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Comments 53651 to 53700:

  1. Climate Change and the Weightier Matters: a Christian view on global warming
    PS A brief comment to others on this thread. I am a Christian ethicist working on a PhD in climate ethics (and ecological ethics more generally) and have spent years studying both climate and theology. I can attest that Villabolo's question about eschatology, while seeming obtuse, is actually very highly relevant since it shapes/illustrates a number of the most basic assumptions about the world and its future held by different groups of Christians. Though I'd point out that there are more than two camps and in my experience a very large number of evangelicals in Australia fall into neither of the two categories above but would be amillennial (which isn't too far from the "pan millienist" mentioned by Jeremy in #25).
  2. Climate Change and the Weightier Matters: a Christian view on global warming
    Thanks John, I really appreciate that you did this talk and hope you get more opportunities to speak in church circles. I have much to say on this topic and will perhaps contact you directly in a few months once I'm getting closer to return to Australia. One tiny typo on one of your slides: "non sequitur", not "non sequitor".
  3. What is the Climate Science Legal Defense Fund?
    Breaking news: Michael Mann has announced on FaceBook that ATI has lost the ATI/UVa FOIA case, where they demanded all emails and communications between Mann and the university - apparently hoping to rake through them and find something, anything, with which to attack Mann and his findings:
    ATI loses ATI/UVa FOIA case. Judge issues final order. Affirms the university's right to withhold scholarly communications and finds that the documents & personal emails of mine demanded by ATI were indeed protected as the university had contended.
  4. Realistically What Might the Future Climate Look Like?
    "widespread coral mortality is expected ~3°C above late 19th Century temperatures" A new study suggests widespread coral mortality at ~1.5ºC above late 19thC temps and close to universal degradation of all tropical corals by 2ºC. http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1674.html Discussed by one of the authors here: https://theconversation.edu.au/climate-change-guardrail-too-hot-for-coral-reefs-9610
  5. New research from last week 37/2012
    Just wondering if I missed this in a previous edition of "New research from last week...": http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1674.html
  6. Otto and Donat Weigh in on Human Contributions to Extreme Heat
    "complementary - not complimentary no ?" No--"complementary" means 'different, but contributing to a greater whole.' "Complimentary" means "saying nice things."
  7. New research from last week 37/2012
    DSL@3, I don't necessary think so. I thought the point of the show was that 97% of climate scientists believe it so and more of the general public believe it so, probably the current warmer weather helped. But the half of our lawmakers don't belive it so or believe it is a hoax. I think it is more of this disconnect between the science community, the general public and the lawmakers. He is a reporter, not a scientist. I don't think he could say one way or another definitely when the half of our senetors and congressmen believe it is a hoax. Yet he did clearly show today's state of the issue. I don't think it would be a good idea to jump on a messenger when the messenger only can carry a message. The messenge showed how it is, I guess.
  8. Otto and Donat Weigh in on Human Contributions to Extreme Heat
    I can’t help but be reminded of a post over at Tamino’s Open Mind Site that concluded with: I’ll continue to do what I can, come hell or high water. Expect both. (http://tamino.wordpress.com/2011/05/07/hell-and-high-water/) Cross posted from a while back, but more relevant than ever...
  9. 2012 SkS Weekly Digest #37
    @ chriskoz#2: Thanks for sharing your thoughts and posting the links.
  10. 2012 SkS Weekly Digest #37
    @ GrahamC #1: Thanks for the suggestion. We will definitely check it out.
  11. 2012 SkS Weekly Digest #37
    Maybe Stefan did not know This Mann Power when he wrote his comment about intimidation. Mike Mann has also anounced his counter-attack on National Review. So, young scientists should not be intimidated anymore. When, in addition to UVA findings, the NR suit succeeds, the others will follow downhill...
