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Comments 113351 to 113400:
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GnDoty at 04:59 AM on 7 August 2010It's the sun
I'd be interested in data on current CO2 output caused by fossil fuels versus the CO2 output of an active volcanic period. Both rapidly increase CO2 levels. Would everyone agree that if the output was similar, the earth and life would simply adapt as it has before? This is assuming we as a species will advance technologically to the point of becoming far less dependent on fossil fuels. In my opinion, we can't come to any realistic conclusion when too many variables such as solar influence are not fully understood. This leads a person with an open mind like me to wonder why such drastic measures are being proposed when the situation is still not factually conclusive.Response: Here is a comparison of CO2 levels and volcanic activity. The 3 largest volcanic eruptions over the past 50 years had an almost negligible effect on CO2 levels:
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Hockey stick is broken
Eric - please read the last two paragraphs of this posting for an answer to that question. -
Ned at 04:44 AM on 7 August 2010Waste heat vs greenhouse warming
VoltairesDistantCousin: BP was right and your "correction" of him is wrong. Temperature decreases with altitude in the troposphere, increases in the stratosphere, decreases in the mesosphere, and increases again in the thermosphere:
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Waste heat vs greenhouse warming
I'm afraid, RSVP, that you are not following the analogy I presented. I DID state that the water pressure drove the outflow rate, with "if the water level rises, it drains faster, if it drops, it drains slower...For fun we can set the output rate to scale with the 4th power of water level". Your analogy of two buckets makes no sense - as has been covered before (repeatedly, by several people), there is only one bucket, one set of energy. It really doesn't matter if the AHF energy comes in fast, slow, through convection, radiation, conduction - the AHF rate is 0.028w/m^2, and it ends up depositing that energy into the mass of the Earth/water/atmosphere at 0.028w/m^2, or 0.028 joules/sec/m^2. That's a rate of energy input to the total Earth/water/air energy. Adding AHF to sunlight, in the analogy I gave, means adding to the water inflow. If 100 gallons per minute are pouring in from the sun, and you add 1 gpm of AHF, well then the water level/pressure (and by analogy temperature) will rise a bit until the output increases to match. If you reduce the outflow rate at the current water level to 90 gpm, water level and pressure will rise until the outflow is again 100 (or 101 with AGH) gpm. Again - there is only one system receiving energy; the sum of Earth+water+atmosphere. There is only one output for that energy, radiation to space. And changes in either the rate of input or output will change the radiative equilibrium temperature of the system. If you cannot understand that, and continue to insist that AHF somehow acts differently than solar energy (does it somehow produce a different flavor of joules - chocolate, perhaps?), then you have a conceptual issue I cannot help you with. -
Doug Bostrom at 04:32 AM on 7 August 2010Confidence in climate forecasts
I'm curious to know what Argus is really arguing about. W/reference to model predictions versus observations, Argus said: [dubious proof omitted] these climate 'forecasts' over-predict global temperatures when compared with observed temperatures. I am guessing there is a purpose behind this. What purpose do you believe that to be, Argus? I ask because this has a lot of bearing on the topic of this post. Quite a large body of research tells us that a given person's confidence in and ability to integrate new information is often dictated not by the quality of that information but instead how it comports with their beliefs about things not directly related but which instead may be affected by actions indicated by the new information. In this case you're harboring some misunderstandings about models that happen to allow you to dismiss them as having no utility in helping us to decide whether to change our actions. Your remark about "purpose behind this" sounds superficially like an irrational buttressing of your misconceptions about models. That's why I'm wondering about the specifics of the "purpose" you see in errors of models. -
daisym at 04:27 AM on 7 August 2010Remember, we’re only human
Do scientists believe that carbon derivatives trading will make significant reductions in carbon fuel usage? The U.S. government seems hell bent on passing Cap and Trade but, without a full-time alternative energy source, how would it force manufacturers to stop using carbon fuels? Should industrialized counties jointly conduct R&D to find a full-time energy source that would replace carbon fuels? -
Doug Bostrom at 04:11 AM on 7 August 2010More evidence than you can shake a hockey stick at
Moscow's been like that for weeks, too. Conditions at 22:00 Moscow time: 81 °F Smoke. Interesting analysis of the Russia phenomenon here by Wunderground's Rob Carver. Jeff Masters has an update here. -
caerbannog at 04:10 AM on 7 August 2010More evidence than you can shake a hockey stick at
Of course, weather events should be treated as data points and not proof, but here are some spooky data-points! -- http://www.tutiempo.net/en/Weather/Moscow_Domodedov/UUDD.htm Projected daytime highs for Moscow, RU: 6-8-2010: 40C (104F) 7-8-2010: 40C (104F) 8-8-2010: 38C (100F) 9-8-2020: 39C (102F) That's Moscow, not Cairo -- Moscow, not New Delhi. MOSCOW, not Riyadh! -
