Arguments
Recent Comments
Prev 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 Next
Comments 92801 to 92850:
-
Climate sensitivity is low
For your amusement - this is now an active topic on Jo Nova's site. One of her readers did a blog post for her on this very thread, claiming that efficacy was a "fudge factor" allowing made-up numbers. Discussion ensued... -
Phila at 14:08 PM on 13 March 2011Examining Hansen's prediction about the West Side Highway
HR: Is it possible that Hansen can be both a scientist and an ideologue? His activism certainly suggests so. I think his "activism" only suggests this if you proceed dogmatically from the assumption that he's largely or entirely wrong. Otherwise, you could just as easily see it as a rational response to an actually existing problem. Hopefully, you're not so wedded to the a priori assumption that AGW is a hoax or an exaggeration that you can't acknowledge this point. And before you ask: Yes, I can imagine the consensus turning out to be wrong, just as I can imagine evolution turning out to be wrong. I just wouldn't care to bet anything valuable on it. You present it as a clear black and white issue, science on one side, ideology on another. No, I really don't. I say that there are people who tend to have a lot of relevant expertise on one side, and people who tend to have little or none on the other. Ideology enters into the equation primarily to the extent that it empowers the latter group to present their generally uninformed and paranoiac speculation as "scientific scrutiny." My position on this question is probably not that different from your position on aircraft mechanics versus pastry chefs: you'd probably prefer the former to service the airplanes you board. Of course, the people who tend to lack relevant expertise could turn out to be right, despite their errors and misrepresentations and demonstrable ignorance. But again, I wouldn't bet anything valuable on it. Especially if it weren't really mine to bet. -
robert way at 13:10 PM on 13 March 2011The name is Bond...Gerard Bond.
It isn't quite so simple as to say warm periods cause the IRD events. In fact evidence suggests that these occurred simultaneously across difference ice regions of the northern hemisphere. Very complicated subject. -
Rob Honeycutt at 12:49 PM on 13 March 2011The Climate Show Episode 8: Kevin Trenberth
cloa513... You clearly do not understand what a baseline is. A baseline is merely a base point to measure an anomaly from. It's really quite irrelevant. -
cloa513 at 12:39 PM on 13 March 2011The Climate Show Episode 8: Kevin Trenberth
There is no way to compare what would happen without Anthrogenic green house gases to with as all the significant data gathering happened well after the start. So no baseline possible. -
HumanityRules at 12:26 PM on 13 March 2011What would a CO2-free atmosphere look like?
18 Chris Colose Thanks for the reply. Do you mind clarifying something. "but non-linearity in sensitivity is rather small over the ranges of climate of interest to us right now. Certainly you don't want to compare snowball Earths to say, the PETM directly, but I haven't seen anything suggesting it's a big deal for evaluating modern global warming." Here you're suggesting that you don't think the magnitude of the problem is so great when comparing modern conditions to say the LGM? Anyway your references lead me to this review (which includes Crucifix as an author). I thought it was useful in presenting the strengths and weaknesses of various CS estimates as well as being easy to follow. Would this be a balanced assessment of the science? Chris ignore this if you think it's straying too far away from the CO2 free atmosphere subject. -
RickG at 12:23 PM on 13 March 2011Examining Hansen's prediction about the West Side Highway
HR: RiskG do you think that the West Side Highway will be inundated by the sea in 2028? Does the evidence suggest it will? Not in 2028, but it eventually will at some point in the future as sea level continues to rise at an accelerating rate as a doubling of pre-industrial CO2 is approached. -
HumanityRules at 12:09 PM on 13 March 2011What would a CO2-free atmosphere look like?
From Peru I thought some stuff from Joel Norris was quite interesting on the subject. The first presentation on this list I thought was easy to follow as a layman. It makes the point that clouds are a dynamic rather than thermodynamic problem although I'm not too clear on what that means :) -
Tom Curtis at 12:07 PM on 13 March 2011The name is Bond...Gerard Bond.
