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MA Rodger at 18:02 PM on 28 July 2011Ocean Cooling Corrected, Again
What is the conversion factor between watt/sq metre or joules/sq metre (used here) & zeta joules (used by Levitus & others)? -
davidh5040 at 17:38 PM on 28 July 2011CO2 is not a pollutant
CBDunkerson@23: Here are the definitions from Macquarie. pollution 1. the act of polluting. 2. environmental pollutants, such as motor vehicle emissions, industrial waste, etc. 3. the results of these pollutants, as city smog, etc. pollutant that which pollutes; a polluting agent. pollute 1. to make foul or unclean; dirty. 2. to make morally unclean; defile. 3. to render ceremonially impure; desecrate. Using the second definition of "pollution", we can get CO2 as industrial waste (in the sense of "anything left over or superfluous, as excess material, by-products, etc."), and therefore as an environmental pollutant. (Interestingly, this particular definition doesn't seem to include damage to the environment as a consideration). And so you are correct. I was largely persuaded by Tom Curtis and muoncounter, but this puts the icing on it by applying a more rigorous application of the authority I have proposed, without having to shift to other definitions. Thanks to you all for your contributions to this. I will now feel a little more relaxed about using the term in future (though I will still use it with care). Finally, one last appeal for patience and empathy: I realise the tremendous frustration at the poor quality of much of the discourse around this issue, but I do believe that there are many out there who genuinely hold different views or who genuinely don't know what to think. We need to make it as easy as possible for them to hear what we are saying... Thanks again all! -
Eclipse at 17:13 PM on 28 July 2011It's the sun
Hi all, Do you have a page dedicated to the Denialist claim that the IPCC itself admits it doesn't know what's happening with solar forcings at the following 2007 report page. IPCC 2.9.1 Uncertainties in Radiative Forcing -
Rob Painting at 16:43 PM on 28 July 2011Michaels Mischief #1: Continued Warming and Aerosols
Dana I didn't choose 1998 as a starting point - Michaels did because Kaufmann did. To be fair, Kaufmann chose it because "skeptics" like Michaels did! -
Chris Colose at 14:46 PM on 28 July 2011How we know we're causing global warming in a single graphic
Actually the TOA radiative forcing for both the sun and CO2 (as well as the potency of the water vapor feedback) are maximized in the tropics...note the spatial structure of the radiative forcing has a complex pattern even for a well-mixed gas. So it's not immediately obvious from simple conceptual thoughts of the forcing that any polar amplification should occur at all The climate sensitivity (for the same forcing) would be higher in the poles for a bare blackbody rock, based on the Stefan-Boltzmann law, where the hotter body must respond more sluggishly to the same input of energy. In reality, the polar amplification (for any forcing) depends on complex dynamical transport processes which "export" sensitivity from low to high latitudes, as well as thermodynamics (radiation, ice-albedo feedback, etc) which tends to produce polar amplification for a wide range of idealized cases and forcing. In the upper atmosphere, the tropics are amplified relative to the poles. See for example, Pierrehumbert RT (2007), The Hydrologic Cycle in Deep Time Climate Problems. Nature 419,191-198 Peter L. Langen & Vladimir A. Alexeev (2007), Polar amplification as a preferred response in an idealized aquaplanet GCM, Climate Dynamics DOI 10.1007/s00382-006-0221-x Ming Cai & Jianhua Lu (2007), Dynamical greenhouse-plus feedback and polar warming amplification. Part II: meridional and vertical asymmetries of the global warming, Climate Dynamics DOI : 10.1007/s00382-007-0238-9 Jianhua Lu & Ming Cai (2010), Quantifying contributions to polar warming amplification in an idealized coupled general circulation model, Climate Dynamics DOI 10.1007/s00382-009-0673-x Also the GISS output shows the patterns I described above as well for solar or CO2 forcing http://data.giss.nasa.gov/efficacy/ -
dana1981 at 14:08 PM on 28 July 2011Michaels Mischief #1: Continued Warming and Aerosols
Albatross @74 clarified nicely. I didn't choose 1998 as a starting point - Michaels did because Kaufmann did. I chose GISTEMP simply to illustrate that not all data sets agree on hemispheric trends - it was a contrasting example with easily accessible data. And as Albatross noted, I also showed the data since 1975, unlike Michaels, to show how the hemispheric trends have changed (I didn't plot the Hadley data for this period, but I did discuss it). I'm forced to conclude Eric's cherrypicking accusation is based on the fact that he didn't read the post very carefully. -
Tom Curtis at 12:57 PM on 28 July 2011How we know we're causing global warming in a single graphic
Chris Colose @26, thank you for your response. I notice that @14 you say:" No, a reduction in the pole-to-equator temperature gradient is one of the most robust responses to any global warming situation."
