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Ned at 01:27 AM on 31 July 2010Waste heat vs greenhouse warming
There is a lot of confusion about very basic physics concepts in this thread. There are also a lot of analogies being used that aren't necessarily helpful. We could start from ground zero and go over exactly how the greenhouse effect works. But we don't really have to do that, since Science of Doom has already done a far better job of explaining it than we are likely to do. RSVP, have you visited that site? Since you seem to be hung up more on the basic principles of greenhouse gases instead of the narrow question of waste heat, you might find it helpful to do some reading over there. -
Doug Bostrom at 01:24 AM on 31 July 2010Waste heat vs greenhouse warming
RSVP: Curiously, [radiation] tends to always want to go to the coolest place (i.e. outer space). No. It goes in the direction it's emitted which is unrelated to its future destination, does not "want" anything, has no idea of its destiny. You'll need to get past that notion in order to make better progress here. -
RSVP at 01:05 AM on 31 July 2010Waste heat vs greenhouse warming
Someone said way back that radiation does not depend on a difference in temperature. Curiously, it tends to always want to go to the coolest place (i.e. outer space). That to me sounds like the difference matters. Likewise, here on Earth, the amount of radiation will depend on the temperature of things. So you wont have radiation happening free just because, especially when things are already getting warmed. So, the GHG will diminish as a function of ambient temperatures especially where something else (like waste heat) is causing a counter force. -
Doug Bostrom at 01:02 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Not another smoking gun? It's hard to force my way out the door in the morning because of all the smoking guns laying about. In fact, thinking along Peter's lines, all the smoke from the smoking guns very well may save us yet. -
RSVP at 01:00 AM on 31 July 2010Waste heat vs greenhouse warming
#138 "This is all nonsense. Not a word of it is true. The laws of physics do not very by geography. " You mean "vary", and I never said anything about geography. The "condition" has to do with energy level or temperature, however you wish. What I am bringin up here is a question that would be actually interesting to discuss... perhaps... That is... I assume 2.9 W/m2 is the average for the entire planet. Is it higher for places that are normally cooler, or higher for place that are normally warmer, or is it the same everywhere??? -
adelady at 00:56 AM on 31 July 2010Waste heat vs greenhouse warming
RSVP at 00:27 AM on 31 July, 2010 "GHG only warm under certain conditions, and actually cause cooling under others. If you dont believe this, go to the desert at night." GHG warm the *atmosphere* under all conditions. Humidity or the lack of it affects the temperature for a few hours or days at individual locations. But this is just the circulation of heat and moisture -within- the atmosphere and the oceans. Global warming is about the fact that energy continues to circulate within these systems instead of making orderly progress through the atmosphere and out to space. Adding more GHG to the system increases the amount of energy held and circulating within the system. That deserts are cold at night and tropical forests are warm most of the time are simple facts about particular locations on land surfaces. It says little to nothing about the whole system of atmosphere and oceans. -
Berényi Péter at 00:54 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
#87 CBDunkerson at 21:51 PM on 30 July, 2010 Yep, the 'alarmists' sure are 'cherry picking' by not concentrating on that SH sea ice OK, let's have a look at NH snow cover trends. Spring snow cover in the Northern hemisphere is declining indeed. However, it is not the end of story. NH snow cover trend for weeks of year, in km2/year units (1972-2009)
Not all "forcings" are born equal. They act on different parts of the climate system, therefore their strength expressed in W/m2 units does not fully determine their effects.
The NH snow cover annual trend graph has a sharp minimum at week 23.5 (summer solstice is week 24.5), while its maximum is at week 52 (winter solstice is week 51). What we can see here is that snow cover trends are almost exactly in phase with insolation. As surface temperatures lag insolation by almost two months due to high heat capacity of the climate system (mostly oceans), the trend observed is not caused by temperature (that is, by trapping outgoing longwave radiation), but by increased absorption of incoming shortwave radiation.
It is a big difference. One might even call it the smoking gun of climate science. It is all the more important because unlike most other climate indicators it is not lost in noise, but stands out very clearly.