Camburn @14, Wanner and Bütikoffer is the paper you linked @9. I am not sure why there is doubt about classifying the LIA as a Bond event, as it shows all the appropriate characteristics. Nor is the interval between it and the preceding Bond event the shortest. The interval between the Bond event of 9400 BP and that of 10300 BP is shorter. So, if we do consider the LIA to not be a "Bond event", then the claim of any of the Bond events to be one is also impeached. We then left with occasional coolings of the NH with not single causation, or periodic nature. In that case, talking about such an event being "due" is a form of the gambler's fallacy. Finally, the gradual drying of the Sahara over the period 5000 BP to 3000 BP seems well confirmed by a number of studies, including near the Nile (previously linked article) and near Lake Chad. This has been a consistent pattern recorded across 5 or so papers I have read on the subject. Interestingly, more southerly locations have a delayed onset of drying, as would be expected if the drying was a result of a shrinking of the northern Hadley cell, with a resulting shrink of the area of monsoonal rainfall, an expected consequence of a cooling climate. Further, models driven by reductions in NH summer insolation, or increased GHG forcing both show an increase in size of the Hadley cell, with a resulting moister Sahara; although there are subtle differences between the two cases. So, unless you can produce a contrary paper as evidence, I think we are wise to assume Saharan drying was not a consequence of Bond events. -
HumanityRules at 11:59 AM on 13 March 2011Examining Hansen's prediction about the West Side Highway
61 Phila We humans are complex beasts. We can take on many roles simultaneously, some of them contradictory. Is it possible that Hansen can be both a scientist and an ideologue? His activism certainly suggests so. Just for clarity I'm not trying to be disparging about him here, I quiet like somebody to take a clear position on things even when I disagree with them. I just think it's too easy to draw the boundaries the way you do. You present it as a clear black and white issue, science on one side, ideology on another. That's surely too simplistic. It's not the way I perceive it anyway. The skeptic argument contains "ideologically motivated ankle-biting" and some of it shows up on WUWT but the argument doesn't end there. There is a basis for scepticism from within the science based on the uncertainty and interpretative nature of the science. (apologies for going OT here) -
HumanityRules at 11:23 AM on 13 March 2011Examining Hansen's prediction about the West Side Highway
53 RickG Given that Hansen is answering one clear question with the answer to another question let's simplify this. RiskG do you think that the West Side Highway will be inundated by the sea in 2028? Does the evidence suggest it will? -
From Peru at 11:04 AM on 13 March 2011What would a CO2-free atmosphere look like?
In my prevoius comments I wanted to talk about the opposite of a CO2-free Earth: a Super Greenhouse Earth, i.e. with CO2 concentrations similar to the concentration of O2(oxygen) in the present day atmosphere, (that is, CO2 over 10%). This happened in the snowball events aftermath and possibly before 3000 million years ago (O2 isotopes suggest a temperature of about 70ºC then). The huge warming (earth temperatures would be above 40ºC) will cause a huge evaporation leading to an extremely high water vapor content in the atmosphere. What the cloud cover would be like in that world? Could the Earth have been 100% cloud covered like today is the planet Venus? And what kind of clouds will be the more common, high altitude cirrus clouds(with a net warming effect), low altitude stratocumulus clouds (with a net cooling effect) or huge troposphere-wide cumulonimbus clouds (with nearly neutral temperature effect)? -
Tom Curtis at 10:55 AM on 13 March 2011It's the sun
johnd, I was responding to Muoncounter, and to a specific challenge by Inconvenient Sceptic. With regard to ENSO, you are neglecting the fact that ENSO involves a redistribution of heat over depth in the pacific ocean. In particular, the deep warm waters of the Pacific Warm Pool are redistributed across the surface of the tropical Pacific. Therefore, as regards to its primary nature, it balances out in terms of energy distribution. Of course, the ocean interacts with the atmosphere through the surface, so an increased warmth at the surface should show similar feedbacks whether the cause is a change in forcing, or a redistribution of heat from the depths. Therefore we should expect a significant additional warming from El Nino events, and a significant extra cooling from La Nina events; which is what we in fact see. This contradicts denier claims of a low climate sensitivity. This additional warming (or cooling), however, will not introduce a trend to global temperatures because the same feedbacks operating in reverse will remove the additional warmth (or cooling) from an ENSO fluctuation from the atmosphere. -
Camburn at 10:36 AM on 13 March 2011The name is Bond...Gerard Bond.
Tom: I thought I was very clear that the stimuli for the Bond events is not known but only suggested at. I don't have the paper at hand, and am only speaking from memory of the paper that showed a shift in hydrological trends in the Sahara that started while a Bond event was in place and continued on after that event was over. There is question that the LIA was an actual Bond type event. If it wasn't, then we are about due for another. I can't seem to find your Wanner and Buttikoffer paper.Moderator Response: [DB] Another Wanner and Bütikofer 2008 can be found here. -
johnd at 10:11 AM on 13 March 2011It's the sun
Tom Curtis at 08:57 AM , I agree with the idea that geography is a factor and have posted on it on some other threads. I have focused more on the cycles such as ENSO which some people feel balances out once a cycle is complete, ignoring that it is the geographic distribution that determines what conditions each phase brings to a region, and thus all things are not equal, or mirror images of one another. This should be taken into account when considering how this plays into the heating or the cooling of the oceans. -
Tom Curtis at 10:01 AM on 13 March 2011The name is Bond...Gerard Bond.
