We don't need to use proxies to estimate the termperatures when we have actual temperature records. It seems like you're trying to make something sinister out of using the best available data.
You kind of do need to if you want to make claims like the one made by the GP that I was responding to. Specifically saying:Never before in history has the temperature changed with more then 1 degree over 100 years. According to the proxy data that shows that historic stability, the temperature hasn't changed by that much since 1900 either. That is a very important observation to make as it shows the claim is lacking in substance.
In addition to the availability of actual direct measurements since the 1900s, which greatly reduces the value of more recent proxy values, there are also some problems with getting recent data from some of the proxies. For instance, there is the divergence problem in dendroclimatology which seems to show that pollution (or other factors) may be inhibiting tree growth since the industrial revolution. I imagine there's probably some difficulty with ice cores as well, since it may be difficult to get recent temperature measurements from glaciers that are shrinking.
Yes, Mann's paper from 2007 notes the same problem you mention. The calibration phase has a consistent problem with early calibration late verification. If you calibrate to the instrumental record from 1900-1950 and then verify the resulting proxy data from 1950 onwards you get observed evidence for a systematic bias in the underestimation of recent warming. Mann's words, not mine. The proxy data isn't registering the recent warming that we see in the instrumental record. I suppose that's no reason not to continue assuming that the same proxy data would have picked up similar warming in the past in your opinion. I'm less convinced. If you look closer at Mann's paper, he also observes the EIV methodology is least susceptible to the bias, and is thus the best method, again in Mann's opinion, not mine. If you check the reconstruction graphs though the EIV goes higher than the 1850-2006 average in 600AD, 1000AD and 1400AD. Mann doesn't graph the EIV from 1900 onwards, but in the calibration problem discussion he shows some portions of it, and it sits no higher than the 1000AD records for EIV from 1950 through 2000. It's all there in Mann's paper and please correct me if I'm in any way misrepresenting things. I've been trying to follow and understand this correctly for a long time now.
Of course, there are actually people studying these problems and even the quality of the calibration period which is used to match instrumental records to proxy values, you might want to try searching with the "proxy calibration" keyword, or reading up on the divergence problem in dendroclimatology.
As I noted above, I've done searches on that and come up with the observations above. The literature basically agrees that the proxy data, for reasons unknown, has a systematic bias in the underestimation of recent warming.
Forgive me for pointing that out when people make the claim that the historic record shows the last century is an anomaly. The instrumental record is anomalous compared to the proxy data. Attributing that entirely to climate change and not the fact those are entirely different data sets and methodologies is dishonest in the extreme. There's a reason the scientists writing the papers have a lot of caveats on the results regarding this, dropping those to make a blanket statement to scare folks is misrepresenting the facts.
"They spike up very quickly after the ice age ends, drop back down, and generally fluctuate a significant amount without any human input at all.
Not according to any the historical temperature graphs [wikipedia.org] that I've seen. The temperature rises rapidly at the end of the ice age and then levels off an eventually begins to fall again.
http://en.wikipedia.org/wiki/H... [wikipedia.org] The graph in the page you linked to shows temperature doing exactly what I claimed it does."
Acually it does not. The spikes you talk about are changes of about 0.3 degrees Celsius during hundred of years. Check the diagram more closely and you will also see that. The last "downspike" is what's called the little ice age and is still just about a dip which is about half a degree during a couple of hundred of years.
Never before in history has the temperature changed with more then 1 degree over 100 years. Even the during the sharp raise in the beginning in the diagram was that the case.
Natural variation in temperature are very slow and does not change as fast as today. The variations in temperature we see today are unprecedented for the last 10 000 years. Thats why scientist are saying its AGW. We, humankind has caused it.
You'd think so wouldn't you. Do yourself a favor and go on google scholar and lookup the proxy reconstructions of temperature of the last 10k or even 2k years. The big names you'll want to check for papers by are Mann et al, Moberg et al and Esper et al. Look at the reconstructed temperatures and try to find anyone that has reconstructed temperatures after the year 1900. I can't find a single one yet that includes those years from out of their proxy data, and I've been looking for awhile. I even dug enough to find Mann had included some of his raw proxy data, and the proxy data does extend past 1900. Interesting thing is the raw proxy data looks like pseudo random noise, most importantly that there is nothing distinctive happening in the raw data after the year 1900.
You know what does get graphed though? The proxy reconstructions up till the year 1900 are graphed, and then the instrumental record is graphed from the year 1900 onwards. As you have observed, it makes for a very, very scary and compelling looking graph. Starting after the year 1900 the trend radically changes, so much you would almost wonder if there was a methodology change starting at that point on the graph... Then you realize it's not just human emissions that started roughly then, but the methodology cut over. And Mann has been selling that straight faced to people for over a decade now.
Don't take my word for any of this though. As I urged from the start, go to google scholar and read the actual work from Mann and his peers doing the reconstructions and check it out for yourself. If you find proxy reconstructed results past the year 1900 please point me to them as I'm still looking myself,
Water vapor is self-regulating in that the amount in the air will usually be determined by other conditions. If we put carbon dioxide in the atmosphere, there's more carbon dioxide in the atmosphere. If we put more water vapor in the atmosphere, it rains. Therefore, although water vapor is more of a greenhouse gas, it can't cause overall warming on its own, while carbon dioxide can. It can amplify warming, since warm air can have more water vapor.
The trouble is water vapor is more complicated than that. Depending on conditions water vapor can be both positive and negative as a feedback. What precedes the rain you note, is clouds and heavy cloud cover obviously blocks a lot of radiation. If you take a look at the CMIP5 studies the impact of water vapor in them is still very poorly modelled and a, if not the, major source of uncertainties. The IPCC notes as severe a difference that the sign of clouds as a feedback is still uncertain, with different models disagreeing on the sign. The current consensus looks to be that the resolution of current models isn't fine enough to accurately model cloud effects.
The fact that energy imbalance has remained constant while CO2 has risen like mad suggests something else in the natural part of the system is offsetting things. Water vapor and clouds would be strong candidates, but we'll have to wait and see as newer models start trying to include those effects in a better way.
I will note that, according to your second paragraph, there's a lot of insane people out there.
Agreed, but arguing with the insane walks the line of joining their insanity.
Actually the article clearly explains what will happen. No piling on is necessary, unless you didn't bother to RTFA.
The CBC article does poorly actually, but if you meant the linked actual journal article then you are correct. In either case you missed my sarcasm, apparently with a good number of mods keeping you company.
Quick, we need everyone to pile on for why this proves catastrophe is imminent and favored policy changes must be passed. Then the other half can pile in and explain why this means nothing and the next ice age is still coming...
Wow that's a lot of down voting. I must have succeeded in angering both sides.
Quick, we need everyone to pile on for why this proves catastrophe is imminent and favored policy changes must be passed. Then the other half can pile in and explain why this means nothing and the next ice age is still coming...
It's also because of the heating up. If we're putting CO2 into the atmosphere, and CO2 is a forcing greenhouse gas (water is a greenhouse gas, but self-regulating so it can't force a change), and the temperature is going up (and those three hypotheticals are indeed true), then it seems to me that AGW is the obvious conclusion, and anybody who thinks it isn't happening has some explaining to do.