I have a problem with this in that, if you ignore feed backs than in increase in CO2 will decrease the temperature gradient, while an increase in insolation will increase it. That being the case, even if feedbacks result in a reduction of the gradient regardless, there should still be a difference in the change of the gradient in the two cases. Is that difference really not detectable in the models? -
Paul Magnus at 12:49 PM on 28 July 2011Earth's Climate History: Implications for Tomorrow
@15 i 2nd that. -
Chris Colose at 12:40 PM on 28 July 2011How we know we're causing global warming in a single graphic
Tom, If you take a look at the studies I cited, CO2 itself (directly) plays a very minor role relative to cloud cover development, precipitation, water vapor feedback, aerosol effects, albedo, and other factors like irrigation and soil moisture as you approach the regional level (see Engelhart and Douglas, 2005 for a discussion on Mexico's DTR for example). The shortwave component of the energy flux seems to exert a much stronger control through changes in aerosol burden (Wild et al., 2007; Makowski et al 2008). I think I can buy that large increases in sunlight would tend to enhance the DTR itself, in the opposite direction of the long term trend. One thing I haven't seen in many of these DTR studies is a consideration of the top of the atmospheric energy balance, as opposed to just the surface forcing. This seems, to me, to be a very incomplete view and I'm not convinced the authors in some of these works appreciate this. When the atmosphere is well-mixed vertically, radiative forcing at TOA has a greater influence upon the surface air temperature than forcing at the surface, since the atmosphere itself adjusting its OLR is a primary way that equilibrium is re-established in response to forcing. Much of this re-adjustment occurs in the high atmosphere, since the bulk of the boundary layer is optically thick due to CO2 and water vapor. -
scaddenp at 12:39 PM on 28 July 2011How we know we're causing global warming in a single graphic
I would have thought not quite so simple. Any warming invokes feedbacks, including water vapour though CO2 effect should be more prominent in cold, dry air, but at the poles there are other factors (especially Antarctica) to muddy the waters (eg ozone). -
barry1487 at 12:32 PM on 28 July 2011Michaels Mischief #1: Continued Warming and Aerosols
So Eric, you think the trend of each of the past two decades is statistically significant at the 95% confidence level? How did you work that out? -
Albatross at 12:16 PM on 28 July 2011How we know we're causing global warming in a single graphic
Anybody got some thoughts on Chemware's question posed @13? "Would not another signature of anthropogenic warming by greenhouse gases be that high latitudes are warming faster than areas near the equator?" Chris? -
Albatross at 11:52 AM on 28 July 2011Earth's Climate History: Implications for Tomorrow
Dr. Hansen, Thank you for a very clear, succinct and sobering account of a complex and potentially alarming situation. I very much appreciate (and admire and respect) everything that you have done regarding the science behind both natural and anthropogenic climate change. Not to mention the great progress that your dedicated and hard work has fostered in this field. Your efforts are especially noteworthy considering the relentless attempts to undermine your credibility and interfere with your work by 'skeptics' and those in denial about anthropogenic climate change. History will reflect very favourably on your admirable, professional and principled approach to this issue-- the same will not be true for Lindzen, Spencer, McIntyre, Christy, Singer and Michaels and their ilk. -
Tom Curtis at 11:49 AM on 28 July 2011How we know we're causing global warming in a single graphic
Chris Colose @17, are you saying that increased CO2 will not decrease the DTR, or that the decrease is small compared to other factors, ie, changes in aerosol load, and or changes in specific humidity? Further, do you have any comment on my points 1) and 2) @21. Am I getting the nuances right? -
Chris Colose at 11:48 AM on 28 July 2011How we know we're causing global warming in a single graphic
Tenney-- The sun can melt ice too :-) -
Tom Curtis at 11:45 AM on 28 July 2011How we know we're causing global warming in a single graphic
