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jpark at 09:28 AM on 26 January 2010On the reliability of the U.S. Surface Temperature Record
And is this helpful too? -
jpark at 09:25 AM on 26 January 2010On the reliability of the U.S. Surface Temperature Record
dhogaza..great answer, I like that. -
shawnhet at 09:15 AM on 26 January 2010Peer reviewed impacts of global warming
Here are a couple of generally positive papers: Nemani, R.R., Keeling, C.D., Hashimoto, H., Jolly, W.M., Piper, S.C., Tucker, C.J., Myneni, R.B. and Running, S.W., 2003. Climate driven increases in global terrestrial net primary production from 1982 to 1999. Science. (June-06-2003). Zhou, L, Tucker, C.J., Kaufman, R.K., Slayback, D., Shabanov, N.V., and Myneni, R.B. Variations in northern vegetation activity inferred from satellite data of vegetation index during 1981 to 1999, J. Geophys. Res., 106 (D17):20069-20083. Cheers, :)Response: Thanks, have added these to the Impacts Page. -
Berényi Péter at 08:45 AM on 26 January 2010Peer reviewed impacts of global warming
Marcus at 23:28 PM on 25 January, 2010: "the fear is that our societies will not be able to adapt quickly enough to global warming [...] so mitigation is seen as our best bet" The best bet is education. Not education about global warming, just plain old education, spiritual, moral, mental & physical. Education of the poor, education of girls. An educated society can adapt quickly enough to almost anything. This is the most efficient use of scant resources. Everything else can wait.Response: I agree that education is crucial to society, especially education for the poor. However, human society is capable of tackling more than one issue at a time. Setting aside global warming until we solve education for the poor is hardly a practical response, particularly as every year of inaction only exacerbates the problem - which happens to impact poor nations the greatest (Mendelsohn 2006). -
Riccardo at 08:20 AM on 26 January 2010We're coming out of the Little Ice Age
michaelkourlas, if i got it right, 30 years are enough to establish a trend. If this is true, then the last 10 years are well inside the measured variability and cannot falsify the trend in any way. But, given that you think that fig. 1 in the link i posted before "shows the measurements not following the IPCC predictions" you problably can say almost anything you like. The numbers tell a different story, though. -
Jacob Bock Axelsen at 08:00 AM on 26 January 2010Peer reviewed impacts of global warming
Since Berényi Péter already mentioned Eugene Koonin and Biology Direct. I invite people to see how tough the peer review process really is (the reviews are directly attached to the article at the bottom of the webpage): http://www.biology-direct.com/content/2/1/32 This paper was four years in the making... -
mspelto at 07:06 AM on 26 January 2010The IPCC's 2035 prediction about Himalayan glaciers
Last year and this year I am authoring the section for the BAMS annual state of the climate on Glaciers and Ice Sheets. This report focuses primarily on climate during that given calendar year and is a great resource for understanding the details of annual climate around the world. Believe me the IPCC report is not a source of information. Since this report is due before the data is generally even reported to the WGMS, the glacier data comes directly from the researchers. Glacier runoff is the product of the area and melt rate of the glaciers. Smaller glacier areas reduce melt season glacier runoff. For most areas the melt season is also the dry season, so this is perfect. This is not the case for streams draining the south side of the Himalaya where the summer monsoon is both the wet season and the main melt season on those glaciers. Note Gangotri Glacier as an example. Note that given the debris cover soot will not matter to the lower section of this glacier, nor will it matter to the area above 5500 meters which is a perpetual accumulation zone, with soot being buried. Thus, soot impacts are limited to that narrow elevation range near the equilibrium line. As a glacier disappears it does not automatically change runoff, that depends on precipitation. It changes the timing. Thus, in the < a href=http://www.nichols.edu/departments/glacier/glacier.htm">Skagit River in Washington for example glacier retreat has caused a reduction in summer streamflow, but winter streamflow has increased due to more winter rain and melt events in the basin. The glaciers are reservoirs that naturally store water that melts during dry periods for most areas. That is the value and is increasingly being utilized for hydropower as for Gangotri Glacier above or many others -
Berényi Péter at 06:19 AM on 26 January 2010Skeptical Science now an iPhone app
doug_bostrom at 06:37 AM on 17 January, 2010: "Ah, the meme du jour [global averages [of specific humidity in upper troposphere] are not too important, according to Pielke], repeated everywhere just now. What does it have to do with what you were discussing?" doug, looking into the physics (yes, I am able to do that) what Pielke says may be right in an unexpected way. The "greenhouse effect" of water vapor is roughly proportional to the logarithm of specific humidity. It means that vapor, if distributed unevenly, lets more IR radiation through than the same amount with uniform density along each pressure level. In fact specific humidity in the mid to upper troposphere is known to fluctuate within wide margins. The bottom line is that trends in arithmetic means are less important than trends in statistical dispersion. This measure may even be safer to rate against alleged instrumental errors (you see, it has quite something to do with the present discussion). Is there such a study about historical radiosonde humidity data in the literature? -
michaelkourlas at 05:56 AM on 26 January 2010We're coming out of the Little Ice Age