Camburn, the paper you linked to @9 shows strong evidence of Bond events in the North Atlantic, but ambiguous evidence for it elsewhere in the globe. It also shows the correlation of Bond events to solar activity it hotly contested. I am not sure how it helps your case. @7 you make several claims, none of which you support with evidence. One at least, is very dubious. The wet conditions in the Sahara arrived suddenly with the warmer conditions following the Younger Dryas, and dissipated slowly in the period 5000 to 3000 before the present. As such, it shows no significant correlation with Bond events that I know of. If you have evidence of such a correlation, please show it. Otherwise it is most logically treated as a consequence of global warmth during the Holocene Climactic Optimum. Your claim that we are "about due" for a Bond event is certainly false. Quite apart from the fallacy of claiming that a recurring event with durations between events varying between 900 and 2300 years is "periodic" and can be "due"; the peaks of the Bond events are "... around 400, 1,400, 2,800, 4,300, 5,900, 8,100, 9,400, 10,300 and 11,100 cal years BP." (Wanner and Büttikoffer (2008)) Clearly the next Bond event will not be "due" for several hundred years at least, and probably not for another thousand years. -
Albatross at 09:37 AM on 13 March 2011Climate Emergency: Time to Slam on the Brakes
Angus @101, Aaah, the goal posts shift :) First, forgive me, but I am not going to take your posted Figure at face value. Given the choice between a practicing climate scientist and you, I choose Dr. Schmidt. Also, I note with interest that you are using HadCRUT-- but "skeptics" claim that the CRU folks fudged the data, despite what the numerous investigations found. And we know very well why HadCRUT has become the darling of "skeptics", despite those allegations-- it is because it runs cooler than NCDC and GISTEMP. Now I expect you to now claim why the GISTEMP cannot be trusted et cetera, but that would just amount to you dismissing the truth again. "I would appear that Mother Nature is putting the brakes on for us." As much as I would like for that to happen, Hansen et al's recent peer-reviewed paper published in Rev. Geophys. disagrees with your opinion. Specifically, referring to their Fig 21. (see hyperlink, used 5 and 11-yr running means to negate impacts of ENSO and the solar cycle) they conclude that: "On the contrary, we conclude that there has been no reduction in the global warming trend of 0.15°C–0.20°C per decade that began in the late 1970s"
[Source NASA GISTEMP]
So feel free to believe whatever you want the data to show you Angus, it does not change the reality or the science. Again, if asked to choose between your opinion and the hard facts and data presented by prominent climate scientists, I choose the scientists.
I'll close with this graph from SkepticalScience which shows the primary global air temperature records--onwards and upwards:
Some advice Angus, the next time you take your car in for a service and the technician informs you that your break pads urgently need replacing or your breaks need servicing, I do hope for the safety of you and your family that you listen. Now they could be wrong, it could be a conspiracy, but in all likelihood s/he is right and is looking out for you and your family.