ptbrown @31, I think there is a crucial logical point that is often missed in popular discussion of the fingreprint of the greenhouse effect. That point is that no individual "fingerprint" is unique to the enhanced greenhouse effect. What is unique is the combined pattern of effects. It is also important to realise that the water vapour feedback, being itself an enhanced greenhouse effect will contribute some of the finger print of an enhanced greenhouse effect to any warming. It will, however, do so by counteracting the primary effect of many warmings, so while it means we cannot be simplistic in our analysis, it does not prevent fingerprinting analysis. With that in mind: 1) An increase in albedo due to increased aerosol optical depth will decrease the Diurnal Temperature Range, as will a decrease in Total Solar Irradiance. However, both of these phenomena will also cool the lower troposphere overall. Cooling the lower troposphere will also reduce average specific humidity, which will tend to increase the diurnal temperature range. So, to the extent that increased aerosol optical depth (or reduction in TSI) is responsible for the reduction in DTR, it is only because some other factor is increasing tropospheric temperatures more than they are tending to decrease them. 2) As it happens, global sulfur dioxide emissions have reduced since 1975. Therefore, to the extent that they do influence the Diurnal Temperature range (which is substantial) we would expect the DTR to have increased over that period. The fact that it has not suggests some other factor is causing the DTR to decrease. Thus we could divide the later part of the 20th century into to intervals. During the period 1950 and 1975 the two factors influencing DTR acted in concert to decrease it, while after 1975 one factor continued to decrease it, while the influence of aerosols was to increase it, with no net effect. This is in effect the reverse of the temperature trend. Between 1950 and 1975, increasing aerosols tended to cool the planet, counter acting some other factor that was warming it with a resulting very small change in global temperatures; while after 1975 both the reduction in aerosols and the other factor have tended to warm the troposphere, resulting in a sharp rise in temperatures. This other factor, which both reduces the DTR and warms is therefore an enhanced greenhouse effect. 3) If your argument at this point were valid, then it would also apply to the effect of aerosols. Hence in that you apparently accept the influence of aerosols on DTR, you are contradicting yourself. -
Albatross at 11:43 AM on 28 July 2011How we know we're causing global warming in a single graphic
My two cents worth on the DTR. In my humble opinion (and understanding) the reduction of DTR is theoretically a (subtle) symptom of an enhanced "greenhouse" effect. The problem with the DTR is finding a suitable dataset (and long enough) that has not been affected by other factors that might influence trends in DTR. I think that Braganza is one record saying that because of the myriad of factors that can affect DTR in the real world, it is not the most robust fingerprint of AGW-- note that does not equate to saying that it is not a fingerprint, or that the enhanced "greenhouse" effect has been overturned. If I recall correctly, Braganza considers the seasonal change in warming to be a far better and unambiguous fingerprint of an enhanced "greenhouse" effect. I suggest reading this informative post by Dr. John Nielsen-Gammon, as well as the recent paper by Zhou et al. (2010). At the end of the day, when we consider the body of evidence, a coherent and robust picture of an enhanced "greenhouse" effect on account of an increase of CO2 levels from humans burning fossil fuels emerges. As to which of the many indicators is the best or more robust, well that is open for discussion. -
Tenney Naumer at 11:32 AM on 28 July 2011How we know we're causing global warming in a single graphic
Nothing about retreating glaciers? -
scaddenp at 11:25 AM on 28 July 2011How we know we're causing global warming in a single graphic
I'm not that fond of any single phenomena being called a "fingerprint of anthropogenic warming". I think it would be better to think of the fingerprint as being a set of phenomena observed together. This is much more discriminatory power for comparing anthropogenic warming to natural forcing. Ideally you run the model with anthropogenic forcings, and then same model but with different natural forcings, all of the same strength and compare outputs. There is some data for that here and perhaps in the Hansen et al 2005 paper -
