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Bob Lacatena at 06:51 AM on 17 June 2011How would a Solar Grand Minimum affect global warming?
16, Eric the Red,If a grand minumium occurred, and it was insignificant, then the role of the sun would be largely removed as a climate driver.
I'm not sure what you mean by that. The sun is clearly a climate driver... it's the energy input into the system, so notable variations in solar output will always have some effect. In a system without us mucking up CO2 levels, it would be the main and possibly only normal short term climate factor. But CO2 is going to overwhelm the sun as a climate driver in coming centuries. And there has been no impact by the sun on recent temperature increases. We don't need a solar minimum with rising temperatures to prove this. It's been proven already. [See the #2 denier argument, It's the Sun by clicking that link, or following the cute little denial thermometer at the top right of every SkS page.] My sole point is that the effect of a minimum in even marginally slowing climate change would have a very bad effect on human nature, allowing people to deny and delay even longer, while there would be no long term savings from such a minimum, because it would inevitably come to an end before all of the added CO2 has fallen out of the atmosphere. -
pbjamm at 06:29 AM on 17 June 2011How would a Solar Grand Minimum affect global warming?
Albatross@32 WOW. The lack of understanding represented in that article is staggering. Disinformer is an extremely accurate descriptor. -
Albatross at 06:21 AM on 17 June 2011How would a Solar Grand Minimum affect global warming?
And enter into the fray, a delightful and invective-filled rant by denier of AGW, Mr. Lorne Gunter at the infamous National Post newspaper. This is how "skeptical" journalists, with agendas, continue to massacre the science. "Skeptics" must be proud to have ideologues and disinformers like Gunter on their side... -
rustneversleeps at 06:04 AM on 17 June 2011Our effect on the earth is real: how we’re geo-engineering the planet
I really liked this post, thanks. In a similar vein, I thought that the visual Desdemonda Despair had up the other day was effective - Earth movement by humans and rivers.:
Earth movement by humans and rivers. Maps of the United States showing, by variations in peak height, the rates at which earth is moved in gigatonnes per annum in a grid cell measuring 1° (latitude and longitude) on a side, by (A) humans and (B) rivers. Hooke (1999) / EPA
Surface mining and reclamation have been identified as the dominant driver of land cover/land-use change in the central Appalachian coalfields and have produced significant changes in the region’s topography, hydrology, vegetation, groundwater, and wildlife (Townsend, et al., 2009; Loveland, et al., 2003; U.S. EPA, 2003, 2005). Coal mining in this region was identified as the greatest contributor to earth-moving activity in the United States (Hooke, 1999).
I also like this graphic, which shows that for the 77 of the 92 naturally occurring elements for which we have good data, anthropogenic flows through the earth system either outright dominate (i.e. account for more than 50% of the total flows (and implying that we are responsible for MORE than 100% of the natural flows!)) or account for between 15-50% of the total flow in 54 of 77 cases.
The data for that is from ELEMENTAL CYCLES: A Status Report on Human or Natural Dominance (R.J. Klee and T.E. Graedel, 2004). The graphic itself is from MIT Prof. Tim Gutowski’s lecture notes for “The Mobilization of Materials by Humans and Natural Activities”. (Warning: 45MB pdf… but some intriguing data points, visuals, etc.)
(Interestingly, carbon falls into their category of "unperturbed" - which is the old chestnut that our emissions are only some small fraction of overall carbon cycling, but still significant because the "stock" nature of the accumulation over time. And I am somewhat surprised that nitrogen is considered "unperturbed". I thought that we were fixing more nitrogen than all the natural processes on land combined. Is the amount cycled in the oceans so vast that our contribution is still less than 15%?)
