consensus distorts the climate picture."

  So, make up your mind, critics: Is it a "mild message" or a "distorted picture?" Consistency, they might well respond, is simply the "hobgoblin of little minds" after all — but in reality, that's only if you ignore the foolishness.

  Indeed, claims that members of the IPCC have downgraded their scientific confidence have been plentiful among the usual purveyors of climate-change misinformation: Fox News, the editorial pages of the Wall Street Journal and various conservative tabloids in the United States, Canada, Germany and Australia. Fox News even sought to mislead its viewers with a bait and switch, focusing attention instead on a deceptive, similarly named report that calls itself the Nongovernmental International Panel on Climate Change (NIPCC), which simply regurgitates standard shopworn denialist myths and erroneous talking points. That non-peer-reviewed report was published by the discredited industry front group known as the Heartland Institute in the lead-up to the publication of the actual IPCC report, presumably to divert attention from the actual scientific evidence.

  In reality, the IPCC has strengthened the degree of certainty that fossil-fuel burning and other human activities are responsible for the warming of the globe seen over the past half century, raising their confidence from "very likely" in the previous report to "extremely likely" in the current one. The IPCC expresses similar levels of certainty that the Earth is experiencing the impacts of that warming in the form of melting ice, rising global sea levels and various forms of extreme weather. [Climate Scientists: IPCC Report Must Communicate Consensus]

  What about the converse claim, promoted by critics, that the IPCC has exaggerated the evidence?

  Well, if anything, the opposite appears closer to the truth. In many respects, the IPCC has been overly conservative in its assessment of the science. The new report, for example, slightly reduces the lower end of the estimated uncertainty range for a quantity know as the equilibrium climate sensitivity — the amount of warming scientists expect in response to a doubling of carbon dioxide (CO2) concentrations relative to preindustrial levels (concentrations that will be seen mid-century, given business-as-usual emissions).

  The IPCC reports a likely range of 1.5 to 4.5 degrees Celsius (roughly 3 to 8 degrees Fahrenheit) for this quantity, the lower end having been dropped from 2.0 degrees C in the fourth IPCC assessment. The lowering is based on one narrow line of evidence: the slowing of surface warming during the past decade.

  Yet there are numerous explanations of the slowing of warming (unaccounted for effects of volcanic eruptions and natural variability in the amount of heat buried in the ocean) that do not imply a lower sensitivity of the climate to greenhouse gases. Moreover, other lines of evidence contradict an equilibrium climate sensitivity lower than 2 degrees C. It is incompatible, for example, with paleoclimate evidence from the past ice age, or the conditions that prevailed during the time of the dinosaurs. (See this piece I co-authored earlier this year for the Australian Broadcasting Corp. for a more detailed discussion of the matter.)

  The IPCC's treatment of global sea-level rise is similarly conservative — arguably, overly so. The report gives an upper limit of roughly 1 meter (3 feet) of sea-level rise by the end of the century under business-as-usual carbon emissions. However, there is credible peer-reviewed scientific work, based on so-called "semi-empirical" approaches that predict nearly twice that amount — i.e., nearly 6 feet (2 m) of global sea-level rise this century. These latter approaches are given short thrift in the new IPCC report; instead, the authors of the relevant chapter favor dynamical modeling approaches that have their own potential shortcomings (underestimating, for example, the potential contribution of ice-sheet melting to sea-level rise this century).

  As some readers may know, the conclusion that modern warming is unique in a long-term context came to prominence with the temperature reconstruction that my co-authors and I published in the late 1990s. The resulting "Hockey Stick" curve, which demonstrates that the modern warming spike is without precedent for at least the past 1,000 years, took on iconic significance when it was prominently displayed in the "Summary for Policy Makers" of the 2001 Third IPCC Assessment report. Thus, the "Hockey Stick" curve, as I describe in my recent book, "The Hockey Stick and the Climate Wars," became a focal point of the attacks by industry-funded climate-change deniers.

  So, it might not come as a surprise that one of the most egregious misrepresentations of the IPCC's latest report involves the Hockey Stick and conclusions about the uniqueness of modern warming. [4 Things to Know About the IPCC's Climate Change Report]

  An urban legend seems to be circulating around the echo chamber of climate-change denial, including contrarian blogs and fringe right-wing news sites. The claim is that the IPCC has "dropped" or "trashed" the Hockey Stick conclusion regarding the unprecedented nature of recent warmth.

  A good rule of thumb is that the more insistent climate-change deniers are about any particular talking point, the greater the likelihood is that the opposite of what they are claiming actually holds. The IPCC has, in fact, actually strengthened its conclusions regarding the exceptional nature of modern warmth in the new report. A highlighted box in the "Summary for Policy Makers" states the following (emphasis mine):

  In the northern Hemisphere, the period 1983-2012 was likely the warmest 30-year period of the last 1400 years (medium confidence).