I'm not trying to make predictions off of a 10 year trend. All I am saying is that 30 years, 10 years of which do not follow predicted trends, is not enough to establish that we are having a large effect on climate. In response to "the models did not predict the last 10 years...because they never attempted to predict them", the link you gave actually shows the measurements not following the IPCC predictions. -
michaelkourlas at 05:51 AM on 26 January 2010It's not bad
I feel that the positives vs. negatives are somewhat biased toward the negative side. For instance, on negative, it says decreased water levels three times, and specifies each individual area where the water supplies will decrease each time: * Decreasing human water supplies... (Solomon 2009) * Decreased water supply in the Colorado River Basin (McCabe 2007) * Decreasing water supply to the Murray-Darling Basin (Cai 2008) However, on positive, it only says: Improved agriculture in some high latitude regions (Mendelsohn 2006) It does not specify what countries or regions, which could inflate it to several points. Seeing as that has been done with the decreasing water supply, I think the same should be done for the positives.Response: This is solely because I'm referencing individual papers. I suggest you take a leaf out of Shawnhet's book and find some positive papers focusing on benefits in specific regions. -
Jacob Bock Axelsen at 05:49 AM on 26 January 2010The chaos of confusing the concepts
@stevecarsonr (I here use 'deterministic chaos' and 'chaos' interchangeably.) If you want to establish chaos you need to prove extreme sensitivity to initial conditions. It is virtually impossible without computer modelling and non-linear mathematics. I understand that you could imagine chaos 'in the error bars' of clouds and aerosol, but you need more advanced arguments than feedbacks. I could be my own devil's advocate by pointing to the surprising fact that all-negative feedbacks can be chaotic: http://arxiv.org/abs/0905.3672 - just to emphasize the necessity of proper mathematical modelling. Personally, I am skeptical that your proposed THC-mechanism is chaotic because I see no possibility of heat being trapped in a truly fluid fashion. Would THC shut down lead to Arctic freezing to start with? I have still not touched upon how to actually detect chaos, but one way is the Lorenz map: take the sequential period-maxima of your data (m1,m2,m3,m4,...) and plot the pairs ((m1,m2),(m2,m3),(m3,m4),...). If you have a predictable cycle, as non-linear as you like, you will get a cloud of points mostly tracing the diagonal (like for ice ages). Do it for a strange attractor and you could get some off-diagonal contour. Lorenz produced a 'teepee' and proved how to extract order from chaos(!): http://ams.allenpress.com/archive/1520-0469/37/8/pdf/i1520-0469-37-8-1685.pdf I note that you use turbulence and deterministic chaos somewhat interchangeably, which is a clear misunderstanding. In your boiling kettle any possible chaos in heat advection is destroyed by turbulence and vapour bubbles. Please visit the links I provided before for a much more precise picture of convection. In searching for origins of minor chaos one obvious candidate is El Niño's trapped equatorial surface waters. In 1998 roughly 10^21 J was transiently trapped in the atmosphere before it could leak to space. It is now understood to be almost entirely due to deterministic chaos in weather spilling over to the global energy budget. Again the Rayleigh number is useful: it is the wind that initially is chaotic because it has a high Rayleigh number. The best way to predict large-scale chaos is then to have El Niño and the Lorenz attractor in mind when hypothesizing about a much stronger mechanism. Finally, the ice core record shows no signs of CO2 and CH4 leading to major chaos despite huge outgassings etc. There were also varying aerosols, clouds and all other feedbacks throughout the period, so the record is a strong indication that we cannot expect spontaneous wild chaotic behavior of the future climate. Again, it is just my highly informal comments - not science. -
Vinny Burgoo at 05:37 AM on 26 January 2010Peer reviewed impacts of global warming
Thanks for your friendly response to my somewhat snarky comment. Alas, the description of the Evans et al. paper is still misleading. This isn't really your fault. The paper itself consistently misdescribed the area it studied as 'the UK'. What it actually predicted was that the range and severity of the disease will increase on the island of Great Britain. It didn't model the offshore islands or Northern Ireland. That's a minor point. More serious objections remain. I've already said that I don't think it's helpful or meaningful to include single, narrowly focused studies in isolation. You have replied that the tabulation is a work-in-progress. Fair enough. But if I had the time, I could probably find peer-reviewed studies contradicting most of the studies listed in your Negatives column. This wouldn't be easy. Climate research tends to concentrate on Negatives. (This isn't necessarily proof of systematic alarmist bias. People need prior information about possible negative impacts; positive impacts can be embraced without little or no prior planning.) But it's possible. You could then restock the right-hand column with more citations. I'd go a-hunting again. Then you. Then me. And so on. I'd do this not to prove that global warming is a good thing (you'd certainly win in the end) but to reinforce the point that lists of single studies don't prove anything. Back to the Evans et al. study. First the increased range. It's insignificant. Evans et al. predicted that phoma stem canker will newly colonize parts of eastern Scotland. A subsequent study of the same disease and its effects on the same crop in the same region (and once again misdescribing it as 'the UK') using the same model and by two of the same authors - Butterworth et al., 