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Daniel Bailey at 05:40 AM on 17 June 2011CO2 Currently Rising Faster Than The PETM Extinction Event
Nice post, Rob! Interested readers may want to follow on over to the Wakening the Kraken thread for even more information. -
Marco at 05:19 AM on 17 June 2011Our effect on the earth is real: how we’re geo-engineering the planet
There's an interesting article on volcano emissions compared to human emissions here. Please note that this is a pdf. -
Eric the Red at 05:04 AM on 17 June 2011There's no room for a climate of denial
Agreed. -
Utahn at 04:44 AM on 17 June 2011There's no room for a climate of denial
I think the "likely" is about certainty etc... but the consenus view on how much of the warming is "likely" or "very likely" due to C02 is probably somewhat reflected in the linked graph (neglected to mention its on page 16). I think the point I was trying to make, which we appear to agree on, is that not being able to change something may foster stronger denial, but the inability to change something is neither necessary nor sufficient for denial. In other words, assuming climate science is correct in that we are causing the great majority of the current warming with C02, we can change it. So the denial doesn't really come from any belief that we can't change it, it comes from the conflicts with our core values of believing in anthropogenic climate change etc... If someone says they believe we can't change our climate for the better, I'd say that stated belief is just an expression of their denial (which is likely caused by a deeper conflict such as mentioned in my last post).. -
Eric the Red at 04:23 AM on 17 June 2011There's no room for a climate of denial
I had not really seen a value attributed to CO2, rather vague statements to the tune of "likely," "very likely," etc. I thought about your last statement, which seems to be more indifference than denial. Is it denial if someone does not really know about it or care? I would call that apathy. Denial is more of a conscious effort to repress what one actually knows to be true. -
Bob Lacatena at 04:11 AM on 17 June 2011Forecast: Permanently Hotter Summers in 20-60 years
49, Eric the Red, My understanding is that the PDO is an observed pattern within the climate system, not a forcing. Like ENSO, it does not and cannot possibly change climate, it merely affects observed global mean temperatures. PDO is not a forcing, but merely another factor (although with a vaguely repeating pattern) in observed global mean temperatures. Studying the PDO allows one to better predict weather, not climate. The net effect of the PDO over long time frames is zero. The PDO cannot, in and of itself, alter the climate of the planet in the way we are seeing. It may add noise to the observations, but nothing more. To hope that that noise is in fact the source of most or all of current warming, or even that it is exaggerating the warming that we do see, and that warming will now reverse itself is, I think, overly optimistic (and pretty much in simple denial of all of the other facts that are available). Beyond this, it doesn't matter all that much what one is seeing at any point in time, or how it is masked by the PDO or anything similar. The fact is that climate sensitivity studies point to a 3˚C increase per doubling, and the existence, non-existence, impact or non-impact of the PDO on observed temperatures is irrelevant. It won't change the end result. To your other point, observation, correlation, and inference have not become extinct, but could never exist with any value in a vacuum, by themselves. To put it another way, observation, correlation and inference without understanding and mechanics amount to nothing more than superstition. They are the incomplete precursor to science (begin speech by Theodoric, Medieval Barber of York here). The PDO is nothing more than a "good blood-letting." -
John Hartz at 04:11 AM on 17 June 2011How would a Solar Grand Minimum affect global warming?
@Albatross #7: Kudos on your repsonse to Poodle. BTW, Joe Romm is now using the word "disinformer" rather than "denier." Perhaps we should follow suite? -
John Hartz at 04:09 AM on 17 June 2011How would a Solar Grand Minimum affect global warming?