  12. Otto and Donat Weigh in on Human Contributions to Extreme Heat
    1:100 years events are already 1:10 year events, as the return time shown here and a similiar one for Texas heat wave shows. And of course the mean is still shifting. Looking at world temperautre for the last 4000 years, with all the swings from LIA, MWP etc, the whole range of variation is about 0.8C arround the normalised 0C anomally, excluding the last 30 years. So if that represents 95% variance or 2SD, 1 SD is ~0.2C for natural millenial scale variations, suggesting that the mean has shifted already by ~1.5SD since 1950-1980, and we have another 3SD to go. That makes 1:100 heat event now a coolish summer to come! This shifting mean to the extreme I find does crytalise the situation of how global warming will affect everyone. What would food production be like if 2012 heat waves in the USA were an every other year cold events?
  13. Himalayan Glaciers Retreating at Accelerated Rate in Some Regions but Not Others
    The abstract of "Different glacier status with atmospheric circulations in Tibetan Plateau and surroundings", a letter that appeared in Nature in July 2012,said "The Tibetan Plateau and surroundings contain the largest number of glaciers outside the polar regions1. These glaciers are at the headwaters of many prominent Asian rivers and are largely experiencing shrinkage[2], which affects the water discharge of large rivers such as the Indus[3,4]. The resulting potential geohazards[5,6] merit a comprehensive study of glacier status in the Tibetan Plateau and surroundings. Here we report on the glacier status over the past 30 years by investigating the glacial retreat of 82 glaciers, area reduction of 7,090 glaciers and mass-balance change of 15 glaciers. Systematic differences in glacier status are apparent from region to region, with the most intensive shrinkage in the Himalayas (excluding the Karakorum) characterized by the greatest reduction in glacial length and area and the most negative mass balance. The shrinkage generally decreases from the Himalayas to the continental interior and is the least in the eastern Pamir, characterized by the least glacial retreat, area reduction and positive mass balance. In addition to rising temperature, decreased precipitation in the Himalayas and increasing precipitation in the eastern Pamir accompanied by different atmospheric circulation patterns is probably driving these systematic differences." the letter is worth a look
  14. New research from last week 36/2012
    @chookmustard The authors were concerned that tree ring WIDTH data at their site may not be a good indicator of past temperatures due to a type of "divergence problem" in which the PROXY (the indirect indicator of the measure/driver sought for: ring width) changes its relationship to the driver (temperature) over time. So they tested to find a potentially better proxy, here isotopic oxygen, or 18O. 18O (the delta just means that 18O is measured relative to a common standard, i.e. something everyone uses, so that data can be easily compared across studies) in water equilibrates with 18O in plant internal CO2, and is stored in cellulose as a result of photosynthesis, the main polymer of wood, and changes in response to its availability in "source water", usually from precipitation, which at this site (and many others) is correlated with temperature. As this is a double step from proxy to driver, the authors made sure they understood the underlying uncertainty of their method, and its skill, aka the accuracy of using cellulose-18O to determine past temperature at this site. They found that their methodology seems to work fine. It shows consistency with another proxy record, tree ring wood density, but divergence from the tree ring width proxy. The divergence appears around mid 19th century and the authors speculate about a seasonal temperature change (longterm stability of summer temperatures, driving the 18O signal, vs. changing spring conditions, driving tree ring width) as a possible reason for the observed divergence. Hope this helps.
  15. New research from last week 37/2012
    Just for balance, let's include the diametric opposite of scientific research: Anthony Watts appears on PBS. Yes, that is an open invitation to let PBS know what kind of hit their reputation has just taken.
  16. Sceptical Wombat at 13:38 PM on 18 September 2012
    Otto and Donat Weigh in on Human Contributions to Extreme Heat
    If I understand it correctly the related issue is the warming of the Arctic which causes slowing of the jet stream, which causes wider meanders which themselves move more slowly and hold weather patterns in place for longer. Hence both hot spells and cold spells can last for longer which in turn greatly magnifies their impact.
  17. Otto and Donat Weigh in on Human Contributions to Extreme Heat
    They might not notice... complementary - not complimentary no ?
  18. It hasn't warmed since 1998
    Steve, I have responded on a more appropriate thread.
