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Tom Curtis at 08:03 AM on 22 June 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
Angusmac @31, as one of the "SkS faithful" (a condescending term I object to) I note that you actually wrote:"Illuminating post Dana but you neglect to mention that Hansen's Scenario C actually gives the best fit to the GISS temperature data, not Scenario B."
(My emphasis) I responded by showing that Dana had shown that temperatures tracked Scenario C best (contrary to your claim), but that if the predictions where scaled based on the ratio between the climate sensitivity of Hansen's original model and the mean of modern accepted values, temperatures track Scenario B - a point you do not acknowledge. That is an interesting point. What is neglected by deniers in their continuous attacks on Hansen 88 is that modern estimates of climate sensitivity have already been adjusted down relative to that model. Indeed, they where adjusted down in 1998 when temperatures where tracking well above scenario B even though forcings at that time where tracking below scenario C. That is because climate scientists look at the full range of data, and do not restrict themselves to try and falsify the whole theory based on the performance of an obsolete model from twenty five years ago. Interestingly, that obsolete model is still doing much better than it is given credit for. Currently GHG forcings are tracking almost exactly half way between Scenario C and Scenario B (see OP). The Scenario C prediction has a linear trend of 0.15 C/decade. The Scenario B prediction has a linear trend of 0.19 C/decade. Based on the ratio of forcings, therefore, we would expect temperatures to be tracking at about 0.17 C per decade. It turns out, once you correct for ENSO and the declining insolation over the last 30 years (not included in Hansen's forcings), that is exactly where the temperature is tracking:
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shoyemore at 07:18 AM on 22 June 2012Christy Exaggerates the Model-Data Discrepancy
I read the U of Guelph press release on the McKittrick paper, and I have to say it made me laugh. An economist claiming that his "simple economic model" made better predictions that a physical model... alarms bells ring straight away. It screams "cherry picking!". Just look at how succesful "simple sconomic models" have been in predicting what they are supposed to predict - the economy. -
cynicus at 06:07 AM on 22 June 2012Adding wind power saves CO2
@16 Paul D, yes, the cited paper was his PhD thesis, he has quite a list of publications but only few after having received his PhD. Afaik Bart currently works in offshore engineering at Siemens Wind Power A/S. -
Bob Lacatena at 04:38 AM on 22 June 2012Christy Exaggerates the Model-Data Discrepancy
I'm curious... who owns the UAH computer code? I understand that a university would not want to step on a researcher's toes in that regard, but could UAH step in and make the satellite interpretation code available, if necessary against Christy's and Spencer's wishes? -
dana1981 at 04:25 AM on 22 June 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
Fred Staples and angusmac - you're being distracted by curve C. Scenario C did not come to fruition, so focusing on that scenario becomes a red herring. It's true that coincidentally, temperatures have risen at a rate similar to Scenario C so far. But you're drawing the wrong conclusions from that. The main reason temperatures are following C is that Hansen's model was probably too sensitive to CO2 changes. If his model had a sensitivity of around 3°C, Scenario B would have accurately reflected the observed temperature change (or more precisely, a trend 16% lower than Scenario B, since the actual forcing has been 16% lower). By focusing on the coincidence that temps happen to have risen at a similar rate as Scenario C thus far, you're completely missing the point and failing to actually learn anything from Hansen 1988, as noted in the final section of the above post. -
KR at 04:25 AM on 22 June 2012Christy Exaggerates the Model-Data Discrepancy
pixelDust - I believe McKitrick's major misstep is more than sufficiently described by Gavin Schmidt at RealClimate, where he commented:"He makes the same conceptual error here as he made in McKitrick and Nierenberg, McKitrick and Vogel and McKitrick, McIntyre and Herman. The basic issue is that for short time scales (in this case 1979-2000), grid point temperature trends are not a strong function of the forcings - rather they are a function of the (unique realisation of) internal variability and are thus strongly stochastic. ... He knows this is an error since it has been pointed out to him before ... There are other issues, but his basic conceptual error is big one from which all other stem. - gavin"
[Emphasis added] -
Composer99 at 03:26 AM on 22 June 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
angusmac: There is rather a large difference between what dana1981 wrote in the OP and what you assert he wrote. He followed up the statement you quoted with: but actual emissions have been closer to Scenario B. This tells us that Hansen's model was "wrong" in that it was too sensitive to greenhouse gas changes. However, it was not wrong by 150%, as Solheim claims. Compared to the actual radiative forcing change, Hansen's model over-projected the 1984-2011 surface warming by about 40%, meaning its sensitivity (4.2°C for doubled CO2) was about 40% too high. which is rather different from what you were going on about on page 2 of this comment thread. I find it interesting that you have omitted reference to this comment thread (which fleshes out the SkS response to your claims) in your complaint about DB's moderator add-on just as you have omitted the rest of dana1981's statement in the OP. -
angusmac at 02:57 AM on 22 June 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
Dana, would you please let me know how you do it? You state in the post that, "The observed temperature change has been closest to Scenario C", and not a peep from the SkS faithful. I stated that, "Hansen's Scenario C actually gives the best fit to the GISS temperature data, not Scenario B" in SkS Lindzen Illusion #2: Lindzen vs. Hansen here. However, I was castigated by the Moderator (DB) and by the SkS faithful. You weren't. A typical comment against me was (by DB), " Repeating a misunderstanding does not unmake it as a misunderstanding ." Dana, I do not see any material difference between my statement and your statement. DB, is Dana repeating a misunderstanding? It just goes to show that it's not what you say but who says it. -
Lowcarbonkid at 02:32 AM on 22 June 2012Adding wind power saves CO2
