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michael sweet at 22:57 PM on 27 June 2012Mercury rising: Greater L.A. to heat up an average 4 to 5 degrees by mid-century
Pierre: It appears to me that Daisym is challenging the OP, claiming that UHI has not been properly taken into effect. Perhaps I am incorrect, Daisym could tell me if that is the case. The link I provided was the first of many that show UHI has a small effect on these types of measurement. My reference "denies" nothing. They provide data that show the UHI effect is small. I could have cited Watts paper where they show "improperly" located weather stations have no effect on temperature trends. In general, UHI is a non effect that deniers cite to confuse people. AGW fake skeptics often raise tone questions of this type to suggest data issues that do not exist. What is your point? -
Paul D at 21:05 PM on 27 June 2012Adding wind power saves CO2
Cheers Shoyemore nice gentle ski slope there! -
Dikran Marsupial at 20:26 PM on 27 June 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
angusmac on what basis would you arrive at plus minus 20% or 30% range? Is this subjective, or is there a scientific methodology that you have used to arive at these figures? -
Pierre-Normand at 19:48 PM on 27 June 2012Mercury rising: Greater L.A. to heat up an average 4 to 5 degrees by mid-century
Michael, you seem to have misread both Daisym's comment and your own reference. Daisym didn't suggest that the UHI has the effect to bias temperature anomaly reconstructions. And your reference only denies that the UHI causes any significant such bias. That's in part because "urban meteorological observations are more likely to be made within park cool islands than industrial regions" -
angusmac at 19:26 PM on 27 June 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
Dikran Marsupial@49 When modelling semi-random systems, I would expect results in the ± 20% range to be good. However, for results that were significantly larger than the ± 30% range, I would suspect that there was something wrong with my physics. -
Fred Staples at 18:38 PM on 27 June 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
(-SNIP-)Moderator Response:[DB] Long, specious "What if...?" strawman rhetorical argument snipped.
You have been counseled against this line of posting, which constitutes sloganeering, previously. Continuance in this line of comment construction will necessitate a revocation of posting privileges. You will receive no further warnings in this matter.
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shoyemore at 17:31 PM on 27 June 2012Adding wind power saves CO2
You can get real time wind power data and CO2 emissions (calculated by a formula) from the Eirgrid website. Anyone who is in the business of refuting Udo & Co may find it useful. Eirgrid data The following shows CO2 emissions on the y-axis, and fraction of demand taken up by wind generation on the x-axis.
I had to split the data because Excel gets huffy with more than 32,000 data points.
Further calculations showed ~0.45tCO2/MWh, which I think is in line with industry expectations.
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scaddenp at 14:05 PM on 27 June 2012Hansen and Sato Estimate Climate Sensitivity from Earth's History
By the way, the albedo estimates and modelling used go back to Hansen et al 2007, which for input relies heavily on the accumulated data from multiple sources in CLIMAP 1981. -
scaddenp at 13:46 PM on 27 June 2012Hansen and Sato Estimate Climate Sensitivity from Earth's History
Past sealevel is important for determine land/sea boundaries in albedo estimates. In a glacial period, the ice-sheets on Eurasia and North America are major contributors to albedo. Antarctica and Greenland were frozen then as now so dont contribute much to change in albedo. Ice extent is from geomorphology etc. Sea ice extent is inferred from plankton in sediment core. Some species only occur in open water, others under ice. This leads to chemical biomarkers too. I dont have the papers but putting "sea ice biomarker" into scholar.google.com will give quite a few papers. There are a number of techniques used to infer paleo sealevel. Try here for coral reef work. Have you had a look at Chpter 6 of the AR4 IPCC? This links to many papers on this topic. -
curiousd at 13:17 PM on 27 June 2012Hansen and Sato Estimate Climate Sensitivity from Earth's History
Questions on great Hanson and Sato paper: 1. They estimate Albedo from sea level since the sea level is determined by the major ice sheets. Clever!! Sea level is unaffected by floating ice packs, of course, such as ice now floating in the Arctic (but not for long, unfortunately). So does this mean that the contribution of the Arctic sea ice pack to the albedo is negligible compared to Greenland and Antarctica? 2. How does one determine sea levels going back 800,000 years? -
scaddenp at 10:18 AM on 27 June 2012Glimmer of hope? A conservative tackles climate change.