Also see Joe Romm's blog post on this topic. -
Utahn at 03:59 AM on 17 June 2011There's no room for a climate of denial
"Getting back to the idea of a consensus, is there a consensus view of what percentage of the warming was a result of increased atmospheric CO2?" I'm probably not the person to ask, but from the 2007 IPCC report summary for policymakers(which I'd say was a consensus document), it appears that the consensus is that 90+% of the current forcing is anthropogenic, the great majority of which is greenhouse gas forcing. I think you're right that there may be stronger denial when there are things we can't change, but they still have to conflict with our core belief or core understanding to foster denial. For example, I can't (truly) change the fact that I have brown hair, but I don't deny it because it doesn't bother any core belief or value I have. I think cancer bothers a core belief that many have that they will not cease to exist, and hypertension fosters denial because some people think they will never be "sick" or "need medicine". You may actually be able to change the conditions so someone survives their cancer at least, or fixes their blood pressure, but the denial is really there due to the conflict with core beliefs... I think anthropogenic climate change fosters denial because believing it is true brings conflict with core beliefs such as "the free market is the best way to go", or core beliefs about our selves such as "I'm not one who hurts the environment" etc... -
Eric the Red at 02:44 AM on 17 June 2011There's no room for a climate of denial
I think there is little doubt that the increase in CO2 is manmade. Although, the warming of the oceans will contribute some. I was not trying to compare the two directly, and in fact, treating the acid will help with the symptoms, but not the cause. However, if we treat the CO2, i.e. switch 100% to alternate energy sources, we will elimate that warming due to CO2. Any warming due to any other cause will not be affected. If only half the warming is abated, it may be analogous to the physician who wonders why his treatment is only partially effective. Getting back to the idea of a consensus, is there a consensus view of what percentage of the warming was a result of increased atmospheric CO2? On the subject of denial, I think the two strongest forms of denial are with regards to those problems which we cannot changes (cancer in your previous post), and those problems we do not want to change. -
angliss at 02:31 AM on 17 June 2011How would a Solar Grand Minimum affect global warming?
Ken (#15) - I think you're missing something, or you're not being particularly clear. TSI already includes time in the definition, given that it's a measurement of power (W/m2), not energy. Power is energy integrated over time (1 J/s = 1 W). The thermal properties of heat capacity and thermal conductance (resistance) define how power relates directly to temperature in conductively cooled/heated systems, and there is no further integration of power over time. Similarly, in radiatively cooled/heated systems, P=σT^4, where σ (Stefan-Boltzman constant) has units of W/m^2·K^4. Again, no integration time, again because power already includes integration. Albatros' image is just fine. -
bibasir at 01:59 AM on 17 June 2011Our effect on the earth is real: how we’re geo-engineering the planet
Another area where we have had a major impact is deforestation. I don't have specific numbers, but we have deforested much of Europe, North and South America. I think 'geoengineering' gets the message across. -
Albatross at 01:54 AM on 17 June 2011How would a Solar Grand Minimum affect global warming?
KR @17, Thanks. -
Albatross at 01:53 AM on 17 June 2011How would a Solar Grand Minimum affect global warming?
Poodle, You allege, "I have made several posts demonstrating the weak assumptions and speculative conclusions that this paper reports." If you are so confident in your results then, please instead of lamenting on a science site, work up your analysis, write it up and then submit it to a reputable journal peer-review to challenge Feulner and Rahmstorf. At that point, should it get published, scientists will pay serious attention. Until then you are just an anonymous person posting on the web you claims to have it all figured out and why the experts are wrong, and trust me, there are many people making those claims, on every scientific field, not just solar science. It would help your case if you at least cited some reputable scientific literature to back up your case. The fact that you are reticent to do so, leads me to think that rather than being interested in understanding and advancing the science you role here it rather to argue for the sake of arguing, or to obfuscate or to fabricate debate, or perhaps all three. And ironically, the one and only silver bullet being flown here is the hypothetical silver bullet and favourite contrarian and "skeptic" argument that AGW is because of "The Sun", or GCRs or internal climate variability, or leprechauns, whatever 'silver bullet' de jour happens to be on the menu. -
Albatross at 01:39 AM on 17 June 2011How would a Solar Grand Minimum affect global warming?