2009, below - predicted that the disease will have such mild effects in the newly colonized area that fungicides won't be necessary. So it's not a big deal. But your description implies that it is. Crop disease to increase its range! Help! Second, the real-world implications of all the Evans et al. predictions. The follow-up, Butterworth et al., predicted that yields of fungicide-treated oilseed rape will increase throughout 'the UK' (Great Britain). That is, despite increased opportunities for the disease, sensible management will result in a net Positive. See? Individual papers can be knocked down - sometimes by papers from the same authors using the same data, techniques and models. Even when done honestly, your tabulation has no hope of being helpful or meaningful. And I have to say that I don't think your intent *is* wholly honest. Else why the note about some of the Positives being tongue-in-cheek? And that hot/cold deaths reference: that also leaps off the screen ... But I've gone on long enough, so I won't get into that now. * Agriculture: Positives Increased oilseed rape yields throughout Great Britain _North–South divide: contrasting impacts of climate change on crop yields in Scotland and England_, Butterworth et al., 2009 http://rsif.royalsocietypublishing.org/content/7/42/123.fullResponse: I've removed Evans 2008 from the Impacts Page - Butterworth 2009 shows that the overall impact of global warming on crop disease is ambiguous. Thanks for the link to the additional paper.
I would be quite happy if you were to take the time to find more papers showing contrary results to papers currently listed. I appreciate the feedback you provided on forest growth and crop disease. It's not a competition to see who gets the biggest list but an effort to portray the state of the science.
The tongue in cheek remark was an artifact of the older version of the paper when I was referencing many media articles as my sources - originally, I was padding out the meagre positives column with entries like "Lots of work and money for lawyers" and "New extreme sport of glacier surfing". Once I got serious with only peer review sources, that comment was out-of-date and I've now removed it. -
Doug Bostrom at 05:36 AM on 26 January 2010Peer reviewed impacts of global warming
J Bowers: "Personally, I see why it's better to go with the peer reviewed literature, but I doubt too many are aware that non-peer reviewed literature was allowed anyway as set out in the IPCC's 'Appendix A to the Principles Governing IPCC Work' Annex 2." Further to that, considering all the grumbling about "suppression" of contra-mainstream findings, if the IPCC had not allowed material not passed through peer review I'm fairly sure we'd be listening now to endless complaints about IPCC censorship. Anyway, everybody participating in the next report will be more careful next time around. Once burnt, twice shy. -
J Bowers at 05:19 AM on 26 January 2010Peer reviewed impacts of global warming
A long-term association between global temperature and biodiversity, origination and extinction in the fossil record. Mayhew et al (2007) Articles from Proceedings of the Royal Society B: Biological Sciences http://ukpmc.ac.uk/articlerender.cgi?tool=pubmed&pubmedid=17956842 -
J Bowers at 05:15 AM on 26 January 2010Peer reviewed impacts of global warming
Saturation of the Southern Ocean CO2 Sink Due to Recent Climate Change Le Quéré et al, 2007 http://www.sciencemag.org/cgi/content/abstract/sci;316/5832/1735 Methane: Anomalies of methane in the atmosphere over the East Siberian shelf: Is there any sign of methane leakage from shallow shelf hydrates? – Shakhova et al. (2008) http://www.cosis.net/abstracts/EGU2008/01526/EGU2008-A-01526.pdf Escape of methane gas from the seabed along the West Spitsbergen continental margin – Westbrook et al. (2009) Abstract: http://www.agu.org/pubs/crossref/2009/2009GL039191.shtml http://sprint.clivar.org/soes/staff/ejr/Rohling-papers/2009-Westbrook%20et%20al%20JR211%20plumes%20GRL.pdfResponse: Many thanks, have added the two methane papers to a subsection of Arctic melt on the Impacts Page. While looking at your papers, I discovered AGW Observer has a page devoted to papers on methane emissions which I'll need to peruse when I get the chance (well, rediscovered as AGW Observer is in my blog reader). -
J Bowers at 05:00 AM on 26 January 2010Peer reviewed impacts of global warming
Personally, I see why it's better to go with the peer reviewed literature, but I doubt too many are aware that non-peer reviewed literature was allowed anyway as set out in the IPCC's 'Appendix A to the Principles Governing IPCC Work' Annex 2. Anyway, here's one concerning the detrimental effects of nitrogen deficit constraining CO2 uptake by plants: http://www.agu.org/pubs/crossref/2009/2009GL041009.shtml Wang et al. Nitrogen constraints on terrestrial carbon uptake: Implications for the global carbon-climate feedback. Geophysical Research Letters, 2009; 36 (24): L24403 DOI: ScienceDaily's take on the paper: "The authors considered the amount of nitrogen plants require to store additional carbon and found that a substantial deficit of nitrogen exists for plants in most areas of the world. They argue that most climate models that do not take into account nitrogen have overestimated carbon uptake and therefore underestimated predicted global warming." http://www.sciencedaily.com/releases/2010/01/100121164209.htm?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+sciencedaily+%28ScienceDaily%3A+Latest+Science+News%29 -
Jesús Rosino at 03:45 AM on 26 January 2010Peer reviewed impacts of global warming
John (inline comment in #32), Ok, thanks! I'll probably wait a week or so for the translation, just in case new comments contribute more relevant papers. -
rookie at 02:31 AM on 26 January 2010On the reliability of the U.S. Surface Temperature Record
