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Ned at 09:06 AM on 4 September 2010Urban Heat Islands: serious problem or holiday destination for skeptics?
Sorry, BP, that's not good enough. What are the statistics for the model? How confident are we that the data you used are actually representative (given that they apparently showed a rather different trend than the actual land surface temperature records)? I'm sure your handwaving argument in your later comment is convincing to you, but that doesn't mean it's going to convince anyone else. That line of reasoning is built on one hidden assumption after another. We can talk about those assumptions, but let's first answer the questions about your regression model. -
johnd at 08:39 AM on 4 September 2010Quantifying the human contribution to global warming
TOP at 23:57 PM, the absorption band chart illustrates very well the role each component plays. It is no coincidence that humans radiate at about 10um which is right in the transmission window. It is also illustrated very clearly that if there was no CO2,then the water vapour alone would allow more thermal energy to be radiated off as the transmission window gradually closed. With CO2 added, the transmission window closes off earlier, so the loss of heat is halted earlier. However it does not overlap the point at which water vapour allows maximum transmission. The only way for CO2 to overlap that portion of the spectrum is for it to change it's properties, or for the properties of water vapour to be altered. The chart represents very well the properties of H2O and the band occupied by water vapour reflects the points at which the changes of state occurs. For the concept of CO2 saturation to apply, the width of the CO2 window would have to either widen or the position occupied on the spectrum shift, something the known properties of CO2 do not allow for. If an analogy helps, water vapour is a sliding window that opens once solar radiation streaming through closed windows heats the room. As the heat increases, the window begins to open becoming almost fully open at about 10um which by coincidence allows us within the room to enjoy a comfortable environment, then as the loss of heat going out the window begins to overtake the heat coming in, the window begins to slide close. However with CO2 present, the final few um of the window opening has already been blocked off so the loss off heat is curtailed a little earlier than it otherwise would have been. -
dana1981 at 08:36 AM on 4 September 2010Empirically observed fingerprints of anthropogenic global warming
Composer - thanks and yes, it was deliberate. apeescape - thanks, I fixed the link. -
dana1981 at 08:32 AM on 4 September 2010Quantifying the human contribution to global warming
Okay I see, your point is that the greenhouse effect is dependent upon the thermal radiation from the Earth's surface, which in turn is dependent upon the incoming solar radiation. My initial reaction to that is that total solar irradiance generally only varies by a fraction of a percent, so treating it as constant is a safe assumption. -
kdkd at 08:20 AM on 4 September 2010Urban Heat Islands: serious problem or holiday destination for skeptics?
BP #37 That's a cop out par excellence. If you do a regression model (which you have) then you can not demonstrate its statistical significance without presenting the results of the F test, to show whether it predicts better than chance or not. Seeing as it's a univariate regression you might as well do the statistical significance of the correlation coefficient as well, to show if r is significantly different from zero. If you're not prepared to do an essential part of the job, then don't make the claims. -
RSVP at 07:52 AM on 4 September 2010Quantifying the human contribution to global warming
dana1981 "I'm not sure why you think the CO2 radiative forcing is dependent upon the atmospheric temperature or solar irradiance." CO2 does not generate energy on its own. Even according to AGW it is only a reflector of IR. The amount of energy assumed to come from CO2 according to your ln function only holds IF solar irradiance patterns do not change. But if it does what? CO2 would contributes nothing in a case where the sun shuts down for instance even if concentrations triples or quadrouples. -
michael sweet at 07:47 AM on 4 September 2010The surprising result when you compare bad weather stations to good stations
Omnologos, Since your post talks about EKG's you have no call to suggest I am off topic. Your analogy is completely wrong. We are talking about measuring a simple result: temperature, not a complicated one. It is simple to measure and, since we are measuring the anomaly, the calibration can be off and still give the correct result. There is no indication that the data has been measured wrongly. You are trying to wish away a clear result. As it has been pointed out several times above, if you visit 100 people for your blood pressure and they all tell you you have a problem, you have a problem. It does not matter if some are not calibrated. The result is clear: no matter how you slice the data you get a strong warming trend. Good sites, bad sites, urban sites, rural sites all show the same warming trend. How can you claim that this somehow indicates that that there is no trend? -
Berényi Péter at 07:39 AM on 4 September 2010Urban Heat Islands: serious problem or holiday destination for skeptics?