Doug Bostrom at 04:09 AM on 7 August 2010Grappling With Change: London and the River Thames
Dorlomin, I think you hit the nail on the head quite nicely. A non-tidal example. At the bottom of my yard there is a creek that has been heavily channelized over the decades. Along this creek we've had some flooding events recently having to do with unusually intense rainfall. The channeled river has very little capacity to handful large excursions in flow and meanwhile the channelization itself was done so that development could cover what used to be the floodplain. When the channel capacity is exceeded the result is nearly instantaneous arrival of water in homes, practically no advance warning in the face of rapid swings due to paving having reduced permeability so much. There's no way to wish the water away so another solution is needed. The upshot is that a number of local structures have been condemned, the flood plain where those buildings stood is being connected to the creek again along a portion of the banks. This will somewhat improve the probability of the remaining homes along the channel remaining dry. A statistical improvement. Oddly enough my particular problem is with groundwater, not the creek itself. -
citizenschallenge at 04:07 AM on 7 August 2010Communicating climate science in plain English
Excellent, Excellent!!! I love the evolution of this site. Even if I don't own anything besides an ancient cell phone and my trusty MacBook. I totally support you making information available at three levels. Keep on truck'in :-) -
Peter Hogarth at 04:03 AM on 7 August 2010The Past and Future of the Greenland Ice Sheet
Arkadiusz Semczyszak at 23:03 PM on 3 August, 2010 (With apologies to moderators for the length of comment). The papers you cite are all interesting and recent papers but none of them appear to be directly concerned with the recent warming of Greenland, though some are very relevant to the paleo record. They do not support your conclusion. The related papers of Swingedouw 2010 and Servonnat 2010 use a state of the art model to examine the effects of TSI, CO2, and orbital changes on temperature and NAO over the past thousand years, and they support the prevailing view from IPCC AR4. They also explicitly provide support for the conclusion from Kaufmann 2009 (which Chris mentions) that the Northern Hemisphere has experienced a slow cooling over the past millennium (- until the recent century when this trend has abruptly reversed). From Swingedouw 2010 when discussing pre-industrial asymmetric NH/SH response to warming: “This type of response is comparable to a certain extent with the temperature response to greenhouse gases increase during the last 50 years (Trenberth et al. 2007), with a large warming at the northern high latitudes, while the Southern Ocean experiences a very small warming and even a slight increase in sea ice cover” From Servonnat 2010: “Using a linear statistical decomposition we evaluated that TSI and CO2 have similar contributions to secular temperature variability between 1425 and 1850 AD” & “The amplitude of the temperature secular variability is in agreement with both temperature reconstructions and IPCC AR4 simulations taking into account the impact of the volcanoes”. I have to emphasise that the authors are looking at preindustrial forcings and confirm and add detail to current prevailing thoughts on pre-industrial forcings and effects Capron 2010 is concerned with rapid temperature changes in the last glacial period using the Greenland and Antarctic ice core records, and in brief examines precursor events (a topic I believe I possibly pointed you to recently) which include CO2 changes, possible AMOC changes (as in Barker 2010) as well as probable insolation effects on ice sheet volume. The present scenario is one where CO2 is rising more quickly than in any of the pre industrial ice core records, AMOC is relatively stable, and orbitally driven NH insolation is gently decreasing. These papers do not provide evidence for rapid Greenland melting at this stage in the current interglacial through any mechanism except rising CO2. The estimated long term orbital changes in NH insolation dwarf the insolation changes over recent centuries. The Vecchio 2010 paper is about an influence of nutation (an 18.6 year wiggle in the tilt angle as the earth precesses) on the phase of the global seasonal variations in temperature, the reported results suggesting a shift of 1.74 days towards earlier seasons over 110 years. What relevance this has I am not sure. -
VoltairesDistantCousin at 03:44 AM on 7 August 2010Waste heat vs greenhouse warming
In comment #189, it was asserted that
"...With current CO2 levels at 15 μm it is about 22 km above the surface. At that altitude the higher you go the higher temperature gets. Therefore putting more carbon dioxide into the system increases the effective radiation temperature at that frequency."
Specifically, the poster asserts that the temperature increases with altitude at 22km. This is incorrect. At 22 km, we would still be in the stratosphere, a layer of the atmosphere in which temperature decreases with altitude. It is only when we reach the thermosphere, above about 95 km that we see temperatures rising with altitude. However, in the thermosphere, the air is so sparse as to be nearly transparent to exiting infrared photons.
Has the level of rational debate degenerated so much that we are having skirmishes over basic facts such as this?