My first post. Not sure if this will help, but here is a link to Thursday's NY Times article: http://www.nytimes.com/2010/01/22/science/earth/22warming.html?partner=rss&emc=rss The article, titled,"Past Decade Warmest on Record, NASA Data Shows," concludes that: "The NASA data released Thursday showed an upward temperature trend of about 0.36 degrees Fahrenheit (0.2 degrees Celsius) per decade over the past 30 years. Average global temperatures have risen by about 1.5 degrees Fahrenheit (0.8 degrees Celsius) since 1880." -
dhogaza at 02:31 AM on 26 January 2010On the reliability of the U.S. Surface Temperature Record
"I guess my instinct would be 'bad data=bad science'." All data is, to some extent, "bad", as there is no such thing as a perfect instrument. The question is whether or not a set of data is *useful* in the context of the task at hand. Making sense of imperfect data is very good science, indeed. -
RSVP at 02:09 AM on 26 January 2010Peer reviewed impacts of global warming
John, OK fine,... climate scientists acknowledge that a global temperature change is possible without man, and likely should happen at a slower rate than what we are seeing. Just out of curiousity, what triggers this change in nature? BUT... That question aside, as I was trying to point out, there seems to be two approaches to dealing with this problem: A) trying to stop global warming B) finding ways to adapt to it Theme B seems more relevant given that there currently are no guarantees that A is possible, again since if Nature wants to, it can change course without our consent.Response: "climate scientists acknowledge that a global temperature change is possible without man, and likely should happen at a slower rate than what we are seeing"
Actually, natural forcings on their own are showing a slight cooling effect over the last few decades (Meehl 2004).
As for the two approaches (mitigation or adaption), we need to be throwing our energies into both mitigation and adaption. This is because if we don't mitigate, future impacts will be even worse. And we need to prepare for adaption because we've already committed to a great deal of warming still "in the pipeline" (a topic I sorely need to write a post about which I will do as soon as I get the time). -
Marcus at 00:58 AM on 26 January 2010Peer reviewed impacts of global warming
Also, I used to try & debate this stuff at places like The Australian's website, but found the place dominated by denialists who had not a clue about holding a decent debate-& instead resorted to name calling & conspiratorial whispers about "global government" (aka the UN) trying to impose their rules on sovereign nations like Australia. It really just got pathetic, so I gave up! -
Riccardo at 00:49 AM on 26 January 2010Peer reviewed impacts of global warming
Ubique, although i'm no expert, there's the obvious answer to your question: there's no such temperature. What i mean is that you always have parts of the ecosystem that will do better and other that will do worse after any change in temperature. So, how could be such a ideal temperature be defined? Things look different if you look from the point of view of our own specie and its current civilization. Given that its development occurred during a relatively stable climate, there is again an obious answer: no change at all. Of course there's some resilience up to a certain level of change, but it has an overall cost. We need to balance the two, some inevitable warming and the costs of limiting it; the former is the science of climate, the latter is economy. -
Daved Green at 00:33 AM on 26 January 2010Peer reviewed impacts of global warming
Hi guys , Ive been reading this site for ages now using it to counter deniers claims all good but , these small mistakes means an even greater effort is needed in the wider press to show the science is not weakened . the denier arguement now where i work (basic blue collar industry ) is that all the data is corrupted or faked and he is the proof .I try but my memory fails me and my debating skills :( . We have Monckton here in Australia and hes useing climategate and the glacier 2035 plus something about Darwin temp data being changed to show a warming trend to basically debunk AGW as either a great socialist /facist conspiracy and or scientists on the make for more funds . He will go down a treat here as most average australians dont trust politicians and dont really understand science . Its great all you guys debateing each other here but all this never get out to the general public , the counter arguement is never seen these people like Monckton never really get pulled up and shown to the people how they are misrepresenting the facts . Still this is a great site just wish i could take it with me all the time . -
jpark at 23:48 PM on 25 January 2010On the reliability of the U.S. Surface Temperature Record
HI looks like I have some apologising to do! I think I did say sorry when I went off topic but I was trying to get an answer I understood. I am genuinely interested in the debate and I realise I have a lot to learn. I will keep plugging away and see if I can get it. I guess my instinct would be 'bad data=bad science'. -
Marcus at 23:28 PM on 25 January 2010Peer reviewed impacts of global warming
Ubique, according to everything I've read, the optimum annual average global temperature-at this particular period of history (namely the Holocene) is probably around 14 degrees. This was approximately the temperature in which agriculture & the very first civilizations truly flourished, around 8,000 years ago-with even slight changes, above or below, being fairly detrimental (the collapse of the Mayan, Anasazi & Khmer civilizations-due to mild warming-& the Viking Greenland colony due to the Little Ice Age-come to mind). Of course how detrimental a temperature change can be will also be down to factors like (a) how quickly the change occurs, (b) how marginal the environment is to start with (in terms of soil fertility & precipitation etc), (c) available technology & (c) the willingness of the whole society to make the necessary sacrifices needed to adapt to changing conditions. Ultimately though, given the current speed of change, the fear is that our societies will not be able to adapt quickly enough to global warming-& its attendant consequences-to save ourselves; especially given the penchant for extreme, short-sighted selfishness on the part of certain quarters of society-& so mitigation is seen as our best bet. -