Snow cover is increasing through mid October to January, when Northern Hemisphere insolation is low, decreasing otherwise. Therefore it is some immediate effect of sunshine, not a delayed one like the alleged thermal radiation trapping effect of carbon dioxide. For thermal radiation getting available to be trapped, surface temperatures have to be increased first. But that does not happen until later in the year.
The most probable candidate for increased SW absorption is decreasing snow albedo due to black carbon (i.e. soot). There is also a positive albedo feedbeck at work here. The more snow is melting, the more bare soil is exposed to the sun. This very albedo change can explain glacier and ice sheet phenomena as well.
The good news is that residence time of soot in the atmosphere is very low (around 1 week), so as soon as emissions are decreased, the effect vanishes. It is also much cheaper to reduce soot emissions than carbon dioxide, as the technology is already available and is mostly installed throughout developed countries.
What about a soot duty on Chinese products? And a ban on small Diesel engines perhaps (like those in cars). Or help to replace heavy soot generating biofuels (like dung) as cooking materials in India and Africa by natural gas or electricity? Or to introduce reasonable woods maintenance practice in North America by making removal of dead wood from managed forests compulsory (as it is done in Europe)?
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CBDunkerson at 00:50 AM on 31 July 2010Waste heat vs greenhouse warming
RSVP #135: "Why do you only think GHG work towards warming?" As written that is asking me why this is the only thing I think. Which is obviously inaccurate. Did you intend to ask why I think GHGs cause only warming? I don't think that either... since they cool the stratosphere. Whatever, it bears no resemblance to anything I've actually said so I'm not sure where you are going. "They should emit as much as they absorb? No?" What about the pool balls aren't you understanding? Pool ball hits a blocked pocket... it bounces off and remains on the table. Photon hits a GHG molecule... it gets emitted back out and remains in the atmosphere. So yes, they emit as much as they absorb... which is precisely why the atmosphere gets warmer. They're bouncing pool balls/photons back onto the table/into the atmosphere rather than allowing them to escape to the pocket/space. "If I am in a dry desert at dusk, temperatures are bound to drop very quickly. Why?" Because water vapor is a powerful greenhouse gas. Dry deserts don't have alot of water vapor. Ergo, they cool down at dusk more quickly than regions which do. "You could have a situation where if waste heat was equal to 2.9 W/m2, then GHG wouldnt do anything." False. GHGs work on all IR regardless of its source. Thus, some of that waste heat would be 'bounced' back down towards the surface and prevented from escaping to space longer than it would have been without the GHGs. Yeesh. At least TRY to understand the analogies. "GHG only warm under certain conditions, and actually cause cooling under others. If you dont believe this, go to the desert at night." This is all nonsense. Not a word of it is true. The laws of physics do not very by geography. -
RSVP at 00:47 AM on 31 July 2010Waste heat vs greenhouse warming
One more thing... and assuming cloudless skies in two cases, desert and beach... the fact that temperatures drop faster in the desert tells you quite a bit about how water vapor acts as a GHG vs CO2. -
Doug Bostrom at 00:46 AM on 31 July 2010Waste heat vs greenhouse warming
If I am in a dry desert at dusk, temperatures are bound to drop very quickly. You're missing a GHG there, RSVP. Think about it. -
RSVP at 00:27 AM on 31 July 2010Waste heat vs greenhouse warming
CBDunkerson #131 "However, if we then block off one of the pockets (add GHGs to the atmosphere" Why do you only think GHG work towards warming? They should emit as much as they absorb? No? This needs to be established. If I am in a dry desert at dusk, temperatures are bound to drop very quickly. Why? I assume IR doesnt have to ask permission from each CO2 molecule it finds on its way upward. You know if this were the case there would no such thing as IR satellite photography. It seems like IR makes it right through for the moment, otherwise there would be no contrasting images. But moreover, here is the crux of this issue.... You could have a situation where if waste heat was equal to 2.9 W/m2, then GHG wouldnt do anything. It would be a "clipping" situation. Another example. Waste heat was 1 W/m2 and GHG in the absense of waste heat was contributing 2.9 W/m2. So in reality GHG only actually added 1.9. Do you see what I am saying? That GHG also serve to emit radiation. They dont push power where it is cant be absorbed. This all has to do with the concept of saturation and a limited amount of surface energy. GHG only warm under certain conditions, and actually cause cooling under others. If you dont believe this, go to the desert at night. -
barry1487 at 00:26 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
I would have been better quoting number 5, where a qualification has got me thinking.Satellites measure less heat escaping out to space, at the particular wavelengths that CO2 absorbs heat
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barry1487 at 00:22 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
Solar radiation, on all levels and cycles, and its effects on Earth, are multiple and diverse, and poorly understood. This means one can't definitely distinguish between these two processes relating to global warming -greenhouse gases and solar variables, and therefore all of your above fingerprints could still be correct and yet greenhouse gases may still not be the main driver of global warming in the last several decades. I didn't say this, solar scientists are saying it.