Declaring that water vapor is 'self-regulating' is a bit naive. It's pretty well agreed that the affects of water vapor will vary based on atmospheric composition, global temperature, ocean currents, and many more factors as well. It is also agreed that water vapor is currently contributing nearly 70% of the over greenhouse affect while CO2 is far, far less. Are you really comfortable just waving away concerns that water vapor will muddy the picture, because climate scientists are not and are actively working to better model and understand it's impacts.
No sane person is arguing against CO2 increasing because of us, nor that CO2 contributes to the greenhouse affect. No sane person is arguing against the fact that recorded temperature has been increasing the entire time we've recorded it. Those two points though don't equate to an answer on just how bad our contribution to the problem is.
Get yourself better informed. Go to sources like the IPCC and look at energy imbalance trends, the amount of energy the greenhouse affect is trapping. Match that to global temperature trends, and you can see that energy has been increasing at a static year to year amount with little trend up or down. Predictably, that matches the linear increasing temperature trend we see, as total energy goes up each year so does the temp. Here's the part though that leads me to say it's not time to panic. Look at CO2 concentrations over that same time, and map them to the energy imbalance(increasing greenhouse effect). CO2 has been rocketing on up and up, but the energy imbalance has been sitting there with no upward trend to match. We know CO2 is contributing, but we still have other factors like water vapor that we are trying to figure out, and the bare numbers suggest that CO2 isn't sending is into a death spiral of accelerating warming, but instead the same continual linear warming we've already seen over the last century.
I beg to differ. They may be vocal, but they are not large, and they're more or less unconnected with the scientists. You're dangerously close to demonizing people because you disagree with them. This is especially important because you seem to be overly concerned with these peoples' perspective. Very few others, especially in political circles, are paying any attention to them. There are a few instances where there is sufficient business case for a given environmental principle for the ruling class to take note of it, but otherwise not. Business always has a very slow response to any sort of moral pressure, and much slower when the principle at hand is environmental as opposed to e.g. human rights.
However, the liberals have at least the advantage of being on the right side of history. Less wasteful use of the Earth's resources is simply inevitable, and on the sound assumption that humans survive the next millennium, the Carbon Crisis will be the first and greatest instance of geoengineering, but not the last. Now that we have determined that it is actually possible, it will be, oh, probably about 200 years until we get sufficient handle on the situation to be able to do a second experiment.
Oh, and your ideas about "massive global actions" are mostly fictional. That is to say, they will happen eventually, but there are very few people who are that stupid. It's mostly a right-wing strawman. No one is dumb enough to try to sell massive changes with a huge price tag. It's in their interest to minimize cost estimates. Since no one is doing much of anything, it's more or less irrelevant what the projected costs are, but there's also no reason to go off the handle about any cost estimates, high or low. Again, you're giving these ideas undue attention. Or rather listening to the people who are trying to stir your outrage. Don't get jerked around by demagogues on either side.
I have to point out you are simply factually incorrect on claiming that massive global actions are fictional or fringe proposals. Look at the actual details of the Kyoto protocol as laid out and signed by a great many nations. At the time it was signed it was agreeing to lower emissions to 10% lower than the average that had existed several years before the agreement was signed. That's why nobody who signed it actually even attempted to meet their obligations. Well, with the exception of Russia, because it lucked into a massive recession after the emission reduction reference year so they had already met their lowered emission goal. Nobody else though was inclined to follow suit on purpose.
Sure Kyoto is an example of nations not following through, but it also demonstrates that the desire and will to propose and even agree on massive global actions is very much real and very much not a mere fringe movement type thing. Unless you don't consider rolling the global economy back to 10% below the average from 5-6 years ago is really all that bad...
...It's a well-kept secret, but 95 per cent of the climate models... have been found... to be in error....
Yes, most, if not all, of the climate are in error. They do not forecast the global climate with 100% accuracy.
.
They never will forecast the global climate with 100% accuracy. So they will always be in error.
However, they currently are accurate enough to forecast a future climate that has problems, and time is running out to prevent those problems from growing so large that they are all but irreversible.
The question is, do we start to address global warming now? Or do we wait until the models have 100% accuracy, at which time it will be too late to do anything about the problem.
How accurate is 'good enough' to make sweeping emissions changes at great economic cost today? I don't think there is much disagreement from anybody about moving towards electric cars and greatly reducing our emissions on a timescale of 10-20 years. I don't there is much disagreement about moving to alternative energy as it improves options like solar or better yet fusion, but that is also on a timescale of a few decades. But in that timeframe and with those advances that are coming for the simple reasons of economic advancement if no other, we will be greatly reducing our emissions.
To make a significantly greater impact than is going to happen all on it's own, we need to basically make pretty large reductions to CO2 emissions within the the next decade and the only way to accomplish that is globally reducing consumption and production. No matter how you cut that, it amounts to a global agreement on taking a big economic downturn for the future benefit of mankind. I'm not sure there exists a high enough level of Good Enough to make that kind of argument.
Now, none of that has much of anything to do with climate science, other than it's all very pertinent realities facing us regarding what actions we need to take.
The science for the climate models though isn't nearly as definitive as many make out. Make no mistake, the CMIP5 and similar experiments are very good and important science. The limitations that they are still working under though are very significant. One major caution is that any of the 95% accuracy style claims made by the models though are based on the caveat that assumptions in the model are 100% accurate and are comparisons made almost exclusively in hindcasting. The trouble is with very complex models, hindcasting is vulnerable to a lot of confirmation bias. Models results are combinations of a lot of things, including the input datasets, initial conditions, and the underlying interaction models themselves. When hindcasts come in too high, we naturally look at why and find sensible adjustments to the models, initial conditions and datasets that will lead to a better result. The same process is repeated for hindcasts that miss certain known trends in the past. After all those iterations though, we have a set of models whose input data, initial conditions and models are all heavily tailored to getting the result we know is the correct one. In ANY other field using such complex models, you would re-verify your results against extra runs of the real world system, and in that way rule out the possibility you are only getting better at predicting a single very specific sub case. With climate, we only have one run of the system available to work with. Worse yet, our most accurate and detailed datasets only span about 100 years, while we are looking at processes that span millennia. Again, the CMIP5 and other experiments are great science, but they are working under very difficult circumstances on a very challenging problem and claiming and extraordinarily high absolute confidence in the current modelled results is over reaching IMO. In truth, if you combine that with a hard push for major policy changes, it's downright irresponsible.
Oh, stop your sighing, you idiotic concern troll. One side is wrong and filled with cranks, nutters, and retired engineers, does no research and advances nowhere. The other is exactly the opposite.
Except for all those crying catastrophe and demanding panic and immediate and massive global actions be taken without any further investigation or consideration of the consequences because it's too urgent to investigate further. That crowd is also very large, very vocal and every bit as anti-science as the extreme deniers.
Can I make an appeal that the comments NOT become dominated by the crazies from both sides? Everytime an article like this comes to Slashdot, the prophets of doom come on decrying how anyone not sufficiently panicked and desperate is an insane denier like the bonafide loonie in the article.
After that it devolves into 'proving' the other side is wrong by pointing at the false claims made by the nuts on the opposite 'side'.
I think any PR person, CEO, and other mouthpiece who says this stuff is perfectly safe should be forced to drink it. Daily. For a year. Their family included.
If the PR clowns are going to claim it's safe, put their money where there mouth is. If they refuse to drink it, assume they're lying and feed them to bears.
