bb113
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February 02, 2012, 03:40:33 AM |
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No one really knows what they are doing, and humans are fallible and subject to biases.
Well.. in paleoclimatics we mostly know what we are doing. It would be a lie to say that we know everything we do, but at least "understanding" the past works. Applying it on todays systems is hard due to the human impact. So whats the deal with the clouds when modeling thousands or millions of years in the past? Without humans or satellites taking records (I think insolation is the term) they seem like a big unknown.
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Nachtwind
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February 02, 2012, 10:29:34 AM |
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No one really knows what they are doing, and humans are fallible and subject to biases.
Well.. in paleoclimatics we mostly know what we are doing. It would be a lie to say that we know everything we do, but at least "understanding" the past works. Applying it on todays systems is hard due to the human impact. So whats the deal with the clouds when modeling thousands or millions of years in the past? Without humans or satellites taking records (I think insolation is the term) they seem like a big unknown. Not sure about the inner workings of many models, but as far as i know clouds tend to be neglected or just described very very roughly. That happens due to the scale of climate models. Clouds are very short "events" in time and show as far as i know pretty constant insulation patterns over longer timeframes. So one cloud cannot be computed, but if you know the average cloudiness of an area in a year or 5 or 10 you can compute with such constants. Climate models mostly work with timeframes of 5yr+ - many that i know even only for 50yr+ intervals. So if you compute 50yrs a few clouds dont create much problems... Also the area observed or simulated is important. Many models work on big scale cells. Europe, for example, is often divided into 200x200 cells - which is a very coarse resolution. Of course, higher resolution is possible but due to the many variables used highly imprecise in simulation. Also Insulation is especially driven by a very few variables that are well understood: astronomical cycles (see milankovic cycles) and water/ice movements. Those impose strong signals that make clouds, if they arent part of special circumstances, quite neglectible. But i am not a pro on this topics..
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Kettenmonster
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bool eval(bool b){return b ? b==true : b==false;}
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February 02, 2012, 07:01:27 PM |
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... but there IS a correlation..
A correlation prooves nothing. The statistics I have learned allows to say if there is no correlation then it is pretty sure not related. Population and temperature is correlated as well, so lets kill some people for a better climate! We can´t safely predict the weather for more than 3 days, but climate for the next centuries?
We're not talking about the weather. Here we talk about climate. True and we can predict that? Use the same technique on weather or stocks and your done. Look at the math inside the computer climate models. It is pure crystal orb contemplation. Its just the vast amount of variables that really makes the job hard..
If you look into the climate models you will see a lot that is certainly not crystal orb contemplation. True so true, but one "crystal orb" is enough to make the result void. Tuning those parameters (you call them variable) until the wanted result appears, is what I consider cheating.
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The paining (sic!) is done with the QPainter class inside the paintEvent() method. (source: my internet)
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dree12
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February 02, 2012, 07:03:45 PM |
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... but there IS a correlation..
Population and temperature is correlated as well, so lets kill some people for a better climate! Unfortunately, this is completely true.
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FlipPro
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February 02, 2012, 07:17:38 PM |
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... but there IS a correlation..
Population and temperature is correlated as well, so lets kill some people for a better climate! Unfortunately, this is completely true. Our "human" impact on this earth can be reduced to almost 0 if we all did what we were supposed to do.. Unfortunately we have people carrying their own blind political agendas (ironically claiming we're the blind ones), who stifle progress every step of the way with their quasi-scientific theories, and poorly thought out methodologies...
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Nachtwind
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February 02, 2012, 07:53:53 PM |
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... but there IS a correlation..
A correlation prooves nothing. The statistics I have learned allows to say if there is no correlation then it is pretty sure not related. Population and temperature is correlated as well, so lets kill some people for a better climate! We can´t safely predict the weather for more than 3 days, but climate for the next centuries?
We're not talking about the weather. Here we talk about climate. True and we can predict that? Use the same technique on weather or stocks and your done. Look at the math inside the computer climate models. It is pure crystal orb contemplation. Its just the vast amount of variables that really makes the job hard..