Patrick, I believe what is meant by revenue neutral is that tax is collected on carbon emission and all of it distribute back on per capita basis. That way is it is not adding to government or redistributing wealth to the unworthy - concerns for the right wing. -
Patrick 027 at 09:37 AM on 27 June 2012Glimmer of hope? A conservative tackles climate change.
'inequities' probably a better word choice for last word of 2nd-to-last paragraph of my first of 2 prior comments; sorry for being nit-picky. -
Patrick 027 at 09:35 AM on 27 June 2012Glimmer of hope? A conservative tackles climate change.
... on national boundaries - the tax itself could come along with some tariff (somehow proportional to emissions (if all countries did this, then I think it would only be the emissions only in what was done to a product/service in the last country, not the entire upstream chain)/export subsidy (not proportional to emissions on a per product/service basis - why reward our own polluters just because another country would?) proportional to the tax and to differences among national policies. -
Patrick 027 at 09:29 AM on 27 June 2012Glimmer of hope? A conservative tackles climate change.
I'm curious about the logic of 'revenue neutral' here. Setting aside general justifications for government R&D for new technology, and some other things, following the concepts of an efficient market and externalities, the tax rate is justified by the public cost, so it would make sense to spend the revenue on those costs. Of course, the way in which the costs are realized is somewhat up to us even given a particular forcing scenario - relocation verses adapation in place, paying for injuries as the happen verses proactive actions. We could concievably spend the money now on adaptive water supply infrastructure - or those bits which we can design now given our climate knowledge (some additions might concievably have to wait until we know more details about where and when the rains will go, etc.). There could also be agricultural R&D. And some costs will be incurred by the government itself, of course. One caveat is that you would generally want to avoid spending money to subsidize innefficient adaptation means. One might want to pay compensation once for a reduction in property value suffered or for upgrades (but maybe only up to a point, since people (setting aside more caveats) already have had opportunity to retreat from coasts and drying and heating-up regions, for example), but wouldn't want to mask the price signals when insurance costs rise at some location, as that may encourage people to relocate to a less risky place. Maybe some mix between tax and dividend (equal per capita) and tax and cut other taxes could be seen as an economic investment, so that there will be more wealth in the future that can be taxed when public spending on the costs of climate change will be necessary, and also as a general compensation to people now for what they or their heirs may deal with later or for there proactive measures taken now, but there will be inequalities. And compensation, in some form, will eventually have to cross national boundaries... -
Tom Smerling at 23:51 PM on 26 June 2012Glimmer of hope? A conservative tackles climate change.
More conservative advocates of a revenue-neutral carbon tax: A short list of quotes from other conservative supporters of a revenue-neutral carbon tax can be found at CarbonTax.org. The Frum Forum hosts a Kenneth Silber post titled, "How the GOP Should Explain Climate Change," with a sample speech for a Republican candidate that includes a ringing call for a carbon tax: "My plan is straightforward and honest. We will raise taxes on carbon emissions across the board, while cutting taxes on payrolls and incomes. That means more money in people’s pockets, and more incentives for industry to develop cleaner and safer energy supplies." [links to the above can be found at the bottom of the original post at ClimateBites.) -
Cornelius Breadbasket at 23:38 PM on 26 June 2012Review of new iBook: Going to Extremes
99p here in the UK. And it is a brilliant piece of work and extremely good value! It is, however, rather depressing, particularly in the light of the failure of Rio. -
michael sweet at 22:52 PM on 26 June 2012Mercury rising: Greater L.A. to heat up an average 4 to 5 degrees by mid-century
Daisym This peer reviewed paper shows little effect from UHI on urban temperatures in the USA. Fake skeptics claim UHI causes everything. Can you provide a peer reviewed study that suggests UHI affects the result of the opening post or are you just hand waving? Hand waving arguments can be dismissed with a hand wave. In any case, UHI changes are well known to have little effect on decade level temperature changes. -