Have they postulated a mechanism whereby the sun cools the stratosphere as it warms the troposphere? Stratospheric cooling is one of the main rebuttals to 'it's the sun.' The whole atmosphere should heat if the sun gets hotter. -
barry1487 at 00:18 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
I have a query about number 6.If less heat is escaping to space, where is it going? Back to the Earth's surface. Surface measurements confirm this, observing more downward infrared radiation (Philipona 2004, Wang 2009). A closer look at the downward radiation finds more heat returning at CO2 wavelengths, leading to the conclusion that "this experimental data should effectively end the argument by skeptics that no experimental evidence exists for the connection between greenhouse gas increases in the atmosphere and global warming." (Evans 2006).
In the picture, there is a caption, "Less heat escaping to space." But:"...the Earth must, on average, radiate the same amount of energy back to space."
AR4 Ch 1, p 115 I may be in error to equate heat with energy in this case, but if I'm not wrong... the Earth is radiating the same amount of heat back to space, but it is happening at a higher level in the atmosphere. It's not that less heat is escaping to space, but that the relatively constant temperature lapse rate through the atmosphere means that the surface warms if heat loss occurs at a higher altitude. Have I got this right? -
chris at 23:46 PM on 30 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
HumanityRules at 13:55 PM on 30 July, 2010 If one is interested in the polar response to global warming, it's helpful to know that we have long expected that the Antarctic response would be delayed compared to the rapid Arctic response. For example, modelling from the early 1980's predicted that enhanced greenhouse-induced warming would be focussed in the Northern polar regions leaving the Antarctic regions relatively unaffected for considerable periods. A recent review of early modelling of the ocean response to global warming described predictions from early modelling: S. Manabe and R. J. Stouffer (2007) Role of Ocean in Global Warming J. Meterolog. Soc. Jpn. 85B 385-403 Here are some excerpts from the sections of this article describing the predicted hemispheric asymmetry (much greater N. hemispheric polar warming and delayed Southern polar warming). So, discussing the early models of Schneider and Thompson (1981) to evaluate the delay in the response of the sea surface temperature to gradual increase in CO2, Manabe and Stouffer say:"Their study shows that the time-dependent response of zonal mean surface temperature differs significantly from its equilibrium response particularly in those latitude belts, where the fraction of ocean-covered area is relatively large. Based upon the study, they conjectured that the response in the Southern Hemisphere should be delayed as compared to that in the Northern Hemisphere because of the inter-hemisphere difference in the fraction of the area covered by the oceans.”
In a later model Bryan et al (1988) made the same sort of analysis, investigating the role of the oceans in modulating the response of surface warming to enhanced greenhouse gases.“They found that the increase in surface temperature is very small in the Circumpolar Ocean of the Southern Hemisphere in contrast to high latitudes of the Northern Hemisphere where the increase is relatively large.”
It’s not just the oceans per se of course. It’s also ocean and air currents, and particularly the mechanisms governing the efficiency of surface heat transfer into the deeper oceans. If this is efficient, the deep oceans will absorb heat and there might be little measured surface warming, at least for a while. So (speaking of Bryan et al (1988)) again:“However, the detailed analysis of the numerical experiment reveals that the absence of substantial surface warming in the Circumpolar Ocean is attributable not only to the large fraction of the area covered by the oceans but also to the deep penetration of positive temperature anomaly into the oceans.”