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RSVP at 03:42 AM on 7 August 2010Waste heat vs greenhouse warming
KR 188 "Water doesn't leave as fast as it's entering." You yourself acknowledge that energy radiates as T to the fourth. So if the surface warms, it should radiate harder. In the analogy, the leaves slow drainage and this would be a problem if the inflow of water remained the same, but as surface radiation increases with T^4, the analogy seems to break down. Even in the analogy, you could have said that outflow increasing due to increased water pressure, but you didnt. I can also make up analogies... imagine two 50 gallon barrels that are filled with 25 gallons of brackish water every morning for one month. At the bottom of each barrel there are two distinct filters. The first has coursely ground activated charcoal, and the second a much finer grid of activated charcoal. Both are allowed to drain during the day. Everyday, by six in the evening, the first one is empty, whereas the second one takes until midnight. Examining the filters, we see that the distribution of dirt in the first is spread thoughtout the filter, whereas in the second most of the dirt remains in the upper layers of the filter. In this analogy, you can see how the density of the filter (GHG concentration) slows the flow, but that the total energy is release in both cases (no accumulation of energy due to filters). The notable difference is the guck profile in the filters (temperature profile in the atmosphere). So I am allowing for warmer temperatures in the lower atmosphere due to GHGs but I am saying that it must be made up for a cooler upper atmosphere given that the net heat flux is constant. Of course higher temperatures at the surface can mess up the biosphere, and melt ice etc., but in terms of energy storage, it is not clear to what extent this is happening, but even you have said that radiation goes as T^4, so a warmer surface would induce more radiation. We dont want to forget about waste heat... During the night, it rains during the last two weeks of the experiment, but no one realizes it. It is noticed that the barrels take longer to drain. In fact during the last week of the month, they are finding water still draining in the wee hours of the morning. Those conducting the experiment are certain that it is due to the accumulated muck. -
Argus at 02:58 AM on 7 August 2010Confidence in climate forecasts
chris at 21:42 PM on 6 August, 2010: So you really believe that a climate model is just a "working replica of the earth" - only it is made from "mathematical equations" instead of "rock and water and other materials"? Just like the "model stream-trains ... are miniature working replicas of real steam-engines"? I am not that easily convinced! I certainly have no personal experience whatsoever of making computer models of the climate, but I have the equivalent of a master's degree in (what in my country is called) technical physics, and I have worked for 25 years as a computer programmer. So I know a bit about how make a program work - you put in what you know, or think you know, for a starter, then test it, compare it to the real world, make some changes, test, change again, etc. Of course the model is based on "known physics" somewhere. I did mention that in my comment. But there must also be a lot of empirical parameters and variables put into it, in order to make its output agree with climate history. And when you achieve that, you are resonably satisfied. In the post How reliable are climate models? a big deal is made out of the fact that the models "successfully reproduce the past". Of course they do. That is what they were made to do. But predicting the future is another matter. To make a really accurate climate model of the earth and its biosphere, in its setting in the solar system, is not like making a model of a microwave oven or a power station. It is immensely harder than that. I imagine it would be almost as hard as making a model of how the human race will evolve during the next million years. We have the physical and chemical laws, we know about natural selection etc, we know our DNA, we can make our model fit the changes of the past million years, but then what? -
It's the sun
GnDoty - you can't ignore volcanic sources of CO2 over the (very) long haul. Temperatures are related to both CO2 and solar input, as described on CO2 was higher in the past. The difficulty now is that we're adding CO2 at an extremely high rate by geologic standards, and the geological weathering feedback and other CO2 sinks are too slow to keep up. We're entering a new domain, as described on On temperature and CO2 in the past. I'm not looking forward to the temperature catching up with current CO2 and solar levels... -
Waste heat vs greenhouse warming
The 'saturation', or rather the GHG emission only range I was looking at on Has the greenhouse effect been falsified?, Figure 1., is the 16-14 micrometer band. -
Waste heat vs greenhouse warming
BP - I found the graph I was looking for. See Has the greenhouse effect been falsified?, figure 1., where the CO2 bands are sending ~1/2 their IR to space, 1/2 back down. Without the GHG blocking the spectra would closely follow the black-body curve at ~267K, or it would until things cooled off. I used "fully saturated" poorly in my posting - what I intended should have been the much wordier "for those wavelengths where there's enough GHG in the atmospheric column to essentially absorb direct ground radiation before it gets out to space uninterrupted, thus preventing direct radiation and only showing spherically distributed thermal radiation from the GHG". Because I, well, thought that was pretty wordy... -
Pete Ridley at 02:23 AM on 7 August 2010Confidence in climate forecasts
In my previous comment I emphasised the change made by the IPCC to its AR2 WG1 Chapter 5 “Climate Model Evaluation” when replacing “prediction” with “projection”. It is worthwhile considering the important distinction between these two words, clarified in a definition buried in AR3 Appendix I - Glossary. “Projection (generic) A projection is a potential future evolution of a quantity or set of quantities, often computed with the aid of a model. Projections are distinguished from predictions in order to emphasise that projections involve assumptions concerning, e.g., future socio-economic and technological developments that may or may not be realised, and are therefore subject to substantial uncertainty. See also Climate projection; Climate prediction.” “Climate projection: A projection of the response of the climate system to emission or concentration scenarios of greenhouse gases and aerosols, or radiative forcing scenarios, often based upon simulations by climate models. Climate projections are distinguished from climate predictions in order to emphasise that climate projections depend upon the emission/concentration/ radiative forcing scenario used, which are based on assumptions, concerning, e.g., future socio-economic and technological developments, that