sol6966 at 22:49 PM on 26 June 20122012 SkS Weekly Digest #25
"Should SkS increase its coverage of the science of renewable energy?" In keeping with this site's MO, Sks could focus on Myths about mitigation options. For example, Renewable Energy, Energy Efficiency, CCS, Nuclear Energy. All these options have their Boosters and Detractors, as a result there are many Myths. I see Sks' roll in Debunking Myths about climate science as being very helpful in informing rational debate about climate change. I believe Sks could be just as helpful in informing rational debate about mitigation options. -
Jen at 19:46 PM on 26 June 20122012 SkS Weekly Digest #25
"Should SkS increase its coverage of the science of renewable energy?" I don't think so - better to concentrate on climate change itself, rather than the various mitigation policies. -
macoles at 18:41 PM on 26 June 2012An exponential increase in CO2 will result in a linear increase in temperature
Turns out GISS gave the highest warming acceleration. Here are my results for all the datasets using the same range and method as before: GISS 0.0579C per decade per decade, or +0.01C per decade every 21 months. UAH 0.0531C per decade per decade, or +0.01C per decade every 23 months. CRU 0.0301C per decade per decade, or +0.01C per decade every 40 months. NCDC 0.0273C per decade per decade, or +0.01C per decade every 44 months. RSS 0.0062C per decade per decade, or +0.01C per decade every 194 months. So while acceleration is apparent, it does look like there is not enough datapoints yet to get a value that all the datasets can agree on. -
Tom Curtis at 13:21 PM on 26 June 2012Hansen and Sato Estimate Climate Sensitivity from Earth's History
curiousd @27, if you want a record of the changes in forcings from different GHG over the last three decades, go here. You will see that CH4 and NO2 forcing rose consistently through to about 1998, after which CH4 forcing leveled of while NO2 continued to rise. In contrast, CO2 forcing rose slowly during the 1990s, but sharply after 2000. Consequently, and contrary to expectations, CO2 was less important as a contributor to warming in the 1990s than it was in preceding decades, and in the 2000s. That in no way challenges Hansen 81. Climate scientists do not, by virtue of their expertise, claim any greater ability to predict things like the collapse of the Soviet Union (the cause of reduced CO2 emissions in the 1990s) or global financial crises. That is why they make projections conditional on certain plausible scenarios of growth in forcings rather than predictions. Of course, fake "skeptics" insist, implicitly, that AGW is falsified because Hansen did not predict that when Reagan said, "Tear down this wall", Gorbachov did so; or that the early 2000's would be dominated by El Ninos while the last few years have been dominated by La Ninas. Real skeptics are more sensible than that.
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curiousd at 12:30 PM on 26 June 2012Hansen and Sato Estimate Climate Sensitivity from Earth's History
Input wanted on Hansen's year 2000 article in Proc.Nat. Acad. Sci 97, pp. 9874 - 9880. Please!! Here he says "..rapid warming in recent decades has been driven mainly by non-CO2 greenhouse gases (GHGs), such as chlorofluorocarbons, CH4, and N2O, not by the products of fossil fuel burning, CO2 and aerosols."" Wow folks, doesn't this contradict the seminal 1981 paper? What happened here????? -
Tom Curtis at 09:08 AM on 26 June 2012Hansen and Sato Estimate Climate Sensitivity from Earth's History
curiousd @23, relative humidity tends to be greater over ocean than over land, so increasing the surface area of the Earth's Oceans would indeed increase the relative strength of the Water Vapour feedback. It would also increase the strength of the negative feedback from the Lapse Rate feedback, which is the reduction of the Lapse Rate with increased humidity. The two effects do not cancel out, so that if the Earth was a 100% water world it would be warmer, all else being equal. However, it would not be sufficiently warm to initiate a runaway-greenhouse effect. The reasons why are discussed by Chris Colose here. The essence of the argument is that positive feedbacks reduce the outgoing radiation for a given surface temperature. If, but only if, the positive feedback reduces the OLR such that arbitrarily large increases of surface temperature are required to match the incoming solar radiation will you get a runaway feedback. For the Earth, with the water vapour/lapse rate feedback, effective insolation (insolation*(1-albedo) would need to be just over 320 W/m^2 rather than the current 240 W/m^2. The effective insolation needed to reach runaway greenhouse is called the Kombayashi-Ingersoll limit. Put another way, the Earth will only achieve a runaway greenhouse effect with current insolation if its albedo is reduced to 0.05 (give or take a bit for uncertainties). -