  19. Most of the last 10,000 years were warmer
    Steve, from another thread - remember that climate changes only with a forcing. The following illustrative image, created by Robert Rohde, helps describe temperature variations since the end of the last glacial stage: The forcings that drove the glacial cycles, and that drove our last deglaciation (~10000 years ago) reached a peak at the Holocene Climate Optimum, about 8,000 years ago. These forces are now operating in reverse, driving a slow trend towards glaciation. Small variations on that slow trend to glaciation have given rise to periods of regional warmth and cooling, popularly known by monikers such as the Roman Warm Perod, the Medieval Climatic Anomaly (in some areas, known as the Medieval Warm Period), and the Little Ice Age. Common causes for these small variations are increased periods of volcanic activity and reduced solar activity. The Little Ice Age was no "Ice Age", but just the latest episode of slightly cooler climate within this overall trend, most noticeable in northern Europe, and associated with both reduced solar activity and increased volcanic activity. When looked at over the whole Holocene, the LIA and MCA are just part of the overall trend towards slightly cooler conditions, largely driven by orbital forcing and most noticeable over NW Europe. But of course, the world is not actually cooling any more... Release of geologically-stored greenhouse gases by humans has given the climate an almighty kick upwards from that slow trend to cooling. As you can see from the inset figure, global temperatures have shot upwards towards the Holocene Opitmum levels, and are on a trajectory to go a very great deal higher than that. At the scale of the main graph, a conservative projection of 2C warming by the end of the century (similar to present warming rates) would have us off teh top of the graph only a couple of pixels to the right of the Y-axis - a nearly vertical rise on this graph scale. It is perhaps the fastest known warming in geological history, much faster than deglacial warming. That is due to the forcing of the CO2 and other greenhouse gases we have injected into the atmosphere. I would second Bernard J's suggestion (other thread) that you spend some time perusing this site for informative articles (Eric linked to a couple on the other thread), and perhaps even reading the linked peer-reviewed papers. That the slow cooling through the Holocene abruptly ended as a consequence of the Industrial Revolution is no coincidence: it was predicted as long ago as the dawn of the 20th Century by Arrhenius, and is a consequence of the inescapable physics of triatomic molecules that do not precipitate out of our atmosphere.
  20. Otto and Donat Weigh in on Human Contributions to Extreme Heat
    Extreme weather is coming to a theater near you. A free ticket to performances with every tank of gas! No reserved seating; the hall is big enough for everybody.
  21. New research from last week 36/2012
    Hii guys. Thanks for the posting Ari! Can someone please interpret the Berkelhammer & stott paper re tree growth ring data above? The terminology was above my head! Thanks Adrian
  22. Philippe Chantreau at 08:59 AM on 18 September 2012
    It's not bad
    I note that AHuntington1 continues to fail providing scientific references to his assertions. His argument seems to consist of associating a supposed higher efficiency of mitochondria when exposed to higher levels of CO2 with overall benefit for animal and human health, together with increased oxygen delivery due to the vasodilatory effect of CO2. It seems a little self contradictory, is beyond a stretch and is not supported by the litterature as far as I could tell. In fact, the whole argument is rather confused and conflates different reactions as well as apparent assumptions. AH1 asserts that people living at high altitude experience an increase CO2 to O2 ratio in their blood compared to low altitude dwellers. I could not find articles supporting that assertion. All known adaptations to high altitude, whether short or long term, are responses to hypoxia and physiological solutions to hypoxemia. I searched "lactate paradox" and found rather a lack of knowledge than anything allowing to make sweeping statements on whole body response, let alone mitochondrial metabolism. Interestingly, one study found increased mitochondrial efficiency, but associated with low levels of carbon monoxide. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0041836 As I could recall, vasodilation/constriction regulation is quite complex and involves both O2 and CO2, but also NO, and effects are different at the central and peripheral levels. If regulation is normal, there is no reason to believe that the range of O2 and CO2 will vary from what we need, since regulatory response will keep the levels where they need to be. People with COPD, who live with high levels of CO2, are not known to derive benefits from the higher CO2. This treats of O2 mediated vasoregulation: http://ajpheart.physiology.org/content/295/3/H928.full I have so far not found articles treating of mitochondrial metabolism's response to increased CO2. Other chemicals, however, are the subject of intense study. Studies of high altitude functional adaptation do not make much mention of mitochondrial metabolism either. However, it is worth noting that prolonged stays at high altitude lead to decreased density of mitochondrial populations, as well as reduced muscle mass (references below). The possibility of increased mitochondrial efficiency has been proposed but, to my knowledge, not investigated, and in any case would be associated with a decreased mitochondial population density, so the overall benefit is highly dubious. It has more signs of being an adaptation to the intense stress of hypoxia. Here are a few references on the subject, and about the so-called "lactate paradox", which does not appear to show in all situations. http://jap.physiology.org/content/83/2/661.abstract http://www.bio.davidson.edu/Courses/anphys/1999/Dickens/Dickens.htm http://www.ncbi.nlm.nih.gov/pubmed/19139048 http://www.ncbi.nlm.nih.gov/pubmed/1623889 It also appears that ventilatory response to CO2 is not significantly different among altitude acclimated subjects, although it is slower. Some hypotheses as to why that may be are briefly discussed at the end of this paper: http://jap.physiology.org/content/94/3/1279.full.pdf
  23. Himalayan Glaciers Retreating at Accelerated Rate in Some Regions but Not Others
    William the mountains are high everywhere in these ranges. It is that the Karokoram is less affected by the summer monsoon and has a greater percentage of total snowfall occur during the summer that makes them different. The glaciers around the highest mountain in the world are all retreating, Imja Glacier, Ngozumpa Glacier, Khumbu Glacier etc
  24. How to Solve the Climate Problem: a Step-by-Step Guide
    Old Mole - further to this. An example of an international treaty that worked well would be the Montreal accord on CFCs. Just because a naval treaty didnt work, doesnt mean that all treaties are futile. I would lay the blame for Kyoto failure squarely at door of the non-signatories. I would consider GATT and WTO as the proper place to work out the international carbon pricing. A per-capita carbon tariff is absurd. You price carbon internally and you charge tariff on any import for the carbon cost that is less than that internal tariff. That way you have a level-playing field for international trade. If you want less tariff imposed on your goods, then eliminate carbon from your manufacture. Because internally carbon is taxed at source, (ie the manufacturer pays it in his energy bill),this is not a tax on exports and so doesnt violate your constitution as far as I can see. (I am not in US so I defer completely to you on such matters).
  25. Himalayan Glaciers Retreating at Accelerated Rate in Some Regions but Not Others
    Isn't this just about what one would expect. If climate change is causing more precipitation, glaciers which are high enough and hence cold enough should grow while lower glaciers should retreat. As the temperature ramps up, higher and higher glaciers will be retreating. Here in New Zealand, two of our glaciers, Fox and Frans Yosef flow down into temperate zones. They can only manage this because of the stupendous amounts of precipitation as snow where they start. Over all they are retreating but a particularly high snow fall leads to advances a few years later.
  26. How to Solve the Climate Problem: a Step-by-Step Guide
    Mole, my apologies. Since the article was "step by step", I took your reference to a first "step" to be a reference to the original article.
  27. New research from last week 37/2012
    Here is Weather Underground's documentary on the Al Azizia temperature record. Interesting stuff: UHI, station moves and reanalyses.
  28. How to Solve the Climate Problem: a Step-by-Step Guide
    Those who favor Carbon Pricing schemes might find the following post from The Oil Drum enlightening. http://www.theoildrum.com/node/9485#more If you have not read much about the current state of coal production in the world there are a number of links in the article which will lead you further.
  29. New research from last week 37/2012
    Interesting papers about the former "World's Hottest" record being overthrown in favour of the Death Valley 1913 record. However, there may be a problem with the Death Valley measurement as well. I seem to remember on Jeff Master's blog him saying that at least one authority doubted the Death Valley figure because it was made during a sandstorm. Pieces of warm sand may have become jammed in the thermometer, skewing its measurement. So we may see another revision in a few years?