#39 michael sweet at 05:47 AM on 4 September, 2010 Since Dr. Hanson has shown here that the warming trend in the rural stations and at very dark stations is the same as at stations that have large urban developments, how can you claim that you have something worthwhile? For once try to think please. Let's suppose (an alternate) Earth had a fairly stable climate with no average surface temperature trend whatsoever. Still, Urban Heat Islands would exist even there. Whenever you drive from the countryside to a city center, you can easily measure a several centigrade increase in air temperature. You can also measure a logarithmic dependence of this UHI effect on city size without referring to history. The only thing you have to do is to visit as many cities as you like multiple times and register temperature differences between centers and surroundings. An order of magnitude estimate of the effect is something like 0.2°C per doubling of city size. As the climate here is not changing, if the population of the same city grows in time, you'd expect the same temperature increase, that is a trend of about 0.2°C per doubling, right? Now, let's suppose population of this alternate Earth is increasing steadily with a fix doubling time of 55 years. Growth rate in different cities may be different, but the average rate would be the same as the global one. Therefore urban weather stations would measure a 0.36°C/century warming trend. Now let's suppose a scientist in this world, call him Dr. James E. Hansen for the sake of convenience, discovers the very same average temperature trend is measured even at rural stations, where local population density is extremely low. I have already mentioned climate is stable in this Earth, therefore in reality surface temperature trend is zero. Still, a global surface warming trend of 0.36°C/century is measured. How can we resolve this paradox? -
apeescape at 07:37 AM on 4 September 2010Empirically observed fingerprints of anthropogenic global warming
link to Zhang et al. (2007) has an extra space at the end. -
citizenschallenge at 07:16 AM on 4 September 2010New presentation debunking Monckton's critique of IPCC predictions
factfinder while you're at it, how about a little detail on the following: "Physics is based on Experimental data - not "empirical evidence that > Has Been Shown To Be Caused By Dozens Of Other Causes." What other causes have shown the physics of GHG's to be false? -
Composer99 at 07:04 AM on 4 September 2010Empirically observed fingerprints of anthropogenic global warming
Was the similarity between the symbols used to delineate the level of the rebuttal and the standard symbols for ski trail difficulty deliberate? Good post, by the way. Even at this level, the site does a good job of making things clear for the non-scientist (such as, say, myself). -
cynicus at 06:37 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
Tobyjoyce, I haven't heard that statement before :-) I browsed around a bit and it appears that the Dutch have been making polders from marshes and lakes for over a 1000 years already (but possibly even 2000 years) where the first polders used gravity to drain the area into (tidal) rivers when their water levels were sufficiently low enough. It was only after 1400 that the first windmills arrived. The windmills were eventually needed because of the compaction of the peat soils (possibly some 2 meters!) due to water drainage and higher boezem water levels due to ever more polders draining their excess water into those canals. Among other things, the need for new polders was created by a fast growing population which needed fuel (from peat in those days) which eventually, due to several factors, resulted in the accidental creation of new lakes and reduced dry land area via erosion of the soft lake banks. This was one of man's earlier environmental 'disasters'. By pumping the lakes dry further erosion was prevented and created new fertile land as a bonus. Early geoengineering to counter environmental challenges at work and the Dutch master it! ;-) Creating and maintaining a sizeable polder is, ofcourse, not a task for a single person, so all who had a stake in the polder would usually cooperate (this period might be the source of your quote!). But not everyone is able to do so ofcourse, hence unions were established. Everyone with a stake was forced to pay to the union, an ancestor to the modern municipality, which in turn would ensure good maintenance. The unions would slowly start to merge into ever bigger unions called 'waterschap' covering multiple municipalities, creating a separate specialist government layer rather unique in the world. The first waterschap was created in 1255. Developing new polders became a profitable speculative business due to high land prices in the years 1550-1650 and more audacious new plans attracted ever more speculators. Eventually this bubble blew like many other bubbles to come when land prices dropped during the construction of polders causing often massive loss of private capital. It looks like the story of the Dutch polders holds some valuable lessons to the current generations which seem largely to have learnt nothing from history. I'm sorry about the length of this post, it got a bit out of hand. :-) -
Ned at 06:12 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
Heh. I wasn't referring to you, or to anyone else in particular. I was just using that as an example of the kind of remark that tends to hinder rather than promote useful discussions. -
Ned at 06:10 AM on 4 September 2010Urban Heat Islands: serious problem or holiday destination for skeptics?