Bob Loblaw at 08:56 AM on 26 June 2012Mercury rising: Greater L.A. to heat up an average 4 to 5 degrees by mid-century
daisym: Well, UHI is usually a function of the logarithm of population (Oke, 1967), so the effect tapers off as growth continues, and it's usually caused by changing land use (pavement replacing natural surfaces, heat retention in artificial structures, etc.). How much more growth can the LA basin handle, and how much of it is still left in a natural state, to pave over? -
Eric (skeptic) at 07:50 AM on 26 June 2012Mercury rising: Greater L.A. to heat up an average 4 to 5 degrees by mid-century
The heat around the LA area depends almost entirely on offshore versus onshore winds. The global model cannot predict that pattern so they used downscaling. Reading through the study here http://c-change.la/pdf/LARC-web.pdf I see in the appendix that the offshore vs onshore parameters (alpha and beta) are determined from a minimizing the error between the global and regional models. Thus, alpha and beta are a function of three parameters from the global model (lapse rate, along with warming and ocean to desert contrast). The most obvious flaw is that the onshore vs offshore regime will depend on the larger climate pattern. For example the past winter's La Nina created more offshore winds. It does not appear that there is any connection from such climate regimes in the global model to the local model as they state in the paper the connections are mostly through temperature, contrast and lapse rate. Here's an alternative scenario: [LINK]Moderator Response: [RH] Shortened link that was breaking page formatting. -
daisym at 06:46 AM on 26 June 2012Mercury rising: Greater L.A. to heat up an average 4 to 5 degrees by mid-century
Los Angeles is one of the largest urban heat islands in the U.S. Is Alex Hall's predicted temperature increase for the L.A. region NET of UHI temp increases arising from projected population growth? What did Hall use as the projected L.A. temperature increase due to population growth through mid-century? -
cynicus at 06:37 AM on 26 June 2012Adding wind power saves CO2
Fyi, Fred Udo is great friends with De Groot and Le Pair, so don't be surprised when his 'science' appears as cherry-picked and deeply flawed like the others. He also trots out the false 'OCGT stations balance wind so CO2 savings are nil' argument. -
funglestrumpet at 06:23 AM on 26 June 2012Mercury rising: Greater L.A. to heat up an average 4 to 5 degrees by mid-century
They are lucky, The U.S.A. being one of the places in the world that will be least affected by climate change. Some poor sods stand little or no chance of adapting to it other than by burying their dead, of course. It would be nice if, when planning their adaptation strategies, these American experts could offer advice to their less fortunate fellow humans who live in parts of the world that will be most affected by it. Especially seeing as these people often have neither the expertise nor the time, what with subsistence farming to cope with, and Aids and water shortages and and and. -
miffedmax at 06:14 AM on 26 June 2012Response to Vahrenholt and Luning
One can only hope there is a special place in academic hell for those who repeatedly cherrypick the work of others to cite conclusions that are the exact opposite of what the original researchers conclude. -
Jim Powell at 03:04 AM on 26 June 2012Review of new iBook: Going to Extremes
It should show up in the Dutch store soon and the price should be $0.99U.S. or the equivalent in each currency. It will only work on an iPad, not in Linux. -
Bob Lacatena at 02:21 AM on 26 June 2012Hansen and Sato Estimate Climate Sensitivity from Earth's History
Here's the image from that link, changed to also include the atmosphere rolled into a ball alongside the oceans. Note that all of the biomatter on earth is an almost invisible spec, the size of one pixel, in this image:
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Bob Lacatena at 02:14 AM on 26 June 2012Hansen and Sato Estimate Climate Sensitivity from Earth's History