Everyone, just hold your horses. This is about a predicted decrease in sun spot activity, now even that prediction has come under critique by a respected solar scientist, Dr. Biesecker here and here, and at least one other solar scientist. I suggest that John update the main post to reflect this. Also of note, Dr. Beisicker asks "One question I have for myself is whether in fact plage regions, which are bright, continued to occur, even during Maunder Minimum? There would have been no way to observe them and if they do occur, then we would still have a solar irradiance cycle." The abhorrent behaviour shown by "skeptics" over this issue the last day or two is sadly typical behavior for "skeptics" (and those in denial about AGW), pouncing on every tenuous and sometimes even hypothetical straw which might suggest that we can continue to dumping GHGs in to the atmosphere, and anything, or that we might be facing imminent cooling. Got to keep that cooling meme going. -
Eric the Red at 01:22 AM on 17 June 2011How would a Solar Grand Minimum affect global warming?
thepoodlebites, The paper also assumes a direct response to total solar irradiance, which does not result in a large temperature response. The other papers show a much larger response, and the temperature record seems to agree with those. Overall, Cook seems to be using a temperature response which is definitely on the low side. -
Tom Curtis at 01:20 AM on 17 June 2011Speaking science to climate policy
Ken Lambert @10 asks rhetorically:"While it is feasible that unmeasured Aerosols from the Chinese and Indian and other Asian economies have taken the place of the 1945-75 lot, one wonders why the window 1975-2000 ever existed. Surely emissions from Asia are not a new thing and have been steadily increasing for the last 30 years."
If he tried for a little less rhetoric and a little more understanding, he would realise that Chinese coal consumption went through the roof after 2001, and that aerosol emissions have risen with it.
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dana1981 at 01:16 AM on 17 June 2011How would a Solar Grand Minimum affect global warming?
Badger #20 - see Solar Hockey Stick -
Alex C at 01:07 AM on 17 June 2011How would a Solar Grand Minimum affect global warming?
thepoodlebites: Hm, well I uploaded the graph (Excel) in question to Flickr, it's here for viewing. -
Michele at 01:04 AM on 17 June 2011The Planetary Greenhouse Engine Revisited
Observing the Heart’s temperature profile, we note that in its atmosphere there are two broad sinks (the tropopause and the mesopause) that collect the upwelling&downwelling thermal energy flows, held by the existing temperature gradients, and radiate them to space. The lower atmosphere, near the surface, is affected by the surface, the troposphere and the tropopause. Simplifying, let’s assume that the atmosphere is restricted to the troposphere. We can say without any doubt that the tropopause emits only a part of the needed heat because its temperature (Tt) is lesser than the effective one (Te) whereas the surface (which has a temperature Ts higher than Te) encounters some difficulties/resistances to radiate to space and its emission takes place with an efficiency (ε) lesser than one. Off course, simplifying, the balance of the thermal fluxes requires that there must be εTs^4 + Tt^4 = Te^4. Also, observing the brightness temperature vs wavelengths, ”(e.g. here)” we read that the Earth’s thermal sinks of the atmosphere are due to CO2 as well as for Venus and Mars (the absence of another sink for the mesopause temperature lets us to claim that it is due also to the CO2 and that it is overlapped by the tropopause sink). We read too that Earth has some others GHGs and so, while several gases take part in reducing the efficiency (ε) of the surface emission, the sole CO2 determines Tt. We can claim that if the Earth’s atmosphere was totally without CO2, both Tt and Ts would be higher and the surface would be warmer. It’s astonishing, the “vituperated” CO2 plays the role of to limit the GH effect. Further. The behavior of the atmosphere has to be analyzed from a fluid-dynamic point of view taking into account that a particle of the atmospheric gas, once heated by the surface, leaves it and climbs adiabatically. Assuming that the changes over the time vanish for all the playing variables, we read: 1) The conservation of the momentum along the vertical direction states that, apart the viscosity, the vertical acceleration of the particle is generally (- g – (1/ρ)δP/δz) and for the adiabatic flow and for an ideal gas it is (- g - CpδT/δz). The acceleration is positive (the rising is accelerated, the falling is decelerated) if δT/δz is lesser than –g/Cp and vice versa. The rising/falling is uniform with δT/δz = -g/Cp. 2) The conservation of the energy (in absence of sources and sinks within the adiabatically rising particle) tells us that the total energy (CpT + u²/2 + gz + … ) is constant, that’s, CpT + gz = constant for the uniform flow, i.e. δT/δz = - g/Cp. In other words a particle that leaves the surface at the temperature T0 is able to reach the height z = Cp(T0 – T)/g and if it has to reach the tropopause to yield a part of the heat that is there emitted, it needs to start from the surface at least at the temperature Ts = Tt + gH/Cp (H is the thickness of the troposphere). Conversely, the surface has to be at least at Ts to be able to heat the particle. Thus, the surface temperature is determined by the thermodynamics and fluid dynamics, once the tropopause has been set up at the height where the pressure allows the largest emission (Earth’s and Venus’ tropopause have similar pressures and temperatures, but CO2 densities tremendously different, as well as for Earth’s mesopause and Mars’ tropopause. All this in agreement with the consolidated physics. I think all others argumentations would integrate it without repudiate it. -
KR at 01:03 AM on 17 June 2011How would a Solar Grand Minimum affect global warming?