Also, a very recent policy brief from the Grantham Research Institute on Climate Change and the Environment, which is chaired by Lord Nicholas Stern, author of the 2006 Stern Review and located at the London School of Economics, looked at the "back-up need" issue for wind turbines and found it to be a myth. In fact, they found that wind turbines are not too unreliable or expensive to contribute significantly to Britain's electricity generation mix, and that it is wrong to think that gas is a useful relatively low carbon fuel. There are three myths commonly repeated in anti-windfarm rhetoric: Myth 1: that there is a requirement for gas-powered backup to counter the unreliability of wind power. “This is plainly untrue," said Bob Ward. “Only 1% of carbon savings are wiped out, because there are many ways of managing both demand and supply due to the intermittency of the wind." The report says: "The cost penalty and grid system challenges of intermittency are often exaggerated. There are several other ways of compensating for the variability, such as bulk storage of electricity, greater interconnection, and a more diversified mix of renewable sources, as well as measures to manage demand, like smart grids and improved load management.” Myth 2: that onshore wind is expensive. “We found that it is the cheapest of all low carbon forms of electricity generation," said Bob Ward. The report says: “A key attraction of onshore wind over other low-carbon forms of electricity generation is cost. In terms of levelised cost – an economic measure which takes into account all of the costs of a technology over its lifetime – onshore wind is currently the cheapest renewable technology in the UK. The choice between more affordable electricity (which would favour onshore wind) and local environmental protection (which may favour other low-carbon technologies) is ultimately a political one." Myth 3: that using gas power generation is low carbon and will help us meet our climate commitments. “This is only true if we stop using gas in 2020," said Bob Ward, because at that point emissions need to drop further than relying on gas can permit. The report concludes: "It is clear that the further decarbonisation required in the 2020s cannot be achieved by heavily relaying on unabated gas power stations. Rational policy-makers need to anticipate this and avoid locking in high-carbon electricity generation.” “The thing is," continued Bob Ward, whom I interviewed on the topic, “those who have an agenda against wind farms then seek to find proof to back it up. They twist the evidence to make it fit." He says he finds the same misinformation cropping up again and again in anti-windfarm rhetoric. It gains credence by being repeated so often, for instance by the Global Warming Policy Foundation, the new Welsh group No To Wind and in the letters written by a hundred Tory MPs recently to George Osborne. -
Lowcarbonkid at 02:25 AM on 22 June 2012Adding wind power saves CO2
I, too, am very surprised by the figures on solar thermal and PV. The US Department of Energy (DoE)10 calculates that the energy payback for polycrystalline modules is four years for systems using recent technology and two years for anticipated technology. However, of course it very much depends where they are installed. Sunnier climates like North Africa will pay back their energy sooner than northern Europe. The DoE adds that on average amorphous silicon takes one to two years to generate the energy needed to make it, and three years including the frame and support structure for a roof-mounted, grid-connected system. For off-grid systems, the payback will be much longer. The DoE refers to findings by Dones and Frischknecht that PV-systems fabrication and fossil-fuel energy production have similar energy payback periods (including costs for mining, transportation, refining and construction). Assuming a system life expectancy of 30 years and that fossil-fuel-based energy was used in manufacture, 87–97 per cent of the energy that PV systems generate will be pollution-free. These figures were from 2004 or earlier, and so it is likely that they are shorter now. I quote it in my book, Solar Technology, where I also outline the other environmental hazards of PV. Thanks for the post, it is very interesting. -
pixelDust at 01:42 AM on 22 June 2012Christy Exaggerates the Model-Data Discrepancy
Thanks Composer. The entire paper is accessible for me using that link, though I now realize it's because I'm accessing the URL from a university (so anyone else in an academic setting should be able to access it as well; it appears to auto-detect if your IP is from a subscriber institution). I don't have a background in statistics, but I'm sure someone who does (and can access the full paper) can easily find any flaws, trickery, and obfuscation therein. -
Kevin C at 01:34 AM on 22 June 2012Christy Exaggerates the Model-Data Discrepancy
The first place I would look is the sign of the socio-economic influence on local temperature. If more growth leads to lower temperatures, then he may have discovered that aerosol emissions have a local impact, but are (AFAIK) modelled as a global term in climate models. In which case, it's something we knew all along. But he may have inadvertently come up with a way of improving climate model inputs. And bears not much relation to the press releases. -
Bob Lacatena at 01:26 AM on 22 June 2012Newcomers, Start Here
220, Brent, The key point you should take is probably that which Dan Bailey gave you, that CO2 levels are now at a point which has not been reached in 800,000 years, and the climate that went with higher CO2 levels was frightening. If you are taken to task on that, I'd point you towards my own post, (Fahrenheit) 451 ppm for a few different perspectives on just what 451 ppm of CO2 could mean. If you are taken to task for the source of CO2 in the atmosphere (your last post implied as much, even though your original post did not suggest it), that is the easiest thing in the world to refute, and anyone who clings to that position is in absolute, complete denial. CO2 Increase is Natural [There are lots and lots of other links on that, but I think that one gives the best overall summary of all of the various lines that put a nail in any idea that CO2 could come from anywhere but fossil fuels (and if it were... where the heck did the 337 gigatons of fossil fuel CO2 go to?).] -
Composer99 at 01:17 AM on 22 June 2012Christy Exaggerates the Model-Data Discrepancy
pixelDust: I can't access the full paper (behind a paywall), but the language in the press release appears to be a lot stronger than the language in the paper abstract. So I suspect in the first place that McKitrick is pulling a "Forbes" and overstating the findings of the paper in the press release. Second, if McKitrick's assertion is that climatologists do not account for land-use changes in either modelling or teasing out different forcings from the empirical data, it appears he is incorrect: from this rebuttal on Skeptical Science we are linked to NASA GISS summary of radiative forcings which quite obviously takes land-use changes into account. To be fair, it doesn't follow that newer GCMs do a great, or even a good, job of accounting for land-use changes. However statements such as McKitrick's: “A lot of the current thinking about the causes of climate change relies on the assumption that the effects of land surface modification due to economic growth patterns have been filtered out of temperature data sets. But this assumption is not true.” (in the press release) appear to be incorrect when the information from NASA GISS is considered. If memory serves the IPCC also has a summary table of radiative forcings, including land-use changes. I'm sure better rebuttals can be made, but that's just what sprang to mind for me. -