Jesús Rosino at 22:49 PM on 25 January 2010Peer reviewed impacts of global warming
Terrific topic, John. Despite being so relevant, it's not easy to find (at least summarized and well documented) information like this. Next on my list for translation! Riccardo, Chris, Marcus, I find your points of view insightful and thought-provoking. Hope you keep on sharing them with us for long ;-). Cheers.Response: Don't translate just yet - still tweaking and adding papers. Maybe give it a few days. -
Ubique at 22:19 PM on 25 January 2010Peer reviewed impacts of global warming
OK, so what do all you experts out there regard as the optimum average world temperature that will best benefit the current eco system (because this is what all this hot air is really all about) and is it actually possible for us to achieve this utopian situation? John, "Finding it hard to think of a positive impact of sea level rise...” Perhaps a positive impact of sea level rise is that it results from an increase in sea water volume and therefore a greater capacity to sequester the extra CO2?Response: Hmm, higher sea levels leading to more CO2 absorption? Not sure if that's true as the ocean's ability to absorb CO2 is expected to diminish. In fact, evidence indicates this is already happening (Quéré 2007, Schuster 2007, Park 2008). But points for creativity - I never would've thought of that! :-) -
RSVP at 21:00 PM on 25 January 2010Peer reviewed impacts of global warming
What greater form of denial is there than to assume that the Earth's temperature can't change over time, or shouldnt be affected by an overdimensioned human footprint? ...as if Global Warming comes as a surprise and should'nt be happening. And even if Global Warming was a purely natural phenomenon, all these positives and negatives would exist just the same. It should be clear that the problem is compounded due to the order of magnitude of the Earth's current human population. On a similar note, if a city wants to install a nuclear reactor, they should be forced to store the nuclear residuals and waste within the city limits. Similarly, dont try to fool yourself about solar panels and windmills being ecological as you have them spreading all over the Earth's surface. There is no free lunch, but there is a large crew of peer deniers.Response: I know of no climate scientist who asserts Earth's temperature can't change over time. So please refrain from strawman arguments.
It is well established and undisputed that climate changes naturally - because climate is sensitive to radiative forcings. When the sun's output changes, climate changes at a rate of 3°C for every 3.7 Wm-2 of radiative forcing from the sun. This is the same climate that changes at a rate of 3°C for every 3.7 Wm-2 of radiative forcing from CO2. The natural climate change you cite actually provides evidence for the climate's sensitivity to CO2. -
NewYorkJ at 19:39 PM on 25 January 2010Peer reviewed impacts of global warming
"Finding it hard to think of a positive impact of sea level rise..." Think Lex Luthor, Superman One (a relatively patient Lex Luthor, perhaps). The "global warming is good" crowd could play that up. Slowly sink the elite Hollywood celebrities so the rest of us can have beachfront property.Response:Hmm, interesting suggestion. Now if only Lex Luthor had published any peer reviewed papers. In Energy and Environment, maybe? :-)
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CoalGeologist at 18:51 PM on 25 January 2010On the reliability of the U.S. Surface Temperature Record
Marcus (#13 and other posts above): I concur with your distinction between skepticism and denialism. One way of describing it is that skeptics doubt, while denialists have no doubt. Unfortunately, there are many difficulties in applying these terms in practice. One problem is that denialists typically insist that their position is science-based and falsifiable, if only someone would present them with credible evidence. Of course, this is impossible from a practical standpoint. Another problem is that skepticism is a “slippery slope” to denialism, particularly in the current environment where criticism of AGW is dominated by confusing and ultimately fallacious arguments. Even a well-intended skeptic can end up becoming a denialist without realizing it, while still believing their position(s) to be rational, unbiased, and based on evidence. Another problem is that deniers resent being called "deniers", which unfortunately heightens the emotionalism of the dialog. Ironically, in many cases deniers even resent being called "skeptics"! This might be a hard to understand, since most scientists regard skepticism as an essential component of scientific method, but I interpret it to be because denialists give zero credibility (meaning "absolute zero") to the theory of anthropogenic climate change. From their perspective, they are the possessors of the only scientific truth. Therefore, it should be someone else’s job to play the role of “skeptic” if they wish. In their view, they are not “skeptics” at all, but simply realists. The distinction between skepticism and denialism is important with respect to the current discussion of the surface temperature data. Denial that warming is occurring had faded from popularity, but like so many other "vampire arguments" in this debate, it refuses to die and has enjoyed a recent resurgence. Moreover, it eventually invokes the denialists' fallback position when all else fails: conspiracy theory. -