Hold these guys to some standard of truth instead of their accustomed truthiness, and see what they do.
I'm so tired of these "think tanks" who are nothing more than paid shills who spout this crap just to obfuscate the truth -- it's no different than the tobacco lobby did. It's slimy and dishonest, and should carry a huge penalty.
As noted before from Article: The chemical, which is also commonly used in paint and cosmetics, is known to have caused tumors in rodents, though scientists have not determined if those carcinogenic properties translate to humans. The authors said the amount found, which was measured in parts per trillion, was within safety regulations and did not pose a health risk.
"If I were to peer-review a paper on this, I would insist on a plausible physical explanation for the claimed measurement." That's stupid. Providing proof that something interesting is happening and repeatable is viable science all on its own. I've read quite a lot of highly-respected papers from highly-respected people in highly-respected journals which did nothing other than document a pattern of behavior without explanation. In fact, most scientists I know will say they rarely ever really think they know *why* something happened, but that doesn't stop them from wanting to know. Some things get thousands of perfectly cromulent papers written prior to anyone really having a firm grasp on the "why" - hell, if you have the "why" then you probably have the last paper that will ever need to be written on the subject. Even farking *gravity* is still a bit of a mystery. We're pretty good on exactly *how* it works, but the *why* that you insist is necessary, for even something we all pretend to understand, isn't really yet known.
Dr. Schweitzer will tell you the same thing. She found what looked like soft tissue in a T-Rex bone back in 1993 and published her results, in shock herself and knowing that it was impossible to really be that. She checked and rechecked to rule out contamination and other causes, never finding one. The entire scientific community though refused the possibility it was soft tissue because Schweitzer couldn't explain how it could be preserved. By the year 2000 though she'd found the same results from enough other fossils that she's finally getting some traction and it's now starting to be taken by others as true, and there is new research now into how the heck it has happened. Not many people would carry that a decade.
When climatologists say geo-engineering is not the solution, they mean a political solution to drastically and immediately reduce CO2 emissions, is a better choice. Of course, that is NOT going to happen. So the choice is not between geo-engineering and some theoretical perfect solution, but between geo-engineering and doing almost nothing. I don't think we are to the point where we should roll out large scale geo-engineering, but we certainly should be doing the research so it is an option in the future. Currently it is politically incorrect to do even minimal research.
Good news, we already are.
The entirety of climate science and all the CMIP5 experiments for the IPCC ARE also geo-engineering research. We can't begin to talk about geo-engineering results until we know a lot better how the climate actually works. We've spent enormous time and effort trying to understand the impacts of CO2, and we still are trying to narrow down it's impacts and interactions. Heck, there still isn't a strong consensus on the SIGN for feedbacks of some water vapour processes like clouds. Yes, we know alot, but we've got a lot left to learn. The steps being worked on today through simulations like CMIP5 and others are helping us better understand climate and the interactions within our atmosphere. That's the first step towards knowing what exactly any geo-engineering is gonna really accomplish, so we are in the most meaningful way doing that research today and opening up options in the future.
A lot of people claim the soft sciences are not 'really science' due to the intangibility of their results - and this plays directly into that bias.
However, it's very much not just the softer sciences that have this issue. There's a growing realization that it's pervasive across many hard science disciplines:
We're inundated with data that, due to the specificity of the field or detail of the results, has to come from 'experts' and doesn't lend itself to a sort of common-sense vetting that we can use to filter bullshit in the usual course of our lives. Whether it's from ignorance of statistical methods, poor experimental technique, motivated mendacity (for whatever reason), or simply experimental results that represent only an unusual end of a bell-curve, there are many, many reasons that scientific data has to be taken with a serious grain of salt. It can't be assumed to be conclusive until we've reproduced it in whatever context we're trying to apply it.
With the exception of climate science. It's settled and you're a heretic if you suggest any uncertainty exists in any part of that field...
"Ocean acidification Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30 percent. This increase is the result of humans emitting more carbon dioxide into the atmosphere and hence more being absorbed into the oceans. The amount of carbon dioxide absorbed by the upper layer of the oceans is increasing by about 2 billion tons per year."
But this seems the worst info to me: http://climate.nasa.gov/vital-... "Data from NASA's Grace satellites show that the land ice sheets in both Antarctica and Greenland are losing mass. The continent of Antarctica has been losing about 147 billion metric tons of ice per year since 2003, while the Greenland ice sheet has been losing an estimated 258 billion metric tons per year. "
Approaching half a trillion tons of ice *per year* being melted seems an astounding amount.
That's great, strip a single comment I make of all context and then counter it.
Yes, I said slashing CO2 doesn't look like the best plan, I followed by noting: "technologies to replace major emission sources like automobiles are, in climate timelines, very close to being solved profitably by folks like Tesla without us hamstringing the economy to force the matter."
Before that I stated I see a serious need to plan how we will cope with linear increasing temperature and sea level rise.
But sure, pretend I said there wasn't a problem. The reality remains I stated a serious need to plan how to cope with it, and even posited that one piece of the solution is electric cars. You care to offer any solutions yourself, or would rather just try and criticize everyone not acting panicked enough for your liking?
As you plan solutions, know that from the current CO2 concentrations in the atmosphere, we have to go to pretty much negative emission levels and fast to make a noticeable difference to conditions in the next 50-75 years. Say whatever you want about the importance of doing it, it's not happening. You might as well wish for world peace while you are at it. What can we do for real solutions is the worthwhile matter.
In my book, electric cars and alternative energy are the best routes. Tesla has the electric car timeline rolling already, and I'm hopeful the next 50 years will see not just profitable solar, but better still cheap fusion power(Lockheed claims to be much closer but we'll know for sure in 3-4 years) finally realized and replacing coal plants. If you really want to curtail CO2 concentrations on a meaningfully faster timeline, I'd love to see the plan for how to do it.
Not a solitary reference to the word has squat to do with your claims of boundary conditions that are unprecedented in the last century.
12.3.2,
The CMIP5 experimental protocol for long-term transient climate experiments prescribes a common basis for a comprehensive set of anthropogenic forcing agents acting as boundary conditions in three experimental phases—historical, RCPs and ECPs (Taylor et al., 2012). To permit common implementations of this set of forcing agents in CMIP5 models, self-consistent forcing data time series have been computed and provided to participating models (see Sections 9.3.2.2 and 12.3.1.3) comprising emissions or concentrations of GHGs and related compounds, ozone and atmospheric aerosols and their chemical precursors, and land use change.
"...historical, RCPs and ECPs"
But then, that's a model and you only believe in observed historical data when it comes to predictions, because if there's one thing we all know, straight-line extrapolations of historical data are the only way to predict the future. Ask any stock trader.
Forgive me but isn't CMIP5...prescribes a common basis for a comprehensive set of anthropogenic forcing agents acting as boundary conditions in three experimental phases describing the use of anthro forcing agents as "a boundary condition placed on variables for model runs", like I listed? Isn't the "...historical, RCPs and ECPs" reference you highlight referring to the three experimental phases rather than boundary conditions?
Maybe more bluntly, care to explain a little more clearly why you believe this description endorses the notion that comparing the model runs to observations is not a valid litmus of which scenarios might be more predictive?
I wish you wouldn't mis-characterize my position. I'm the one that started out referencing the IPCC model runs, and here you want to claim I'm the one throwing them away? Is it really heresy to suggest value in comparing observation to model predictions, like the IPCC itself printed in Fig 11.9?