vrooomie at 01:12 AM on 22 June 2012Adding wind power saves CO2
ModComm@14...I *resemble* that comment!!!! >;-) -
bmac3130 at 00:55 AM on 22 June 2012Newcomers, Start Here
Please do not misunderstand. I am not the one questioning the science. I am a believer in the, what seem to me to be, obvious truths of global climate change and mankind's significant role in that process. The question I posted is from a thread I started on the environment in an Amazon discussion board and is one which one of the skeptics I have been talking with posted. Since I am a recent convert to believing there is a climate change problem occurring (I used to be right-wing, conservative, fundamentalist Christian pastor) I am not as well versed in some of the scientific data available as I would like to be. I ended up providing the questioner with a link to the National Research Council's "Climate Change Science" Report I then added this, "Here is a quote from the report which I provided a link for, which addresses some of the points which you brought up in your post. "That the burning of fossil fuels is a major cause of the CO2 increase is evidenced by the concomitant decreases in the relative abundance of both the stable and radioactive carbon isotopes and the decrease in atmospheric oxygen. Continuous high-precision measurements have been made of its atmospheric concentrations only since 1958, and by the year 2000 the concentrations had increased 17% from 315 parts per million by volume (ppmv) to 370 ppmv. While the year-to-year increase varies, the average annual increase of 1.5 ppmv/year over the past two decades is slightly greater than during the 1960s and 1970s." The key for me is the fact that while an increase of 1 to 2 ppm/yr. by itself would not raise temperatures greatly, the cumulative increase over time would begin to raise Earth's temperatures and cause greater issues. An increase of 55 ppm from 1958 to the time of the writing of this report is more significant and concerning. If these numbers continue increasing at the current rate of 1 to 2 ppm/yr. by 2058 the ppm levels of CO2 in the atmosphere will be between 415 ppm (low end) and 515 ppm (high end). (I did those numbers in my head as I was typing this so they might be off a little but I am pretty sure they are right). So, the increase in a one hundred year period between 1958 and 2058 would be 31.7% (low end) and 63.49% (high end). Now we are starting to get into areas of greater concern than simply stating that the increase is simply 1 to 2 ppm/yr." Thank you all for this site and for the information which you have provided me so far. :) Brent McCay -
Composer99 at 00:37 AM on 22 June 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
I probably know less about statistics than any other participant on this thread, but at least I can spot a fallacy of composition, such as: Dana, statististical significance for a trend does not depend on the length of the time scale. It depends on the probability (usually 1 chance in 20) that the observed trend is different from zero. Fred appears to assert that in noisy time series the chosen temporal resolution should not mask discerning the trend - and there lies the fallacy. In addition: My "moderated" posts are all based on original data, scrupulously tested courtesy of Excel. seems like comedy gold. -
Bob Lacatena at 00:03 AM on 22 June 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
Fred, 26, No. The divergence stems from comparing apples to oranges. Known differences:- Large differences in the amounts of other major greenhouse gases (CH4, CFC12, etc.)
- Incorrectly chosen climate sensitivity (4.2 vs. 3)
- Greater aerosols (see China)
- Lower solar output
- A recent, probably random spate of La Niña episodes
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pixelDust at 23:52 PM on 21 June 2012Christy Exaggerates the Model-Data Discrepancy
Speaking of "model discrepancies", please debunk this: Climate Models Missing Key Component of Temperature Changes One of the co-authors is a known AGW denier, so I have a strong feeling this is a case of "lies, damn lies, and statistics". The actual paper can be found here. -
Dikran Marsupial at 23:41 PM on 21 June 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
Fred, saying that "statististical significance for a trend does not depend on the length of the time scale" clearly suggests that you don't understand statistical power. If the timescale is too short for the test to have useful statistical power then the "Popperian test" is meaningless as lack of statistical significance is what we would expect to see even if the null hypothesis is false. Statistical power depends on the timescales involved, so if you want a fair Popperian test then you need to show that the timescale is long enough for the test to have adequate statistical power. If you want to suggest a fair Popperian test, then that is something that I would be very much in favour of. However the onus is on you to perform the analysis of statistical power required to show that the test is reasonable. -
Bob Lacatena at 23:40 PM on 21 June 2012Newcomers, Start Here
bmac, 19, [Please note that while most links are to Skeptical Science articles, virtually all include multiple references to peer-reviewed literature. But you're not going to understand the answer very often by taking one, single paper in isolation. Science is the body of work, as it is (well) understood by the people who do it every day. So you need the Skeptical Science articles to help provide introduction and context where you may be lacking in background knowledge. But Skeptical Science articles are very heavily cross-linked to supporting material. Follow the links.] There are so many fallacies in what you posted, both in the argument that you presented and the way the components that you posted, that I don't know where to begin. I will remember that your main question was on that puny 1-2 ppm CO2, but:...we know that the earth warms and cools in natural cycles...
This is the first "gotcha" that implies that (a) climate changes a lot (it doesn't) and (b) we don't understand those magical, mystical cycles. Both implications are dead wrong. Internal Variability It's a Natural CycleHas human activity been speeding up the warming...
This is like asking if you are still beating your wife. How do you answer? Human activity is not speeding up warming, it is causing warming. Without human activity the planet would be cooling right now. Solar activity is down, dimming aerosols are up. Lean and Rind (2008) Gillett et all (2012) It's not the sun...and create a run-away greenhouse effect?