Chris Colose at 11:07 AM on 28 July 2011How we know we're causing global warming in a single graphic
muon-- Hopefully we'll gear future posts away from that meme, or at least clarify the many nuances. ptbrown-- Thanks! I got my B.S. there too, but am doing graduate work elsewhere. Room 1411 will be missed. -
ptbrown31 at 10:59 AM on 28 July 2011How we know we're causing global warming in a single graphic
10, Chris Colose Thanks for the support. By the way, I have seen your posts around the climate blogosphere before and I noticed you are at Wisconsin. I got my undergrad from the AOS dept in '08. Go Badgers! -
muoncounter at 10:58 AM on 28 July 2011How we know we're causing global warming in a single graphic
DTR looked better than a weak fingerprint on this prior thread. We are currently experiencing global warming. If an increased greenhouse effect is a significant part of this warming, we would expect to see nights warming faster than days. There have been a number of studies into this effect, which confirm that this is indeed the case. One study looked at extreme temperatures in night and day. They observed the number of cold nights was decreasing faster than the number of cold days. Similarly, the number of warm nights was increasing faster than the increase in warm days (Alexander 2006). -
Chris Colose at 10:53 AM on 28 July 2011How we know we're causing global warming in a single graphic
ptbrown-- There's a lot of examples of erroneous but popularly held notions that many people have :-) Don't blame the site too much, hopefully that will correct itself. Keep in mind that something not being a 'fingerprint' doesn't necessarily imply it is consistent with everything either. There's no indication that the trends in DTR are consistent with a pure natural forcing. Chemware-- No, a reduction in the pole-to-equator temperature gradient is one of the most robust responses to any global warming situation. -
muoncounter at 10:49 AM on 28 July 2011Earth's Climate History: Implications for Tomorrow
Sally #12: "Are we able to scientifically link the rise in extreme/severe weather events in terms of being attributable to climate change ?" That's a hot button issue. Most people will respond with a cautious 'maybe'; statements like the probability of extreme events has increased due to global warming. See the prior extreme weather thread for cautious discussion of 2010's events. The frequency of extreme warm anomalies increases disproportionately as global temperature rises. "Were global temperature not increasing, the chance of an extreme heat wave such as the one Moscow experienced, though not impossible, would be small" See this recent Scientific American series for this year's version: Increasingly, the answer is yes. Scientists used to say, cautiously, that extreme weather events were "consistent" with the predictions of climate change. No more. "Now we can make the statement that particular events would not have happened the same way without global warming," says Kevin Trenberth, head of climate analysis at the National Center for Atmospheric Research (NCAR) in Boulder, Colo. Is it a good sign that the language used by the experts is changing? Sorry, didn't mean to give you another reason to lose sleep. -
Chemware at 10:46 AM on 28 July 2011How we know we're causing global warming in a single graphic
Would not another signature of anthropogenic warming by greenhouse gases be that high latitudes are warming faster than areas near the equator ? This is the opposite of what one would expect from increased insolation, and is only explicable by a mechanism that increases the insulating properties of the atmosphere. -
Rob Painting at 10:44 AM on 28 July 2011How we know we're causing global warming in a single graphic
ptbrown31 - let me refine my comment. The DTR is weak evidence for the increased Greenhouse Effect, but insofar as a human 'fingerprint' on climate, that seems to be on far safer ground. This is evident in the 'weekend effect' in heavily industrialized areas for instance. The DTR undergoes change over the weekend when industrial sources of pollution abruptly drop. -
ptbrown31 at 10:40 AM on 28 July 2011How we know we're causing global warming in a single graphic
Rob - Yes, that is exactly how I understand it as well. It is also what the literature indicates. This is why it bothers me that SKS continues to imply that the DTR changes are a fingerprint of an enhanced greenhouse effect. It undermines the credibility of the site and I am a big fan of the site in general. -