curiousd, No. It's really, really hard to get to a runaway. It has nothing to do with the surface of the earth, or how much water. Surface area means nothing, (everything is in units per square meter, it doesn't matter how many square meters in total). There's more than enough water on earth, too, the problem isn't that the system runs out of water. But there are negative feedbacks in place as well, the largest of which is the Planck effect... the hotter it gets, the more it radiates (power of 4), so it gets harder and harder to push that envelope. The "doubling" rule of CO2 applies to water vapor as well. Then there's the lapse rate feedback... as the earth warms, the lapse rate changes, and it becomes easier to radiate energy to space (i.e. more of the temperature change is higher up, where it can escape more easily to space). In the end, achieving a runaway is really, really hard. On how much water there is on earth... enough, but just for fun look at this. -
curiousd at 00:48 AM on 26 June 2012Hansen and Sato Estimate Climate Sensitivity from Earth's History
O.K. think I kind of dig it, esp thanks scaddenp who points out about the time step in the computer models respond to each temperature so the kind of effect I am talking about is IMPLICITLY calculated. One follow up question...I get the feeling from the old 1981 Hansen paper that his water vapor feedback on the CO2 initial temperature increase is positive but less than unity which is a really good thing!! The temp of the earth if no greenhouse gases would be given by (S is solar constant) S/4 = emissivity x stef boltz const x T^4, so the surface area of the earth cancels out. But if the surface area of the earth were larger, and it contained proportionally more water, then once the greenhouse effect were taken into account I suspect you could get closer to a runaway condition, even if distance from sun is same as in real case. Yes? No? (Here I am trying to see the kinds of things that go into the modeling....probably one of them is how much water there is on earth?) -
Bob Lacatena at 00:04 AM on 26 June 2012Response to Vahrenholt and Luning
renewable guy, Until the link is properly fixed in the post, you can find this excellent talk by the American geologist Richard Alley here.Moderator Response: [DB] All links fixed. -
Bob Lacatena at 23:40 PM on 25 June 2012Hansen and Sato Estimate Climate Sensitivity from Earth's History
19, curiousd, The short answer to your question is "yes." The long answer is that climate sensitivity (in addition to Tristan's distinction between transient, fast feedback and Earth System) is a lot of different things, because it doesn't really exist as some fixed universal constant. As explained previously, every system configuration will respond differently. In casual conversation and for simple box models we use a single scalar to represent sensitivity relative to a doubling of CO2. But in a physics based climate model, for instance, you don't tell it the sensitivity, you tell it how atmospheric water vapor responds to a change in temperature, and how temperature responds to a change in water vapor... and a hundred other things. Then the model plays out and tells you what the climate sensitivity is in that scenario, as a (grossly oversimplified) scalar value. So to answer your question more directly, if you are talking about a climate model, the non-runaway-vapor-thing is included as a matter of physics, and if you're talking about a simple scalar value from paleoclimate or other observational study, the non-runaway-vapor-thing is included because you're looking at the "end result difference," and if it's a value computed in some other way it includes the non-=runaway-vapor-thing unless the person who put the number together was stupid. -
macoles at 23:34 PM on 25 June 2012An exponential increase in CO2 will result in a linear increase in temperature
I was curious to see if global warming trend acceleration was noticeable in the Foster and Rahmstorf Trend Calculator. I used the GISS dataset option and Excel to plot 17 year trend values over 16 years (ie from 1979-1996 to 1994-2011). Here it is:
Excel's TREND function calculated the increase of these trends to be 0.0579C per decade per decade.
Another way to think of that acceleration is every 21 months the per decade rate increases by 0.01C
Extrapolating that rise to a 2012 midpoint indicates that the current rate of warming is around 0.26C per decade, which compared to the often quoted average of 0.17C per decade (over the period 1979-2011) is rather alarming.
Now I'm just a humble engineer with only a basic grasp of statistics and climate science, so I'll concede that maybe 17 year trends over 16 consecutive years is a bit too short or not enough data to pass a significance test, but the Foster and Rahmstorf datasets are far less noisy than the raw datasets that require 30 year trends.