-
Albatross at 09:07 AM on 13 March 2011Christy's Unconvincing Congressional Testimony
Camburn @45 and 49, "It disputes Mr. Zwiers assertion that the recent winters are tied to AGW in the US. First, this thread is about Christy (a "skeptic") recently misleading Congress and the public about the science of climate change. Now you might be OK with that, others are justifiably not. So please stop trying to detract from Christy's misconduct. Now regarding Dr. Zwiers. This is what he actually stated in his written testimony: "Recently we have seen a spate of extreme climate and weather events that have drawn intense media interest, including this winter’s intense storms affecting the US and Canadian eastern seaboard,....." Canada indeed experience some severe nor'easter events these past winter. If you do not believe me go and look at the media reports. Also from NCDC: December 2010: "Several large winter storms affected the U.S. during the month. According to data from the Rutgers Global Snow Lab, the December snow cover extent was the seventh largest on record for the continuos US. Several cities across the Midwest and Northeast broke monthly snowfall records including Minneapolis, Minnesota and Syracuse, New York. January 2011: "Several winter storms impacted the northeastern U.S. during January, causing New York City and Hartford, Connecticut to break January snowfall records. The 57.0 inches (145 cm) which fell at Hartford's Bradley International Airport was the city's all-time snowiest month on record. The snowstorm that traversed the northern plains, Great Lakes and Northeast United States on January 9-13 ranked as a Category 3, or "Major" snowstorm, according to preliminary analysis on the Northeast Snowfall Impact Scale (NESIS). The NESIS score of 5.31 was slightly greater than the "Christmas 2010" blizzard and slightly less than the storm of late February 2010." February 2011: "Several record breaking snowstorms caused the U.S. to have above average snow cover extent during February. The "Groundhog Day Blizzard" dropped at least 5 inches of snow in 22 states." Dr. Zwiers is correct, and you have misrepresented his statement. -
Tom Curtis at 08:57 AM on 13 March 2011It's the sun
muoncounter @795, I'm afraid you are showing a Northern Hemisphere bias. Perihelion is not winter, but winter in the Northern Hemisphere, while being summer in the Southern Hemisphere. The reverse is true of aphelion. And the interesting facts about solar radiation and outgoing radiation that you point to apply approximately to all temperate and polar locations, regardless of their location in either the Southern or Northern Hemisphere, so it is not in itself the explanation of the phenomenon. This is complicated by geography, which influences the rate at which heat is transferred from the tropics to the poles. London, sitting close to a branch of the Gulf Stream, for example, will show a smaller (more negative) net radiation because it is substantially warmed by that current. Seattle would show a larger (less negative) net radiation because of the cold current of its coast (I believe). Both of these cities would show a larger net radiation in summer than, for example Moswow which would have hotter summers and cooler winters because of its inland location. In fact, overall the NH would display less of the disreprancy you indicate because of its larger land mass. That means fewer of its locations are close to the coast. It is that fact which in fact accounts for the Earth being warmer at perihelion (the NH summer). Temperature variations are smaller in the SH because so little of its land is far from the ocean, and there is so much more ocean. The greater heat capacity results in a smaller overall seasonal fluctuation in temperature. That means the NH seasonal fluctuation dominates overall, resulting in greater warmth during the NH summer, which coincidentally is at the moment during aphelion. -
Rob Honeycutt at 08:44 AM on 13 March 2011The name is Bond...Gerard Bond.
Camburn @ 9... There are definitely differing opinions on Bonds events. That's why I linked that last paper, Maslin 2009. That's the most recent paper I could find on the topic, which suggests that Bond events are there. My biggest takeaway from this topic is that the planet often redistributes temperature around the planet. And the difference with today is that we see nearly all indicators of temperature going in one direction. I believe that is the unprecedented nature of warming this past century. -
Phil at 08:30 AM on 13 March 2011The name is Bond...Gerard Bond.
Camburn and Daniel #9 and #10 This is the syntax exactly: <a href="http://geography.cz/sbornik/wp-content/uploads/2009/09/g08-4-1wanner.pdf">http://geography.cz/sbornik/wp-content/uploads/2009/09/g08-4-1wanner.pdf</a> -
Paul D at 08:25 AM on 13 March 2011Wrong Answers dot com
Chemware@1 One of their investors (Redpoint), invests in 'green' research and technology: http://www.redpoint.com/portfolio/energy-and-environment/ -
Camburn at 07:04 AM on 13 March 2011The name is Bond...Gerard Bond.
Moderator: I am somewhat frustrated. I have tried to do the link correctly, but it seems to disappear. DB: Your eplanation was good, but I must be missing a step.Moderator Response: [DB] See my response to you in the previous comment. You'll get it. Without the interior label, your link (though constructed properly) would not echo back to the screen (the interior label serves as a graphical placeholder for the link).I figured it out, eventually. If I can, anybody can.
-
Camburn at 07:02 AM on 13 March 2011The name is Bond...Gerard Bond.