Later models predict the same hemispherical asymmetry that is seen in the real world. e.g. discussing the simulations of Manabe et al (1992):“Figure 3 also reveals that there is a large asymmetry in surface warming between the two hemispheres. In the Northern Hemisphere, the surface warming increases with increasing latitude, and is particularly large in the Arctic Ocean. This is in sharp contrast to the Southern Hemisphere, where warming is relatively large in low latitudes and decreases with increasing latitudes. It becomes small in the Circumpolar Ocean of the Southern Hemisphere, particularly in the immediate vicinity of Antarctic Continent.”
Why is this, one might ask?! Here’s what Manabe and Stouffer say:“One can ask: why the polar amplification of warming does not occur in the Southern Hemisphere, despite the existence of extensive sea ice which has a positive albedo feedback? As discussed in the following section, the absence of significant warming in the Circumpolar Ocean of the Southern hemisphere is attributable mainly to the large thermal inertia of the ocean, which results from very effective mixing between the surface layer and the deeper layers of ocean in this region. This is in sharp contrast to the Arctic Ocean, where very stable layer of halocline prevents mixing between the surface layer and the deeper layer of the ocean.” and “In view of the absence of significant surface warming, it is not surprising that the area coverage of sea ice hardly changes in the Circumpolar Ocean despite the CO2-doubling.”
(n.b. remember this is a prediction from a model; we’re nowhere near CO2 doubling yet!). However that's what we're seeing in the real world. So the delayed warming in the deep Southern oceans and Antarctic is consistent with models/predictions from more than 20 years ago. -
Ken Lambert at 23:42 PM on 30 July 2010Waste heat vs greenhouse warming
CBDunkerson #126 "Essentially, you are arguing that if 50% of all temperature measuring stations are located in the most heavily populated 7% of the globe then that 7% of the planet determines 50% of the global temperature anomaly." No I am not arguing that. I said "then it is reasonable to expect that temperatures would be affected by waste heat which roughly adds 0.9 + 0.4 = 1.3W/sq.m over those areas." "over those areas" refers to the 7% of the globe (land) releasing this waste heat. It depends on the 'tricks' used by researchers to correct this 7% of the land area which would have a relatively high number of measuring stations compared with sparsely populated areas. Yes - waste heat moves about - but it is an energy flux ie an instantaneous heating power measured in W/sq.m or Joules/sec-sq.m. A 3D thermal gradient will be established from source to any remote point. Other sources will add to the complexity and multiple sources will distribute heat from power station stacks, cooling towers, cooling lakes by evaporation, convective and radiative means driven by winds etc. -
Lou Grinzo at 23:23 PM on 30 July 201010 Indicators of a Human Fingerprint on Climate Change
John: Great job as always, and on all fronts. -
chris at 23:14 PM on 30 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
HumanityRules at 22:07 PM on 30 July, 2010 "Why does The State of the Climate 2009 document state in one line that Arctic ice multiyear ice has increased by 11% from 2008 to 2009 then move on in the next line to state that these two numbers are similar?" You're contriving confusion by imprecise precis HR. The full paragraph of which you speak is reproduced below [*]. "What does this mean?" (i.e. re data available for bona fide research purposes). The first answer is that you could enquire to the NOAA for their precise reason for that statement. However there are lots of possible reasons. In my experience that sort of statement comes up quite frequently in various contexts; e.g.: (i) Publically-funded research is specifically made available for research purposes (even if there may be some increasingly out-dated "embargos" involving commercial publishing of publically-funded research). However it shouldn't be used, for example, by commercial organisations to advance their interests (e.g. climate data used by a company selling weather forecasts). (ii) protection of intellectual property and copyright. For example as a "bona fide" researcher, I can download figures from other peoples published papers and to display these in lectures (e.g. for teaching or for scientific presentations). However I am not allowed to do this for commercial gain. etc. etc. "If your looking for reasons I express cynical statements... I get the impression that the "reasons [you] express cynical statements" may be because you like to maintain a"rolling boil" of contrived indignation about science that happens not to suit your fancy! (in the UK we call that behaviour "Daily Mail syndrome"). Thus your tendency to false precis. Generally scientists go to some efforts to state clearly what they mean. it's unfortunate when others incorrectly precis their writing in order to contrive an impression of confusion! ---------------------------------------- [*]STATE OF THE CLIMATE IN 2009 p S113-S114In the past decade, the extent of multiyear sea ice rapidly reduced at a rate of 1.5×106 km6 per decade, triple the reduction rate during the three previous decades (1970–2000). Springtime multiyear ice extent was the lowest in 2008 in the QuikSCAT data record since 2000 (Nghiem et al. 2007). QuikSCAT results in March 2009 showed a multiyear ice extent of 3.0 ± 0 .2 million km2. This was 0.3 million km2 larger (11% increase) than the multiyear ice extent on the same date in 2008, even though the total sea ice extent was similar in the spring of 2008 and 2009. While the multiyear ice extent was similar in March 2008 and 2009, its distribution was quite different. More specifically, in 2008 there was a significant amount of multiyear ice in the Beaufort Sea and in 2009 there was a large amount of multiyear ice in the central Arctic Ocean.