Would you care to point out where the IPCC speaks of your 'boundary' conditions?
Boundary conditions are mentioned eight times in Chapter 12 alone. If you take the Fifth Report as a whole, they are mentioned 24 times and in 6 of the figures. Specifically, and with great import, they are mentioned in 12.5 and 12.13.
The full text from IPCC Chapter 12, basic science for Figure 12.5: Figure 12.5 | Time series of global annual mean surface air temperature anomalies (relative to 1986–2005) from CMIP5 concentration-driven experiments. Projections are shown for each RCP for the multi-model mean (solid lines) and the 5 to 95% range (±1.64 standard deviation) across the distribution of individual models (shading). Discontinuities at 2100 are due to different numbers of models performing the extension runs beyond the 21st century and have no physical meaning. Only one ensemble member is used from each model and numbers in the figure indicate the number of different models contributing to the different time periods. No ranges are given for the RCP6.0 projections beyond 2100 as only two models are available.
No reference to boundaries.
Same chapter, Fig 12.13: Figure 12.13 | CMIP5 multi-model mean geographical changes (relative to a 1981–2000 reference period in common with CMIP3) under RCP8.5 and 20-year smoothed time series for RCP2.6, RCP4.5 and RCP8.5 in the (a, b) annual minimum of daily minimum temperature, (c, d) annual maximum of daily maximum temperature, (e, f) frost days (number of days below 0C) and (g, h) tropical nights (number of days above 20C). White areas over land indicate regions where the index is not valid. Shading in the time series represents the interquartile ensemble spread (25th and 75th quantiles). The box-and-whisker plots show the interquartile ensemble spread (box) and outliers (whiskers) for 11 CMIP3 model simulations of the SRES scenarios A2 (orange), A1B (cyan), and B1 (purple) globally averaged over the respective future time periods (2046–2065 and 2081–2100) as anomalies from the 1981–2000 reference period. Stippling indicates grid points with changes that are significant at the 5% level using a Wilcoxon signed-ranked test. (Updated from Sillmann et al. (2013), excluding the FGOALS-s2 model.)
No reference to boundaries.
You stated that there are boundary conditions that render the observations from the last century irrelevant. I've looked at each reference to the word 'boundary' from a simple search of the chapter, thanks very much. Not a solitary reference to the word has squat to do with your claims of boundary conditions that are unprecedented in the last century. In fact, the references to the word boundary all are in reference to the boundary between layers of ocean or atmosphere, for boundary conditions placed on variables for model runs, and boundaries in the geographical sense to note the difference between global and local trends.
If you aren't going to give the quote you say your going from, I'm not inclined to take your word on it after looking up your two stated references above.
Me:...we know we are emitting a lot of CO2 and that CO2 contributes to warming. You:...The science has shown that reducing CO2 levels will help reduce the rising temperature. The fact that don't understand this doesn't matter.
Are you new to the language, cause it seems you agree with me, then call me out as dense for agreeing with you.
I think maybe I confused you by later saying I do not see compelling evidence that slashing CO2 is a good course, and see the balance of evidence actually suggesting it is a waste of time.
When I say slashing, I mean forced and abrupt cuts of 10% or more on global emissions for no other reason than lowering our carbon footprint. The economic cost to achieve that today is huge. The alteration to each of the IPCC projections for future temperatures though wouldn't change enough to notice it at the resolution their figures are printed. That's how dominant the current CO2 concentrations are against what we will undoubtedly add to it in the future. That's not a lot of benefit at great cost. Much better we spend the same billion plus dollars on adaptation measures like dikes and water management in at risk regions. I then later reference Tesla, because the switch to electric cars that WILL happen in the next 50 years will cut that same 10% of emissions or more and with an economic boost too in place of a huge cost.
I know, nuanced opinions have no place in the climate debate, but I hold one none the less.
At the risk of repeating myself, because I said it in my first post, that is the line followed by the OBSERVATIONS.
By observation? What is the importance of observed increases in a system where the function is becoming unstable? How much are your observations of the past century going to help when you've reached a boundary condition? (which is what the report says is expected to happen).
What is the importance of observations???? Are you making a joke or something? Computer models are simulating one of the most complex systems imaginable. A lot of assumptions and simplifications are required to build those simulations. We use observations to verify those models, by necessity.
Would you care to point out where the IPCC speaks of your 'boundary' conditions? In Chapter 12 the question of "Abrupt Changes" is addressed which would seem to fit your notion of boundaries, and mentions things like loss of the Greenland Ice Sheet, but they summarize by saying in general there is low confidence and little consensus on the likelihood of such events over the 21st century.
You were cherry-picking that report to claim that the IPCC doesn't really believe that climate change is important enough to be a moral issue, when the report says just the opposite.
Sorry for sticking to the basic science portion of the IPCC's assessment report. The morality of x or y didn't make it into the CMIP5 runs. Other than leaving out the IPCC's higher level morality assessments(which I don't believe they have in the other reports by the way, but feel free to direct me to it), I pretty accurately presented the IPCC's model runs and predictions. The only links I provided are to their two complete chapters on short and long term predictions. I then pointed out that of THEIR chosen scenarios, the OBSERVATIONS thus far for both energy balance and temperature track well with the low end of their 4.5 scenario. That's not cherry picking. Maybe you don't like it, but that's just looking at the basic science and facts and presenting them. If I'm wrong on any point do please correct me and help me out, otherwise don't through cheap shots.
Yes, that's the definition. it plots future temperature with respect to 1986-2005 out until the year 2300
But using that same definition, the average pre-industrial temperature was -0.8C.
So, if we want to limit warming to pre-industrial + 2C, we should limit it to +1.2C in that graph.
Correct, we are entirely agreed what you have stated is correct.
We are currently at +0.8C to that same reference. Worded another way, we are +1C compared to 1900 a little over 100 years ago. If you can forgive rounding that to 1C/100years as describing our experience over the last century, then is it not also accurate to characterize the low end of the 4.5 scenario as more of the same by 2300? By the same reference, rising by just shy of 2C, over 250 years is a continued trend of warming by 1C per century.
My response to that is to suggest we not characterize that as catastrophe.
stupid me for not previewing, should read "We are currently at +0.2C not +0.8C, apologies.
Yes, that's the definition. it plots future temperature with respect to 1986-2005 out until the year 2300
But using that same definition, the average pre-industrial temperature was -0.8C.
So, if we want to limit warming to pre-industrial + 2C, we should limit it to +1.2C in that graph.
Correct, we are entirely agreed what you have stated is correct.
We are currently at +0.8C to that same reference. Worded another way, we are +1C compared to 1900 a little over 100 years ago. If you can forgive rounding that to 1C/100years as describing our experience over the last century, then is it not also accurate to characterize the low end of the 4.5 scenario as more of the same by 2300? By the same reference, rising by just shy of 2C, over 250 years is a continued trend of warming by 1C per century.
My response to that is to suggest we not characterize that as catastrophe.
In that chapter, they are talking about temperature anomalies with respect to 1986-2005 average. That applies to the entire graph, from now to 2300.
Yes, that's the definition. it plots future temperature with respect to 1986-2005 out until the year 2300. The low end of scenario 4.5 plots under 2C at the year 2300. That's what I claimed from the start, that's how the graph is labelled, drawn and meant to be read.