Peer reviewed impacts of global warming
I am of the opinion that most websites dealing with the issue of climate change, both pro and anti the theory of AGW, are rapidly loosing credibility as they tend to utilize the ‘straw man argument’ which is generally propped up by the postings of sycophants. This approach does not lead to a more informed common understanding of the issue and in fact appears to be polarizing and entrenching opinions with the members of both camps refusing to impartially consider and evaluate differing views and resorting to name calling and demeaning the views expressed by contributors who are not members of what they perceive to be the ‘accepted scientific community’. This is clearly not in the interests of science and undermines efforts to formulate appropriate strategies to enable the human population to respond to changing circumstances, whether these caused by natural processes or human activity or a combination of both. Perhaps Skeptical Science could break the stalemate and before posting an article, why not submit it for review by a credible peer who has a different view (I am sure that many of the 141 signatories to the open letter to the Secretary-General of the United Nations, dated 8 December 2009, would oblige) and then post the article and review simultaneously with both authors being afforded the opportunity to respond to the subsequent postings of the contributors? -
Marcus at 17:22 PM on 25 January 2010Peer reviewed impacts of global warming
HR, that's because it was the end of a mini ice-age. Glaciers were in a very slow retreat throughout the 19th & early 20th century-in line with a solar induced warming trend. Then, around 1950, they stabilized & even grew again, but have been in a state of accelerated retreat for the last 30 years-& are, according to my best information, at levels lower than they've ever been since we first started studying them in the mid 19th century. -
CoalGeologist at 16:56 PM on 25 January 2010On the reliability of the U.S. Surface Temperature Record
kforestcat (Post #17 & 21): The U.S. National Climate Data Center has tried to be clear in explaining the methodology they've used in an effort to optimize the usefulness of the data they are constrained to work with. If you type "NCDC temperature methodology adjustments" into your browser, you'll find plenty of information, including this page: http://www.ncdc.noaa.gov/oa/climate/research/ushcn/ushcn.html#QUAL As noted by other posters, you can find links to scientific studies assessing the precision and accuracy of the data. Although I find your response (#17) rather draconian, as a U.S. taxpayer I concur with you that our Federal employees should be held to highest performance standards. Assuming you are no less demanding on yourself than you would be toward your PhDs, you might want to consider what measures are appropriate under the circumstances. ;-) (Sorry... This is more of a general response to those whose judgment is swift and merciless (and typically wrong) regarding the quality of data that indicate warming, while being substantially more lenient toward data that appear to show the opposite. Even if one is inclined to be skeptical regarding the accuracy of the surface temperature data, bear in mind that glaciers and ice caps have no political agenda.) -
Doug Bostrom at 16:54 PM on 25 January 2010The chaos of confusing the concepts
Sorry, I did a poor job w/the last sentence of my last post. The point I was trying to make is that the central effects being predicted by climate models are so large as to require a rather enormous and therefore unlikely unidentified lacuna in order to make those central findings significantly less threatening. Steve did a nice thought experiment w/some rough numbers describing a scenario resulting in a discontinuity in the predicted mode of forcing of major scope, yet that change was not enough to fully offset the net impact of our activities. Another more fundamental problem comes along with relying for comfort on model errors of the type envisioned as accompanying failure to identify and include various dynamic features of the climate. For instance, if as Steve hypothesizes we should upset the accustomed thermohaline circulation of the North Atlantic as an upshot of our activities, though it might reduce warming roughly as he suggests we'd still have a major climate disaster on our hands. Errors in models unaccounted for do not change the basic physics underpinning AGW. The energy budget of the planet is being altered and though we may make errors in predicting the effects of that change we're very unlikely to find net benefit as a result. We and the rest of the biological systems here are adjusted for a particular energy budget and if that budget changes too fast we'll have a hard time coping. -
HumanityRules at 16:26 PM on 25 January 2010Peer reviewed impacts of global warming
The problem with the Himalayan glacier data wasn't so much that it wasn't peer-reviewed rather that it was just plain wrong. Peer-reviewed data can just as easily be wrong, especially when its re-inforcing the particular concieved notions and prejudices of the day. Ned post #1 Just to be even more accurate. Global glacier reached their most recent maxima around 1750 and have generally been in retreat ever since. -
Doug Bostrom at 15:45 PM on 25 January 2010The chaos of confusing the concepts
stevecarsonr at 13:18 PM on 25 January, 2010 Good points, and thank you for the illustrations. So in sum insufficient help from turning the subarctic into an ice cube and refreezing the Arctic, unless forcing estimates are wildly inaccurate. I guess that illustrates what I've been thinking, which is that any unidentified issues w/the current crop of models are going to have to be huge and thus likely quite difficult to overlook. -
rrvau at 15:29 PM on 25 January 2010Why is Greenland's ice loss accelerating?