Took me some digging, but I finally found this again: Relates to the validity of Bond cycles. Are they real or imaginary correlations? http://geography.cz/sbornik/wp-content/uploads/2009/09/g08-4-1wanner.pdfModerator Response: [DB] You were almost there. The html tag string has an interior set of right-and-left arrows, between which goes the name of the link or whatever you're calling whatever you're linking to, which was missing. Here's the string with no arrows, substituting the number 1 for the left arrow (shares the same key as the comma on my keyboard) and the number 2 for the right arrow (shares the same key as the period on my keyboard):1a href="http://geography.cz/sbornik/wp-content/uploads/2009/09/g08-4-1wanner.pdf"2http://geography.cz/sbornik/wp-content/uploads/2009/09/g08-4-1wanner.pdf1/a2
or1a href="http://geography.cz/sbornik/wp-content/uploads/2009/09/g08-4-1wanner.pdf"2Here's a link to an interesting study I found1/a2
Which (substituting the appropriate arrows back in for the 1's & 2's) yields: -
Interactive animation of the climate change impact on agriculture
johnd - You handle long term changes such as that the same way we handle the aerosols in the 1950s-1970s: you note the active factors and look at long term trends in light of them. Long term shifts do not introduce noise, they introduce long term slope changes. And the 30-year averaging is intended to average out noise, variability that we don't have a handle on due to chaotic factors and details of local interactions. I'll note that I have yet to see a 60-year cycle actually extractable from the data; many have tried, but it just doesn't hold up under numeric analysis as periodic events. -
muoncounter at 05:02 AM on 13 March 2011It's the sun
Rob, I often see this in students. They take a position based on something they've heard (or, sadly, been told by a parent or prior teacher) and cling to it no matter what. If, after a little Socratic give-and-take, you can see their doubt level rising, you can make a difference. However, some are afraid to simply admit that they've been misinformed or are just plain wrong. In the case of some of the most ardent skeptics, clinging to a pre-conceived notion frequently results in highly unscientific thinking -- and down goes credibility. In a case like this, realizing that net radiation is what matters leads to the next logical step: if we reduce the earth's outgoing radiation, the planet must warm. But that requires a greenhouse effect ... and that violates the pre-conceived notion. Illogical, does not compute! -
johnd at 04:34 AM on 13 March 2011Interactive animation of the climate change impact on agriculture
KR at 12:30 PM, we know from research that the climate in various regions has regularly alternated between wet phases and dry phases, with the corresponding effects on temperature, for periods up to double the 30 year standard. Please demonstrate how the 30 year standard would provide usable data in such circumstances. The projections made whilst in the midst of such periods are going to yield different results. This can be a problem for forecasts produced by statistically modeling. Most of this identification of such longer term cycles has only come about through recent research, thus is unlikely to have been taken into account when discussions on this subject were taking place a century ago. -
Camburn at 04:25 AM on 13 March 2011The name is Bond...Gerard Bond.
Rob: The Byrd ice core is interesting in itself because it does show continued warmth during the Holocene. This is in direct contrast to some of the proxy literature of lower latitudes. I have to thank you for posting about the Bond events. These events allow good discussion about world wide climate without the "political" flare. I appreciate this. -
Camburn at 04:20 AM on 13 March 2011The name is Bond...Gerard Bond.
From the papers I have read it seems to me that the regional hydrological cycles have more information in them than "temperature" cycles. To change regional hydrocycles, such as the Sahara changing to desert, or Western NA having 400+ years of drought and then turning to a wet cycle show global circulation changes. These events are tied to temperature, but temperature does not always lead to these events occuring. There are indications that temperature shift are a result of these hydrological shifts, rather than the hydrological shift being a result of a change in temperature. Bond events from the past are tied to the suns strength. I am not only talking about TSI, but rather isotope data showing the changes in UV etc. TSI is not always a predictor of temperature. There have been several long term basin studies done throughout the world showing the correlation between solar cycle strength and precipitation over a large area. One thing that is certain, when a Bond event occurs, hydrological cycles throughout the world change very very quickly and this is off concern as we are about due for a Bond type event cycle wise. If we could only be sure what causes this event it would certainly make it easier to understand its scope and total dynamics. -
Rob Honeycutt at 04:19 AM on 13 March 2011Wrong Answers dot com
cloa513 @ 21... That's a fascinating perspective. Do you have anything at all to back you up on that position other than just saying it? -
Rob Honeycutt at 04:17 AM on 13 March 2011Wrong Answers dot com
hengistmcstone... That is really fascinating! Did you document it at all? -
Rob Honeycutt at 03:55 AM on 13 March 2011It's the sun
It's so clear what is happening with TIS, and I see it in so many others who hold his position. They are in this constant process of confirmation bias. They start with the conclusion that AGW can't be correct and waltz through their way through the science locating the points that support that position. What they don't do is push past any of those points to fully understand the science because that endangers the conclusion they want to find. -
muoncounter at 03:44 AM on 13 March 2011It's the sun
Another observation re TIS' comment: "Explain the warmer July to me without using geography. ... if accurate, it does prove that geography plays a very strong role in global temperature." That's hardly an adequate 'proof.' But let's play with it anyway. Here's something that doesn't appeal to geography: Your statement 'the earth gets more energy in winter than in summer' clearly refers only to incoming solar radiation. It is certainly true that the peak value of solar insolation averaged across all latitudes at the time of perihelion (winter) is 7% greater than at aphelion (in summer), but isn't that primarily because the earth is closer to the sun in winter? However, basic Physical Geography (the name of textbooks, not part of the explanation) gives the control on temperature as the net radiation: the sum of incoming (daytime) and outgoing (nighttime). For example, this is London:
--from physicalgeography.net
During the winter months, outgoing longwave radiation actually exceeds incoming insolation producing negative net radiation values.