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renewable guy at 23:28 PM on 25 June 2012Response to Vahrenholt and Luning
Is it possible to get the link to Richard Alley working? -
ajki at 21:49 PM on 25 June 2012Response to Vahrenholt and Luning
Thanks for keeping up the tedious work of myth rebuttal. German readers might be interested in a wiki especially dedicated to the book (KalteSonneCheck) by Vahrenholt, Lühning & Consortes, that tries to show the many gross misreprensentations by chapters (often recurring to SkS-pages along the way) - though this may be next to impossible to do since there are so many of them. -
Tristan at 21:19 PM on 25 June 2012Hansen and Sato Estimate Climate Sensitivity from Earth's History
curiousd What do you mean by 'real climate sensitivity'? There are three different 'lengths' of climate sensitivity. A) Transient Climate Response (TCR) is the warming due to CO2 equiv at the point at which CO2 concentration has doubled, assuming a 1%/yr increase. Central estimate is around 2.0. B) Fast-Feedback/Equilibrium Climate Sensitivity (ECS), the most used definition, takes quite a while to realise (hundreds of years after doubling) and includes the diminishing positive feedback due to water vapor and sea ice albedo. Central estimate is around 3.0. C) Earth System Sensitivity includes the slow feedback resulting from large-scale glacial retreat and the long-term ocean responses. It could be as much as twice the ECS and takes thousands of years to realise. -
scaddenp at 20:05 PM on 25 June 2012Hansen and Sato Estimate Climate Sensitivity from Earth's History
Electrical engineers see feedback and try to construct climate in terms of something they know. With multiple non-linear feedbacks operating on different time-scales, it doesnt work well. What you ask would happen - but implicitly - as at each time-step in the model, the systems would respond to current temperature. Note also the AR4 models did not include carbon-cycle feedback (what would big for ice-age) as far as I know. This is because feedback is assumed to be too slow to have much effect in the next 100 years. I believe some AR5 models are full earth system model with a carbon cycle. (I am echoing comments heard from climate modellers sorry which isnt the most reliable source). -
scaddenp at 19:53 PM on 25 June 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
Not to forget also that there a robust and not-so robust predictions from climate models. Sensitivity, especially short-term sensitivity is not so robust, especially in older models. If you want to talk about model/data comparisons, then better to talk about model skill (models predictive power compared to naive prediction). " Eventually they must diverge, and we will have to wait to see which line the actual temperatures follow." So at what point would you say that data has changed your mind? -
kampmannpeine at 19:47 PM on 25 June 2012Review of new iBook: Going to Extremes
I do not have Itunes because I am working under LINUX ... any idea to download the book (wine produces error-message und Debian Lenny Linux) -
curiousd at 18:27 PM on 25 June 2012Hansen and Sato Estimate Climate Sensitivity from Earth's History
O.K. I waded into one of the threads here on runaway greenhouse etc and found an incredible hornets nest of advanced electrical engineering analogues. Also found - I think - versions of my argument above which involves the simplest feedback model, maybe, with a positive feedback that is less than unity. So let me sharpen my question....does the real climate sensitivity include this effect of adding up increasingly smaller positive feedback terms in the water vapor feedback? Do real climate modelers include this effect? -
Paul D at 18:20 PM on 25 June 2012It's the sun
test comment -
Glenn Tamblyn at 14:26 PM on 25 June 2012Simply Wrong: Jan-Erik Solheim on Hansen 1988
Fred To talk about 'falsifying' something, to the extent that the concept of falsifiability can be applied, one needs to define what it is one is seeking to falsify. Are we going to totally falsify something if it doesn't behave exactly as predicted? Are we going to say that we may have falsified the extent to which it occurs rather than whether. Where there is a range of science involved in a 'hypothesis', do we need to falsify all those aspects? Or just one of them? and to what extent. If a theory makes multiple predictions and most of them are validated but a few aren't, does that mean the entire theory is wrong? Or that we don't understand certain aspects of it? Consider what AGW 'predicts'. 1. Rising GH gases will cause the Earth to go into energy imbalance wrt space. 2. As a consequence we expect heat to accumulate in various parts of the climate systems. 3. This will have some distribution over space and time. 4. Then these components of the system will then interact in ways that may redistribute some of this additional energy 5. These different components of the system are of quite magnitudes so interactions between the system components can have significant impacts on the smaller components compared to the larger components. So if the smallest component of the system happens to not behave quite as we expect for a moderate period of time what are we to conclude? Exactly what has been falsified? So what is happening to the climate systems? - The oceans are still absorbing most (90%) of the heat; several Hiroshima Bombs per sconds worth. - Ice is still melting, 500 GTonnes /year which requires more heat - that 3% of the extra heat - Temperatures within the Earth's surface crust are still rising slightly - thats about 4% of the extra heat - Atmospheric temperatures have risen as well (around 3% of the extra heat) but over the last decade have relatively plateaued. - Over the same period, thanks to the ARGO float array network we know that warming in the surface layers has plateaued as well because heat is being drawn down to