Slashdot Mirror
We don't need to use proxies to estimate the termperatures when we have actual temperature records. It seems like you're trying to make something sinister out of using the best available data.
You kind of do need to if you want to make claims like the one made by the GP that I was responding to. Specifically saying:Never before in history has the temperature changed with more then 1 degree over 100 years.
According to the proxy data that shows that historic stability, the temperature hasn't changed by that much since 1900 either. That is a very important observation to make as it shows the claim is lacking in substance.
In addition to the availability of actual direct measurements since the 1900s, which greatly reduces the value of more recent proxy values, there are also some problems with getting recent data from some of the proxies. For instance, there is the divergence problem in dendroclimatology which seems to show that pollution (or other factors) may be inhibiting tree growth since the industrial revolution. I imagine there's probably some difficulty with ice cores as well, since it may be difficult to get recent temperature measurements from glaciers that are shrinking.
Yes, Mann's paper from 2007 notes the same problem you mention. The calibration phase has a consistent problem with early calibration late verification. If you calibrate to the instrumental record from 1900-1950 and then verify the resulting proxy data from 1950 onwards you get observed evidence for a systematic bias in the underestimation of recent warming. Mann's words, not mine. The proxy data isn't registering the recent warming that we see in the instrumental record. I suppose that's no reason not to continue assuming that the same proxy data would have picked up similar warming in the past in your opinion. I'm less convinced. If you look closer at Mann's paper, he also observes the EIV methodology is least susceptible to the bias, and is thus the best method, again in Mann's opinion, not mine. If you check the reconstruction graphs though the EIV goes higher than the 1850-2006 average in 600AD, 1000AD and 1400AD. Mann doesn't graph the EIV from 1900 onwards, but in the calibration problem discussion he shows some portions of it, and it sits no higher than the 1000AD records for EIV from 1950 through 2000. It's all there in Mann's paper and please correct me if I'm in any way misrepresenting things. I've been trying to follow and understand this correctly for a long time now.
Of course, there are actually people studying these problems and even the quality of the calibration period which is used to match instrumental records to proxy values, you might want to try searching with the "proxy calibration" keyword, or reading up on the divergence problem in dendroclimatology.
As I noted above, I've done searches on that and come up with the observations above. The literature basically agrees that the proxy data, for reasons unknown, has a systematic bias in the underestimation of recent warming.
Forgive me for pointing that out when people make the claim that the historic record shows the last century is an anomaly. The instrumental record is anomalous compared to the proxy data. Attributing that entirely to climate change and not the fact those are entirely different data sets and methodologies is dishonest in the extreme. There's a reason the scientists writing the papers have a lot of caveats on the results regarding this, dropping those to make a blanket statement to scare folks is misrepresenting the facts.
"They spike up very quickly after the ice age ends, drop back down, and generally fluctuate a significant amount without any human input at all.
Not according to any the historical temperature graphs [wikipedia.org] that I've seen. The temperature rises rapidly at the end of the ice age and then levels off an eventually begins to fall again.
http://en.wikipedia.org/wiki/H... [wikipedia.org]
The graph in the page you linked to shows temperature doing exactly what I claimed it does."
Acually it does not. The spikes you talk about are changes of about 0.3 degrees Celsius during hundred of years. Check the diagram more closely and you will also see that. The last "downspike" is what's called the little ice age and is still just about a dip which is about half a degree during a couple of hundred of years.
Never before in history has the temperature changed with more then 1 degree over 100 years. Even the during the sharp raise in the beginning in the diagram was that the case.
Natural variation in temperature are very slow and does not change as fast as today. The variations in temperature we see today are unprecedented for the last 10 000 years. Thats why scientist are saying its AGW. We, humankind has caused it.
You'd think so wouldn't you. Do yourself a favor and go on google scholar and lookup the proxy reconstructions of temperature of the last 10k or even 2k years. The big names you'll want to check for papers by are Mann et al, Moberg et al and Esper et al. Look at the reconstructed temperatures and try to find anyone that has reconstructed temperatures after the year 1900. I can't find a single one yet that includes those years from out of their proxy data, and I've been looking for awhile. I even dug enough to find Mann had included some of his raw proxy data, and the proxy data does extend past 1900. Interesting thing is the raw proxy data looks like pseudo random noise, most importantly that there is nothing distinctive happening in the raw data after the year 1900.
You know what does get graphed though? The proxy reconstructions up till the year 1900 are graphed, and then the instrumental record is graphed from the year 1900 onwards. As you have observed, it makes for a very, very scary and compelling looking graph. Starting after the year 1900 the trend radically changes, so much you would almost wonder if there was a methodology change starting at that point on the graph... Then you realize it's not just human emissions that started roughly then, but the methodology cut over. And Mann has been selling that straight faced to people for over a decade now.
Don't take my word for any of this though. As I urged from the start, go to google scholar and read the actual work from Mann and his peers doing the reconstructions and check it out for yourself. If you find proxy reconstructed results past the year 1900 please point me to them as I'm still looking myself,
Water vapor is self-regulating in that the amount in the air will usually be determined by other conditions. If we put carbon dioxide in the atmosphere, there's more carbon dioxide in the atmosphere. If we put more water vapor in the atmosphere, it rains. Therefore, although water vapor is more of a greenhouse gas, it can't cause overall warming on its own, while carbon dioxide can. It can amplify warming, since warm air can have more water vapor.
The trouble is water vapor is more complicated than that. Depending on conditions water vapor can be both positive and negative as a feedback. What precedes the rain you note, is clouds and heavy cloud cover obviously blocks a lot of radiation. If you take a look at the CMIP5 studies the impact of water vapor in them is still very poorly modelled and a, if not the, major source of uncertainties. The IPCC notes as severe a difference that the sign of clouds as a feedback is still uncertain, with different models disagreeing on the sign. The current consensus looks to be that the resolution of current models isn't fine enough to accurately model cloud effects.
The fact that energy imbalance has remained constant while CO2 has risen like mad suggests something else in the natural part of the system is offsetting things. Water vapor and clouds would be strong candidates, but we'll have to wait and see as newer models start trying to include those effects in a better way.
I will note that, according to your second paragraph, there's a lot of insane people out there.
Agreed, but arguing with the insane walks the line of joining their insanity.
Actually the article clearly explains what will happen. No piling on is necessary, unless you didn't bother to RTFA.
The CBC article does poorly actually, but if you meant the linked actual journal article then you are correct. In either case you missed my sarcasm, apparently with a good number of mods keeping you company.
Quick, we need everyone to pile on for why this proves catastrophe is imminent and favored policy changes must be passed. Then the other half can pile in and explain why this means nothing and the next ice age is still coming...
Wow that's a lot of down voting. I must have succeeded in angering both sides.
Quick, we need everyone to pile on for why this proves catastrophe is imminent and favored policy changes must be passed. Then the other half can pile in and explain why this means nothing and the next ice age is still coming...
It's also because of the heating up. If we're putting CO2 into the atmosphere, and CO2 is a forcing greenhouse gas (water is a greenhouse gas, but self-regulating so it can't force a change), and the temperature is going up (and those three hypotheticals are indeed true), then it seems to me that AGW is the obvious conclusion, and anybody who thinks it isn't happening has some explaining to do.