This is denial-alarmism for a you, a strawman created to make the opposing position look ridiculous, by exaggerating it to the point where it is ridiculous. No one is saying there will be a run-away greenhouse effect. No one has to. A plain, ordinary 3˚C to 5˚C of warming can be catastrophic to civilization and people, all by itself. It won't be a runaway effect, but it can be very bad. Runaway Warming VenusOver 90% of that increase is from industrial processes...
Industrial processes that do what? Make cars, televisions, and plastic toys? Make ships and trucks and airplanes that move the cars, televisions and plastic toys? This is another strawman, making any effort to separate what you use individually. You are a member of society, a complex, interwoven, technological-industrial society. You use everything society creates, and that includes the tanks and the planes that guard your borders, even if you never sit in them yourself.So we would have to devastate industrial production...
More denial alarmism. The only people who say that taking immediate, deliberate action will devestate economies are denial-alarmists, who are trying to frighten you away from thinking clearly. CO2 Limits Economy Renewable EnergyCan you cite me some scientific literaure that would support the idea that a 1-2 parts-per-million increase in carbon dioxide would have a significant impact on the thermodynamic properties of the atmosphere?
First, this contains yet another debate-tactic, the implication that human contributions are so small on an annual basis that it can't possibly matter. CO2 is Just a Trace Gas But what really matters isn't the 1-2 parts-per-million per year, it's the 337 gigatons that mankind has added (split between the atmosphere and the ocean, which is another huge, huge problem all by itself). That raises CO2 from 285 ppm to currently 400 ppm. That's not 1-2, that's 115. That's not a small percentage, that's a %40 increase. "A significant impact on the thermodynamic properties of the atmosphere?" The question you are asking is covered by the body of scientific literature on the subject. No, scientists didn't write one nice, neat paper to explain it to your friend because they thought he might ask. They've written hundreds of thousands of papers, discussing various details including everything from climate sensitivity to radiative properties. In that light, I think that your question is best answered by reading (sorry, it's long, but really, it's necessary) Spencer Weart's The Discovery of Global Warming. This will tell you, in a rather easy to read format (given how dry the subject matter can be) how science developed, from the beginning to the near present, to the point where we understand fairly well (and continue to improve our knowledge, in spite of denial attempts to interfere with science and keep us in the dark):- The radiative properties of gases in the atmosphere
- The climate components of the atmosphere and ocean
- The impact of the sun
- Climate sensitivity and feedbacks
- Past climate change
- Everything else So... I'm sorry that the bottom line answer to your question is not "Hansen et al (2004) Everything Anyone Wants to Know About Climate Change in An Easy, 5 Page Peer Reviewed Paper." That's never going to happen. But everything your friend said, including the things he falsely implied, is easily answered. The information is there, and the falsehoods need to stop. If deniers want to argue about things, let them argue about real things, not made-up strawman arguments intended to frighten people away from thinking clearly.
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dhogaza at 23:35 PM on 21 June 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
"I make two assertions. One, it has not happened yet, and two, when the probability becomes vanishingly small we must reject the AGW theory." Or, we must reject Hansen's earlier 4.2C sensitivity to a doubling of CO2 as being too high ... which we already know it is. And there is no "AGW theory" per se. Expected warming is a consequence of physics and a wide range of knowledge of climate, paleo, past and present. You can't reject "AGW theory" without overturning 100 years of science covering a range of things. Good luck, Fred. -
Daniel Bailey at 23:24 PM on 21 June 2012Newcomers, Start Here
One must consider the fact that over the previous 400,000+ years, atmospheric CO2 levels have never exceeded 298.7 ppm:
[Source]
Additionally consider that the range of atmospheric CO2 from glacial to interglacial is about 100 ppm, which corresponds to a temperature range of 6ºC. This factors in time for the system to reach temperature equilibria with the CO2 forcings.
What is different now from previous interglacials is the injection of previously-sequestered CO2 back into the carbon cycle sufficient to raise global atmospheric CO2 levels by more than 100 ppm. And that this rise began with CO2 already at CO2 interglacial apex...
This is all documented on this website on many, many threads of the more than 4,000 threads that exist here. All with links to the published, peer-reviewed literature.
The Search function is your friend, and doorway to learning, at Skeptical Science.
We have embarked on a journey to a climate last seen in the Miocene or Pliocene, with no possibility of return to the preindustrial, stable, climate that saw the rise of agriculture and civilization:
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MarkR at 22:37 PM on 21 June 2012Adding wind power saves CO2
#19 bmac - there is a search function at the top left of the site, and you can go to the 'Most Used Climate Myths' section to look for particular claims too. The claim that it will 'devastate' economies is just not right, according to the economic analyses here. But I'm a natural scientist, not an economics one, and I feel much more confident answering the other comments. The human caused increase in atmospheric CO2 is now around 120 ppm or parts per million, from ~280 to ~400. There are 15 references here showing fingerprints of human caused global warming, but to start with I'd go here. The heating caused by CO2 has been calculated using physics and has been measured by satellites. Harries 2001, Griggs 2004 and Chen 2007 are all scientific articles reporting the satellite results. It seems unlikely that your questioner looked very hard at the science if he claims he didn't find these papers, or the hundreds of others that contradict what he said. -
Composer99 at 22:36 PM on 21 June 2012Christy Exaggerates the Model-Data Discrepancy
As far as I can see, tying any single weather event to global warming is a bit like tying an individual smoker's lung cancer to his or her smoking habit - you can't really do it. But as soon as you start looking at larger and larger groups of individuals - hey presto! The smoking gun (pun intended) emerges from the statistical noise. Likewise, I expect the global warming signal in the weather - the loading of dice, or the training of the boxer, so to speak - becomes clear when one reviews aggregates of increasingly large weather events. Indeed, if I am not mistaken that is the sort of thing Hansen et al 2011 (reviewed on Skeptical Science here) or the Cuomo & Rahmstorf 2012 paper (press release republished here) set out to quantify. -