Chris Colose at 10:34 AM on 28 July 2011How we know we're causing global warming in a single graphic
Sphaerica, Actually, there's nothing in ptbrowns post that indicates he doesn't know what he is talking about. Indeed, I believe he is mostly right in describing the complexity of the variations in the diurnal temperature range, and how it depends on cloud cover, vegetation, and in some studies, aerosol effects-- many of these forcings (or feedbacks) are of anthropogenic origin, but it's not obvious that increasing CO2 alone is a primary factor here, or that it is a significant attribution tool (see e.g.,Dai et al., 1999, J. Climate; Stone and Weaver, 2003, Climate Dynamics; Makowski et al., 2008, Atmos Chem Phys; Zhou et al., 2009, Climate Dynamics). -
ptbrown31 at 10:27 AM on 28 July 2011How we know we're causing global warming in a single graphic
7, Sphaerica - Please enlighten me of the errors that I have made rather than simply being dismissive and condescending. -
Rob Painting at 10:26 AM on 28 July 2011How we know we're causing global warming in a single graphic
ptbrown31 - actually there's far better case to be made that human-caused aerosol pollution explains the DTR trend, moreso than the increased Greenhouse Effect. It would also explain the patchy distribution of DTR trends. As aerosol pollution is short-lived in the atmosphere, local effects depend upon where the pollution came from and the seasonal atmospheric circulations (weather patterns). The massive increase in industrialization and growth after the 2nd World War pumped huge amounts of aerosols into the air. This would have served to decrease solar radiation reaching the Earth's surface - ergo daytime cooling. At the same time, the increased Greenhouse Effect would have kept nights warmer. After the clean air acts of the 70's were introduced, and sulfates particularly were dramatically reduced, days would have warmed up because of the increase in solar radiation now heating the Earth's surface. What we'd expect to see is an increase in the DTR range, and indeed that is what happened. The timing matches well. I'm covering all this in some posts on aerosols and 'Global Dimming/Global Brightening'. The DTR range as a GHG 'fingerprint' is not compelling IMO. -
scaddenp at 10:24 AM on 28 July 2011Earth's Climate History: Implications for Tomorrow
"Anyone know a ball park figure for the carbon footprint in switching our fossil fuel infrastructure to a sustainable one? " Lets look at two things that would make most difference. 1/ Stop building FF power stations. No immediate effect but once an aging power station has to be replaced, then the replacement generation needs to be non-FF type. Since you are only replacing stations that would be have to be built anyway, the carbon footprint of changing to sustainable is zero unless the carbon-footprint of renewable generation is significantly higher than than of construction FF power. Also, once you have around 50% of energy from non-FF, then carbon cost of construction would also start to drop off significantly. You do know that say windmills and solar very rapidly produce more energy than the cost of creating them? 2/Electrification of transport. If vehicles are replaced with electric ones at end of life only, then again, the carbon footprint of change neutral, then decreasing if energy of construction is from non-FF. -
Hopeful at 10:12 AM on 28 July 2011Earth's Climate History: Implications for Tomorrow
My background is health science not climate science. Thankyou to all the contributors to Skeptical Science for dedicated and heroic efforts in reporting and explaining the science. This nightmare is almost too difficult to comprehend, wakes me up at night in fear for my children's future and the future of millions of people in terms of food supply and wars - it is probably waking some of you up at night also. Up until now I had been telling people that 2 degree C was the guardrail - not so. Are we able to scientifically link the rise in extreme/severe weather events in terms of being attributable to climate change ? To me it seems like having a cohort of smokers and finding increased rates of cancer, stroke, heart attacks, peripheral vascular disease and emphysema as predicted by science. -
Bob Lacatena at 09:45 AM on 28 July 2011How we know we're causing global warming in a single graphic
6, ptbrown31,...I do not think...