  30. Solar cycles cause global warming
    Falkenherz, Just for reference... the IPCC does nothing more than accumulate and report on the state of the science. When you say "the IPCC says..." what you really mean is "back in 2007, based on the state of the science at that time, the IPCC reported that..." The main takeways are: 1) The IPCC is merely reporting the primary belief of scientists in the field at the time, based on published and un-refuted papers. 2) The science and the world keep advancing. There have been a large number of studies since 2007 that affect both the value (0.76) and how that value is interpreted (e.g. Huber and Knutti 2011, Foster and Rahmstorf 2011). Any time anyone takes the approach "The IPCC says..." that should immediately give you pause. Quoting an IPCC statement on the state of the science 5 years ago, as if time is frozen and the IPCC are themselves experts declaring truth, is just wrong.
  31. Solar cycles cause global warming
    .... aaand my english becomes more and more horrible, sorry for that, this kind of shows my confusion. Let me restate with some corrections: "So... the answer to my original question is; ACCORDING TO CURRENT DATA, the TSI should not GO upward during the last few years, but even IF THERE WOULD still be AN upward TREND on a longer time axis, THIS ALSO cannot explain the increasing decadal trend of rising global temperature???" [I hope that is a slightly less horrible english] I stop posting now, but am grateful for all answers.
  32. Solar cycles cause global warming
    Uhm... I think I lead myself astray from the original question. I came here because of the WP graph, which shows a continuous upwards trend of TSI, as does also the graph "historical TSI reconstruction" on http://lasp.colorado.edu/sorce/data/tsi_data.htm So... the answer to the original is, the TSI should not got upward during the last few years, but even it it may still be upward on a longer time axis, it still cannot explain the increasing decadal trend of rising global temperature???
  33. Dikran Marsupial at 01:18 AM on 18 September 2012
    Solar cycles cause global warming
    "the whole report is about AGW, isn't it." well actually, no, it discusses both natural and anthropogenic climate change. The Technical Summary makes it very clear that both natural and anthropogenic forcings are necessary to adequately explain the observed patterns of climate change.
  34. Solar cycles cause global warming
    KR, yes I hunt for any stick, because I want to be able to reply to any sceptic argument. So I am assuming the role of one, here. You can be sure I do the opposite on a sceptic website. So let me summarize so I can use this in discussions: - global temp increase from 1850 to 2005 is about 0,76 Degree - TSI factors into this figure, but latest since 1965 cannot explain the increase by the observed amounts ... aaaand I am back to what puzzled me and why I started commenting here: How much of those 0,76 Degree is TSI and what is GHG (before/after 1960)??? It is just, as KR pointed out, I don't really seem to understand how to put this decadal trend figures into context. At least roughly speaking, there should ne some connection between absolute rise between absolute increas and the the calculated decadal trend figures? How? Why do IPCC and others throw them together without making at least a distincion?
  35. Solar cycles cause global warming
    Hey, thanks for the explanations and links. IPCC should really ready the next report and be a bit more clear about this part. They filed 0,76 Degree under "Direct Observations of Recent Climate Change", so yeah, they did not directly attribute it to AGW, but neither they did to other factors, and the whole report is about AGW, isn't it. Also, in the passage I quoted, the IPCC speaks of a linear warming trend of 0,13 Degree per Decade over the last 50 years, which in sum would be 0,65 Degree for 50 years. So, putting numbers together as IPCC placed them, not more than 0,09 Degree (0,65+0,09+0,74) was caused by TSI before GHG became a dominant factor from 50 years ago. That again seems to be too much the other way around, and this result is also in conflict with the temperatures shown in the graphs by KR here, at 06:15 AM on 15 September, 2012. And if I put that together in an incorrect way (because you probably cannot add up trend figures to an absolute total?), this shows for me that the data was presented in an incorrect context. I think, all the explanations are fine and sound kind of logic, but the data needs to be presented in a clear and coherent way, first. Again, thanks a lot for the explanations.
  36. It hasn't warmed since 1998
    Steve at #209:
    I would like to see how the temperature of the earth has increased since the last ice age and whether we are seeing an increase that has been happening for a long time rather than just during the industrial era. I haven't heard anyone explain the global warming that began at the end of the mini ice age in the middle ages.