may or may not be realised, and are therefore subject to substantial uncertainty.” Climate prediction: A climate prediction or climate forecast is the result of an attempt to produce a most likely description or estimate of the actual evolution of the climate in the future, e.g. at seasonal, interannual or long-term time scales. See also: Climate projection and Climate (change) scenario. As I indicated previously, these distinctions, although conveniently overlooked by supporters of The (significant human-made global climate change) Hypothesis, are by no means trivial. On the contrary, they are fundamental to the debate. As far as projecting changing global climates are concerned the most important words providing that clarification are “assumptions .. subject to substantial uncertainty ..” particularly in relation to uncertainty and assumptions about radiative forcing. Kevin Judd underplays this high level of uncertainty and the associated highly dubious assumptions made by supporters of The Hypothesis. He says “Of course there will always be some doubt and uncertainty about how the details of climate change will play out, but there is no doubt on the basic story that the earth's average temperature is going to rise 2 to 3 degrees over the next 50 to 100 years. Anyone who says otherwise, either does not understand how science works, or is being deliberately misleading..” He is wrong. Those projections of 2-3C rise in mean global temperature are pure conjecture. As Professor Barry Brook (Note 1), Sir Hubert Wilkins professor of climate change at Adelaide University said over a year ago, “There are a lot of uncertainties in science, and it is indeed likely that the current consensus on some points of climate science is wrong, or at least sufficiently uncertain that we don’t know anything much useful about processes or drivers” (Note 2 – please read the whole paragraph for the full context). It is that poor scientific understanding of global climate processes and drivers that forces supporters of The Hypothesis to speculate about future trends and other agenda unrelated to climate change that causes them to speculate about a catastrophic trend. Those Implications by Kevin Judd (is this Professor Kevin Judd of the University of Western Australia?) that today’s computer models are able to predict global climate change are totally misleading. Because of those unfounded assumptions made as a result of the significant uncertainties in the underlying sciences upon which the models are based, any attempts at predicting global climates are little better than fortune telling through gazing into crystal balls. John Cook’s lead article on the “How reliable are climate models?” thread says that sceptics argue “Models are unreliable .. “. This understates what many skeptics say, which is that climate models are incapable of predicting global climates. Specious claims are repeatedly made by supporters of The Hypohesis about the ability of climate models to predict global climates. In a plethora of comments on that thread the claim is made that this is substantiated by mean global temperature change predictions attempted by Dr. James Hansen in 1988. In these, one of the three scenarios produced results that show some alignment with claimed global temperature changes to 2000. The fact that this alignment disappears for the period 2000-2010 is conveniently overlooked. Because of the enormous scientific uncertainties about global climate processes and drivers, no climate model can be considered capable of predicting anything relating to global climates until it has reliably predicted global temperature trends over the accepted minimum period of 30 years. This test run would have to be undertaken under strict control procedures monitored by independent validation professionals before sceptics would accept that the models are reliable. Until that has happened climate models have no more validity that the fortune teller’s crystal ball. NOTES: 1) see http://www.adelaide.edu.au/directory/barry.brook 2) see http://bravenewclimate.com/2009/04/23/ian-plimer-heaven-and-earth/ Best regards, Pete Ridley. -
Tom_the_Bomb at 02:23 AM on 7 August 2010Talkin bout the Skeptical Science phone apps
ROFL the title of your article is hilarious! XD Nice one. -
GnDoty at 02:12 AM on 7 August 2010It's the sun
"We actually have many lines of evidence that clearly point to the burning of fossil fuels causing rising CO2. " Sorry, I should have stated more clearly I was inquiring about past warming cycles with higher CO2 concentrations (with a cooler sun). I think KR posted above providing a potential cause for rising CO2 levels which cause warming with a much cooler sun compared to present. If I understood your first response correctly, previous warming was caused by increased CO2 levels caused by non-solar forces. I'm trying to understand what causes CO2 levels to rise high enough to cause warming (excluding fossil fuels, volcanic activity, and the sun). This also begs the question: if current global warming is caused by solar forces AND CO2, are we not fast-tracking the earth to provide a natural balance as seen in the past (assuming an origin for increased CO2 is the sun). -
Pete Ridley at 01:59 AM on 7 August 2010Why I care about climate change
Hi John, thanks for that bit of background. As the ATE advert says "To communicate is the beginning of understanding". About a year ago I started debating on Australian (Family First) Senator Steve Fielding's blog. Steve is a committed Christian but is also a sceptic. Another committed Christian and supporter of The (significant human-made global climate change) Hypothesis, Phil (AKA Stormboy - http://bloodwoodtree.org/category/climate-change) and I had numerous exchanges of opinion on climate change. I approach this subject from the other side of the debate, suspicious of the real motivations of the politicians in driving what I see as a confidence trick. After months of debate neither of us changed our opinions on the issue. Only time will tell whether or not the scientific speculation about our use of fossil fuels is having any significant impact upon global climates or whether such impacts are beneficial or detrimental to the most important form of life on the planet, humans. Best regards, Pete Ridley -
angliss at 01:39 AM on 7 August 2010Three new studies illustrate significant risks and complications with geoengineering climate
Thank you for catching that, Jenikhollan. I'll update the post to the right figure when I get home tonight. -
Berényi Péter at 01:31 AM on 7 August 2010Waste heat vs greenhouse warming
#188 KR at 00:42 AM on 7 August, 2010 where GHG's are fully saturated the IR at that wavelength is half the black-body value What do you mean by "fully saturated"? As pressure decreases steadily as you go up, there is always a height from where radiation can escape to space, that is, above it air gets "transparent". With current CO2 levels at 15 μm it is about 22 km above the surface. At that altitude the higher you go the higher temperature gets. Therefore putting more carbon dioxide into the system increases the effective radiation temperature at that frequency. I can't understand your "half the black-body value" allusion either. Half the black body value for what temperature? -