Thanks for the link, Michael. I agree that it's important to know how significant BP's regression model is. However, it's also very important to know how representative BP's set of stations is. As I noted above, his stations show a much larger warming than other people's reconstructions using station data over the same decade. That bias seems like an indication that his stations aren't necessarily representative of the actual land surface record. That wouldn't be as big a concern if he were using gridding, kriging, or some other method to compensate for the irregular distribution of stations. As we recently saw in another case, the "cooling" he reported after just averaging a bunch of met stations in Canada turned out to actually be "warming faster than the world as a whole" once the spatial autocorrelation in his data was taken into account. If the F-statistic indicates very low significance for his model, then it's probably not worth bothering about anything further. (And in fact, my purely uninformed guess is the model is not at all significant.) But if the model seems prima facie strong, I'd like to see a map of the stations used, or a table of their coordinates, or something like that. -
werecow at 06:03 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
#29 Ned I wasn't getting riled up, I was just rolling my eyes a bit, and hoping I was being Poed. }|Ned at 05:49 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
This is a good topic for discussion, by the way, if sensible people can avoid getting riled up over silly remarks like "just another attempt to scare up more support for the warmista agenda!" It's an area where the science is genuinely still being worked out, and where there really is more fertile ground for genuine skepticism.michael sweet at 05:47 AM on 4 September 2010Urban Heat Islands: serious problem or holiday destination for skeptics?
BP: Since Dr. Hanson has shown here that the warming trend in the rural stations and at very dark stations is the same as at stations that have large urban developments, how can you claim that you have something worthwhile? You have cited a blog post on WUWT as your primary source. You claim your correlation is "not very strong" without saying what the correlation is. You have not said anything that Dr. Hanson has not already shown in a peer reviewed study is wrong. "I think" is no better than "I doubt it" if you have no supporting data. Your claim that one person moving into a 10 km2 area would raise temperatures significantly is completely unbelievable without solid data. Extraordinary claims require extraordinary proof. You have "not very strong" so far. That doesn't make the grade.Ned at 05:38 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
Since I tend to be harshly critical of many of BP's do-it-yourself analyses, let me say that I think his graph is pretty robust this time. It doesn't matter whether you use a 25-year smoothing, 10-year smoothing, or no smoothing. It also doesn't matter whether you just count the number of hurricanes, add up their category #s, or only look at major storms. There isn't really any long-term trend in hurricanes making landfall on the US. Now, maybe "hurricanes making landfall on the US" is not a good proxy for global tropical cyclone numbers, I don't know. But this isn't an issue of smoothing or of how you count the storms.Rob Honeycutt at 05:15 AM on 4 September 2010New presentation debunking Monckton's critique of IPCC predictions
factfinder... Can you direct us to where the greenhouse effect was disproved in 1909?Berényi Péter at 05:13 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
#24 Turboblocke at 03:38 AM on 4 September, 2010 what does that do to the trend, as it dilutes the recent rise? Ten year running average looks like this:
There is a recent rise indeed, but it's a far cry from being unprecedented. More like a recovery, even if it is a bit fainter than the scary surge around 1880.
See The Deadliest, Costliest, and Most Intense United States Tropical Cyclones From 1851 to 2006 from NOAA National Hurricane Center.
BTW, there are only three category 5 hurricanes on record that made landfall in the US.