Declaring that water vapor is 'self-regulating' is a bit naive. It's pretty well agreed that the affects of water vapor will vary based on atmospheric composition, global temperature, ocean currents, and many more factors as well. It is also agreed that water vapor is currently contributing nearly 70% of the over greenhouse affect while CO2 is far, far less. Are you really comfortable just waving away concerns that water vapor will muddy the picture, because climate scientists are not and are actively working to better model and understand it's impacts.
No sane person is arguing against CO2 increasing because of us, nor that CO2 contributes to the greenhouse affect. No sane person is arguing against the fact that recorded temperature has been increasing the entire time we've recorded it. Those two points though don't equate to an answer on just how bad our contribution to the problem is.
Get yourself better informed. Go to sources like the IPCC and look at energy imbalance trends, the amount of energy the greenhouse affect is trapping. Match that to global temperature trends, and you can see that energy has been increasing at a static year to year amount with little trend up or down. Predictably, that matches the linear increasing temperature trend we see, as total energy goes up each year so does the temp. Here's the part though that leads me to say it's not time to panic. Look at CO2 concentrations over that same time, and map them to the energy imbalance(increasing greenhouse effect). CO2 has been rocketing on up and up, but the energy imbalance has been sitting there with no upward trend to match. We know CO2 is contributing, but we still have other factors like water vapor that we are trying to figure out, and the bare numbers suggest that CO2 isn't sending is into a death spiral of accelerating warming, but instead the same continual linear warming we've already seen over the last century.
Same problem in Europe.
Europe also has a ban on Neonic pesticides... Too bad that's not likely to silence the anti-pesticide fud over here.
I beg to differ. They may be vocal, but they are not large, and they're more or less unconnected with the scientists. You're dangerously close to demonizing people because you disagree with them. This is especially important because you seem to be overly concerned with these peoples' perspective. Very few others, especially in political circles, are paying any attention to them. There are a few instances where there is sufficient business case for a given environmental principle for the ruling class to take note of it, but otherwise not. Business always has a very slow response to any sort of moral pressure, and much slower when the principle at hand is environmental as opposed to e.g. human rights.
However, the liberals have at least the advantage of being on the right side of history. Less wasteful use of the Earth's resources is simply inevitable, and on the sound assumption that humans survive the next millennium, the Carbon Crisis will be the first and greatest instance of geoengineering, but not the last. Now that we have determined that it is actually possible, it will be, oh, probably about 200 years until we get sufficient handle on the situation to be able to do a second experiment.
Oh, and your ideas about "massive global actions" are mostly fictional. That is to say, they will happen eventually, but there are very few people who are that stupid. It's mostly a right-wing strawman. No one is dumb enough to try to sell massive changes with a huge price tag. It's in their interest to minimize cost estimates. Since no one is doing much of anything, it's more or less irrelevant what the projected costs are, but there's also no reason to go off the handle about any cost estimates, high or low. Again, you're giving these ideas undue attention. Or rather listening to the people who are trying to stir your outrage. Don't get jerked around by demagogues on either side.
I have to point out you are simply factually incorrect on claiming that massive global actions are fictional or fringe proposals. Look at the actual details of the Kyoto protocol as laid out and signed by a great many nations. At the time it was signed it was agreeing to lower emissions to 10% lower than the average that had existed several years before the agreement was signed. That's why nobody who signed it actually even attempted to meet their obligations. Well, with the exception of Russia, because it lucked into a massive recession after the emission reduction reference year so they had already met their lowered emission goal. Nobody else though was inclined to follow suit on purpose.
Sure Kyoto is an example of nations not following through, but it also demonstrates that the desire and will to propose and even agree on massive global actions is very much real and very much not a mere fringe movement type thing. Unless you don't consider rolling the global economy back to 10% below the average from 5-6 years ago is really all that bad...
...It's a well-kept secret, but 95 per cent of the climate models ... have been found ... to be in error....
Yes, most, if not all, of the climate are in error. They do not forecast the global climate with 100% accuracy.
.
They never will forecast the global climate with 100% accuracy. So they will always be in error.
However, they currently are accurate enough to forecast a future climate that has problems, and time is running out to prevent those problems from growing so large that they are all but irreversible.
The question is, do we start to address global warming now? Or do we wait until the models have 100% accuracy, at which time it will be too late to do anything about the problem.
How accurate is 'good enough' to make sweeping emissions changes at great economic cost today? I don't think there is much disagreement from anybody about moving towards electric cars and greatly reducing our emissions on a timescale of 10-20 years. I don't there is much disagreement about moving to alternative energy as it improves options like solar or better yet fusion, but that is also on a timescale of a few decades. But in that timeframe and with those advances that are coming for the simple reasons of economic advancement if no other, we will be greatly reducing our emissions.
To make a significantly greater impact than is going to happen all on it's own, we need to basically make pretty large reductions to CO2 emissions within the the next decade and the only way to accomplish that is globally reducing consumption and production. No matter how you cut that, it amounts to a global agreement on taking a big economic downturn for the future benefit of mankind. I'm not sure there exists a high enough level of Good Enough to make that kind of argument.
Now, none of that has much of anything to do with climate science, other than it's all very pertinent realities facing us regarding what actions we need to take.
The science for the climate models though isn't nearly as definitive as many make out. Make no mistake, the CMIP5 and similar experiments are very good and important science. The limitations that they are still working under though are very significant. One major caution is that any of the 95% accuracy style claims made by the models though are based on the caveat that assumptions in the model are 100% accurate and are comparisons made almost exclusively in hindcasting. The trouble is with very complex models, hindcasting is vulnerable to a lot of confirmation bias. Models results are combinations of a lot of things, including the input datasets, initial conditions, and the underlying interaction models themselves. When hindcasts come in too high, we naturally look at why and find sensible adjustments to the models, initial conditions and datasets that will lead to a better result. The same process is repeated for hindcasts that miss certain known trends in the past. After all those iterations though, we have a set of models whose input data, initial conditions and models are all heavily tailored to getting the result we know is the correct one. In ANY other field using such complex models, you would re-verify your results against extra runs of the real world system, and in that way rule out the possibility you are only getting better at predicting a single very specific sub case. With climate, we only have one run of the system available to work with. Worse yet, our most accurate and detailed datasets only span about 100 years, while we are looking at processes that span millennia. Again, the CMIP5 and other experiments are great science, but they are working under very difficult circumstances on a very challenging problem and claiming and extraordinarily high absolute confidence in the current modelled results is over reaching IMO. In truth, if you combine that with a hard push for major policy changes, it's downright irresponsible.
Oh, stop your sighing, you idiotic concern troll. One side is wrong and filled with cranks, nutters, and retired engineers, does no research and advances nowhere. The other is exactly the opposite.
Except for all those crying catastrophe and demanding panic and immediate and massive global actions be taken without any further investigation or consideration of the consequences because it's too urgent to investigate further. That crowd is also very large, very vocal and every bit as anti-science as the extreme deniers.
It might be that panic is the correct response. An extreme position (like predicting "the oceans will boil") isn't extreme if science backs it up.
Please tell me you are trolling. No food for you.
Can I make an appeal that the comments NOT become dominated by the crazies from both sides? Everytime an article like this comes to Slashdot, the prophets of doom come on decrying how anyone not sufficiently panicked and desperate is an insane denier like the bonafide loonie in the article.