LewisC at 01:11 AM on 7 August 2010Three new studies illustrate significant risks and complications with geoengineering climate
It's a real pity that there's so little recognition of the actual complexities of the jeopardy we face, as it means that widespread mal-assumptions obstruct appropriate strategy. This greatly reduces the chance of avoiding catastrophic outcomes. For example, how many people posting here factor in the 30 to 40-year timelag on emissions' warming potential coming into effect ? This timelag not only means that present warming is from around 330ppmv in the mid '70s, and that we'll see what 350ppmv does in about 12 years time, and that we'll see the effects of 390ppmv in about 2045. It also means that a radical cut of global GHG outputs - say 98% by 2040, would be similarly timelagged in effect, which is anyway merely to stop adding to the problem. Entirely necessary, but grossly insufficient. Meanwhile, the interactive feedbacks of forest combustion, permafrost melt, cryosphere decline, etc, are now evidently already accelerating at very damaging rates. Addressing the actual problem of excess airborne stocks of GHGs is a very different matter to merely ending additions to them. Those who urge that we leave it to nature are patently unaware of the practicalities. Nature, in the form of carbon sinks, has been removing around 1.0ppmv/yr of CO2, but with ocean acidification and warming even this small service is forecast to decline. Meaning that even with a rapid end to anthro emissions, airborne GHG stocks would not decline significantly for many decades. That period would be greatly extended by marine stocks of anthro-CO2 being returned to the atmosphere, with the timelag then still further delaying the effect of those changes. Meanwhile, the feedbacks would have had well over a century of acceleration and of potentially massive release of additional GHGs, and the oceans would be dead. In short, the problem of excess airborne anthro GHGs is way beyond nature's capacity to handle in a manner we can survive. We dropped the spanner in the works – we have to get it out. Unwelcome as it may be to received wisdom, under the NAS definition, this means applying geo-engineering techniques [Geo-E]. It has nothing whatever to do with the genocidal corruption that seeks Geo-E as a means to maintain its emissions and thus shareholder profits. The primary form of Geo-E is carbon recovery, which attracts little opposition in principle. If it is done via sustainable forestry optimised for biochar, fuels and biodiversity (using around a gigahectare of non-farm land) together with biomass wastes, it is estimated that over 4ppmv/yr of CO2 could be recovered. In addition, it would not only greatly raise farm yields (as is already becoming critically necessary) and provide liquid & gas fuels in rural areas, but also provide vast additional habitat for hard-pressed biodiversity. There are also various proposed techno options for carbon recovery, but none as yet are self-funding, nor socially or ecologically constructive, nor demonstrably practical on the required scale of handling gigatonnes of carbon per year. The limitation of carbon recovery is that it cannot be done fast enough to keep ahead of the feedbacks’ acceleration. It would certainly take over half a century to recover sufficient airborne stocks, which would then be replenished with the marine stocks seeking equilibrium, and thus needing further decades for their recovery. In short, to avoid the feedbacks swamping the atmosphere with their emissions while carbon recovery is under way, they must be decelerated back to an insignificant level of output. That imperative demands the use of Geo-E in the form of albido restoration for the period of carbon recovery needed to restore 280ppmv of airborne CO2. Nothing else, so far as I can see, will prevent the feedbacks from imposing utterly catastrophic change. As to which of the many albido restoration techniques should be applied, there is great and urgent need of both discussion and research. Personally I see little prospect of sulphur aerosols being viable due to their dubious net benefits affecting negotiations. My own (far fetched) favourite would be large orbiting facilities robotically producing and releasing massive tonnages of cloned sterile thistledown into the stratosphere. (Max albido for minimal impact). The most promising option appears to be the Jetspray vessels that Professor Salter has been working on for some years. In being wind-powered and in putting up spray to generate additional bright clouds where and when appropriate it avoids both the pollution and control problems of sulphates. But given that is has yet to reach protototype stage, its eventual function is far from proven. However, until there is public recognition of the need for appropriate Geo-E, we are still just wasting more precious time. For this reason it seems a real shame that all three of the studies posted above should fail to seek the most viable formats for a practical program to meet the indisputable need of Geo-E. Regards, Lewis -
It's the sun
Actually, I think GnDoty has a good question, one which has occurred to me. What caused such high levels of CO2 in the past?" I believe the answer is a "DaisyWorld" scenario, described in the CO2 was higher in the past thread - with a lower solar output, glaciers cover the world, and block weathering absorption of CO2 by rocks. Over geologic time, CO2 from continuing volcanos accumulate, until enough ice melts to allow weathering to catch up again. It's a slow feedback cycle. I could be wrong, though; I'm certainly not a geologist - I invite corrections if I'm just making things up here :) -
muoncounter at 00:43 AM on 7 August 2010More evidence than you can shake a hockey stick at
"Fire seasons are starting earlier, last longer and are harder to control" This year's fire season is already ugly. Alaska Siberia Canada And there's satellite evidence that an NWP is soon to open up ... despite the good "news" reported by Watts and co. -
Waste heat vs greenhouse warming