1935 "Labor Day"
1969 Camille
1992 Andrew
Years with category 4 storms: 1856, 1886, 1893, 1898, 1900, 1915(2), 1919, 1926, 1928, 1932, 1947, 1954, 1957, 1960, 1961, 1989 and 2004. Again, no increasing frequency is seen.
werecow at 05:08 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
Dammit, I must not have been fully awake when I read that graph. Though in fairness, I wasn't the one making the comparison. Anyway,in that case, BP's findings directly contradict what I've heard in talks on this issue and read in sources like the 2008 CCSP report, at least on Atlantic hurricanes (although I'll admit that my investigation into this issue has been somewhat limited). I'd still like to see what it looks like with a lower amount of smoothing, though. As for your statement about the "last couple of years", this is too vague to tell me anything useful. If you're talking about ten years, then maybe it's relevant. If you're talking about two, then it's meaningless in this context. And I'd want to know your source for those claims. Also, I don't know if you were being facetious about "warmist agendas", but I'll just hope you were.citizenschallenge at 04:24 AM on 4 September 2010New presentation debunking Monckton's critique of IPCC predictions
Ditto to that. Great educational video. Keep them coming! Since we are on the topic of Monckton I'd like to mention my layperson's critique of SPPI and their braintrust Chris Monckton. I'm reviewing aspects of Monckton's message that are beneath the dignity of serious scientists to pursue. Claims and issues that are nonetheless relevant to the struggle against the "AGW is a Hoax" industry. If you curious please visit: http://citizenschallenge.blogspot.com Peter M.adrian smits at 04:13 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
Werecow We're talking apples and oranges here one is about frequency the other about intensity. Over the past couple years the worlds total cyclonic energy has dropped to at or near all time recorded lows.This is just another attempt to scare up more support for the warmista agenda!Rob Honeycutt at 03:39 AM on 4 September 2010New presentation debunking Monckton's critique of IPCC predictions
Alden is putting together some really great presentations here. I hope he keeps more of these coming.Turboblocke at 03:38 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
BP: it's all very well taking a 25 year average and justifying it by saying we're talking about climate not weather... but what does that do to the trend, as it dilutes the recent rise? What's the trend just using basic yearly data?tobyjoyce at 03:18 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
Cynicus, I concede your superior knowledge of the Netherlands. Diamond uses polders as a metaphor for the nations of the world as a whole. He quotes a Netherlands acquaintance: "You have to be nice to your enemies because he may be the one operating the neighbouring pump in your polder". I am sure polders could not have been maintained without co-operation within and between the people who live in them. If one fails, they all fail.davidwwalters at 03:01 AM on 4 September 2010Climate change: Water vapor makes for a wet argument
CBDunkerson@ 35, Thanx for replying.....I understand now the mechanism of how greenhouse gasses work. I guess my question now is why CO2 trumps water vapor as the prime greenhouse gas even though there is so much more water vapor in the atmosphere relative to CO2 and other greenhouse gases.Paul Magnus at 02:46 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
This is very confusing, indeed. The data (NOAA) analyzed below seems to suggest that in the NA the frequency is increasing. Not only is it increasing, but follows the temp variations pretty close. The analysis also tries to take in to account the reporting problem and appears to be pretty thorough. http://residualanalysis.blogspot.com/2010/04/intensity-or-frequency.htmlmuoncounter at 02:39 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
#16: "There is no increase in severity whatsoever, a slight decrease, if anything. " I still maintain, as I did the last time this came up, that this isn't a valid measure. Ask anyone who lives on the Gulf Coast: a season with 3 cat 2 storms is NOT more severe than a single cat 5. And tropical storms, which are missing from your severity index are counted in number making landfall -- as they should be. The supposition that older storms are uncounted is just that -- supposition.dana1981 at 01:34 AM on 4 September 2010Quantifying the human contribution to global warming
Lots of comments to respond to overnight. RSVP - I'm not sure why you think the CO2 radiative forcing is dependent upon the atmospheric temperature or solar irradiance. The solar forcing is a different calculation entirely. The CO2 forcing should just depend on the increase in atmospheric CO2 concentration, as the formula shows. HumanityRules - yes, the warming from a doubling of CO2 alone should be about 1.2°C. However, climate sensitivity takes into account all variables which change in response to increasing CO2, not just water vapor. I'll be working on a rebuttal on "climate sensitivity is weak" this weekend which will discuss this to some degree, but estimates of the value are based on empirical observations, among other things. It's not just the water vapor feedback which determines the sensitivity value. As for the Arctic study you reference, unfortunately I don't have access to the full paper. However, they suggest that when the Arctic warms, the Antarctic should cool. Currently both are warming, which would seem to throw a wrench in the spokes of this natural warming theory. TOP - as Ned shows, CO2 is not saturated. Additionally, if you check the formulas in this post again, you'll see that it's not a linear relationship between the radiative forcing and CO2 concentration, but a logarithmic one.werecow at 01:29 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
Ah, yeah, sorry, I Guess I missed the part about assigning it to the middle year. You compiled these data yourself? Could you post the ten year running mean for comparison purposes?Ned at 01:28 AM on 4 September 2010Urban Heat Islands: serious problem or holiday destination for skeptics?