After that it devolves into 'proving' the other side is wrong by pointing at the false claims made by the nuts on the opposite 'side'.
sigh, I know it's naive, but it needs saying.
I think any PR person, CEO, and other mouthpiece who says this stuff is perfectly safe should be forced to drink it. Daily. For a year. Their family included.
If the PR clowns are going to claim it's safe, put their money where there mouth is. If they refuse to drink it, assume they're lying and feed them to bears.
Hold these guys to some standard of truth instead of their accustomed truthiness, and see what they do.
I'm so tired of these "think tanks" who are nothing more than paid shills who spout this crap just to obfuscate the truth -- it's no different than the tobacco lobby did. It's slimy and dishonest, and should carry a huge penalty.
As noted before from Article:
The chemical, which is also commonly used in paint and cosmetics, is known to have caused tumors in rodents, though scientists have not determined if those carcinogenic properties translate to humans. The authors said the amount found, which was measured in parts per trillion, was within safety regulations and did not pose a health risk.
"If I were to peer-review a paper on this, I would insist on a plausible physical explanation for the claimed measurement." That's stupid. Providing proof that something interesting is happening and repeatable is viable science all on its own. I've read quite a lot of highly-respected papers from highly-respected people in highly-respected journals which did nothing other than document a pattern of behavior without explanation. In fact, most scientists I know will say they rarely ever really think they know *why* something happened, but that doesn't stop them from wanting to know. Some things get thousands of perfectly cromulent papers written prior to anyone really having a firm grasp on the "why" - hell, if you have the "why" then you probably have the last paper that will ever need to be written on the subject. Even farking *gravity* is still a bit of a mystery. We're pretty good on exactly *how* it works, but the *why* that you insist is necessary, for even something we all pretend to understand, isn't really yet known.
Dr. Schweitzer will tell you the same thing. She found what looked like soft tissue in a T-Rex bone back in 1993 and published her results, in shock herself and knowing that it was impossible to really be that. She checked and rechecked to rule out contamination and other causes, never finding one. The entire scientific community though refused the possibility it was soft tissue because Schweitzer couldn't explain how it could be preserved. By the year 2000 though she'd found the same results from enough other fossils that she's finally getting some traction and it's now starting to be taken by others as true, and there is new research now into how the heck it has happened. Not many people would carry that a decade.
When climatologists say geo-engineering is not the solution, they mean a political solution to drastically and immediately reduce CO2 emissions, is a better choice. Of course, that is NOT going to happen. So the choice is not between geo-engineering and some theoretical perfect solution, but between geo-engineering and doing almost nothing. I don't think we are to the point where we should roll out large scale geo-engineering, but we certainly should be doing the research so it is an option in the future. Currently it is politically incorrect to do even minimal research.
Good news, we already are.
The entirety of climate science and all the CMIP5 experiments for the IPCC ARE also geo-engineering research. We can't begin to talk about geo-engineering results until we know a lot better how the climate actually works. We've spent enormous time and effort trying to understand the impacts of CO2, and we still are trying to narrow down it's impacts and interactions. Heck, there still isn't a strong consensus on the SIGN for feedbacks of some water vapour processes like clouds. Yes, we know alot, but we've got a lot left to learn. The steps being worked on today through simulations like CMIP5 and others are helping us better understand climate and the interactions within our atmosphere. That's the first step towards knowing what exactly any geo-engineering is gonna really accomplish, so we are in the most meaningful way doing that research today and opening up options in the future.
A lot of people claim the soft sciences are not 'really science' due to the intangibility of their results - and this plays directly into that bias.
However, it's very much not just the softer sciences that have this issue. There's a growing realization that it's pervasive across many hard science disciplines:
http://www.wsj.com/articles/SB... : 64% of pharma trials couldn't be reproduced.
http://retractionwatch.com/201... - half of researchers couldn't reproduce published findings.
We're inundated with data that, due to the specificity of the field or detail of the results, has to come from 'experts' and doesn't lend itself to a sort of common-sense vetting that we can use to filter bullshit in the usual course of our lives. Whether it's from ignorance of statistical methods, poor experimental technique, motivated mendacity (for whatever reason), or simply experimental results that represent only an unusual end of a bell-curve, there are many, many reasons that scientific data has to be taken with a serious grain of salt. It can't be assumed to be conclusive until we've reproduced it in whatever context we're trying to apply it.
With the exception of climate science. It's settled and you're a heretic if you suggest any uncertainty exists in any part of that field...
I do not see compelling evidence that slashing CO2 is a good course
The ocean hates you.
http://climate.nasa.gov/eviden...
"Ocean acidification
Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30 percent. This increase is the result of humans emitting more carbon dioxide into the atmosphere and hence more being absorbed into the oceans. The amount of carbon dioxide absorbed by the upper layer of the oceans is increasing by about 2 billion tons per year."
But this seems the worst info to me:
http://climate.nasa.gov/vital-...
"Data from NASA's Grace satellites show that the land ice sheets in both Antarctica and Greenland are losing mass. The continent of Antarctica has been losing about 147 billion metric tons of ice per year since 2003, while the Greenland ice sheet has been losing an estimated 258 billion metric tons per year. "
Approaching half a trillion tons of ice *per year* being melted seems an astounding amount.
That's great, strip a single comment I make of all context and then counter it.
Yes, I said slashing CO2 doesn't look like the best plan, I followed by noting: "technologies to replace major emission sources like automobiles are, in climate timelines, very close to being solved profitably by folks like Tesla without us hamstringing the economy to force the matter."
Before that I stated I see a serious need to plan how we will cope with linear increasing temperature and sea level rise.
But sure, pretend I said there wasn't a problem. The reality remains I stated a serious need to plan how to cope with it, and even posited that one piece of the solution is electric cars. You care to offer any solutions yourself, or would rather just try and criticize everyone not acting panicked enough for your liking?
As you plan solutions, know that from the current CO2 concentrations in the atmosphere, we have to go to pretty much negative emission levels and fast to make a noticeable difference to conditions in the next 50-75 years. Say whatever you want about the importance of doing it, it's not happening. You might as well wish for world peace while you are at it. What can we do for real solutions is the worthwhile matter.
In my book, electric cars and alternative energy are the best routes. Tesla has the electric car timeline rolling already, and I'm hopeful the next 50 years will see not just profitable solar, but better still cheap fusion power(Lockheed claims to be much closer but we'll know for sure in 3-4 years) finally realized and replacing coal plants. If you really want to curtail CO2 concentrations on a meaningfully faster timeline, I'd love to see the plan for how to do it.
12.3.2,
"...historical, RCPs and ECPs"
But then, that's a model and you only believe in observed historical data when it comes to predictions, because if there's one thing we all know, straight-line extrapolations of historical data are the only way to predict the future. Ask any stock trader.
Forgive me but isn't CMIP5 ...prescribes a common basis for a comprehensive set of anthropogenic forcing agents acting as boundary conditions in three experimental phases describing the use of anthro forcing agents as "a boundary condition placed on variables for model runs", like I listed? Isn't the "...historical, RCPs and ECPs" reference you highlight referring to the three experimental phases rather than boundary conditions?
Maybe more bluntly, care to explain a little more clearly why you believe this description endorses the notion that comparing the model runs to observations is not a valid litmus of which scenarios might be more predictive?