mdenison at 22:16 PM on 21 June 2012Christy Exaggerates the Model-Data Discrepancy
Not the subject matter of this article but... from 'poised to come back and haunt us': "Heat buried in the deep ocean remains there for hundreds to thousands of years." from this article: "where heat is funneled into the deeper oceans where it remains only temporarily" Despite its title 'poised to come back and haunt us' does not describe the heat coming back, which is correct; It doesn't. I think a small correction to this article (erase 'where it remains only temporarily,' would help prevent a misleading concept getting established. PS. I suggest anyone wanting to comment on this should add comments to poised to come back and haunt us -
Fred Staples at 21:58 PM on 21 June 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
I do understand statistical power, Dikran, and the way that sample size reduces the probability of a type 2 error. But that is not the issue here. The divergence between lines A, B, and C stems from the CO2 driven AGW theory that Hansen built into his model. Lines B and C must continue to diverge, because Hansen line C assumes no increase in CO2 emissions after year 2000. Up to year 2006 the GISS. HardCrut3, B and C lines moved together. After 2006 B and C diverged, and the temperatures and the C line moved together, contradicting the theory. Now I agree that there is a calculable probability that the actual temperatures will one day leave the C line and head off along the B line. It is also certain that the greater the B to C divergence, and the longer temperatures continue to follow C, the lower will be that probability. I make two assertions. One, it has not happened yet, and two, when the probability becomes vanishingly small we must reject the AGW theory. -
CBDunkerson at 21:27 PM on 21 June 2012Arctic sea ice takes a first nosedive
Right there with you Sphaerica. One interesting thing with the thin ice this year was how early the Laptev Sea and Beaufort sea ice broke up. This actually appears to have been caused by relatively 'warm' water from the rivers (Lena and MacKenzie) feeding into those seas being sufficient to melt the ice. That's just shocking, especially for the Beaufort which used to be locked in thick ice. The projections showing that Arctic sea ice will continue to hold out for a few more decades (which are themselves a significant downward revision from the last IPCC projections) have seemed increasingly tenuous as the volume continued to disintegrate. If the volume trend continues, the ice will be gone (in September) within just a few years. As you note, the only thing preventing that at this point is the small core of older ice along the north edge of the Canadian archipelago. CryoSat II may have been launched just in time to observe the final few years of the Arctic disintegration... rather than to gather enough data to more accurately predict in what future decade that might occur. -
Paul D at 20:49 PM on 21 June 2012Adding wind power saves CO2
bmac3130@19 The actual contribution individuals make to CO2 emissions is greatly influence by where you live. So from a policy perspective, driving a car in the UK or US has a major contribution to emissions, but from a science perspective (eg, local CO2 emissions are less important than the total global concentrations) then an individual driving a car in the UK or US would seem less important. And there is the misinformation. In order to confuse the issue all one has to do is use the science perspective to imply local policy does not need to impact on the car driver in a developed nation. Hence the antagonist only has state that their car driving habit has little impact globally. Locally in the UK road vehicles contribute a massive 25% to UK emissions, but from a global perspective when the huge number of non car drivers are included, then vehicle emissions would seem small. Ironically the implications for the 'skeptic' is that they are implying they would need a world government to control car emissions. Where as the AGW proponent recognises a local policy needs. In order for a skeptic to consider national borders, they would need to accept local emissions factors and that their car driving habit is a big issue. -
Dikran Marsupial at 20:17 PM on 21 June 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
Fred Staples wrote: "Dana, statististical significance for a trend does not depend on the length of the time scale. It depends on the probability (usually 1 chance in 20) that the observed trend is different from zero." The probability that the observed trend being different from zero depends on the noise in the observations, on the size of the actual trend and on the amount of observations you have. It is fairly obvious even yo a non-statistician that the more noise you have, the more difficult it will be to detect a non-zero trend. Likewise the larger the trend actually is, the more easy it will be to detect if it is actually there. Similarly, a longer period gives more evidence on which to base the decision, and obviously it is easier to detect a non-zero trend if you have more evidence. The real problem with the statistics of trends is not in statistical significance, but a lack of statistical power (that is a statistical term with a specific meaning), which means that the probability of rejecting the null hypothesis when it actually is false is very small. This means that the statistical test is essentially meaningless as you would expect not to be able to reject the null hypothesis for short timescales even if the planet is warming at the rate suggested by the IPCC projections. -
Fred Staples at 19:43 PM on 21 June 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
Dana, statististical significance for a trend does not depend on the length of the time scale. It depends on the probability (usually 1 chance in 20) that the observed trend is different from zero. This depends on the signal (if any) to noise ratio. More precisely, on the variance explained by the regression divided by the residual variance. For example, Tamino in his post on diminishing Arctic sea-ice claims significance for 10 year data. My "moderated" posts are all based on original data, scrupulously tested courtesy of Excel. What has this to do with Hansen's predictions/projections? Very little. His projections are the nearest thing we have in Climate Science to an appropriate test in the Popperian sense. He makes predictions based on his theory, which can be tested by events. It is the temperatures that matter, Tom, not the CO2 predictions. Clear your mind, Dana, and look at the Real Climate Chart. The A line temperatures climb steeply after 1990, and head off the page. It was originally the "business as usual" but is now disowned. The B line, which Real Climate claim as the "real" prediction diverges sharply from both the C line and the actuals after 2006. To date the divergence is almost 0.5 degrees C. Actual temperatures are somewhat behind the "C" line, comprehensively contradicting the projections, and the science behind them. Now of course this may change. The "C" and "B" lines must continue to diverge, but the actual temperatures may change direction and move close to the "B" line. If this happens I will change my mind on AGW. If it does not happen, Dana, what will you do? -