Berényi Péter, there are a number of lines of reasoning that suggest that the eventual "downstream" impact of UHI on global temperature trends is pretty small. Given that, it's hardly surprising that most scientists who hold that view haven't focused on trying to quantify this effect better. There are plenty of problems worthy of investigation in science. What seems interesting and important to you won't necessarily seem equally interesting and important to others. But that doesn't address KDKD's question! Given that you have done a regression analysis that seemed convincing enough to be worth writing about here, what was the statistical significance of the model? You did the regression; I assume you must have the numbers for F-test, 95% CIs, things like that. Is your model relating population density and warming trend significant? You say the correlation between the two is "not very strong" ... can you be a little more informative than that?jdsykes at 01:25 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
Thanks for the reference to the Power Dissipation Index, which would seem to be a fairly critical piece of science. I would suggest that an article be written about the history of increasingly powerful storms, their impact, and projections. The insurance companies have already incorporated this into their operating models, as evidenced by the difficulty in getting homeowners insurance for coastal residences.Berényi Péter at 01:22 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
#17 werecow at 01:18 AM on 4 September, 2010 No, it runs up to 2009. The 25 year running average makes it look shorter. But anything less than three decades is just weather, not climate, is it?werecow at 01:18 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
#16 Your graph runs up to 1995. Pretty much all of the increase over normal values seen in the Pew Center graph comes after that year.Berényi Péter at 01:11 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
"this graph, also from the Pew Centre, shows a 40% increase in North Atlantic tropical storms over the historic maximum of the mid-1950" "North Atlantic tropical storm" is a very bad concept if it comes to history. Before the satellite era many such storms must have gone unnoticed. Hurricanes making landfall in the US on the other hand are pretty well documented, if not for any other reason, because of insurance issues. There is no increase in severity whatsoever, a slight decrease, if anything. You can check it here.
Berényi Péter at 00:44 AM on 4 September 2010Urban Heat Islands: serious problem or holiday destination for skeptics?
#34 kdkd at 00:20 AM on 4 September, 2010 Yes, pretty good job description. It's just not my job. In fact I am surprised it is not done already, because it is the only reasonable way to quantify temporal UHI effect on surface temperatures. Comparing trends for "urban" and "rural" sites is worthless.ianw01 at 00:25 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
I would suggest that the scale for the y-axis for the storm frequency plot seems like it was chosen to deliver a certain impression. How about a 0 to 16 scale to improve the appearance of objectivity? However in any case, this is a great summary. Some clearly unsettled science makes for a different tone to the discussion, which I enjoy.Ned at 00:21 AM on 4 September 2010Quantifying the human contribution to global warming
TOP writes: CO2 is about saturated so adding more has little effect compared to other GHG which are not saturated. Sorry, nope. This is a common misconception, however. See Is the CO2 effect saturated? on this site, or (for more detail) A saturated gassy argument (by Spencer Weart) ... or see the really excellent explanation of this issue over at Science of Doom: CO2 – An Insignificant Trace Gas? – Part Eight – Saturationkdkd at 00:20 AM on 4 September 2010Urban Heat Islands: serious problem or holiday destination for skeptics?