If you look into the climate models you will see a lot that is certainly not crystal orb contemplation. True so true, but one "crystal orb" is enough to make the result void. Tuning those parameters (you call them variable) until the wanted result appears, is what I consider cheating. AS i said, climate reflects large scale cycles and not so much irregularities or pseudo random events if you take a reasonable timescale. Weather is pure "randomness" - as are the stockmarkets. Also noone is predicting future climate, noone sane would ever try to. Our current models cant even simulate the known past well enough to be considered good for predicting. But with the error margin known for remodeling the past scenarious can be created for the future. Sorry if it sounds like talking down on you - i really dont want to do that, but you must be sure you know your vocabulary. Weather is not climate and predictions are not scenarios. We can predict weather to a certain degree, but as you know with a high error for more than three days - simulating climate or creating scenarios is totally different. Noone tells you it will be 3K warmer in 100years, scenarios tell you it MIGHT be between 2K and 5K warmer in roughly 100years IF certain parameters wont change or worsen. Also the models for climate modelling are changed every few years at the moment, each time they get better or at least higher in resolution and take more parameters into account, but normally they show quite the same results which is NOT a result of cheating or tampering with parameters to make them fit..
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RandyFolds
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February 02, 2012, 08:07:35 PM |
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AS i said, climate reflects large scale cycles and not so much irregularities or pseudo random events if you take a reasonable timescale. Weather is pure "randomness" - as are the stockmarkets. Also noone is predicting future climate, noone sane would ever try to. Our current models cant even simulate the known past well enough to be considered good for predicting. But with the error margin known for remodeling the past scenarious can be created for the future. Sorry if it sounds like talking down on you - i really dont want to do that, but you must be sure you know your vocabulary. Weather is not climate and predictions are not scenarios. We can predict weather to a certain degree, but as you know with a high error for more than three days - simulating climate or creating scenarios is totally different. Noone tells you it will be 3K warmer in 100years, scenarios tell you it MIGHT be between 2K and 5K warmer in roughly 100years IF certain parameters wont change or worsen. Also the models for climate modelling are changed every few years at the moment, each time they get better or at least higher in resolution and take more parameters into account, but normally they show quite the same results which is NOT a result of cheating or tampering with parameters to make them fit..
The current models take more parameters into account, but what does that mean when there are literally infinite parameters? We are talking about nature.
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Kettenmonster
Sr. Member
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bool eval(bool b){return b ? b==true : b==false;}
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February 02, 2012, 08:18:29 PM |
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... Sorry if it sounds like talking down on you - i really dont want to do that,
Don´t worry about that. I am vaccinated against it. The difference of weather and climate is well known to me. But both plus stock exchange have something in common. The best prediction known is: Same as yesterday. Which works even better if you call it scenario. Rereading the stuff i guess you got me all wrong. Look what I wrote beneath: I hate it when people come along with brilliant ideas, good plans but then spoil it all with wrong arguments. p.s. I must admit being sometimes rather obfuscating than explaining my reasoning.
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The paining (sic!) is done with the QPainter class inside the paintEvent() method. (source: my internet)
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FirstAscent
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February 03, 2012, 04:55:41 AM |
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Ah sorry about the quote, it got messed up. And once again I think everyone agrees the earth has been warming. If you think something must be done about it whether or not it is due to man-made causes, ok. I would counter that perhaps adapting would be easier than developing climate control technology.
I, and about 7 billion others would benefit if you and others like you would drop this viewpoint. Let's review adaptation: The rapid rate of heating (100 years) is far too fast for adaptation to occur the way you think of adaptation. Species are being forced to migrate northward in the Northern Hemisphere at the rate of a couple of feet a day due to increased temperatures. As they migrate northward at such astonishing speeds, they run into barriers, such as suburbs, mountains, etc. As a result, they become extinct. Such mass extinctions reduce the productivity of the biosphere. It has been shown time and again that increased biodiversity, from the microscopic organisms in the soil to wolves which allow riparian environments to flourish (due to herds not grazing near creeks and rivers when wolves are present because of limited escape routes), allow the landscape to be more productive. What does that mean? It means that more biodiversity allows for greater production of food, greater cleansing of the atmosphere, and greater recycling of the elements within the soil. It means a healthier Earth. Adaptation, like you imagine it, is really massive unprecedented extinction due to a rapid rise in global temperature, and a massive reduction in the natural productivity of our planet. If that's what you want, keep on tooting your horn like you are.
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bb113
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February 03, 2012, 05:06:18 AM |
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First of all look up punctuated equilibrium. Rapid environmental change has probably been THE DRIVER of adaptation throughout the history of life on earth, it is not unprecedented at all. I am not saying it would not cause humanity trouble though. We benefit from a consistent climate.
Please provide historical data indicating that a 1 K average change in temperature is indeed much more rapid than normal and causes extinction. This may be true, and I will come across it in my own good time if you don't do it.
I'm not positive you a right about the biodiversity thing, but it makes sense. What is the evidence? See above if you don't provide it.