MarkR at 18:57 PM on 21 June 2012Adding wind power saves CO2
#11 jimvj: it's worth bearing in mind that Kubiszewski brought together studies from as far back as the '80s and that for newer technologies, the probability of big leaps in EROI is higher. Sherwani et al 2010 considers mostly post-2000 solar PV reports and gets values of energy payback time of 1-3 years in most cases. Since the panels tend to last for decades, it seems realistic that modern solar PV could be somewhere around 10-30 EROI depending on how sunny your area is. Production efficiency, reduction in silicon use and higher efficiency panels needing less materials (double efficiency and you half the panel mass and all the framework etc) probably explain most of the advances since then. Whether there have been similar improvements in CSP I don't know. I have only really read about wind & solar because my country is building lots of wind farms, and my masters was on new electrical contacts for solar cells based on quantum tunnelling. Solar PV is just more fascinating to me! -
scaddenp at 17:59 PM on 21 June 2012Newcomers, Start Here
1-2ppm is not that significant, but 50-100 is and it adds up year by year. Adelady has given you a start but look at The Big Picture. It gives you lots of links and note also the sections on solutions. Your "90% is industry" is a false dichotomy. Who uses the power? A better and highly readable breakdown can be found at Sustainable energy without hot air. The effect of GHG on the radiative properties of the atmosphere has been known since Arrhenius, but the foundational physics can found in Ramanathan and Coakley 1978. Note that the model applies to any rotating planet not just earth. -
Thomas1 at 17:33 PM on 21 June 2012Adding wind power saves CO2
@bmac3130, The number of peer reviewed papers making up the body of evidence of AGW is significant. In order to find some guidance for an obvious novice like yourself I would recommend to use this website's Resources section: http://www.skepticalscience.com/resources.shtml where you will find all the science you will need for a good start on your quest. BTW: Since the industrial revolution we have gone from 280ppm to just about 400ppm now and are on a clear path to DOUBLING the CO2 content of the atmosphere in as little as a century and a half with significant implications to the climate, the ocean acidity and the future of our civilization. -
adelady at 15:58 PM on 21 June 2012Newcomers, Start Here
You could start with Climate Myth Number 30 Some good graphics extracted from a couple of papers and you can follow the research references from both the Intermediate and the Advanced versions. There's also the Intermediate version of Myth 33 Have a look at the whole list of Climate Myths and see if you can spot others that might give leads to the sort of thing that could help you. -
bmac3130 at 15:39 PM on 21 June 2012Newcomers, Start Here
I need help and am not sure where to ask this question, so I will ask the question here and if someone can redirect me it would be appreciated. I am in an online discussion on Amazon about climate change and I recently have received this post. It is the first one I have not known how to answer. Here is the posters question, any advice would be appreciated. "A couple of years ago I surveyed some of the scientific literature on global warming. (The actual scientific literature, not the NYT Science Column or something of that nature.) Now, we know that the earth warms and cools in natural cycles, and the question is "Has human activity been speeding up the warming, and has it done so to such an extent that it will overpower those natural cycles and create a run-away greenhouse effect?" The atmosphere is about 360ppm, that's parts-per-million, carbon dioxide. Due to human activity, this number is increasing by about 1-2 ppm per year. Over 90% of that increase is from industrial processes, and less than 10% is from the day-to-day activities of people, such as driving cars. So we would have to devastate industrial production, including agriculture and electrical generation to make a dent in that 1-2 ppm increase per year. Now, here is my question. Can you cite me some scientific literaure that would support the idea that a 1-2 parts-per-million increase in carbon dioxide would have a significant impact on the thermodynamic properties of the atmosphere? I don't want to hear "but all the scientists who receive large grants from the EPA agree", I want an actual reference to something published in a peer-reviewed journal that would support that statement about the thermodynamic properties of the atmosphere. Will you (or anyone else) please send me that information?" Thoughts? Or peer-reviewed articles which address this topic? -
bmac3130 at 15:38 PM on 21 June 2012Adding wind power saves CO2
I need help and am not sure where to ask this question, so I will ask the question here and if someone can redirect me it would be appreciated. I am in an online discussion on Amazon about climate change and I recently have received this post. It is the first one I have not known how to answer. Here is the posters question, any advice would be appreciated. "A couple of years ago I surveyed some of the scientific literature on global warming. (The actual scientific literature, not the NYT Science Column or something of that nature.) Now, we know that the earth warms and cools in natural cycles, and the question is "Has human activity been speeding up the warming, and has it done so to such an extent that it will overpower those natural cycles and create a run-away greenhouse effect?" The atmosphere is about 360ppm, that's parts-per-million, carbon dioxide. Due to human activity, this number is increasing by about 1-2 ppm per year. Over 90% of that increase is from industrial processes, and less than 10% is from the day-to-day activities of people, such as driving cars. So we would have to devastate industrial production, including agriculture and electrical generation to make a dent in that 1-2 ppm increase per year. Now, here is my question. Can you cite me some scientific literaure that would support the idea that a 1-2 parts-per-million increase in carbon dioxide would have a significant impact on the thermodynamic properties of the atmosphere? I don't want to hear "but all the scientists who receive large grants from the EPA agree", I want an actual reference to something published in a peer-reviewed journal that would support that statement about the thermodynamic properties of the atmosphere. Will you (or anyone else) please send me that information?" Thoughts? Or peer-reviewed articles which address this topic? -
Bob Lacatena at 13:56 PM on 21 June 2012Medieval Warm Period was warmer
Eric,I am not a scientist, so your complicated graphs and explanations mean very little to me.
Then you shouldn't have an opinion on the subject -- or rather, any opinion you hold is by your own admission an entirely uneducated one.Explain to me the definitive proof that shows there is a cause and effect scenario with CO2 and rising temperature.