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Mats Frick at 23:08 PM on 30 July 2010Models are unreliable
I can recommend Paul N. Edwards (2010) "A Vast Machine: Computer Models, Climate Data, and the Politics of Global Warming". I'm just starting on the final chapter and its by far the best text on the origins and applications of modeling in climate science. Highly recommended! -
CBDunkerson at 22:29 PM on 30 July 2010Waste heat vs greenhouse warming
Hey John. Yeah, I was trying to get across the way that photons bounce around in the atmosphere, but any analogy of things trying to move through constrained exits (e.g. the dam analogy) covers the central concept. They each have benefits. The pool table simulates the 'brownian motion' of the photons, the dam has the increasing pressure at the bottom correlating to the increasing surface temperature, and the stadium crowd helps get across the vast number of individual photons involved. -
HumanityRules at 22:07 PM on 30 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Why does The State of the Climate 2009 document state in one line that Arctic ice multiyear ice has increased by 11% from 2008 to 2009 then move on in the next line to state that these two numbers are similar? (S113-114) Increased multiyear ice doesn't fit the complete story of unidirectional metrics. [pointless speculation about motivations deleted]Moderator Response: Please bear in mind that if you mix potentially useful questions about science with speculation about conspiracies and the like, you may end up wasting the time of other people when entire swathes of comments are removed. Try your best to stick with discussing science. -
John Russell at 21:56 PM on 30 July 2010Waste heat vs greenhouse warming
CBDunkerson at 21:16 PM on 30 July, 2010 Wow, what a truly wonderful analogy. As a analogyphile myself I admire your creativity (I'm assuming it's not a cut and paste job!). If I may, the only thing I could suggest that might improve it is to substitute a crowd in a large stand at a football match looking for one of a number of exits -- with a stream of additional spectators joining them from the tier above. This has that advantage that one doesn't have to imagine balls being self-powered. Does that work? Someone ought to collect all the analogies together! -
CBDunkerson at 21:51 PM on 30 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
HumanityRules #77, to be CLEAR those are results modeled based on the available measurements. Hence my calling them estimates. Also note that when IceSAT was online we DID have direct measurements of ice volume... and they matched the PIOMAS estimates very closely. Thanks to CryoSAT II we'll know in a few months whether PIOMAS has continued to be that accurate, but given the complete collapse of ice thickness and concentration (as shown even on the PIPS site you have previously preferred to cite) it is clear that ice volume has undergone a huge collapse. As to 'cherry picking' when talking about ice melt... by all means let's look at the full picture; NH sea ice: Declining NH land ice: Declining NH all ice: Declining SH sea ice: Increasing SH land ice: Declining SH all ice: Declining Global sea ice: Declining Global land ice: Declining Global all ice: Declining Yep, the 'alarmists' sure are 'cherry picking' by not concentrating on that SH sea ice. -
CBDunkerson at 21:43 PM on 30 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
GeoGuy #71, the paleoclimate CO2 record is established by multiple lines of proxy evidence in addition to DIRECT measurements from the ice core samples. For instance isotope analysis of pedogenic minerals, long-chained alkenones in haptophytic algae, marine carbonate, and liverworts are all CO2 proxies which match the ice core results. The stomata proxy you cite assumes that CO2 levels are the only factor which can have a significant impact on the plants. Given the disparity between those results and the other sources I'd have to doubt that. It seems plausible that airborne particulates (from volcanoes or humans), insolation, humidity, rainfall, soil quality, and any number of other things could play a part. There are also several stomata studies which AGREE with the prevailing CO2 record (e.g. Van der Burgh et al., 1993; McElwain and Chaloner, 1995). Thus, this is not a question of one CO2 proxy vs another. It is one dubious writeup on a WEB-SITE vs overwhelming evidence to the contrary. -