    If you haven't "seen" anything or "heard" any explanation, then you are simply demonstrating that you are ignorant of the science. There's a whole Interweb out there with which you can UTSE, or you could go through Skeptical Science's own archives to find the relevant commentary.
  37. Solar cycles cause global warming
    Falkenherz - ...we are basically not talking about a GHG-attributed warming of 0,8 Degree increase in 100 Years, but about a 0,2 Degree increase in 50 Years. Where are you getting that? The 1901-2005 land global temperature trends in that table are 0.84, 0.68, 0.69, and 0.69 C, with ocean global temperatures increasing over that period at 0.67 C. Over the more recent 25 year period of 1979-2005 the numbers are much higher: ~0.31 C per decade land, ~0.134 C per decade ocean - certainly not 0.2 C. I believe you have misread something; and claiming miscommunication from the IPCC based upon misreading a table is quite inappropriate. Actually, without human activity, based on the natural forcings, we should have seen roughly a 0.2 C decrease in temperature over the last 100 years, or a difference from current temperatures of ~0.8 C. --- I really hate to say this, but you seem to be hunting for any 'sticky' skeptic point possible - and in the process not fully reading the references, or looking at the data. If you consider the full set of data, you will not (IMO) find any significant support for the 'skeptic' arguments; the data, the evidence points all but a tiny minority of climate researchers towards AGW.
  38. Solar cycles cause global warming
    Falkenherz, your central argument seems to be that because there are other factors in play it is incorrect to attribute all of the 0.8 C observed warming to GHGs. The problem with this is that research indicates that the net effect of all those other factors has been cooling... such that without them the impact of GHGs alone would have been greater than 0.8 C. Milankovitch cycles involve a lot of factors, but the primary glacial/interglacial trigger corresponds to an orbital tilt. Basically, when the tilt of the planet causes the northern hemisphere to be angled closer to the sun the net absorption of sunlight increases (because there is more land in the northern hemisphere than in the southern) even though the total amount of sunlight reaching the surface hasn't changed (the SH gets just as much less as the NH does more). The 'no warming since 1998' bit is an outdated statistical fallacy even when properly constrained to the surface atmospheric temperature. It was derived by taking the anomalously high temperature in 1998 as a starting point and then pretending that because the trend of increasing temperatures after that point had not gone on long enough to reach 95% statistical significance yet (i.e. passed a mathematical test to indicate that the observed trend was likely 'real' rather than caused by random 'noise' in the data) that there 'was no warming'. That was nonsense to begin with... but it is now outdated nonsense. The increasing temperature trend since 1998 now does pass a 95% statistical significance test. Try 'no statistically significant warming of the surface atmosphere since 2005'... the next really hot year in the record which is still too recent to pass 95% statistical significance. It'll still be deceptive nonsense, but not outright false like the 1998 claim you were repeating.
  39. Solar cycles cause global warming
    27, Falkenherz, Some points of reference for you to research: 1) Milankovitch cycles overall only fractionally change the amount of energy received by the Earth. What changes, rather, is the distribution of that energy over the globe in space and time (i.e. how much at what latitudes during what season). Look here. 2) The atmosphere has warmed since 1998. And both 1998 and the end of 2011 are cherry picks, because 1998 was the strongest El Niño in memory, while 2011 was a La Niña. It's like comparing your income on the day you work two jobs to the day you sleep in. It says nothing about how much you are likely to make in a year. Look here. And here. And here. 3) "I still need to understand which factors make the models..." Yes. Look here. And here. And here. 4) "...but all models advertise that they match up with historical data." Yes. Look here. [And I wouldn't put too much weight behind what Pielke Sr. (or Jr.) posts on the subject.]