Arkadiusz Semczyszak - It is well worth considering the relative scale of the forcings. TSI changes for a long term minimum will be on the order of about -0.25 to -0.5 W/m^2; this is equivalent in scale to about 15 years of GHG accumulation. Forcing changes due to greenhouse gas accumulation for a doubling of CO2 are 3.7 W/m^2. Considering our continuing emission of greenhouse gases, a prolonged minimum will only delay global warming by about 15-20 years. And we will have to deal with "...the duration of the forcing with potentially larger effects for longer lasting or repeated forcings.”, as you put it. -
Albatross at 01:00 AM on 17 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
Dikran, Many thanks for all your incredibly informative posts here. -
Alex C at 00:56 AM on 17 June 2011How would a Solar Grand Minimum affect global warming?
thepoodlebites: I just downloaded the annual data from your link and applied a linear fit to the data from the minimum which started cycle 21 to the minimum that ended cycle 23 - there is a very weak decrease in overall TSI during this interval (-0.001452 W/m^2/year). From eyeballing it, it does not seem like it is as much of a drop as shown in the PMOD data, but there is still a slight decrease. I'm going to go have a look-through how I can add in graphics here to give you the figure... -
John Hartz at 00:33 AM on 17 June 2011How would a Solar Grand Minimum affect global warming?
The latest findings about the causes of solor storms.... "Scientists Prove Existence of ‘Magnetic Ropes’ that Cause Solar Storms" ScienceBlog, June 15, 2011 -
John Hartz at 00:20 AM on 17 June 2011How would a Solar Grand Minimum affect global warming?
Where can I find a plot of TSI over a geological timeframe? -
thepoodlebites at 00:19 AM on 17 June 2011How would a Solar Grand Minimum affect global warming?
Why does Mr. Cook keep pushing the (Feulner & Rahmstorf 2010) paper as some sort of silver bullet, non-refutable proof that an extended period of unusually low solar activity would cause a decrease in global temperature of no more than 0.3 C? I have made several posts demonstrating the weak assumptions and speculative conclusions that this paper reports. And the links to the original paper are still not working, Feulner & Rahmstorf 2010. The paper assumes a minimal response to reduced solar irradiance (0.025 C), an enhanced response to CO2 doubling of 3.4 C (from A. Levermann, private communication, 2010). Plug these assumptions into the CLIMBER-3a model, and the model results support the assumptions. This result is a faulty form of reasoning that assumes the conclusions in the premises, i.e., circulus in probando. The conclusions here are speculative, not even close to being a silver bullet. The argument is still wide open, the effects of an extended period of unusually low solar activity on subsequent global temperatures. And Mr. Cook seems intent on continuing to push the PMOD solar data when the LASP data shows a better representation of TSI. The TIM instrument has measured a lower and more accurate TSI (1360.8) for solar min than PMOD and the LASP historical TSI reconstructions show no decrease in TSI levels over the last three solar cycles (21-23). But cycle 24 is indeed unusual and time will be the best laboratory to study the impacts on climate. -
KR at 00:12 AM on 17 June 2011How would a Solar Grand Minimum affect global warming?