deeper levels. - Simple thermodynamics says that if the upper layer of the oceans hasn't warmed much, the atmosphere won't warm much either. So with all this, what might possibly have been falsified (even allowing for the fact that a decade or so still isn't long enough to make that judgement let alone any statistical arguments)? Have the GH properties of those gases suddenly turned off? Is the Earth no longer in an energy imbalance? No! Heat is still accumulating unchanged. Just that most of it is happening, as it has for the last 1/2 century, in the oceans. And the amount of extra heat is too great to have originated from somewhere else on Earth. To have a lack of warming that might be statistically significant after some years to come, first you have to have a lack of warming in the first place. And we don't! 97% of the climate has continued accumulating heat unabated. And the other 3% accumulated it for much of that period but has slowed recently, for understandable reasons. So is there even a prospect from the data we have available to date that the basic theory of AGW might be falsified? Nope! No evidence for that. Is there a prospect from the data we have available to date that the aspects of the theory that tell us how much heat will tend to go into which parts of the system might befalsified? A small one perhaps. Heat is largely going where we expect it to. What about the possibility that the aspects of the theory that deal with the detailed distribution of heat within different parts of the ocean might be falsified? That although we have a good understand of the total amount of heat the oceans are likely to absorb, that our understanding of its internal distribution in the oceans, spatially and temporally might not be perfect. Yep, a reasonable prospect of that. Although at least one GCM based study - Meehl et al 2011 has reported the very behaviour we are observing. So is that what you mean by the falsification of AGW theory? That our understanding of how flow patterns in the ocean might change isn't 100 reliable? If that is your definition then I agree with you. We can probably already say that the statement that we can model ocean circulation with 100% accuracy has already been falsified. However the statement that we can model ocean circulation with reasonable accuracy and can model total heat accumulation in the ocean very well has definitely not been falsified; so far there is no prospect of that. And certainly the statement that we can model the underlying causes of the Energy imbalance of the Earth has even a prospect of being falsified any time soon is simply unsupported by the evidence. If you want to investigate evidence that might confirm or falsify the core theory of AGW, focus on the total heat content of the ocean. If that levels off then there really is something to talk about. But there has been absolutely no sign of that. If we need to wait x years for that key data to become significant wrt any 'lack of warming' then we are at year zero now. 'lack of warming' hasn't even started yet. Believe me, if total OHC data showed the sort of pattern we have seen in the merely atmospheric data (the 3%) over the last decade, that really would be BIG NEWS. And we would report it here, believe me! Unfortunately, it just ain't happening! -
scaddenp at 13:50 PM on 25 June 2012Ten Things I Learned in the Climate Lab
Which means the question cant be answered till pluvial tells us more. Embedding a WRF model into GCM is a cool idea for resolving process. -
Bob Loblaw at 12:36 PM on 25 June 2012Ten Things I Learned in the Climate Lab
Actually, PluviAL's question isn't that unreasonable. Do a google search on "Regional Climate Model" - there has been a lot of work of using a fine-mesh local grid in the region of interest (say, the continental U.S.) imbedded in a courser-grid GCM. -
Bob Lacatena at 09:54 AM on 25 June 2012Ten Things I Learned in the Climate Lab
PluviAL, Like scaddenp asks... what is the point of your questions? Climate models often work with lots of grid sizes (different for ocean, land, atmosphere). The world is also three-dimensional. Grid choices are made primarily for execution time (twice as many cells in the grid along its width and height means four times as many calculations, four times as many means 16 times the calculations, etc.). To go to a scale of 10 meters instead of 10 km, you have 1,000 times as many cells across, and 1,000,000 times as many cells in total. Climate models don't even run at scales of 10 km.. more like hundreds of kilometers, so your scale change would blow things way out of the water. No, you're not likely to find a computer on earth that will even get things done at the 10 km scale (although that's really not necessary, either). Sometimes what you are looking at doesn't require better resolution, and can even be confounded by it (it requires even more complex and detailed modeling of physical processes to resolve the interaction at the higher resolution -- things that can easily be dispensed with at larger resolutions). The CMMAP project is particularly interesting. One of the great problems in climate models is cloud behavior, because the scales needed to properly model clouds are far too small to be performed efficiently, and most climate attributes do not need that small scale. Their approach is to model the climate on an achievable scale, and to model clouds for just one small grid cell within the larger cell, and then to apply that result throughout the cell (effectively assuming that their single result will apply, on average, throughout the larger cell). -
piloot at 09:23 AM on 25 June 2012Review of new iBook: Going to Extremes
I Can't find it in the Dutch ibook store? -
peter prewett at 08:37 AM on 25 June 2012Review of new iBook: Going to Extremes
It may be $3.99 as per download link - then I do live in Australia which is costly!!
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