Your post is riddled with errors. You seem to have a very, very weak grasp of how the greenhouse effect works, and as a result you draw many invalid conclusions from invalid premises and illogical arguments. I started to detail them for you, but really, it just became too much. I would strongly suggest that you put your cynicism aside and spend a lot of time studying and learning what is involved, and then make a judgment on this issue when you are actually qualified to do so. -
Paul Magnus at 09:14 AM on 28 July 2011Earth's Climate History: Implications for Tomorrow
"To me, food supply is the most serious risk. If a poor man runs out of food, he starves, if a man with a gun runs out of food, bad things happen." Bad things.... survival of the fittest.... -
Paul Magnus at 09:12 AM on 28 July 2011Earth's Climate History: Implications for Tomorrow
Anyone know a ball park figure for the carbon footprint in switching our fossil fuel infrastructure to a sustainable one? -
ptbrown31 at 08:58 AM on 28 July 2011How we know we're causing global warming in a single graphic
I have made the comment quite a few times at SKS that I do not think there is adequate evidence that DTR changes are due to an enhanced greenhouse effect. Here are my main points: 1) I have looked quite a bit and I have never found a peer reviewed article that attributes the observed change in DTR to an enhanced greenhouse effect alone. All of the references above either do not attempt to attribute the change in DTR to anything or they attribute it to cloud/aerosol suppression of daytime warming (while both tmin and tmax are presumed to be warming do to an enhanced greenhouse effect). This makes a change in DTR an anthropogenic fingerprint but that is very different than an enhanced greenhouse effect fingerprint. 2) the IPCC AR4 Summary for Policy Makers says the following: " A decrease in diurnal temperature range (DTR) was reported in the TAR, but the data available then extended only from 1950 to 1993. Updated observations reveal that DTR has not changed from 1979 to 2004 as both day- and night-time temperature have risen at about the same rate. The trends are highly variable from one region to another. {3.2}" They are saying that DTR has not changed during the time period when greenhouse warming is thought to have been largest. This certainly does not seem to support DTR changes as a signature of an enhanced greenhouse effect. Not to mention, if it really was a signature of an enhanced greenhouse effect wouldn't that have made it into the report? 3) The following conceptual model seems over simplified: " This is because at night, the Earth's surface cools by radiating heat out to space. Greenhouse gases trap some of this heat, slowing the night-time cooling." For one thing the earth is always radiating heat to space and it actually should radiate more heat to space during the day when its warmer. Therefore it does not seem obvious why an enhanced greenhouse effect should cause more warming at night than during the day. I believe the argument goes something like this: "relatively speaking, nighttime temperatures are effected more by the greenhouse effect because daytime temperatures are a product of solar radiation + back radiation whereas nighttime temperatures are dominated by back radiation." My main issue with this is that it seems to imply that Tmin and Tmax are independent. They are not. The greenhouse effect suppresses cooling at night but then when the sun comes up it will cause the temperature to begin rising from wherever nighttime cooling left off. Therefore any suppressed cooling at night should feed back into daytime warming and thus effect the tmax as much as tmin. -
John Hartz at 08:54 AM on 28 July 2011Michaels Mischief #1: Continued Warming and Aerosols
If Eric the Red is just regurtitating stuff that he has previously posted on other threads, why indulge him on this thread? SkS is not obliged to provide a forum for repeat performances. -
spencerd at 08:41 AM on 28 July 2011CO2 limits will harm the economy