  The original 1999 Hockey Stick study (and the 2001 Third IPCC Assessment report) concluded that recent Northern Hemisphere average warmth was likely unprecedented for only the past 1,000 years. The 2007 IPCC Fourth Assessment extended that conclusion back further, over the past 1,300 years (and it raised the confidence to "very likely" for the past 400 years). The new, Fifth IPCC Assessment has now extended the conclusion back over the past 1,400 years. By any honest reading, the IPCC has thus now substantially strengthened and extended the original 1999 Hockey Stick conclusions.

  Only in the "up is down, black is white" bizarro world of climate-change denial could one pretend that the IPCC has failed to confirm the original Hockey Stick conclusions, let alone contradict them. [How Words Affect Climate Change Perception]

  The stronger conclusions in the new IPCC report result from the fact that there is now a veritable hockey league of reconstructions that not only confirm, but extend, the original Hockey Stick conclusions. This recent RealClimate piece summarizes some of the relevant recent work in this area, including a study published by the international PAGES 2k team in the journal Nature Geoscience just months ago. This team of 78 regional experts from more than 60 institutions representing 24 countries, working with the most extensive paleoclimate data set yet, produced the most comprehensive Northern Hemisphere temperature reconstruction to date. One would be hard-pressed, however, to distinguish their new series from the decade-and-a-half-old Hockey Stick reconstruction of Mann, Bradley and Hughes.

  

  Green dots show the 30-year average of the new PAGES 2k reconstruction. The red curve shows the global mean temperature, according HadCRUT4 data from 1850 onward. In blue is the original hockey stick of Mann, Bradley and Hughes (1999), with its uncertainty range (light blue). Graph by Klaus Bitterman.
  Credit: Klaus Bitterman, Stefan Rahmstorf

  Conclusions about unprecedented recent warmth apply to the average temperature over the Northern Hemisphere. Individual regions typically depart substantially from the average. Thus, while most regions were cooler than present during the medieval era, some were as warm, or potentially even warmer, than the late-20th-century average. These regional anomalies result from changes in atmospheric wind patterns associated with phenomena such as El Niño and the so-called North Atlantic Oscillation. [U.S. Will Warm Dramatically By 2084, NASA Model Shows (Video)]

  Colleagues and I, quoting from the abstract of our own article in the journal Science a few years ago (emphasis mine), stated:

  Global temperatures are known to have varied over the past 1,500 years, but the spatial patterns have remained poorly defined. We used a global climate proxy network to reconstruct surface-temperature patterns over this interval. The medieval period [A.D. 950-1250] isfound to display warmth that matches or exceeds that of the past decade in some regions, but which falls well below recent levels globally.

  These conclusions from our own recent work are accurately represented by the associated discussion in the "Summary for Policy Makers" of the new IPCC report (emphasis mine):

  Continental-scale surface-temperature reconstructions show, with high confidence, multidecadal periods during the Medieval Climate Anomaly (year 950-1250) that were, in some regions, as warm as inthe late 20th century. These regional warm periods did not occur as coherently across regions as the warming in the late 20th century(high confidence).

  However, never underestimate the inventiveness of climate-change deniers. Where there's a will, there is, indeed, a way: A meme now circulating throughout the denialosphere is that the IPCC's conclusions about regional warmth contradict our findings, despite the fact that those conclusions are substantially based on our findings.

  One could be excused for wondering if climate-change deniers have lost all sense of irony.

  The most egregious example of this latest contortion of logic found its way into the purportedly "mainstream" Daily Mail, courtesy of columnist David Rose, who admittedly has a bit of a reputation for misrepresenting climate scientists and climate science. Rose wrote in his column on Sep. 14, "As recently as October 2012, in an earlier draft of this report, the IPCC was adamant that the world is warmer than at any time for at least 1,300 years. Their new inclusion of the 'Medieval Warm Period' — long before the Industrial Revolution and its associated fossil-fuel burning — is a concession that its earlier statement is highly questionable."
• 

  slimboyfat

  The data of the past 20 years do not support global warming. To state that future figures will prove 'interesting' is actually a concession to those who still uphold the theory. If we relied on the figures and predictions since the IPCC was founded we would have to conclude they simply got it wrong.

  Ben Goldacre may believe in global warming, but my point is that his book Bad Pharma shows just how badly empiricism can go wrong. We have drugs on the market that don't work and we should know don't work, including some that cause real harm. How can this happen in such a rigorous hard scientific field as medicine? Because not all studies conducted are published. Not all promising cures are studied. Not all published studies convey findings in an accurate and helpful way. It is no great leap to wonder if something similar could be happening in climate science, especially with all the financial and institutional interests involved. Empiricism is great in theory, but can be thwarted at so many levels and it often imbues false confidence.