  40. Solar cycles cause global warming
    Falkneherz, you seem to expect a linear response from changes in GHG forcing. I suggest doing a little more research on transient climate response and equilibrium climate response. What the article I linked to was pointing out, as gws notes, is that solar was the dominant forcing in the early 20th century, and GHG forcing was dominant in the last half of the century. GHG forcing became detectable during the 1940s, but it didn't overwhelm solar variation until the early 1960s. That also doesn't mean that the solar signal has no effect on the trend. That's why studies like Foster & Rahmstorf (2011) are so important. F&R removes the signals of solar, aerosols, and ENSO from the last 30 years of the major surface/lower trop temperature analysis ensemble. If no AGW exists, F&R should have found a slightly bumpy flat line or an insignificant trend. Instead, they found a trend of about .17C per decade over the period.
  41. Solar cycles cause global warming
    Falkenherz, I cannot answer in detail all your questions as that would be equivalent to reciting much of the AR4 and associated literature. But I shall make an attempt at some of your inquiries. - TSI is the measured "output" from the sun; it changes on geological time scales based on the nuclear reaction cycle in our star, which is and has been very stable; as you can see from the y-axis in your own link, its relative change (sun spots cycle, impacting radiation arriving at Earth on "short" time scales) is small - no, the atmosphere has further warmed since 1998, check, e.g., here - the IPCC has not attributed all observed warming ("0.8 deg C") to increased GHG alone - you are making the mistake of wanting to assign a single measure to a single cause; observed warming is a combination (sum) though between different forcings, and while the GHG forcing is currently the largest one, it is counteracted by an also anthropogenically caused increase in atmospheric aerosols; some people use the term "masked" to characterize the apparent lack of more warming caused by aerosols vs GHG only - these facts enter the IPCC graphs you see above to create the "match" between model and observations, and the lack of such when ignoring GHG forcing - aerosol levels are not expected to continue increasing much further (that will be reevaluated in light of rapid FF development lacking particle filters in Asia), while GHG levels are
  42. Symphony of Science - Our Biggest Challenge
    Actually, this video brings up an interesting point: There is a distinction between effective in-group and out-group communication. This video is an excellent example of in-group communication - it communicates powerfully to people who already accept its message it contains. It forms a mechanism for social bonding, motivation and worldview reinforcement within our group. I'm guessing however that it wouldn't make much impression with out-group members - those who reject the message. By contrast, outgroup communication is communication directed at people with a different worldview or social network. It can be for collaboration, proselytization, or even conflict. To communicate to out-group members you generally have to identify their worldview (Lewandowsky uses the term 'mental model' here), and communicate using the signs, symbols and narratives of that worldview, although other strategies are possible. The fact that we find this video compelling says nothing about whether it is effective for outgroup communication. The effectiveness of a messaging technique for outgroup communication is something which has to be raised with every effort at communication - and can't be judged by in-group members, except sometime by those who are gifted at thinking outside their own worldview. There will normally be multiple outgroups, and strata within those groups - for example some climate skeptics regard themselves as science-sympathetic, whereas others are simple hostile to science. Interesting question: What are the target worldviews of SkS, ETOM, Potholer54, Tamino, Climate Crocks and other resources? How effectively do they communicate to those worldviews.
  43. Solar cycles cause global warming
    gws, let's not start with polemics, I am seriously interested in AGW, what I just do is trying to link things together. These here are some factors I don't understand. I think I understand now the way GHG work, but TSI still is a topic I have to learn about. So sorry when I confuse TSI with Milankovitch cycles, I just assumed TSI is what arrives from the sun as measurable on earth, whether it comes from sunspots or from a shifted orbit or axis. I also understand that oceans still have warmed since 1998, and the total is still a warming. But at the same time it is also a fact that the atmosphere has not warmed any further since 1998, right? But that was not my point in my above post. I just wanted to say that it makes sense that a dropping TSI could lead to a non-warming up atmosphere because it is the fastest feedback, compared to the ocean. My point in my last comment was, that I always understood and read about 0,8 Degree/last100years attributed to AGW. But, based on what I read here and in the IPCC report, that is not really true. Can you confirm that at least that? The essay linked by DSL says in its conlusions: "At the same time greenhouse gases total radiative forcing has shown a strong Granger causal link with temperature since the 1940s up to the present day." So, they also do not start at 1890, but at 1940 (again a different date, instead of 1960). But, bottomline, that only that is my point, we should rather look at and communicate the historical amount of GW that can really be attributed to aGHG. This seems to be less than 0,8 Degrees so far, even though I know we are not in equilibrum yet. I still need to understand which factors make the models match the facts that ~0,2 Degree in the past 50 years leads to a possible new equilibrum at +3-6 Degrees for a CO2-doubling. Models might not extrapolate historical data, that would indeed be too simple, but all models advertise that they match up with historical data. So first let's clarify the observable historical data.