BP #34 Actually your analysis is worthless until you report the statistical significance of your regression model. What's the value of its F statistic (does it predict better than change)? What's the value and statistical significance of the correlation coefficient (i.e. is the slope significantly different from zero)? Until you report these key parameters, it's not actually possible to determine whether your model is any use at all.Berényi Péter at 00:17 AM on 4 September 2010Climate change: Water vapor makes for a wet argument
"when something else causes a temperature increase (such as extra CO2 from fossil fuels), more water evaporates. Then, since water vapor is a greenhouse gas, this additional water vapor causes the temperature to go up even further—a positive feedback" Not so fast. Water vapor distribution in the atmosphere is always uneven (it is not a so called well mixed gas). GHG effect also depends on its distribution (which is pretty fractal-like), not only on its quantity. If upon heating this distribution does not simply scale up, but gets a bit more uneven, WV "feedback" can easily get neutral or even negative. Any empirical data on higher moments of atmospheric humidity distribution? One thing is sure. The more uneven water vapor distribution gets, the higher the radiative entropy production of the Earth system becomes. In an open thermodynamic system with many degrees of freedom the maximum entropy production principle tends to hold. It is like self organized criticality (e.g. in sandpile dynamics). In even more simple terms as soon as some radiative flux gets "trapped" by GHSs, it punches a hole in the water vapor canopy where the excess radiation can freely escape to space. The exact mechanism by which it happens is not important, it should happen somehow due to pretty basic principles. Anyway, hot and humid air usually ascends, expands, cools down adiabatically, water condenses, latent heat released, precipitation falls down to surface, relatively hot dry air is released at cloud top, moves sideways, cools down radiatively to space, descends. It is a hole like the one I've mentioned above.Ned at 00:13 AM on 4 September 2010Urban Heat Islands: serious problem or holiday destination for skeptics?
Nice, BP. Of course, I have a lot of reservations and concerns about your analysis, starting with the question of how representative the data are. You've narrowed the GHCN list down to a fraction of the list, and the time period to a single decade. That's going to make your analysis quite noisy, I would expect. And in fact, the mean trend you find (3.2C/century) before you apply your population correction is quite a bit warmer than most of the land-only reconstructions for that same decade (1990-2000). The seven I looked at averaged 2.25C/century for the same period. So there are two possibilities -- either your station sample is unrepresentative, or your process does not provide a good estimate of the final impact of UHI on the gridded (or otherwise spatially weighted) land temperature reconstructions that other people are doing. If we assume that your subset of stations is representative, and the actual 1990-2000 land trend (after correction for UHI) really is 1.5C/century as you report, this would reduce the global (land/ocean) trend over the same period by about 12% ... from 1.87C/century to 1.65C/century. Given the various weaknesses in your analysis, I think this 12% is probably an overestimate for the effect of UHI on the global trend. I don't know whether it's as low as the 3% calculated above, but I would be very surprised if it's as high as 10%. Oh, yes ... I probably agree with BP's comment here: Perhaps satellite shots of night light distribution is a better proxy for UHI than population density trends averaged over administrative districts.HumanityRules at 00:08 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
Maybe an analogy to this might be a person found guilty of murder, sentanced to death, killed by the state only later to be found innocent. You're going to struggle to convinced everbody this is an example of justice working.HumanityRules at 00:04 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
There is another possible spin to this rather than this is the scientific method at work. It strikes me the real contention around this subject is the heat generated on the subject around 2005/2006. Maybe much less should have been made around the short number of years of rise, whether the data was flawed or not isn't really the issue. You also neglect to show that the past few years have been fairly ordinary storm seasons which I guess also makes it difficult to keep on screaming about the subject in the same way. It's really not good enough to say things are OK because we now have balance, the question should be what was the driving force of the frenzy in the first place.TOP at 23:57 PM on 3 September 2010Quantifying the human contribution to global warming
Looks nice until you put it in context including H2O.
CO2 closes off the right hand side of the H2O absorption band and CH4 contributes to the left hand side. One thing that is clear from this graph is that climate sensitivity changes with absolute temperature.
The total spectrum of all atmospheric gases is given in the bottom plot. This shows a "window" between 0.3 and 0.8 microns (the visible window), which allows solar radiation (without the lethal UV component) to reach the earth's surface. "Earth radiation", the upwelling infrared radiation emitted by the earth's surface, has a maximum near 10 microns. The total atmosphere plot shows that a narrow window (except for an oxygen spike) exists in the range of wavelengths near 10 microns.Iowa State
The effect of CO2 on absorption of IR and re-radiation is not linear as the equations above suggest. Once a certain level is reached adding another molecule has much less effect. Think of window shades. Once they are shut, closing them more has little or no effect. Nor does a decrease in CO2 below 280ppm cause a negative forcing which the equation for dF suggests. The absorption bands (wavelength regions) for carbon dioxide are nearly saturated, but those for other gases are not, so one additional molecule makes a larger impact.