And how are we to do that, when our "complicated graphs and explanations mean very little to" you? Sort of a Catch-22, isn't it? But everything you need is already here. All of the answers are here, if you're willing to look for them. You should spend less time lecturing, founded on an ignorant opinion, and more time studying. Or you can just go on believing what you'd like to believe, simply because that's in your comfort zone. That's where you're at now, that's where all deniers are (yes, all), and I rather suspect that that is where you're going to stay. Actual facts mean nothing to you. It's much easier to accept the (false) declarations that fall nicely in line with your predetermined beliefs than to work through all of those "complicated graphs and explanations." -
SoundOff at 11:03 AM on 21 June 2012Adding wind power saves CO2
A study questioning the need for back-up generation for wind power Wind power plants have been installed in the United States for long enough that detailed studies have been completed on the impacts and costs of its intermittency. A recent study concluded that, “...the results to date also lay to rest one of the major concerns often expressed about wind power: that a wind plant would need to be backed up with an equal amount of dispatchable generation. It is now clear that, even at moderate wind penetrations [up to 20%], the need for additional generation to compensate for wind variation is substantially less than one-for-one and is often closer to zero. … While wind power does have some costs associated with grid operations, it also has some advantages from the utility’s point of view, including short construction lead times, modularity, no emissions, and higher customer approval” - Utility Wind Interest Group (UWIG) “Wind Power Impacts on Electric-Power-System Operating Costs, Summary and Perspective on Work Done to Date, November 2003” [UWIG is a consortium formed by of a number of US utilities] http://www.scribd.com/doc/77535536/UWIGOpImpFinal11-03 -
DSL at 11:01 AM on 21 June 2012Medieval Warm Period was warmer
Let me briefly add to what scaddenp says: if you haven't read the science, and you claim to be a skeptic, then you shouldn't have any opinion on the science. Actual skeptics use evidence-based reasoning to establish event probabilities. With that having been said, my advice is to back away from the foregone conclusions and actually engage the science. Spend time with it. If you took the time to write on this blog, you must feel somewhat strongly about the issue. If you do feel strongly, make no assumptions, start with the basics, and ask questions. There are plenty of posters here willing to answer questions. Also, as scaddenp indicates, proxies are based on testable physics. Proxy data rules out a great deal of uncertainty. When astrophysicists determine the type of newly discovered extra-solar planets, they do not get clear resolution. They get a rough approximation. Yet even a rough approximation tells them that what they are looking at must fall within a certain range of physical phenomena. They're not looking at a dog or a beer can. Same goes with paleo studies. Because proxy studies are cross-referenced and anchored to known physics, the range of physically possible scenarios for a given point in time gets very slim. -
Tom Curtis at 10:56 AM on 21 June 2012Medieval Warm Period was warmer
Eric from Indiana @126: 1) The article does not say that all, or even nearly all deniers use this argument. It merely says that it is "one of the most cited arguments". Indeed, when I check the list of 173 denier arguments listed by frequency of citation, I find the closely related argument that that global warming is not anthropogenic because "Climate has changed before" is first on the list. The also related argument that "The Hockey stick is brocken" is 16th, and this argument is 30th. That certainly makes it one of the most frequently cited denier arguments. So, the claim in the article is accurate, and it is you who are being unfair "almost to the point of dishonesty" by putting words into others mouths. That, however, is a side issue for me. What I wonder is, do you argue against these claims when you see your fellow deniers make them? If you think the argument absurd, but sit in silence while fellow deniers make these claims, you show that truth is not what you are interested in. 2) No scientist has set out to expunge the MWP from the record books. Nor have scientists made conclusions based on very limited and dubious data. As an example, consider the following graph:
The important line for this discussion is the greenline, which is a temperature reconstruction excluding all tree ring data, and all data from proxies that have been considered dubious by deniers. It still shows a MWP that is cooler than current temperatures. The myth (and it is a myth) that you have been fed saying the temperature reconstructions are based on just one tree in the Yamal series are false. (The easiest clue that it was false was that it was made on a denier site.)
3) If you want proof that increasing CO2 increases temperature, read this post. Having done so, please point out the flaw in the logic. If there is no flaw, than increasing CO2 increases temperature.
Note, posting on Skeptical Science is a privilege based on your compliance with the comments policy. You have already violated several comments policy, and continuing to do so may well result in portions, or the entirety of future posts being deleted.
Finally, I have referred to you as a "denier". You may object to being classified by a stereotyped and negative description. You may even find it offensive. However, you yourself are using stereotyped negative descriptions ("alarmist") in your post, so I figure, "Sauce for the goose is sauce for the gander".