In a recent press release, Lord Monckton claimed:- "Forestalling all of the 0.24 C° global warming predicted by 2020 would demand almost $60,000 from every man, woman and child on the planet. That cost is equivalent to almost 60% of global GDP to 2020. He repeated these figures at his National Press Club debate. Treasury modelling states that the carbon tax will reduce Australian GDP by 0.3% in 2020 ($171 per head per annum)and reduce our CO2 equivalent emissions by 25% over business as usual. Why should a global solution cost 60% of GDP? Not surprisingly, Monckton employs a number of "tricks" to exaggerate the cost of a climate change solution. Firstly he calculates the cost of implementing a solution with NO manmade CO2 emissions. This raises the cost to 0.3%*4 =1.2% of GDP. Next he uses the reduction from 2000 levels (5%) instead of the reduction from business as usual 2020 levels(25%). That multiplies the result by another factor of 5 to get to 6% of GDP. This is still not large enough, so Monckton calculates the gross value of the tax rather than the impact on GDP. Even when calculating the gross value of the scheme, he adds both the tax received and the expenditures from the tax (such as administration, renewable energy support and coal and steel support). By this means, Monckton estimates the net cost of the current scheme as $13 billion per annum or 1% of GDP instead of Treasury's figure of 0.3% This calculation brings Monckton's calculation of the global abatement cost up to 20% of GDP but Monckton has a few more "tricks" up his sleeve. Monckton assumes that the carbon pollution measures only the impact of CO2 - 51% of manmade forcings. He therefore doubles the cost again to allow for eliminating all the other manmade forcings such as methane - bringing us up to 40% of GDP. Of course the Australian carbon tax does tax methane emissions ( as the coal industry will attest to ). Monckton understands that Australia has 2% of global GDP but contributes only 1.2% of global CO2 because we have high energy efficiency. He therefore implicitly assumes that the cost of abatement in countries with low energy efficiency would be the same as Australia's. Multiplying 40% by 2%/1.2% brings Monckton up to his 60% of GDP. Just in case all the tricks haven't been enough to scare the public, Monckton has one last card to play. He calculates the cost per head over a 10 yesr period rather than a cost per year. The cost per head becomes $59,000 instead of $5,900 per head per annum. The bottom line is that Australia will reduce its emissions by 25% over business as usual levels at a cost of 0.3% of GDP per annum or $172 per head per annum. I could only conclude that Lord Monckton deliberately set out to deceive his audiences with a patently ridiculous cost for tackling climate change. -
Tom Curtis at 08:25 AM on 28 July 2011Michaels Mischief #1: Continued Warming and Aerosols
Badgersouth @70, no! -
Albatross at 07:43 AM on 28 July 2011Michaels Mischief #1: Continued Warming and Aerosols
EtR @72, "You criticized Michaels for cherrypicking his datasets (CRU) and time frames (1996-), then you did the same thing (GISS and 1998-)." You are very confused, and wrong. Dana showed the GISTEMP data for the same period as the HadCRUT data 1998-2010. Had you read Pat's piece, is seems that you have not (or at least not properly) you will have noticed that Pat refers two different time frames in order to fabricate his deception: monthly HadCRUT data from November 1996 through 2010; and annual HadCRUT data from 1998-2010. Dana made it very clear that the GISTEMP data show a different story to the HadCRUT data with reference to Pat's cherry-picked 1998-2010 window. Unlike Pat, Dana showed data going back to 1975, not just for the cherry-picked 1998-2010 window. To achieve his deception Pat had to 1) Cherry-pick the data set, 2) Cherry pick the time frame. Disingenuous and deceptive at best. I could say more but doing that would violate the comments policy. Pat can play this game of cherry picking ad infinitum all the while the long-term and statistically significant temperature trend is UP. KR is correct, most "skeptical" scientists (e.g., Lindzen, Spencer and Michaels), are interested in advocacy, not the advancement of science. -
KR at 07:28 AM on 28 July 2011Michaels Mischief #1: Continued Warming and Aerosols
Eric the Red - Dana simply used available data to look at Michaels' claims in the context with which they were made. In my opinion (your mileage may vary) it's a decent article. "More work is needed to ascertain the temperature effect." (aerosols) Correct, although statements like this are often presented when someone wishes to use uncertainties to claim that we don't know well enough (or, alternatively, anything) to act upon. Michaels' statements about aerosols and their effects are really quite distorted - I would classify them as advocacy statements (from a PR person) driven by the desire to present a particular point of view on policy, not objective statements about the science. And hence Dana is quite right to show that even when Michaels cherrypicks recent data, he's still wrong - even with that small of a data set. -
Eric the Red at 07:12 AM on 28 July 2011Michaels Mischief #1: Continued Warming and Aerosols