  44. It hasn't warmed since 1998
    Steve, this post Is sea level rise accelerating? shows an acceleration in sea level rise corresponding to recent CO2-induced warming on top of the ongoing rise since the end of the LIA in the 1800's or so. The explanation of the global warming that ended the LIA is here
  45. How to Solve the Climate Problem: a Step-by-Step Guide
    @Estiben This is being done in some form since years. You can read a bit at this link (no endorsement intended)
  46. Symphony of Science - Our Biggest Challenge
    Four truly great science communicators, and great composition too. Chriskoz - I think you are on to something interesting there.
  47. Dikran Marsupial at 20:24 PM on 17 September 2012
    It's not bad
    AHuntington1 Sorry this is getting tiresome. I asked for evidence that the mechanism you mention actually has a significant benefit in vivo and you still have provided precisely nill. Epidemiology of those living at altitude is not evidence that the differences between population are due to differences in CO2, so it is a non-sequitur. I am willing to accept your point about increased metabolic activity, but you are still expecting me to take your word for it that (i) the observed increase in atmospheric CO2 has even a measurable effect on metabolism and (ii) that increase matabolism is purely beneficial. If there were a measurable effect from the sort of changes in CO2 that are likely to ocurr due to anthropogenic emissions then it should be a cause for some skepticism for you that you don't seem to be able to point to a study that directly proposes this mechanism or demonstrates evidence to suggest it is significant.
  48. Solar cycles cause global warming
    Falkenherz, even if we assumed your discovered "serios and intentional miscommunication from IPCC" were true, your following statements are non sequiturs (logical fallacy): - past temperature increases are not extrapolated forward by the climate models; the models are based on atmospheric physics not statistics - because some relationships existed in the past (increasing CO2 being a feedback) does not mean that it has to be like that now (CO2 being a forcing agent) - correlation is not equal to causation As the responses to your comments above and the IPCC report you studied explain, the increase in TSI can possibly explain early 20th century warming, but not late 20th (and current) century warming. Current warming has not yet reflected the observed CO2 increase, aka we are in equilibrium yet. Your hint towards "it has not warmed since 1998" is a myth dealt with on another thread. If you find a way to get your hand on TSI data covering the glaciations, and a way to show that it was rather TSI not Milankovitch cycles driving them, make sure you publish that. (sorry for the satire, but your comments have drifted into trolling)
  49. Solar cycles cause global warming
    KR, DSL, thanks again. So, taking into account of what we think we know about TSI, we are basically not talking about a GHG-attributed warming of 0,8 Degree increase in 100 Years, but about a 0,2 Degree increase in 50 Years. I looked up the 4th IPCC report summary to confirm this, here: http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch3s3-2-2.html (the average from the table should be around said 0,2 Degree) 0,2 Degree is something very different to 0,8 Degree. Nevertheless IPCC includes the latter in its summary here (first bulletpoint): http://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm-direct-observations.html This is for me a serios and intentional miscommunication from IPCC. So, setting things straight, the current models take those 0,2 Degree and extrapolate from it a future GHG-induced rise of 3 Degrees for 100 Years. I must admit that makes me now much more sceptical than I was before. How can this possibly fit to the icecore-data, where CO2 lags behind (=still rises up) and temperature nevertheless is falling in accordance with the TSI, maybe even with a lag to declining TSI which would correspond to what we observe today? Where can I find more information on TSI data related to the icecore-data?
  50. Do we know when the Arctic will be sea ice-free?
    an interesting visualisation of PIOMAS arctic sea ice volume data

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