The linked page gives examples for several other locations.
So when length of day is taken into account, the 7% additional energy 'received' in winter is radiated away during those long winter nights; winters are colder than summer.
-
Rob Honeycutt at 03:34 AM on 13 March 2011The name is Bond...Gerard Bond.
Camburn @ 5... I think you are correct, to an extent. I believe that, in general, Vostok is actually considered to be more representative of the planet as a whole. Reading through a bunch of papers on ice cores I find that the Byrd ice core is used as often Vostok for comparing NH/SH. The interesting thing you find there is that Byrd shows an overall warming trend over the Holocene, and also shows the same D-O and Bond antiphase events you see in Vostok. I'm currently trying to locate the actual data for Byrd during the Holocene. All the data at NOAA ends prior to the Holocene. -
Rob Honeycutt at 03:27 AM on 13 March 2011It's the sun
TIS... (From previous thread) What you are missing saying that the planet warms and cools 4C during the year is the trend. Take that same monthly series that I linked from NOAA and plot it on a graph. You see the series rise and fall the ~4C that you state. But read the rest of the page. This data is the basis for the anomaly. As the the planet warms that same series you plotted is moving upward. All the datasets plot this. UAH, RSS, GISS, CRU... They are all taking this annual cycle into account. -
Rob Honeycutt at 03:19 AM on 13 March 2011What would a CO2-free atmosphere look like?
TIS... I'm posting a response to #45 on the proper thread per the moderator response above. -
Camburn at 03:17 AM on 13 March 2011Interactive animation of the climate change impact on agriculture
I don't know what in the world I am doing wrong, but I can't seem to get the fancy direct link working. Anyways, here is another link concerning soybeans and elevated levels of co2: http://www.eurekalert.org/pub_releases/2009-02/uoia-hcb020609.php -
Camburn at 03:15 AM on 13 March 2011The name is Bond...Gerard Bond.
pbjamm: I am not sure that it is all in one direction. The ice core data from Volstock is for Volstock. An isolated area with a small change in actual temperature verses the lower latitudes. Comparing Greenland to Volstock is not a fair comparison, but must be taken into consideration and evaluated further to a more regional perspective and then graduated out to a global perspective. I am more interested in the hydro cycles that accompany a Bond type event. There are large shifts in that cycle that occur when a Bond event happens and they take 100's of years to move back to "normal". -
Camburn at 02:59 AM on 13 March 2011Interactive animation of the climate change impact on agriculture
Back to co2. This research confirms that soybeans respond very positively to higher levels of co2. http://farmtalknewspaper.com/crops/x1327129664/Research-looks-at-crop-response-to-CO2 -
hengistmcstone at 01:30 AM on 13 March 2011Wrong Answers dot com
Hmmmm I just corrected an answer on Answers.com and it took less than 3 hours to be reverted back to it's original. -
les at 00:01 AM on 13 March 2011It cooled mid-century
12: Dikran MarsupialHowever, I suspect this should be discussed further on another thread.
and, indeed, was touched on previously in the Climate Sensitivity: The Skeptic Endgame where Giles didn't understand it either. Someone might do an intro to modeling, simulation, log-likelihoods and MC methods...Moderator Response: (Daniel Bailey) Are you offering...? -
adelady at 23:06 PM on 12 March 2011Wrong Answers dot com
cloa513. A "meaningless unmeasurable quantity with no scientific value"? The same thing could be said about the average weight of 10 year olds or the average family size. No family has 2.3 or 1.8 or 4.5 children. However, scientists (and policy-makers) concerned with =average= =trends= in family size or health of school age children find numbers representing such trends very useful. The fact that they don't represent anything we can see or feel is entirely beside the point. -
adelady at 21:53 PM on 12 March 2011What would a CO2-free atmosphere look like?