I wish you wouldn't mis-characterize my position. I'm the one that started out referencing the IPCC model runs, and here you want to claim I'm the one throwing them away? Is it really heresy to suggest value in comparing observation to model predictions, like the IPCC itself printed in Fig 11.9?
Am I made of wood or something?
Boundary conditions are mentioned eight times in Chapter 12 alone. If you take the Fifth Report as a whole, they are mentioned 24 times and in 6 of the figures. Specifically, and with great import, they are mentioned in 12.5 and 12.13.
The full text from IPCC Chapter 12, basic science for Figure 12.5:
Figure 12.5 | Time series of global annual mean surface air temperature anomalies
(relative to 1986–2005) from CMIP5 concentration-driven experiments. Projections are
shown for each RCP for the multi-model mean (solid lines) and the 5 to 95% range
(±1.64 standard deviation) across the distribution of individual models (shading). Discontinuities
at 2100 are due to different numbers of models performing the extension
runs beyond the 21st century and have no physical meaning. Only one ensemble
member is used from each model and numbers in the figure indicate the number of
different models contributing to the different time periods. No ranges are given for the
RCP6.0 projections beyond 2100 as only two models are available.
No reference to boundaries.
Same chapter, Fig 12.13:
Figure 12.13 | CMIP5 multi-model mean geographical changes (relative to a 1981–2000 reference period in common with CMIP3) under RCP8.5 and 20-year smoothed time
series for RCP2.6, RCP4.5 and RCP8.5 in the (a, b) annual minimum of daily minimum temperature, (c, d) annual maximum of daily maximum temperature, (e, f) frost days (number
of days below 0C) and (g, h) tropical nights (number of days above 20C). White areas over land indicate regions where the index is not valid. Shading in the time series represents
the interquartile ensemble spread (25th and 75th quantiles). The box-and-whisker plots show the interquartile ensemble spread (box) and outliers (whiskers) for 11 CMIP3 model
simulations of the SRES scenarios A2 (orange), A1B (cyan), and B1 (purple) globally averaged over the respective future time periods (2046–2065 and 2081–2100) as anomalies
from the 1981–2000 reference period. Stippling indicates grid points with changes that are significant at the 5% level using a Wilcoxon signed-ranked test. (Updated from Sillmann
et al. (2013), excluding the FGOALS-s2 model.)
No reference to boundaries.
You stated that there are boundary conditions that render the observations from the last century irrelevant. I've looked at each reference to the word 'boundary' from a simple search of the chapter, thanks very much. Not a solitary reference to the word has squat to do with your claims of boundary conditions that are unprecedented in the last century. In fact, the references to the word boundary all are in reference to the boundary between layers of ocean or atmosphere, for boundary conditions placed on variables for model runs, and boundaries in the geographical sense to note the difference between global and local trends.
If you aren't going to give the quote you say your going from, I'm not inclined to take your word on it after looking up your two stated references above.
Me:...we know we are emitting a lot of CO2 and that CO2 contributes to warming.
You:...The science has shown that reducing CO2 levels will help reduce the rising temperature. The fact that don't understand this doesn't matter.
Are you new to the language, cause it seems you agree with me, then call me out as dense for agreeing with you.
I think maybe I confused you by later saying I do not see compelling evidence that slashing CO2 is a good course, and see the balance of evidence actually suggesting it is a waste of time.
When I say slashing, I mean forced and abrupt cuts of 10% or more on global emissions for no other reason than lowering our carbon footprint. The economic cost to achieve that today is huge. The alteration to each of the IPCC projections for future temperatures though wouldn't change enough to notice it at the resolution their figures are printed. That's how dominant the current CO2 concentrations are against what we will undoubtedly add to it in the future. That's not a lot of benefit at great cost. Much better we spend the same billion plus dollars on adaptation measures like dikes and water management in at risk regions. I then later reference Tesla, because the switch to electric cars that WILL happen in the next 50 years will cut that same 10% of emissions or more and with an economic boost too in place of a huge cost.
I know, nuanced opinions have no place in the climate debate, but I hold one none the less.
By observation? What is the importance of observed increases in a system where the function is becoming unstable? How much are your observations of the past century going to help when you've reached a boundary condition? (which is what the report says is expected to happen).
What is the importance of observations???? Are you making a joke or something? Computer models are simulating one of the most complex systems imaginable. A lot of assumptions and simplifications are required to build those simulations. We use observations to verify those models, by necessity.
Would you care to point out where the IPCC speaks of your 'boundary' conditions? In Chapter 12 the question of "Abrupt Changes" is addressed which would seem to fit your notion of boundaries, and mentions things like loss of the Greenland Ice Sheet, but they summarize by saying in general there is low confidence and little consensus on the likelihood of such events over the 21st century.
You were cherry-picking that report to claim that the IPCC doesn't really believe that climate change is important enough to be a moral issue, when the report says just the opposite.
Sorry for sticking to the basic science portion of the IPCC's assessment report. The morality of x or y didn't make it into the CMIP5 runs. Other than leaving out the IPCC's higher level morality assessments(which I don't believe they have in the other reports by the way, but feel free to direct me to it), I pretty accurately presented the IPCC's model runs and predictions. The only links I provided are to their two complete chapters on short and long term predictions. I then pointed out that of THEIR chosen scenarios, the OBSERVATIONS thus far for both energy balance and temperature track well with the low end of their 4.5 scenario. That's not cherry picking. Maybe you don't like it, but that's just looking at the basic science and facts and presenting them. If I'm wrong on any point do please correct me and help me out, otherwise don't through cheap shots.
Yes, that's the definition. it plots future temperature with respect to 1986-2005 out until the year 2300
But using that same definition, the average pre-industrial temperature was -0.8C.
So, if we want to limit warming to pre-industrial + 2C, we should limit it to +1.2C in that graph.
Correct, we are entirely agreed what you have stated is correct.
We are currently at +0.8C to that same reference. Worded another way, we are +1C compared to 1900 a little over 100 years ago. If you can forgive rounding that to 1C/100years as describing our experience over the last century, then is it not also accurate to characterize the low end of the 4.5 scenario as more of the same by 2300? By the same reference, rising by just shy of 2C, over 250 years is a continued trend of warming by 1C per century.
My response to that is to suggest we not characterize that as catastrophe.
stupid me for not previewing, should read "We are currently at +0.2C not +0.8C, apologies.
Yes, that's the definition. it plots future temperature with respect to 1986-2005 out until the year 2300
But using that same definition, the average pre-industrial temperature was -0.8C.
So, if we want to limit warming to pre-industrial + 2C, we should limit it to +1.2C in that graph.
Correct, we are entirely agreed what you have stated is correct.
We are currently at +0.8C to that same reference. Worded another way, we are +1C compared to 1900 a little over 100 years ago. If you can forgive rounding that to 1C/100years as describing our experience over the last century, then is it not also accurate to characterize the low end of the 4.5 scenario as more of the same by 2300? By the same reference, rising by just shy of 2C, over 250 years is a continued trend of warming by 1C per century.
My response to that is to suggest we not characterize that as catastrophe.
In that chapter, they are talking about temperature anomalies with respect to 1986-2005 average. That applies to the entire graph, from now to 2300.
Yes, that's the definition. it plots future temperature with respect to 1986-2005 out until the year 2300. The low end of scenario 4.5 plots under 2C at the year 2300. That's what I claimed from the start, that's how the graph is labelled, drawn and meant to be read.