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scaddenp at 10:40 AM on 21 June 2012Medieval Warm Period was warmer
Whoops - forgot the link. Start with the Big picture -
scaddenp at 10:38 AM on 21 June 2012Medieval Warm Period was warmer
Eric, I'm a little unsure on where to start here. You are saying that your "your complicated graphs and explanations mean very little to me" so how much are you prepared discuss this really? Oddly, you readily swallow "that used only 12 trees in your tree ring data, including one freak tree to bend the graph favorably in your direction." How skeptical were you of that claim? What about proxy reconstruction that dont include trees? (and yet give same picture) As has already be pointed out, MWP is a/ different from today in that it occurred in different places at different times, b/ something that climate models reproduce from known forcings. This is not proof, but you cannot have proof in science, only in mathematics. What we do have is observation that are consistent with the predictions of climate theory. Furthermore, note that if it was hotter globally (little evidence to support this) than today, then this is evidence for high sensitivity and you should be more worried. "Explain to me the definitive proof that shows there is a cause and effect scenario with CO2 and rising temperature." Warning - this involves understanding some science but I doubt you would be visiting this site unless you had some interest in what the truth was. Start with -
michael sweet at 10:21 AM on 21 June 2012Adding wind power saves CO2
This newspaper article describes severe coal shortages in India. I have seen articles saying private companies in India are installing solar PV because it is the cheapest source of power during blackouts (which are usually during the day). New sources of coal for the life of a power station are difficult to obtain even in the US. Perhaps we will get lucky and coal will run low before we fry from AGW. Wind looks good now. The problem with wind is long transmission wires to bring it to many major cities. In the USA we have large resources for both solar and wind. I would be interested in seeing a study comparable to the OP that looks at Spain. Spain has installed a lot of wind recently. In February Spain generated 22% of its electricity from wind. They have reached peak output of over 50% of electricity from wind at times. The linked newspaper article claims they saved a lot of money (power is apparently cheap in Spain) and didn't emit as much CO2. -
Composer99 at 10:19 AM on 21 June 2012Medieval Warm Period was warmer
Eric from Indiana: Suffice it to say, it doesn't strike me as properly skeptical behaviour to make claims of scientific incompetence or even malfeasance with regards to studies of the medieval climate anomaly without substantiation. -
Eric from Indiana at 09:37 AM on 21 June 2012Medieval Warm Period was warmer
"One of the most often cited arguments of those skeptical of global warming is that the Medieval Warm Period (800-1200 AD) was as warm as or warmer than today. Using this as proof to say that we cannot be causing current warming is a faulty notion based upon rhetoric rather than science." This is not fair. Almost to the point of dishonesty. I am a skeptic by nature. No, the Warm Period does not PROVE that the warming is not caused by man, but at the same time all the alarmists models do not prove that it is. You are putting words into half our mouths by claiming that all of us skeptics use this as evidence that definitively proves our point. That is far from the truth. The alarmists do themselves a great disservice to their cause by ridiculing their opponent for not jumping onto their bandwagon. You just make it more difficult for us to agree with you when you do this. You all were the ones that excluded the Warm Period to get more drastic results. You were the ones that used only 12 trees in your tree ring data, including one freak tree to bend the graph favorably in your direction. Why is it that the Medieval Warm Period is excluded as being an anomaly, yet this freak tree is considered good scientific evidence? Don't treat us skeptics all the same. We have different ideas and mindsets. I am not a scientist, so your complicated graphs and explanations mean very little to me. Because even with my limited knowledge of astrophysics, I know that all it takes is 1 little miscalculation to throw everything out of whack. Accurate temp records have only been kept for the last 100 years. So when you point to ice core records that shows "accurate" records over the last million years, forgive me if I don't jump to a conclusion from them. Explain to me the definitive proof that shows there is a cause and effect scenario with CO2 and rising temperature. Because I could just as easily do the same thing as this author did and point out the flaws in the logic of showing the rise in CO2 leading the rise in temperature during the 80's, and saying that is proof of cause and effect. Of course CO2 is going to continue to rise even if the temperature drops if the temperature had been relatively high for the previous 80 years. Yes the warming may have started around the same time as the Industrial Revolution, but this is also when accurate temperature recordings were beginning to be kept, as well as it was the same point in time when we began moving out of a 500 year cold period, which had been the coldest period in the last 10,000 or so years. Like I said, I am not a scientist. But I do understand the scientific method, and what I see with these models, and the definitive conclusions being made from them, goes against everything I been taught about the scientific method. -
Tom Curtis at 08:56 AM on 21 June 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
thepoodlebites @16, here are Hansen's projections for various GHG concentrations in 2011, and the current (2011) annual concentrations for those gases: Year: 2011 Actual Scen A Scen B Scen C CO2 (ppmv) 390.5 393.74 391 367.81 NO2 (ppbv) 322.5 334.1 329.94 313.93 CH4 (ppbv) 1810.5 2617.77 2234.52 1915.84 CFC11 (pptv) 240 1220.89 553.99 275.49 CFC12 (pptv) 533 2096.56 960.92 523.59 You will notice that for all values,the closest value is either Scen B or Scen C, and that only three values (CO2, NO2 and CFC12) exceed scenario C, with none exceeding Scenario A. There is no basis for being skeptical about actual emissions being closer to B other than a determination to ignore the evidence. -
Paul D at 08:23 AM on 21 June 2012Adding wind power saves CO2
Re comment 1 (cynicus). I think Bart Ummels was a post grad student when he wrote that report?? It did get a lot of publicity. Has he continued research in wind energy since then? -
Bob Lacatena at 08:09 AM on 21 June 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
It is just amazing to me that "skeptics" can't understand something as utterly simple as this, and that "skeptic-wannabees" latch so readily onto arguments like this one, without the slightest trace of skepticism (because if they had, they'd immediately see how silly this position is). Why is it that we never, ever see the skeptic sheep step up and say "wait a minute, that's not right." I mean, with all of the ridiculous arguments that are out there, how come not once do the skeptics go "wait, this is embarrassing." Everything from this constant attack on 1988 Hansen, to attacks on 1999 Mann, to Postma's nonsense... Really? Skeptics can't take any of these laughable arguments to task? Not one? -
Bob Lacatena at 07:36 AM on 21 June 2012Arctic sea ice takes a first nosedive
I have looked at this incessantly (really, I should get help) for years now. I have a list of bookmarks a mile long. I glance at but ignore the charts. I instead look at a number of different sites that show concentration and thickness. I also tend to try to watch the animations, to get more of a temporal/spacial sense of the change. And this year is NOT your father's Arctic ice melt. The starting point was very, very different, not in extent but in thickness, and the progression has been very different. I will not be at all surprised if the bottom completely drops out this year, but if it doesn't, it's only because it's laying the groundwork for the bottom to drop out next year. Two things matter (IMO): 1) The ice is now so thin and fragmented that wind and currents are making a major contribution to the process. This wasn't possible 20 years ago, because the ice was too thick and interconnected until too late in the season. 2) What really matters is each year's "annual progress" on the thick, mostly permanent ice off the north coasts of Greenland, Ellesmere Island and the Queen Elizabeth Islands. That ice looks to me like the foundation on which everything else rests. The end will come quickly when that fragments enough to drift out and be carried physically, by wind and current, in fragments, to places where it can more easily melt away. This year looks like it could be "that year."
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