Thanks for that Tom. I cannot see how geography is of any interest in climate calculation length periods. It doesn't change - or at least until Australia's 5cm a year northward movement gets us nearer the equator it won't. One degree of latitude is over 100 kilometres. At 200 years per metre, 200,000 years per kilometre, this is not of any relevance, let alone interest, except to seismologists and a very small subset of geologists. And I really cannot understand how seasonal temperature effects are of any more concern than tidal or diurnal effects. They're all just cycles. Climate is about whether future cycles will be the same, temporarily different (ENSO for example) or permanently different as in ice ages or warming. Permanent is a human generations word here not a geological period word.Moderator Response: [muoncounter] TIS has veered off-topic. This is a thread about a CO2-free atmosphere. Discussion of seasonal solar radiation belongs on It's the sun. Comments there can link back here by including an HREF="" with the URL of the originating comment between quotes. -
cloa513 at 21:14 PM on 12 March 2011Wrong Answers dot com
The real scientific answer to has the global mean temperature changed is the global mean temperature is meaningless unmeasureable quantity with no scientific value. You can't just take a massive list of numbers and take and think its a representative number. Those numbers have a physical meaning which can't be averaged. A boulder of rock at 30C has far more energy than a similar size amount of gas. Supposing it did exist by somehow calculating the internal energy of the climate system (a very tough task) and dividing by the mass- there is no way we could reasonably derive before decent array of temperature measuring satellites was available. Before that very large errors getting worse back in time- basically some time in early history could only be able say its hot or cold. -
Tom Curtis at 21:08 PM on 12 March 2011What would a CO2-free atmosphere look like?
Inconvenient Sceptic @22, 37, and 45: First, you plainly do not understand how the greenhouse effect works, as is shown by your comment @22. The GHE is a consequence of the difference between the energy of the IR radiation to space from gases in the atmosphere, and the energy that would have radiated to space from the surface at those same frequencies has those gases not been present. Because it is the energy balance between radiation to space and radiation from the sun, the energy balance for energy transfers between atmosphere and surface is of only minor interest. Certainly increasing those transfers will not increase the greenhouse effect by itself, and nor will changing the form of the energy transfer. The simple fact that should convince you of your error is the fact that energy radiation from a gas is a function of the gases temperature. Therefore, cooling the atmosphere will reduce the energy radiated by green house gases in the atmosphere, and hence increase the difference between that radiation and that from the surface in the same frequencies. In other words, simply warming the atmosphere weakens the greenhouse effect, not increases it as claimed by you at your blog. Finally, the difference between July and January global temperatures is due to the high proportion of land in the NH, whose low heat capacity results in much faster temperature rises for a given forcing, and much faster falls if that forcing is removed. So much is obvious. What is also obvious is that this is irrelevant to your original and false claims. -
Dikran Marsupial at 20:32 PM on 12 March 2011It cooled mid-century
Giles@11: (a) No, the use of multiple models is not "really strage", it is not even unusual. There is uncertainty in the details of the physic is involved and in the parameters, the use of multiple models captures some of that uncertainty. Secondly if different models give similar results, that indicates that the uncertainty in the physics is small and the climate projections are not greatly sensitive to them. That is a good thing from the modelling point of view, not a bad one. If anything it actually means the data do constrain the models relatively tightly as it constrains them all to say the same basic thing. As to scientific validation, you obviously don't understand there is no such thing as scientific validation, only scientific invalidation. You can't prove a theory right, only disprove it. (b) Complaining that bad models are not selected is pretty daft, if the model is inconsistent with reality it means the assumptions underpinning that model are incorrect, so why should we look at it. The CMIP ensemble were not selected in that way, it is an ensemble of models from leading modelling groups, so your objection is incorrect anyway. Complaining that the black line doesn't go out of the corridor is basically saying "the models must be wrong because they give the right answer"! (c) The models should not expect to produce temperatures that precisely match the observations, that comment shows a complete lack of understanding of Monte Carlo simulation methods. We can't predict the chaotic weather, so the model runs will always be different. The model mean won't match the observations either as it is an estimate of only the forced component of climate, not the unforced response - the observed climate has both components so there is no reason to expect that close a match. "That is not, by far, what I would call an accurate fit of data" well possibly that is because you don't understand the effects of the major sources of uncertainty. Given internal climate variability (which models cannot be expected to be able to model), the hindcast is pretty impressive. However, I suspect this should be discussed further on another thread. -
Gilles at 18:53 PM on 12 March 2011It cooled mid-century
I agree , that's the point. And if I look at the comparison between models and data, I'm not convinced again that the agreement during the first half is so good
Of course at first glance it seems that the match is almost perfect. But if you look carefully at the first half of the century, and if you look also carefully at the methodology used to produce these curves, you will notice that
a) curves are generated by a variety of different models, which is really strange, since it means that different modelling can produce the same kind of visual output - this really means that observations are only LOOSELY constraining models - which is the opposite of a scientific validation.