Ken Lambert "Temperature should be roughly proportional to energy added to the system - which is the time integral of TSI. You should show curve of the integral of TSI wrt time in comparison with temperature. If TSI of 1365.5 is your baseline then the TSI-time integral will be roughly linear upward - roughly matching your temperature curve. " Minus, of course, the integral of TOA radiation to space. Otherwise the pure integral of TSI would result in a surface temperature cooking us millions (billions) of years ago. The increasing difference between TSI and temperature trends indicates that TOA radiation has decreased in relation to temperature, increasing energy accumulation/temperature, which would be the effect of GHG's. Your insistence on treating the climate as a single variable system (TSI), without considering other forcing changes, continues to lead you astray. -
Chris G at 00:00 AM on 17 June 2011The greenhouse effect is real: here's why
Daniel B (#34), That is a very interesting observation. Another round of thanks. Though, I'm not sure how to distinguish an introduction of positive feedbacks from an acceleration of FF use. Either would produce a greater number of months with increasing levels. The timing of the peaks or the shape of the curve might make do it, but that is likely a difficult signal to filter from the noise. I'll have to give it more thought. -
Utahn at 23:59 PM on 16 June 2011There's no room for a climate of denial
Eric the Red: "Now, back to climate. How much does CO2 drive climate? 100%, 75%, 50%, less? If a loose consensus thought it was about 75%, and scientific research determined it was only 50%, does that really overturn the original belief?" I would say no, unless all of the other 50% turned out to be some previously undiscovered factor... I think the H.Pylori thing is really interesting too, but even that didn't exactly overturn a consensus, as it turns out H.Pylori causes ulcers in large part by increasing gastric acid secretion. So acid is still causing the ulcers, lowering acid still treats and prevents ulcers (even if you don't kill the H.Pylori), it's just that in many cases a germ is causing the high levels of acid to be secreted, and you can better prevent recurrence of ulcers by also killing the germ. To me this would be analogous to finding that C02 still was warming the globe, that we were emitting it, but that something else was causing us to emit it besides our various desires leading to industrial and personal energy use. Maybe if God were causing us to use all these fossil fuels...which is actually probably true in some way! Do you know of any antibiotics that work on God? -
Chris G at 23:45 PM on 16 June 2011The greenhouse effect is real: here's why
Scaddenp, Glenn, Hmm, I'd figurede that the bacteria producing methane were eating plant material and that would mean the same ratios throughout. I did not remember about the C3 versus C4 pathways. Interesting, thanks. -
Ken Lambert at 23:24 PM on 16 June 2011Speaking science to climate policy
Michael Sweet #7 One of the oft used reasons for the post-WW2 cooling up to about 1975 was the masking effect of Aerosols. Do you remember the argument that the 'Clean Air Acts' - cleaned up North American and European sulphate and other emissions - had unmasked that CO2GHG forcing - hence the increase in temperatures since 1975? Well - Hansen has brought them back to explain another masking of CO2GHG forcings - the last 10 years or so. While it is feasible that unmeasured Aerosols from the Chinese and Indian and other Asian economies have taken the place of the 1945-75 lot, one wonders why the window 1975-2000 ever existed. Surely emissions from Asia are not a new thing and have been steadily increasing for the last 30 years. "According to Bart's 0.8 C/W/m2 @3, that is over 1C of committed warming in addition to what is in the pipeline due to ocean thermal inertia." What is in the pipeline? Temperature rise or a rise in sequestered heat energy? Ocean thermal inertia can only redistribute heat already sequestered as temperature rise (or ice melt) in many places and temperature drops somewhere else. This is an 'internal' forcing effect. At any instant in time, the storage of heat energy will be represented by a mass phase change (WV or Ice) and a mass temperaure increase somewhere. If Hansen's rediscovered Aerosols are masking CO2GHG forcing by closing the imbalance gap - less heat energy is being sequestered for the oceans thermal inertia to redistribute. The 'warming' is not in the pipeline - its in the time tunnel - dependent on future imbalance. -
Eric the Red at 23:01 PM on 16 June 2011Forecast: Permanently Hotter Summers in 20-60 years