RSVP - Aha! I believe I see the (perceived) issue. First of all, the presence of GHG's reduce the surface emission of IR where they absorb. This is partially replaced by thermal emission of the GHG's, but only partially - only half the IR emitted by the GHG's will escape to space - the rest heads back down to the surface. You can see that in thermal spectra for the Earth from space - where GHG's are fully saturated the IR at that wavelength is half the black-body value. So the rate of Earth's energy loss at a particular temperature (integrated spectrum of IR) DECREASES with increasing GHG concentration. This is crucial to the discussion. I will therefore completely disagree with on your statement: GHG DO NOT imply overall energy accumulation from the Sun, but yes, a change in energy storage distribution. No! GHG's directly cause energy accumulation! An analogy: You have a water tank with an open top (Earth/water/atmosphere energy in joules). You pour water in at a steady rate (Sunlight, waste heat, internet discussion, whatever). At the bottom of the tank is a drainpipe (radiation to space). The water level (temperature) is set by the pressure required to push as much water out through the drainpipe as is pouring in the top - if the water level rises, it drains faster, if it drops, it drains slower, but that tank will reach equilibrium with output flow = input flow. For fun we can set the output rate to scale with the 4th power of water level. Now throw in some leaves (GHG's blocking IR) partially clogging the drainpipe, reducing the outgoing flow. What happens? Water doesn't leave as fast as it's entering. And guess what - the water level in the tank rises (accumulating). It rises until the output rate equals the (unchanged) input rate; the temperature rises. Rising GHG's induce an energy accumulation - Output energy at a particular temperature decreases, output is less than input, energy accumulates, temps rise causing more output energy, until we're back at equilibrium with the output energy at the new temperature equals what's coming in. Warmer Earth, warmer water, warmer atmosphere, more energy present. -
Berényi Péter at 00:38 AM on 7 August 2010Confidence in climate forecasts
#38 scaddenp at 14:49 PM on 5 August, 2010 I would say GHG increase should increase entropy - the earth has become more efficient at converting high entropy photons to low entropy photons. I see. But what do models say? -
GnDoty at 00:37 AM on 7 August 2010It's the sun
"Response: The difference between the past and now is the sun was much cooler in past periods of high CO2. Currently, we're heading towards high CO2 and high solar output. As it gets hotter, drought severity increases (it's been increasing over the last century). This has a significant impact on plant growth and agriculture." I am still working towards my geophysics degree so I apologize for the continued questions. In a period with a "much cooler" sun, other than increased volcanic activity, what would be another source that could contribute global increases in CO2 to the point of global warming?I could see ice melting releasing methane and CO2, but wouldn't solar influence be the cause for this to happen? If so, would the origin of of all global warming or cooling be the sun? I understand the complexity of climate changes, but I'm trying to simplify the process to find the origin.Response: "what would be another source that could contribute global increases in CO2 to the point of global warming?"
If I understand you correctly, you're asking what could be causing the rise in CO2 levels other than human activity? We actually have many lines of evidence that clearly point to the burning of fossil fuels causing rising CO2. Firstly, the simple numbers that we're emitting around 28 billion tonnes of CO2 per year while the actual amount of CO2 in the air is going up by around 15 billion tonnes per year. Secondly, the type of carbon in the air matches the type of carbon that comes from fossil fuels - a distinct human fingerprint. Thirdly, we see the same pattern in carbon isotopes in corals - another fossil fuel fingerprint. So there is really only one explanation for the sharp rise in CO2 and it's the common sense explanation - much of the CO2 we're throwing into the air is staying there. -
Ken Lambert at 00:22 AM on 7 August 2010Confidence in climate forecasts
Chris #44 Of course the climate 'sensitivity' refers to surface warming. The crux of the AGW theory is that CO2GHG forcing and positive WV feedbacks will cause an enhanced T1-T2 differential across the atmospheric column from the surface to the level in the atmosphere where the temperature averages around 255degK. This is approx the S-B radiating temperature of the earth. -
Ken Lambert at 00:08 AM on 7 August 2010Confidence in climate forecasts
Ned#42, #43 It seems to me that the +2.1W/sq.m of WV and ice albedo feedback, and the aerosol, cloud and direct albedo currently showing in Dr Trenberth's balance are the places to illuminate with Eqans we can all understand. -
omnologos at 23:31 PM on 6 August 2010Confidence in climate forecasts
doug_bostrom (#46): not really indicative of any problem w/scientific understanding I used to believe that, but then I have seen the f-word used so often by otherwise knowledgeable people, I am now inclined to think those using it have really lost its real-world meaning. chris (#50): No, nobody thinks they have a crystal ball, but (too) many people talk to the general public as if they did! I confess I am always amazed at how much I agree with Schmidt on this point. And especially about society’s expectations. Perish the thought there would be a +3C increase by the year 20XX apart from a 1C drop due to a series of volcanic eruptions, with the resulting 2C hailed a victory for humanity's efforts and politicians' especially (come to think, if you look at the Copenhagen Accord cloosely, it's worded ambiguously enough...) And for the record, yes, I am all for the use of climate models, even if like with string theory, I do think there's been too much focus on them and them alone. Like secret dossiers for journalists, climate models make a climatologist's life easier, maybe too much so. -
Rob Painting at 22:15 PM on 6 August 2010More evidence than you can shake a hockey stick at
What about global trends in the frequency of extreme precipitation events?. I'm aware of a number of regional analyses, that show an increasing frequency of these, but globally?. -
John Mason at 22:10 PM on 6 August 2010Remember, we’re only human
Tim, that's a fascinating read. My take on the situation is broadly similar in that in the most technologically-advanced societies today a great disconnect has occurred between humanity and the environment - so that people perceive the environment as somewhere "out there" - somewhere they perhaps go on vacation, for example. This is a very dangerous mindset to get into, given that without a functioning environment there is no breathable air, potable water or food, and any environmental malfunction can have severe effects on humanity - as the Russians are finding out. Muscovites are now well aware of the environment as it continues to give them a hard time. Cheers - John -
Rob Painting at 22:05 PM on 6 August 2010Confidence in climate forecasts
Argus @ 49 "As proven by angusmac (#20), these climate 'forecasts' over-predict global temperatures when compared with observed temperatures. I am guessing there is a purpose behind this." Actually Angusmac provided a graph without sufficient explanation, which was provided by Chris @ 27 - I expect climate science has moved on a bit since 1988. Still pretty good work by Jim Hansen, considering what was known at that time. And I hardly think we know for a fact that models "over predict" global temperatures.