b) the models contain parameters , especially for clouds, so there is an obvious selection bias due to the fact that bad models are simply not selected here. In other words, adding a superposition of approximate models with a selection of parameters giving results close to the data, will ALAWAYS produce an interval, a corridor , containing these data - it's almost certain and doesn't prove much. Note how curiously the black observed curve travels throughout the corridor and never crosses the border : is it not surprising that a unbiased set of models just reproduces exactly the range of natural variability, without any "lost space" in the yellow interval or without the black curve goint out of it? this cannot for sure be obtained without a selection of the sample.
c) models produce temperature that are not precisely matching the reality in absolute. What is displayed here is ANOMALIES. Anomalies with respect to which baseline ? you have to read carefully the report to find the answer : with respect to the 1900-1950 period. So the agreement at least on the central point of the first half is automatically insured - no surprise here.
So the real test of the preanthropic period is not the average value, but the details of the shape around this value. Is it well reproduced ? not so much. The break around 1940 is NOT reproduced in models - it just the width of the interval that blurs out the comparison. The only break in the models are in major volcanic eruptions - first Agung in 1963. Note also that volcanic eruptions are NOT so conspicuous in data. Actually if you look only at data, you couldn't say when these eruptions occured, contrary to the models. So it seems that models "play" with eruptions to try to reproduce breaks that are not really at the right place - playing with a whole interval of parameters to blur out the disagreement.
That is not, by far, what I would call an accurate fit of data.
-
angusmac at 18:30 PM on 12 March 2011Climate Emergency: Time to Slam on the Brakes
Albatross @99 the paper I refer to is Hansen (2006) which is not too old. Your diagram @63 from realclimate appears to be quite impressive; however the temperature data does not look quite so impressive when used in context with AR4.
Figure 1: IPCC Scenarios A1B, A2 & B1 Compared with Measured HadCRUT3 Temperature Data (after AR4, 2007)
Figure 1 is based on IPCC AR4 Figure TS.26 on to which I have plotted the latest HadCRUT3 data. The black dots in the original diagram appear to be HadCRUT3 data but they are slightly misaligned with actual HadCRUT3 data (my blue dots). Therefore, I offset the HadCRUT3 data by adding 0.018°C to achieve a reasonable fit with the individual data points shown in AR4. The blue line with white dots is the smoothed HadCRUT3 data.
It is evident from Figure 1 that the smoothed HadCRUT3 curve give an excellent fit with observed data presented as the solid black line in AR4. It is also evident that the observed temperature trends are significantly below the "likely" warming/emission scenarios presented in AR4. Indeed, the current trend is similar to the emissions-held-at-year-2000-level scenario.
I would appear that Mother Nature is putting the brakes on for us.
-
The Inconvenient Skeptic at 17:44 PM on 12 March 2011What would a CO2-free atmosphere look like?
Rob and Alb and Muon, I do understand what global warming is about..... Really. Thanks for linking the NOAA site. I hope people will accept that as not made up. I believe that Jones himself did the study that provided the NOAA the data. Also, the average temperature of the Earth does not change during the day. Half is cooling, half is warming. It stays constant over the course of a day. It does change over the course of the year, by 4C. Here is my question. A serious and legitimate question. Define a forcing mechanism that causes July (lowest solar forcing) to be warmer than January (maximum solar forcing). Forcing doesn't fit. Describe to me a mechanism that causes the minimum energy point to be the warmest time of the year. By CO2 models January should be warmer than July. Please check. In January the Earth gets ~7% more energy than it does in July, but July is also ~4C warmer. Explain the warmer July to me without using geography. It cannot be done, not matter how hard you try. If you don't think that matters, that is fine. But if accurate, it does prove that geography plays a very strong role in global temperature. Convince yourselves that I am either right or wrong on that point. Then we can talk more. -
pbjamm at 15:37 PM on 12 March 2011The name is Bond...Gerard Bond.
Camburn, I think the point is (and I am sure I will be corrected if wrong) that the Bond Event may be a global temperature variation but it is not all in one direction. So the net change is neither positive nor negative, more flat.
Prev 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 Next