Where did Greenland get its name from? Could have it been "green" at some time when Vikings roamed? Is the ice thinning? I have seen evidence that the warming and cooling, the thickening and thinning of the Arctic (readings from the 80th parallel) has remained remarkably consistent over the past century. Naturally there are deviations from the mean but it shows that it has always thinned and thickened at roughly the same time and rate each year. http://ocean.dmi.dk/arctic/meant80n.uk.php http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm Best Regards, Royce R. Vines Unintended consequences rule when busybodies get on their "high horses" - Emmett -
DonMorton at 15:11 PM on 25 January 2010Why does CO2 lag temperature?
Would somebody please help me understand the fallacies in T.J. Nelson's web page, "Cold Facts on Global Warming" available at http://brneurosci.org/co2.html I've seen some rebuttals dating back to 2005, but this guy seems to update his page quite frequently. His major premise (and the one that denialists seem to grab at) seems to be that the warming response to increased CO2 is logarithmic, and that we are "far out" on the curve, so greater increases in CO2 would result in less and less warming, to the point of being insignificant. -
stevecarsonr at 13:39 PM on 25 January 2010The chaos of confusing the concepts
doug_bostrom: "..unless one can envision a chaotic process that removes heat from the planet. What might that be?" Other effects (apart from THC as already outlined) include aerosols in reflecting incoming radiation and creating more clouds. As the IPCC AR4 (2007) shows, the error bars for aerosols match the size of the CO2 effect. The error bars are there because as yet the effects of aerosols are not really understood. "Medium low level of scientific understanding" is the description by the IPCC. -
stevecarsonr at 13:18 PM on 25 January 2010The chaos of confusing the concepts
doug_bostrom: "how can thermohaline currents affect global temperature?" By refreezing the arctic and northern europe and therefore increasing the albedo of the planet. If the albedo of the planet increases by 1% that's equivalent to about 3W/m^2, or a little more than the current impact of CO2. The current albedo of the northern mid to high latitudes is around 45-55%. If we took an area that was grassland, soil or forest and covered it with snow or ice it would go from around 20% to 60%-80% albedo. If we took ocean and covered it with ice it would go from 6% to 60% albedo. So an extra 7M km^2 of water with ice and an extra 3M km^2 of land with snow/ice would make that change. That's about 50% more sea ice in the arctic at the moment and a pretty big increase in northern europe/n.russia ice & snow. Also, if as a result of the THC shutdown the energy in the climate system is simply "re-arranged" then the tropical/sub-tropical regions will be warmer as a consequence of the northern high latitudes being colder. As energy is radiated at T^4, this will also result in a higher overall radiation. Back of envelope.. 20% of the world's surface decreases from 0 to -5'C and 20% of the world's surface increases from 15-20'C then there will also be a 1.1W/m^2 increase in radiation from the earth's surface (averaged across the whole planet). -
bit_pattern at 12:58 PM on 25 January 2010Peer reviewed impacts of global warming
Can you do a section on natural disasters? It's the latest "scandal" being promoted by The Times, would be good to have something to counter it with. -
NewYorkJ at 12:54 PM on 25 January 2010Peer reviewed impacts of global warming
My contribution (for now): Coastal erosion, with a focus on Nigeria. http://idosi.org/wasj/wasj1(1)/10.pdfResponse: Many thanks for the link, much appreciated! I've added (belatedly) a sea level section to the Positives/Negatives of global warming and included coastal erosion.