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dorlomin at 22:03 PM on 6 August 2010More evidence than you can shake a hockey stick at
In my post yesterday, I reported that fourteen countries had set their all-time hottest temperature record this year. I neglected to mention that one country has also set its coldest temperature in recorded history mark in 2010. Guinea had its coldest temperature in its history on January 9, 2010, when the mercury hit 1.4°C (34.5°F) at Mali-ville in the Labe region. Of the 229 countries with extreme coldest temperature records, 14 of these records have occurred in the past ten years (6% of all countries). There have been five times as many (74) extreme hottest temperature records in the past ten years (33% of all countries.) My source for extreme weather records is Chris Burt, author of Extreme Weather. http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=1560 -
Peter Hogarth at 22:00 PM on 6 August 2010Confidence in climate forecasts
angusmac at 02:43 AM on 5 August, 2010 I agree with the comments (27) made by Chris on the Hansen 2006 paper about the 1988 model. Hansen points out the original model used a higher climate sensitivity than the currently accepted estimates, and therefore the original model is likely to slightly overestimate temperature trends. Even so, your “update” seems a little biased in that you omit the station data which Hansen includes, (and justifies inclusion) based on what the model is actually modeling. I have updated again with rolling 12 month values for the latest GISS data.
As others have pointed out we should not be misled (either way) by short term variations (eg 1993 or 1997). We should also remember that adding appropriate error bars will make the question of divergence academic, at least for the moment.
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chris at 21:42 PM on 6 August 2010Confidence in climate forecasts
Argus at 21:21 PM on 6 August, 2010 I don't think there's much merit in your argument Argus, and if Kevin's top post is a little simplistic (but note that the communication of science at varying levels of "simplicity" is a current topic of discussion here), then your's is unhelpfully simplistic (not to mention wrong) in the other direction! For your description of how models are constructed and used is quite incorrect. Models are parameterized according to known physics, and isn't adjusted to fit reality in the manner you suggest. It would be foolish indeed to do so (although on consideration, there might be good reasons for testing this under some circumstances). The value of doing good quality models and comparing these to reality is they increase our understanding and really help to focus on specific empirical measurements. So, for example, when ideas of water vapour response to atmospheric warming conflicted with models, one could focus on addressing real world water vapour data to assess the discrepencies. Now we know that water vapor is behaving pretty much as expected from models. Likewise a long-standing discrepancy between models and satellite measures of tropospheric warming stimulated a focus on addressing real world measurements and the apparent confusions were resolved pretty much in favour of the models. Computational models are astonishingly useful in most areas of science. -
CBDunkerson at 21:41 PM on 6 August 2010Remember, we’re only human
mothincarnate, plenty of people reject evolution even today... that has not prevented it from transforming the biological sciences and resulting in many advancements which benefit even those who disbelieve the science. I think it will be the same with advances going forward. Just as some religious groups reject modern medicine now others in the future will reject gene therapy, performance improving implants, cloned organs, and many other things... and just like the groups that reject modern medicine this will lead inevitably to those groups becoming marginalized minorities. When a new advancement gives the ability to save their life or their child's life most people are going to take it. GM foods are stigmatized without much justification now... but not so much in places where they are the only way of stopping starvation. If food availability becomes scarce people WILL change their tune on GM foods VERY quickly. Religions get re-written on a regular basis... the survival instinct does not. -
dorlomin at 21:32 PM on 6 August 2010Grappling With Change: London and the River Thames
I am just thinking and I realised that sea level rise may hit esturine cities much harder than either sea level or up river cities. Basically when a river gets to the sea is slows down and spreads out, this is the estuary. However as sea level rises the estuary will move back but it will have no where to spread out as it starts getting to the city parts that have been built on, so the total volume of water in those segments of the river will increase much quicker than sea level. It will be effectively squeezing the wide estury into a narrow river channel, probibly with build up river walls to try prevent flooding. Looks like some major engineering to keep the water flowing past the cities built up limits..... -
chris at 21:23 PM on 6 August 2010Confidence in climate forecasts
omnologos at 10:52 AM on 6 August, 2010 Yes you have a point Omnologous, although I think we might recognise that much of what you say is implicit in the sort of arguments used here. So when the term "prediction" is made, we should recognise that we really mean projection, and that this projection is being made to test a particular scenario (e.g. emission scenario). Likewise it's implicit that we recognise the inherent uncertainty about the future and that stochastic and contingent events are unpredictable (even if we can model some of these pseudo-stochastically - e.g. we can parameterize ocean current changes that give ENSO-like behaviour). I don't think anyone thinks they're "crystal balls" (I agree there is lots of confusion about this), and I personally don't think they tell us very much about future global warming over and above what we know from the seperate assessment of the forcings and their projected increases and so on that are themselves used to parameterize the models. The value of models (of the sophisticated computational variety) is that they allow us to assemble and incorporate our understanding into a representation of natural phenomena, which allows testing of future projections. They may also give insight into smaller scale phenomena (e.g. regional variability of distribution of thermal energy in a warming world), and provide reasons for more focussed investigation of experimental/empirical observations (e.g. to address apparent differences in tropical tropospheric temperatures between models and real world observations). So extraordinarily useful tools.....but not crystal balls! -