Dana, You criticized Michaels for cherrypicking his datasets (CRU) and time frames (1996-), then you did the same thing (GISS and 1998-). There is enough scientific data to not argue on a similar level. Aerosols are a much bigger question, which needs to be answered. Michaels was referring to sulfate uncertainty, not sulfate effect. This was probably intentional on his part, and meant to confuse. The geographic dispersion of aerosols may very well be as Michaels claims. The atmospheric interaction between the hemispheres is limited. More work is needed to ascertain the temperature effect. -
dana1981 at 06:44 AM on 28 July 2011Michaels Mischief #1: Continued Warming and Aerosols
I'm a bit confused as to how I'm supposed to have cherrypicked anything. I showed the hemispheric trends in GISTEMP to illustrate that they're different from HadCRUT, and because they had the most easily-available hemispheric temperature data. Since when is it cherrypicking to criticize cherrypicking? I should also note that probably half of the post was about aerosols, which I don't think anybody has mentioned in the comments yet! Fortunately Rob P is working on a post devoted exclusively to aerosols, so hopefully we can get an interesting discussion the subject there without being bogged down in statistically insignificant cherrypicking silliness. -
John Hartz at 05:58 AM on 28 July 2011Michaels Mischief #1: Continued Warming and Aerosols
Out of curiosity, is Eric the Red arguing anything on this comment thread that he hasn't previously argued on the threads to other SkS articles?Response:[DB] Not AFAIK.
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muoncounter at 05:20 AM on 28 July 2011Did Global Warming stop in
1998,1995,2002,2007, 2010?
EtR#176: "These oscillations occurred about the linear trend, which has remained unchanged." That same linear trend, which you said was man made, is unchanged since the 1880s, 1910s, 1940s? Despite significant differences in man made and other environmental (forcing) factors? How strange. How unphysical. But your comment explains quite a bit; you are another 'line and sine' man. No physical mechanism exists to support this purely observational exercise, but then again, no mechanism is needed as you can rely on the mythic 'natural cycles'. What next, the harmony of the spheres? -
Eric the Red at 04:56 AM on 28 July 2011Michaels Mischief #1: Continued Warming and Aerosols
Barry, Statistical significance is understood to be the 95% confidence level. This commonly applies to standard deviations, t-tests, etc. -
Eric the Red at 04:48 AM on 28 July 2011Did Global Warming stop in
1998,1995,2002,2007, 2010?
Muoncounter, The two datasets show similar trends. The slope is the same for both sets (I use monthly data, but annual should produce similar results). The changes in slope that occurred in 1880, 1910, 1940, and 1970 are real; it is too soon to ascertain if a change har occurred in 2000. These oscillations occurred about the linear trend, which has remained unchanged. Tom, The oscillation could be fitted about an exponential trend. In this case the R2 for the linear would be 0.81, while an exponential would be 0.80, essentially no difference. Sphaerica, ( -Snip- ). We were comparing the periods of steep slopes, not the last decade which you pointed out were not part of the slope.Response:[DB] Inflammatory snipped. I suggest taking a deep breath to cool off prior to composing your messages.
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barry1487 at 04:06 AM on 28 July 2011Michaels Mischief #1: Continued Warming and Aerosols
Eric, could you describe what you understand statistical significance to be? It might clear the confusion. -
Eric the Red at 03:59 AM on 28 July 2011Michaels Mischief #1: Continued Warming and Aerosols
Albatross, I thought I answered all three of your questions. About what else were you inquiring? ( -Snip- ).Response:[DB] Argumentative & inflammatory snipped.
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John Hartz at 03:33 AM on 28 July 2011How we know we're causing global warming in a single graphic
I’m not particularly enamored with the following two sentences of John’s essay: “If the sun was causing global warming, it would cause summers to warm faster than winter, days to warm faster than nights and the upper atmosphere to warm. Observations rule out the sun.” Although the statements are correct in science-speak shorthand, they may not make sense to the average person reading the article. After all, the ultimate source of the infra-red radiation that is reflected back to Earth via the greenhouse effect is the sun. Perhaps John should tweak these two sentences.
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