No, I do not propose that. However, much research has shown (not proven) that the PDO has significant climate implications. If much of the recent warmer is attributable to decadal oscillations rather than climate feedbacks, then that needs to be incorporated into climate models. It is not the physics of climate science that is resulting in the greatest uncertainty, but rather the mathematically-modelled responses to the physics. I think you are deluded yourself if you think that testing mathematical models is alchemy. When did observation, correlation, and inference become extinct? The modern day term for model testing is called engineering. I know a new thread has started since I first brought up a potential grand minimum, but what if a combination of a negative PDO and solar minimum reduced global temperatures significantly more than modelled? -
Eric the Red at 22:47 PM on 16 June 2011There's no room for a climate of denial
Utahn, You present a good point. (I just happened to glance back at this thread to see if there was any recent activity). Let us say that a medical advance did not overturn a medical belief, but simply reduced its significance. Now the "consensus," which may have been rather loose, is not exactly overturned, but minimized. Now, back to climate. How much does CO2 drive climate? 100%, 75%, 50%, less? If a loose consensus thought it was about 75%, and scientific research determined it was only 50%, does that really overturn the original belief? I would agree that a true consensus does not get overturned often, but one of the biggest medical changes would be the discover of bacteria-causing ulcers revamping ulcer treatment. -
John Russell at 22:41 PM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
Thanks, Dikran.Moderator Response: [Dikran Marsupial] No problem, lets see if it has any success! -
Eric the Red at 22:33 PM on 16 June 2011How would a Solar Grand Minimum affect global warming?
Sphaerica, I would agree with your statement that it would be frightening if a grand solar minimum resulted in a large temperature decrease masking a less large temperature increase from CO2. Temperatures were particularly depressed in the U.S. and Europe during the Maunder. http://earthobservatory.nasa.gov/IOTD/view.php?id=7122 If a grand minumium occurred, and it was insignificant, then the role of the sun would be largely removed as a climate driver. The following paper does a nice job of comparing solar activity to different temperature reconstructions (Mann and Moberg). From a purely scientific viewpoint, another grand minimum would present an excellent opportunity for solar-related climate research. http://www.acrim.com/Reference%20Files/Scafetta%20&%20West_Phenomenological%20reconstructions%20..since%201600.pdf -
Ken Lambert at 22:29 PM on 16 June 2011How would a Solar Grand Minimum affect global warming?
Albatross #6 Temperature should be roughly proportional to energy added to the system - which is the time integral of TSI. You should show curve of the integral of TSI wrt time in comparison with temperature. If TSI of 1365.5 is your baseline then the TSI-time integral will be roughly linear upward - roughly matching your temperature curve. -
Eric (skeptic) at 22:11 PM on 16 June 2011How would a Solar Grand Minimum affect global warming?
Mod, thanks. I just noticed that the paper says the same. The paper also acknowledges that TSI is perhaps an oversimplification. They seem to think that solar spectrum changes manifest more as short term factors in solar cycles (which then balances out) than as an effect that would be prominent in a deep minimum. They don't mention solar magnetic except as a proxy for TSI. My view is spectral effects are a complete unknown and magnetic effects are only barely understood. Neither translates to a forcing of any consequence in a simple GCM. People like Lockwood (e.g. http://www.eiscat.rl.ac.uk/Members/mike/publications/pdfs/2010/267_Woollings_2010GL044601.pdf) show the effect as weather pattern changes like blocking, not forcing changes. Certainly the blocking in the recent past has shown to lead to localized Arctic warming and associated warming feedbacks. But there may be more dramatic weather pattern effects with a deeper minimum that may cause cooling or, more likely, change the sensitivity to CO2 doubling. If nature decides to run that experiment, it will interact in interesting ways (for weather forecasters) with CO2 warming and associated moisture. -
barry1487 at 22:06 PM on 16 June 2011Our effect on the earth is real: how we’re geo-engineering the planet
It's sometimes said we are conducting an experiment with the Earth's atmosphere. That it is unplanned only emphasises the folly. Similarly qualifying our 'geoengineering' of the atmosphere works the same for me. -
snapple at 21:25 PM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