CO2 is plant food. There are other factors at play, it is not as simple as Rise in Temperature = Bad for life. Why do you think the current CO2 and temp levels are ideal?
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bb113
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February 03, 2012, 05:09:11 AM |
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And also you have entirely skipped over the possibility that it is not human CO2 emissions that is causing it, and therefore our efforts to curtail the temp rise will be worthless.
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bb113
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February 03, 2012, 05:50:48 AM |
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I really want to emphasize that in the end it is likely I come to the same conclusion as the climatologists (not the media portrayal). Once I looked a tiny bit into it, it was obvious that the media's narrative has been way overblown, a lot of people "believe in" AGW without knowing what they are talking about, and many people studying the climate think this is true as well. It is probably like Natchwind said and there are a few noise-makers in the bunch getting all the attention.
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FirstAscent
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February 03, 2012, 06:32:56 AM |
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I know all about punctuated equilibrium. It's irrelevant. The reason why it's irrelevant is because using it as a defense of your arguments is like saying the Chernobyl meltdown is fine because it forces adaptation.
But there's nothing fine about forcing adaptation when it simultaneously causes a near term apocalyptic scenario and is harmful to the current majority of residents of the planet, and is furthermore, unintentionally the result of a single species' activities.
An apocalyptic scenario is indeed beneficial to future surviving species far in the future after the planet regains its productive natural systems. But that doesn't mean it's desirable.
I am right about the biodiversity thing. You are free to wear blinders regarding it if you choose. But I don't know why you would choose to do so unless you think it might hinder your current views. Read some papers on wolves and riparian zones, or water quality programs in the state of New York, or agricultural studies of multi-plant crop productivity, or methods of pollination, etc., etc., etc.
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bb113
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February 03, 2012, 09:35:21 AM |
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I know all about punctuated equilibrium. It's irrelevant. The reason why it's irrelevant is because using it as a defense of your arguments is like saying the Chernobyl meltdown is fine because it forces adaptation.
But there's nothing fine about forcing adaptation when it simultaneously causes a near term apocalyptic scenario and is harmful to the current majority of residents of the planet, and is furthermore, unintentionally the result of a single species' activities.
An apocalyptic scenario is indeed beneficial to future surviving species far in the future after the planet regains its productive natural systems. But that doesn't mean it's desirable.
I am right about the biodiversity thing. You are free to wear blinders regarding it if you choose. But I don't know why you would choose to do so unless you think it might hinder your current views. Read some papers on wolves and riparian zones, or water quality programs in the state of New York, or agricultural studies of multi-plant crop productivity, or methods of pollination, etc., etc., etc.
Can you state what my argument is? You don't seem to be arguing against it. Actually, I haven't even begun to look at the modeling or data but so far the introductions to the IPCC documents seem pretty much in line with what I've been saying: The AGW theory is plausible, but far from proven: At the continental scale, it is likely that there has been significant anthropogenic warming over the past 50 years averaged over each of the continents except Antarctica. http://www.ipcc.ch/pdf/technical-papers/climate-change-water-en.pdf (page 15) Where uncertainty in specific outcomes is assessed using expert judgement and statistical analysis of a body of evidence (e.g., observations or model results), then the following likelihood ranges are used to express the assessed probability of occurrence: virtually certain >99%; extremely likely >95%; very likely >90%; likely >66%; more likely than not >50%; about as likely as not 33% to 66%; unlikely <33%; very unlikely <10%; extremely unlikely <5%; exceptionally unlikely <1%. There is historical evidence of climate changes much more extreme and abrupt than what we have witness so far: The importance of other sources of climate variability was heightened by the discovery of abrupt climate changes. In this context, ‘abrupt’ designates regional events of large amplitude, typically a few degrees celsius, which occurred within several decades – much shorter than the thousand-year time scales that characterise changes in astronomical forcing. Abrupt temperature changes were fi rst revealed by the analysis of deep ice cores from Greenland (Dansgaard et al., 1984). Oeschger et al. (1984) recognised that the abrupt changes during the termination of the last ice age correlated with cooling in Gerzensee (Switzerland) and suggested that regime shifts in the Atlantic Ocean circulation were causing these widespread changes. http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter1.pdf (page 106) Clouds remain an important unknown parameter: The strong effect of cloud processes on climate model sensitivities to greenhouse gases was emphasized further through a now-classic set of General Circulation Model (GCM) experiments, carried out by Senior and Mitchell (1993). They produced global average surface temperature changes (due to doubled atmospheric CO2 concentration) ranging from 1.9°C to 5.4°C, simply by altering the way that cloud radiative properties were treated in the model. It is somewhat unsettling that the results of a complex climate model can be so drastically altered by substituting one reasonable cloud parametrization for another, thereby approximately replicating the overall intermodel range of sensitivities. http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter1.pdf (page 114) The other thing is that I realized I have been stupidly creating a false dichotomy between adapting to and mitigating climate change. Obviously both strategies can be used at the same time.