CBDunkerson at 21:16 PM on 30 July 2010Waste heat vs greenhouse warming
How about another analogy? Imagine a pool table (the Earth's atmosphere) where all the pool balls (IR photons) move of their own accord and bounce around until they hit one of the pockets and leave the table (escape to space). Now, say that on average it takes 30 seconds for a pool ball to leave the table... but every 30 seconds another pool ball (photons from sunlight, waste heat, et cetera) is added. Thus the system is in equilibrium and will continue that way indefinitely with a relatively fixed number of balls (stable temperature) on the table. However, if we then block off one of the pockets (add GHGs to the atmosphere) the pool balls cannot escape as fast and the number on the table begins to increase (it gets hotter). These extra pool balls mean extra collisions and more kinetic energy and thus result in balls hitting the remaining pockets more often... until eventually the average time for a ball to leave the table again reaches 30 seconds and the table returns to equilibrium... just with more balls on it (a higher average temperature). An even closer analogy would be if the pool table were three dimensional and different parts of it caused the balls to travel at different speeds (conductivity of solids, liquids and gases the heat is passing through), but essentially that's how it works. There is no great and impenetrable mystery here... and the one white cue ball from waste heat does not behave any differently than all the other balls from solar energy. -
Hoskibui at 20:46 PM on 30 July 201010 Indicators of a Human Fingerprint on Climate Change
#13 thingadonta AGW observer also has a good resource on the non-significant role of cosmic rays in climate. It's actually a very good resource on many aspects of climate science - highly reccomended. -
thingadonta at 20:10 PM on 30 July 201010 Indicators of a Human Fingerprint on Climate Change
#12 Hoskibui Thanks, this is a good resource of solar science. Thinking laterally, I would say if you want to convince the skeptics that it isn't the sun causing recent global warming, do more research on the sun. It's easy to get a research grant to see how c02 might affect marmots or lizards, but get a grant on how solar magnetics affect cosmic rays and the skeptics will be more easily convinced. -
Hoskibui at 19:11 PM on 30 July 201010 Indicators of a Human Fingerprint on Climate Change
#8 thingadonta Why not read the peer review? Papers on minor role of the Sun in recent climate change -
JMurphy at 18:36 PM on 30 July 201010 Indicators of a Human Fingerprint on Climate Change
thingadonta wrote : "The Earth's magnetic field is also slowly declining, and is expected to once again flip poles in a geologically relatively short time-within the next few hundred thousand years, or so, apparently." They come at irregular intervals averaging about 300,000 years; the last one was 780,000 years ago. Are we overdue for another? No one knows. -
Joe Blog at 18:31 PM on 30 July 201010 Indicators of a Human Fingerprint on Climate Change
Dappledwater at 18:05 Thanks for the response, i did follow the link in the article on it, and it has the same reason stated as for the stratospheric cooling. Which is basically that co2 acts as an emitter at those molecular densities. It just seemed counter intuitive in the extreme upper atmosphere, because co2 is a relatively heavy molecule, and this is basically talking space, where i would have thought we would be looking more at atomic N and O. And i did read a something on the thermosphere, not that long ago, from nasa... and they had a different hypothesis. These things have a way o sorting themselves out with time though. -
Jesús Rosino at 18:28 PM on 30 July 201010 Indicators of a Human Fingerprint on Climate Change
#8 thingadonta, I think that all solar parameters vary in phase with solar activity (at least cosmic rays do), so we can say that there's no significant solar trend in the last 50 years. In any case, I find your points are pure speculation without any real evidence. You cannot base a hypothesis on what we don't know. What we know shows that the sun hasn't done it. I compare evidence in John's article and evidence in your comment and my conclusion is that that it is highly unlikely that the sun played a role and it is highly likely that the greenhouse gases have. Cheers -