Denialist "cherrypicking" from this BBC editorial really opened my eyes. Even I know what statistically significant means, but most people don't. You did not mention in your article what Pravda and the 9-11 Truther publication "Rock Creek Free Press" said about Dr. Jones. They made the same claims as the media you mention. Pravda even cited FOX News as their source. Pravda was actually slightly more accurate than the Daily Mail or the Fox News article they cited because they mentioned "statistically significant," but they didn't explain that term. The Pravda article was titled "Phil Jones Backs Out Of Global Warming Fuss" (2-16-10), but Pravda actually did report: The scientist behind the so-called "climate-gate" e-mail scandal now admits there has been no statistically significant global warming since 1995. http://legendofpineridge.blogspot.com/2010/02/daily-mail-and-fox-news-tell-b ig-lie.html These papers left out important information that Phil Jones told the BBC and that the BBC did report: BBC: How confident are you that warming has taken place and that humans are mainly responsible? Phil Jones: I'm 100% confident that the climate has warmed. As to the second question, I would go along with IPCC Chapter 9 - there's evidence that most of the warming since the 1950s is due to human activity. -
CBDunkerson at 21:20 PM on 16 June 2011Websites for Watching the Arctic Sea Ice Melt
PIOMAS (see link in #33 above) has released an update through the end of May based on a revised model and a new baseline (1979 - 2010 average). The new model is showing a less severe declining trend, but the minimum is still ~4000 km^3 ice last September. That would seem to imply that some of the older values have been reduced such that the overall trend is lower while still arriving at the same end result. There are also some new materials like a graph showing the baseline values compared to 2007 and the current year. There are new links to validation information and the values used for the anomaly graphs, but the links on the PSC page currently have some '-2' extensions which I had to manually remove to find the intended pages. Also, there is apparently going to be an announcement about Cryosat-2 data next week. Sounds like they are going to start releasing results.Response:[DB] Thanks for pointing that out. I was going to post this last night but my PC died:
The new graphics more clearly depict the 2-sigma bounds.
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John Russell at 20:55 PM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
Dikran: please do me a favour: come over to 'Carbon Brief' and make the definitive expert comment on this thread. Preferably one that is understandable to the sort of person Bern describes.Moderator Response: [Dikran Marsupial] Done (I have made a long and detailed post, I'll happily discuss it further if it was over the top ;o) -
John Brookes at 20:55 PM on 16 June 2011Our effect on the earth is real: how we’re geo-engineering the planet
Thanks Mike for a thoroughly illuminating article. Its nice to know that some geologists can see what is happening. -
Dikran Marsupial at 20:44 PM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
Bern, quite. Perhaps Prof. Jones problem is that he does understand it! ;o) -
Bern at 19:44 PM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
Dikran: I share your pain, but not quite as acutely. After all, I actually took (and passed!) a stats class as part of my engineering degree, and I only have a vague understanding of confidence & statistical significance. Mind you, some of that might be due to it being close to 20 years since I needed to apply it... :-P But if someone who did stats at university level (even if only basic stats) has trouble with statistical significance, what chance those people who struggled with algebra in high school, and have not gone beyond basic financial arithmetic since? -
Glenn Tamblyn at 17:58 PM on 16 June 2011Our effect on the earth is real: how we’re geo-engineering the planet
Bart In a limited semantic sense you are right. However, actions such as large scale mining are intentional in their more limited scope. And I'm not sure the term Geo can be used only for planetary scale. What would be the right term to use for an intervention that isn't intentional? Perhaps simply GeoIntervention? But certainly the sense that our interventions are planetary in scale is an important one before we get into questions of intentionality. -
Dikran Marsupial at 17:39 PM on 16 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
Journalist at BBC wrote: "If a trend meets the 95% threshold, it basically means that the odds of it being down to chance are less than one in 20." AAAAAAARRRRRGGGGHHHHH!!!!!!!! ;o)
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