Argus at 21:21 PM on 6 August 2010Confidence in climate forecasts
For whom was this propaganda post written? For the average 10-year old? It is full of oversimplifications and half-truths. I agree with Einstein, as quoted by omnologos in an excellent comment (#45). An example: "Perhaps you have seen, or even had a ride, on one of those model stream-trains. These are miniature working replicas of real steam-engines. Climate models are the same; they are a working replica of the earth, only instead being made of rock and water and other materials, they are made from mathematical equations." There is no likeness other than the name 'model'. A model of a locomotive is a small-scale replica of a physical object already existing and well-known in every minute detail. You know exactly what the original object is like, and you can make the replica as precise as you like. On the other hand, a climate modelling program is a total artefact, a computer program fed with parameters and variables that are a mixture of basic physical laws, empirical data, and guesswork. You can not take a ride on it. All you can do is look at the diagrams it produces, and see if they agree with what you expected. If not, you change something and make a second run, etc. Change one parameter (for instance something to do with cloud production), and (hep!) you have a 'model' where the earth's average temperature is going to fall 2 to 3 degrees over the next 50 to 100 years. As proven by angusmac (#20), these climate 'forecasts' over-predict global temperatures when compared with observed temperatures. I am guessing there is a purpose behind this. -
Rob Painting at 20:01 PM on 6 August 2010Confidence in climate forecasts
Omnologous @45 - I can predict that summer will be generally much warmer than winter. Or is that unknowable?. -
jenikhollan at 19:57 PM on 6 August 2010Three new studies illustrate significant risks and complications with geoengineering climate
The proper Fig 3 is this one. -
Berényi Péter at 19:55 PM on 6 August 2010Remember, we’re only human
#38 John Russell at 18:09 PM on 6 August, 2010 See where the UK comes on this list. If I were you I would not use the list of the Optimum Population Trust. It is absolutely bogus. It says "All source data from The Ecological Footprint Atlas 2009 (Global Footprint Network), based on 2006 figures". They also say actual population of EUROPE (EU) is 731.28 million. Now, in fact actual population of EU was 493,226,936 in 2006. -
Rob Painting at 19:54 PM on 6 August 2010Confidence in climate forecasts
Chriscanaris @ 36 - "With respect, you missed the point. I have no overwhelming desire to get on the plane. I'd just like to make sure the models are right." Yes, what I wrote earlier wasn't quite on point. The analogy itself isn't a valid fit, but a better extension would be: We're already on the plane, we didn't know there was a problem when we took off, but we do now - the models predict a crash if we continue much longer. Bits and pieces seem to be falling off the plane, which suggest the models might be on to something. I think we should try to land before we crash, we can't afford to wait for the models to be perfect. But you seem to be saying, "hang on a minute, about these models, only 90%?.......". -
tobyjoyce at 18:46 PM on 6 August 2010Remember, we’re only human
"Malthus was wrong. He believed the Isles of Britain could not support more than 7 million people." Malthus may have had an adjacent country in mind when he was writing: Ireland, where the population was exploding in his time, millions of those dependent on a single crop: potatoes. Ireland was place with many poor, and early, fecund marriages. Malthus' critics argued that birth rates would adjust to circumstances, but many thought the Irish Famine of 1845-1852 was his vindication. All in all, 1 million Irish died of starvation and disease, a further million fled overseas. Yet, the aftermath to an extent vindicated Malthus' critics - Ireland became a country of late marriages with small numbers of children. Sexual repression and clerical control became notorious. The birthrate only began to rise again, and emigration reverse, in the 1960s. Today, demographic historians see these trends beginning BEFORE the famine, but they were too late to mitigate the catastrophe of the potato blight, which no one foresaw. So Malthus was possibly only half right - the Irish were cognisant of there situation and the population was adjusting - families were getting smaller, marriages later, the safety valve of emigration was coming into use. But with the onset of blight these adjustments were insufficient in the short time abvailable & a terrible tragedy ensued. As an Irishman, I would be loath to write off old Malthus as totally "wrong". Contingencies can happen that drive an already precarious situation past a tipping point. It is tempting to see 21st century civilization dependent on a limited supply of carbon-based fuels as similar to the 19th century Irish poor, dependent on a single food crop. Is that too simplistic? -
RSVP at 18:11 PM on 6 August 2010Three new studies illustrate significant risks and complications with geoengineering climate
Ann #18 Well put. -
John Russell at 18:09 PM on 6 August 2010Remember, we’re only human
HumanityRules at 09:50 AM on 6 August, 2010: I can't agree with the bald statement that 'Malthus was wrong'. Malthus was right in principle, but couldn't take everything into account. Most notably he didn't foresee the massive increase in carrying capacity cheap fossil energy would provide. That's a perfect example of why scientists should avoid making predictions. They can be essentially correct but if they gamble on occasional 'best guesses' in order to create their equations it will often be those weak links that let them down. You say, "Malthus was wrong. He believed the Isles of Britain could not support more than 7 million people." That's a bit like seeing a field full of cows and saying, "see how many cows that field can support". There's current population and there's sustainable population. The difference is quite dramatic. See where the UK comes on this list . -
Berényi Péter at 18:04 PM on 6 August 2010Grappling With Change: London and the River Thames
#39 doug_bostrom at 16:05 PM on 6 August, 2010 Allowing economists to decide whether or not particular sets of physical facts should be addressed or acknowledged is arguably quite bizarre, actually seems like something lifted from anachronisms like Soviet Russia. There used to be a joke about a mythic soviet paper clip factory that was required to produce 100 tons of paper clip in a month. They have solved the problem by producing just ten pieces, 10 tons each.
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