thingadonta at 18:07 PM on 30 July 201010 Indicators of a Human Fingerprint on Climate Change
re: Response to #2: "The fact that the sun has been cooling in recent decades coupled with the observations of all this heat trapped by greenhouse gases puts the matter beyond any doubt in my mind." Solar irradiance/solar heat output is almost certainly not the only solar variable that effects earth temperature. 1) We already have the idea about the increased solar wind, less cosmic rays reaching the earth, and lower cloud formation. Even if the theory is wrong, the concept itself is valid: less clouds due to solar effects other than heat, would mean higher earth temperatures. It would be difficult to distinguish this effect without longer term data on clouds, which is not available. So how could the issue be beyond doubt? 2) Another idea relates to the Sun's magnetic field, which has increased substantially over the 20th century (perhaps doubled). We don't know what effect this has had on Earth climate dynamics. (The Earth's magnetic field is also slowly declining, and is expected to once again flip poles in a geologically relatively short time-within the next few hundred thousand years, or so, apparently). 3) Recently, is was also widely reported that the earth's upper atmosphere had shrunk markedly more than was expected, associated with the last few years decrease in solar output. This suggests that perhaps the effects of solar variation is greater than we know, and also within current climate modelling. #4 and #5 The scientists who are stating this can be found on the net. Here is one: http://opinion.financialpost.com/2010/05/19/lawrence-solomon-solar-scientists-worldwide-working-to-counter-global-warming-hypothesis/. Another: "The sun is currently at its most active for 300 years. That, say scientists in Philadelphia, could be a more significant cause of global warming than the emissions of greenhouse gases that are most often blamed." http://anhonestclimatedebate.wordpress.com/2009/05/30/scientists-blame-sun-for-global-warming/ Of course, one can cherry pick the net to say anything, but I'm not personally convinced we know enough about the sun to draw the conclusions of J.Cook above. -
Rob Painting at 18:05 PM on 30 July 201010 Indicators of a Human Fingerprint on Climate Change
Joe Blog @3 - the increased Greenhouse Effect should trap more heat in the lower layers of the Earth's atmosphere, meaning less is reaching the upper atmosphere. This cooling effect in the upper layers causes the Thermosphere to contract. Some climate models predict quite severe cooling in the Thermosphere for a doubling of CO2 (40-60k) -
Jesús Rosino at 17:54 PM on 30 July 201010 Indicators of a Human Fingerprint on Climate Change
Great summary, John, many thanks! This is very interesting because the A in AGW is usually the crux of the social debate (there's no scientific debate). I guess that models should also be added as another evidence: models are able to replicate recent climate if anthropogenic forcings are included. Excellent inline answer in #2 too. I would add that, in any case, if the judge is to condemn a suspect, he doesn't need evidence that no other person could have possibly done it. He just needs enough evidence that this specific subject did it. The demand to show that no other thing could have done it is always unachievable (you never know whether we live in The Matrix and tomorroy the machines will just change the code of physic laws). The demand to show that everithing else didn't do it is just an inquisitorial probatio diabolica. -
RSVP at 17:52 PM on 30 July 2010Waste heat vs greenhouse warming
To EliRabett #129 If not ocean water, it will be rivers or lakes. What difference does it make? -
kdkd at 16:39 PM on 30 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
chriscanaris #82 "This paper has been posted on this site before. Basically, it says it's all very hard to predict." Nope. Basically it says that things are somewhat unpredictable, but expect perturbations cyclic behaviour during the transitional stage, just like the kinds of things we're observing with the sea ice extent measurements in the antarctic. It's a fascinating paper, and well worth a read. Google scholar tells me that pdfs are accessable without a subscription. -
Doug Bostrom at 16:22 PM on 30 July 2010What do you get when you put 100 climate scientists in a room?