Iowa State
CO2 is about saturated so adding more has little effect compared to other GHG which are not saturated.
Iowa StateHumanityRules at 23:51 PM on 3 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
Thanks Graham "two recent peer-reviewed studies completely contradict each other" Is this Landsea and Holland? If not any chance of the references?huntjanin at 23:49 PM on 3 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
Cynicus (no. 10). Good post. I'm going to use Rotterdam as one of my "poster children of sea level rise." You seem to know a lot about the Netherlands: I'm guessing that you are Dutch. In any case, if you do know a lot about Rotterdam and sea level rise, I'd like to hear from you off-list. Email me, if you want, at huntjanin@aol.comNed at 23:34 PM on 3 September 2010How we know an ice age isn't just around the corner
You know, I don't think there's enough information in the graph above. Here's an improved version, with some additional content -- I've added in total solar irradiance (TSI).
Clearly, over the last 30 years, CO2 and temperature keep rising (green and red or dark-red lines), while PDO (blue) is fluctuating and solar irradiance (yellow) is stable or declining.
It should be noted that this kind of visual correlation is not actually how scientists attribute climate change. This graph doesn't prove that CO2 causes the observed warming. But the graph is certainly consistent with the claim that CO2 causes the observed warming, and that solar and PDO are not the cause.
So ... anything else we should add into this figure? There's still a little white space left in there....
:-)
Apologies for straying off-topic.
--------------
More fine print:
See above for sources of PDO, temperature, and CO2 data. Solar irradiance data from University of Colorado, shown annually and with a 22-year LOESS smoothing function.
cynicus at 23:08 PM on 3 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
tobyjoyce, a bit offtopic, but your polder-to-polder pumping strategy you described is not correct. Polders are usually surrounded by two ring levees with a canal in between the levees which is called the 'boezem'. Excess water from the polder is pumped into the boezem canal. The boezem canals are interconnected by even more canals, eventually leading to the sea or the IJsselmeer lake where the surplus water is pumped (or under free-fall via a 'spui' which is a type of sluice that can provide an open passage) into the Northsea. The water level in the boezems is approximately equal to the old lands and thus higher then levels in the polders (which used to be lakes), up to several meters. In times of drought or stale-water conditions in the polder fresh water can also be let in from the boezem into the polder, effectively reversing the flow of water. On the subject of AGW and sea level rise: Pumping is a lot more costly (in terms of construction, maintenance and energy use) then free-fall dumping of excess water into the sea. So as sea levels rise and the lands in the western Netherlands are slowly sinking due to isostatic rebound from the last ice age as well as compaction of peat soils due to deep level water extraction, the time excess water can be cheaply dumped in free-fall during low tides will shorten. Unfortunately rainfall is also expected to intensify, causing greater peak demands for water removal. These factors combined will require more pumping installations and more energy usage for keeping the lands (and polders) dry. Which, ofcourse, will cost society some serious money.Rob Painting at 23:03 PM on 3 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
Huntjanin @ 6 - indeed, storm surges have been the principal cause of salt intrusion into soils of the Pacific Islands for some years now. 2005 was a particularly bad year for powerful cyclones in the region. The Cook Islands were hammered by 5 cyclones in just over a month!. Check out some of the photographs here: Five Weeks of Fury I don't know if you're familiar with Niue, but my wife and I holidayed there back in the late 1990's. It's basically a giant rock thrust up out of the ocean. The Niue Hotel, where we stayed sits atop a cliff face perhaps 30 meters high. I fished off it a few times, it's quite a drop, the few fish I did catch fell back into the ocean. Anyway, cyclone Heta hit the island in 2004 & the accompanying storm surge completely obliterated the hotel room we stayed in. I couldn't believe it when I first saw the press coverage, 40 + meter waves!. If you have a look at these photos here, near the bottom of the page you can see the hotel manager standing outside, and the sea in the background gives some idea of how high above sea level it actually is. In fact most of the dwellings pictured are well above sea level - along the same cliff face. Must have very frightening when the highest point on the island is only about 60 meters above sea level.
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