Finding it hard to think of a positive impact of sea level rise... -
yocta at 12:34 PM on 25 January 2010Peer reviewed impacts of global warming
RE#19 Chris The physicist Jan Hendrik Schön incident at Bell Labs is probably the worst I've heard of. He went so far as to include the same noise in his data for two experiments done at different temperatures. He eventually got busted due to scientists out there by doing their job. That is, critically assessing other peoples work and independently trying to replicate/verify their results. The only criticism I could have is that his colleagues eagerly slapped their name on his work as part of the "et al" without themselves bothering to check up on it's integrity. And I believe it was the editors of Nature were the ones who first discovered his misconduct. Shouldn't we then be congratulating the peer review system? http://en.wikipedia.org/wiki/Jan_Hendrik_Schön -
Berényi Péter at 12:26 PM on 25 January 2010Peer reviewed impacts of global warming
chris at 10:54 AM on 25 January, 2010: Thanks, chris for the clarification. The IPCC could use whatever it saw fit after all. What passed its own review process, of course ("The circulation process among peer and government experts is very wide, with hundreds of scientists looking into the drafts to check the soundness of the scientific information contained in them"). One can get a clear enough impression about the depth of this process by considering the Himalayan glacier case (10.6.2). I am not allowed to cite or quote anything from it, for in order to access the reviews I was forced to accept a kind of non-disclosure agreement. But anyone can have a look. http://ipcc-wg2.gov/publications/AR4/ar4review_access.html Both the First & Second Order Draft Comments worth reading. Search for Himalaya or glacier. Evaluation is OK, I suppose. Almost all the expert comments are vague, except E-10-468 in First Order Draft Comments. It implies glaciers in the Karakoram region are growing (true) but was dismissed. The Japanese GOVT comment (G-10-121) is the only one which expresses some doubt, if only indirectly. No one notices the year 2035 thing. -
Bern at 12:22 PM on 25 January 2010Peer reviewed impacts of global warming
"Scientific discussion should stick to the evidence, I would have thought." Well said, Chris! "Truth" is a dangerous thing. Just look at the many & ongoing religious wars over whose version of the "Truth" is correct. Lee Grable @ #9: Are you seriously suggesting that the generation of acoustic pressure waves is dependent upon whether there is a human observer present? Amazing, then, how all those animals that evolved in areas with no human population developed such a good sense of hearing... :-) -
PT_Goodman at 12:21 PM on 25 January 2010The IPCC's 2035 prediction about Himalayan glaciers
"In order to the glaciers in the Himalayans to melt completely, the freezing level would have to raise nearly 10,000 feet, for the summer freezing level in the area is about 13,000 ft. If it were to be reduced on a Moist adiabatic lapse rate, that would equate to a surface temperature at the base of the Himalayan Massiff to over 150F, and that is at 5000 ft. Dry adiabatically, it would be nearly 180F... I don't think that area is ready for that, as it would continue to warm gradually down to sea level and that would push it up to nearly 190F in BomBay (Mumbai as they say today). You could fry eggs on the sidewalk, maybe bake bread in a reflection oven, and roast corn on the cob in the same manner." The above is not my argument against the Himalayan glaciers melting. It is from a denialist. I'm brushing up on my physics (my 40 yo B.S. in Math/Physics isn't helping me much, anymore). I do know what an adiabatic lapse rate is, seem to recall that they are an idealization for estimating purposes only (although they do occur fairly precisely), and believe that the scenario described here is neither achievable nor sustainable in the real world (on earth). It would seem that the conditions described here would result in a very unstable atmospheric situation, and quickly and dramatically break down. I'm hoping someone here can provide a more complete refutation, although I'll be looking into it more myself. -
David Horton at 11:58 AM on 25 January 2010On the reliability of the U.S. Surface Temperature Record
I had a great conspiracy theory going there John, and you've ruined it. Perhaps they have exchanged emails ...?Response: Sorry to rain on your tinfoil hat parade :-) -
Marcus at 11:20 AM on 25 January 2010Peer reviewed impacts of global warming
You make a good point there Chris. Why does Peter assume that Peer Review is the "last line of defense" against bodgey science, when in truth it is the 1st & 2nd. Should a error laden paper somehow slip through the cracks, the scientific community as a whole is usually quick to highlight its flaws. Case in point is the original Manne paper relating to Paleo-climatology. Fellow researchers complained to the National Academy of Science, their claims were found to be valid & Manne was forced to redo & resubmit his original paper. If only the non-scientific world were subject to the same levels of scrutiny. Oh, & compare the level of peer-review in ISI journals to that of a journal like Energy & Environment. Remember that awful paper by the biology teacher Beck? The one which apparently proved that CO2 levels were higher in the 19th century than they are today (in spite of error bars which were almost as large as the actual values). That paper was utterly riddled with errors-errors easily pointed out by analytical chemists, atmospheric scientists & the like-yet it still got published, & is now held up as *proof* against global warming by those in the denialist industry. -
Marcus at 11:03 AM on 25 January 2010On the reliability of the U.S. Surface Temperature Record
#60 (dhogaza), yes I found that confusing too, not least because we're not really talking about models in this case-we're talking about directly observed changes in average temperatures. -
Doug Bostrom at 10:54 AM on 25 January 2010The chaos of confusing the concepts
As we while away our Amateur Hours here, lest we get too lost discussing various subsystems it's a good thing to remember that-- chaos at or near the surface or not-- energy has to escape from the Earth if it is not to become warmer. So maybe it would be good to focus on effects that can actually change the planetary radiation equation. It seems to me that it's easy to pay too much attention to surface temperatures, ocean and land. Surface temperatures can be misleading; absent some means for improved radiation from the planet, there is not going to be any net "cooling" in absolute terms going on regardless of what surface dynamics and temperatures indicate. The elephant in the room here is the oceans; energy hidden in the ocean does not disappear. For example, can thermohaline currents affect global temperature? How? If energy is released at a unusually high rate from the oceans in one region it does not follow that it will automatically escape back into space. Focusing on chaotic processes is a bit of a distraction, unless one can envision a chaotic process that removes heat from the planet. What might that be?
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