What do you get when you put 1 climate scientist in a room with 99 not-climate-scientists? This. Roy Spencer attempts to explain back radiation. He's a -really- patient guy. -
Marcus at 16:15 PM on 30 July 201010 Indicators of a Human Fingerprint on Climate Change
You're dead right Matt. Claiming that you've read "solar scientists" making these claims-without attribution-just doesn't wash. John has been kind enough to cite about a dozen references which all essentially say the same thing-current warming *cannot* be explained by changes in the heliosphere. -
chris1204 at 16:13 PM on 30 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
kdkd @ 82 Early-warning signals for critical transitions in Nature This paper has been posted on this site before. Basically, it says it's all very hard to predict. Isn't that the problem we're currently grappling with? I think a teeny weeny bit of humility is called for when looking at extraordinarily complex systems. -
Rob Painting at 15:54 PM on 30 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Humanity Rules @ 78 - If both poles were similar in geography, I'd expect sea ice trends would be similar, however they're not, and the situation in the Antarctic is exacerbated by the ozone hole. And yes, with continued global warming the sea ice trend will eventually reverse and begin to decline. -
kdkd at 15:32 PM on 30 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
HR #81 The behaviour of complex systems is less linearly predictable than you might suppose from thinking about it intuitively. Have a look at this paper from Nature on Early-warning signals for critical transitions for a detailed exposition. As well as this, the sheer amount of ice at the Antarctic, dampens the effect of global warming on the weather systems around the continent, and the sheer amount of ice and its high enthalpy of melting means that we can expect rather counterintuitive weather around Antarctica for quite some time to come. -
HumanityRules at 15:00 PM on 30 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
I know I'll get accused of straw men or cherry-picking or evading the issue or whatever but I think it's still worth focussing on the antarctic just because many aren't and also because I also think it goes some way to explaining what we are seeing in the arctic as well. The melt season section of the 2009 report (page S129) is interesting. This year show's a melt season in the antarctic 50% shorter than the long term average, a continuation of the recent declining trend. When highlighting extreme climate metrics I wonder why that particular one is ignored? The seesaw nature of the poles seems un-avoidable. As does the natural variability associated with that. -
gallopingcamel at 14:43 PM on 30 July 2010What do you get when you put 100 climate scientists in a room?
John, I forgot to thank you for telling me about Barry Brook's blog! -
gallopingcamel at 14:38 PM on 30 July 2010What do you get when you put 100 climate scientists in a room?
John Cook, Thanks for your comment. Barry Brook may have what it takes to lead a broad alliance that will promote a future where cheap electricity from NPPs powers our civilisation. As an admitted "Sceptic" I have no problem marching under Barry's banner. -
MattJ at 14:37 PM on 30 July 201010 Indicators of a Human Fingerprint on Climate Change
thingadonta- There is another problem with your claim: it is "hearsay evidence". WHAT "solar scientists" are saying this? I haven't heard any. And there are certainly enough of them who agree with the conclusions of the IPCC and ALL the Science Academies of ALL the major developed nations: global warming aka "climate change" is real, and manmade CO2 is the major cause of it. -
HumanityRules at 14:06 PM on 30 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
55.villabolo at 01:32 AM on 30 July, 2010 I live in Melbourne, weather affected by antarctic conditions. If you're going to take that position then I'm happy not to give a stuff about what's occuring in the Arctic :) -
HumanityRules at 14:03 PM on 30 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
49.CBDunkerson at 22:51 PM on 29 July, 2010 A new study says that phytoplankton in the oceans have decreased by 40% since 1950. We'd better pray this is erroneous because if it isn't we're looking at a massive decrease in human population within this century. It doesn't seem to be the way the data is moving in this report! -
HumanityRules at 13:55 PM on 30 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
39.Dappledwater at 21:29 PM on 29 July, 2010 It always strikes me there is no real point arguing about SH sea ice. If it's increasing it's AGW. The year it starts to shrink it will be AGW. Having all the bases covered means there is no room for anything else.Response: You don't need to be so cynical. There's been a number of peer-reviewed examinations of southern sea ice which carefully and meticulously account for the various regional trends in sea ice across the Southern Ocean. -
HumanityRules at 13:51 PM on 30 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
36.CBDunkerson at 21:18 PM on 29 July, 2010 To be clear those aren't measurements you're talking about they are modelled data. -
Joe Blog at 13:24 PM on 30 July 201010 Indicators of a Human Fingerprint on Climate Change
Just another random query from me in regards to the graphic in the article... how is the shrinking thermosphere related to greenhouse warming? I would assume this would far more likely be due to variable space "weather"(variable UV through solar cycle etc) What is the proposed mechanism through co2?
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