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bb113
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February 03, 2012, 09:53:23 AM |
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Is it? Look at the temperatures and CO2 levels involved and compare those to the most drastic IPCC predictions.
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P4man
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February 03, 2012, 10:46:24 AM Last edit: February 03, 2012, 11:28:51 AM by P4man |
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Is it? Look at the temperatures and CO2 levels involved and compare those to the most drastic IPCC predictions. If one assumes climate scientists can be dead wrong with their current predictions, it stands to reason they could err both ways, agreed? Moreover, IPCC predictions are relatively short term (up to the year 2100 I believe), while the build up to previous anoxic events happened over 10s of 1000s of years. We could accomplish the same now in less than a century, but Im not saying its very likely you and I would live to witness this. Lastly, IPCC projections are if anything, by its very nature and due to the consensus model, very conservative. Its one of the greatest criticism that the IPCC only reports "lowest common denominator" findings. Personally I find that a completely reasonable approach as it greatly increases its credibility, but one shouldnt assume IPCC projections to be the worst possible case, because it definitely isnt. FWIW, so far most of the earlier IPCC predictions relating to temperature rise, ice melting that have been proven to be wrong, is in the sense that they were too conservative. BTW, I should check, but I believe previous anoxic events were triggered by a 6C temperature rise. I dont even think thats outside of IPCCs scenarios, but like I said, I should check both of those statements.
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bb113
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February 03, 2012, 11:33:17 AM |
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Agreed on the error, not so much on the equal plausibility. But, plausibility is subjective so whatever... FWIW, so far most of the earlier IPCC predictions relating to temperature rise, ice melting etc have indeed proven to be wrong; in the sense that they were too conservative. Do you have a source for this? The only good one I could find goes up to 2005 and the "temperature anomaly" has flattened out since then at about .4 C. Note that I may be confused as to the different baselines and temp records (global average, surface temp) so I am not positive if I am comparing correctly to get that flattening at .4 value. http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter1.pdf (page 98) FAR=1990 -> Overestimate SAR= 1996 -> Underestimate (or correct?) TAR= 2001 -> Overestimate (or within range)
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P4man
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February 03, 2012, 12:28:30 PM |
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bb113
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February 03, 2012, 01:44:42 PM |
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"Normally, you would use the heat content of the surface layer of water rather than just using the surface temperature because the surface temperature is affected by a lot of other factors," Dr Holgate observed. http://news.bbc.co.uk/2/hi/science/nature/6179409.stmWell I'm not really able to assess the virtues of these different ways of measuring temperature. But I would say that this is just talking about what a model has predicted if you plug in different parameters, it is not about actual measurements. So nothing has been proven wrong. In fact it looks like the trend of .25 cm/yr (so a rise of 25 cm in 100 years) has been breaking since that article. The model may be more complex than simply extrapolating a trendline though. The second article is about emissions, not atmospheric concentration. Just to convert to GtC from metric tons, lets use this link: * CO2 emissions grew 5.9% in 2010 to reach 9.1 GtC (33.5Gt CO2), overcoming a 1.4% decrease in CO2 emissions in 2009 http://co2now.org/Current-CO2/CO2-Now/global-carbon-emissions.htmlIPCC predictions from 2000: http://www.ipcc.ch/pdf/special-reports/spm/sres-en.pdfIt appears the current level of emissions is at the low end of all the projections from 2000. From the third article: The new report notably fails to take into account a batch of dramatic recent evidence, including the shrinkage of the Arctic ice cap, glacier loss in Greenland, a surge in levels of atmospheric carbon dioxide (CO2) and an apparent slowing of Earth's ability to absorb greenhouse gases, they say. I will leave it up to you to find out what has happened since 2007, looking at the data I saw a consistent rise +2 ppm of CO2 each year for the last decade. So I'm not sure what surge they are talking about. Maybe it is measured in different ways? I can't tell because that article doesn't provide sources. I didn't bother with the ice cap and glacier loss because everything else was overestimated rather than underestimated and I have no source to follow. I would suggest you find the data to support your claim.
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