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Tom Dayton at 11:15 AM on 9 April 2010CO2 lags temperature
nhthinker, you did write something that does have appropriate threads on this site: "But it certainly does not seem that it is coming from scientific curiosity when you make a choice not to consider the question of whether there is any amount of human induced CO2 that could be considered valuable to the environment as a scientifically valid question." Your comments in that regard would be on topic in either of these threads: Global warming is good, which lists side by side the claims of positives and negatives of global warming or CO2 is not a pollutant But further comments on this thread you are reading now, probably will be deleted if they are off topic. -
Ned at 10:50 AM on 9 April 2010A database of peer-reviewed papers on climate change
Well, Poptech, maybe it's just me, but I don't see any obvious non-subjective way to assess the quality of a journal. A successful journal is one that publishes papers that are cited frequently, open avenues for new productive research, and generally raise the reputation of the journal among scientists working in its field. When that happens, people will submit more papers to the journal because publication in its pages is now considered a mark of distinction. The editors can then be more choosy and pick only the best papers, which further raises the journal's reputation ... that's what every journal editor wants to happen. This spiral can also go in the opposite direction. When a journal publishes a paper that can't be replicated, or that has clearly demonstrable analytical flaws, that's a bad sign. Likewise, if its papers don't seem to be stimulating new ideas or opening up new areas of research, it won't be cited as often and people will choose to submit their good papers elsewhere. As I said with E&E, there have been a series of very poor papers that seem to indicate a problem with the peer review process there -- either it doesn't exist at all, or it's not very effective, or somehow papers are getting routed around the review process, or something. So people tend not to take E&E very seriously. Yes, this is all subjective, but the end result is real. Active scientists don't have much time in their lives, especially those working in academia (as my friend says, "It's a great job, having all this flexibility ... I can work any 80 hours a week that I choose!") So they make judgments about what to spend their time on and reading E&E tends not to make that cut. Anyway, I'd agree that what I'm talking about is very subjective. If you have suggestions for a more objective way to assess the quality of a journal, one that doesn't involve the opinions of the scientists working in its field, I'd be interested in discussing that. -
scaddenp at 10:47 AM on 9 April 2010CO2 lags temperature
Just to further clarify that. I would accept as reasonably safe, CO2 increases such that rate of temperature change was no faster than that due to Milankovich solar forcings. ie a lot lower than what we doing now. -
scaddenp at 10:41 AM on 9 April 2010CO2 lags temperature
The fossil record would indicate that abrupt change is very bad, not that it doesnt happen. Asteroids especially come to mind. Single volcanoes certainly make short term changes to temperature but the aerosols are short lived. There is evidence that climate change due to mass volcanism is also highly undesirable. (from the point of view of species that went extinct). The natural ice age cycle has rates that are a/ very slow compared to current change b/ entirely predictable. While I don't know what you regard as "good analysis" of CO2 addition rate, you should be making some risk assessments. The various economic analyses of cost have considered sea level rise of 1m by 2100. The effects of water-cycle disruption are harder to assess but that is what IPCC WG2 is all about. Have you read it? Does that sound "safe" to you? Whether the temp. now are less than previous interglacial periods is irrelevant- in the past those temperatures were reached with warming rates much lower than now. Rate is far more important than absolute level because adaptation takes time. -
Rob Honeycutt at 10:18 AM on 9 April 2010Skeptical Science Housekeeping: Preview, translations and icons
That's great you've got someone translating Chinese. My wife is Chinese and sometimes I have a hard time explaining complex climate issues to her. Now I can just show her the Skeptical Science article! -
nhthinker at 10:06 AM on 9 April 2010CO2 lags temperature
scaddenp- Thanks very much for your thoughtful assessment. As to abrupt changes changes- sometimes they occur naturally- Volcanoes and asteroids come to mind. Thus having the CO2 in the atmosphere prior to the occurrence of the abrupt cooling event may be necessary to speed the rewarming. How fast can humans safely add CO2 to the atmosphere? I'm not sure there is good analysis on this. The current modern temperatures are still significantly less than the highs of the previous interglacial periods. -
Doug Bostrom at 09:59 AM on 9 April 2010Antarctica is gaining ice
BTW, CryoSat uses radar sensing as opposed to lasers so it's not really a direct substitute for ICESat, whose replacement is laconically scheduled for 2014. However CryoSat will be able to provide extent measurements which can combined w/NASA'a stopgap coverage to continue gathering data. Another splicing controversy smorgasbord for rejectionistas, doubtless, but unfortunately priorities in the U.S. leading up to ICESat's final failure precluded timely launch of a substitute. -
scaddenp at 09:50 AM on 9 April 2010CO2 lags temperature
nhthinker - the issues associated with human-induced climate are about RATE of change. Who knows what an "optimal level" of CO2 is? What we do know is that changing the climate too fast is highly undesirable. Suppose you decided that 3 degrees would be better earth, would avoid an ice age etc. What you then have to decide is how fast is it safe to make that change over. The environment is stressed by change from ice age to interglacial but not too bad. If you accept rate as safe, then we need to by changing the temperature at around 1/10 of rate we are doing so at the moment. Also, I think such engineering is premature. Your efforts would reduced by natural sequestration by the time you needed it. A safer strategy would be as Ned said. Hold your carbon reserves for a few thousand years (or whatever the optimal point is) and then burn them - SLOWLY. -
Doug Bostrom at 09:47 AM on 9 April 2010Antarctica is gaining ice
ESA CryoSat 2 successfully launched, replacing spacecraft lost in the 2006 launch attempt and neatly slipping into place to take over for ICESat, now (RIP) to be retired by NASA after a final laser failure late last year. Excellent article w/many interesting details here at SpaceFlightNow. ESA mission homepage here Interesting note: this launch was from a old missile silo, the subterranean type. Talk about swords to plowshares, eh? -
CoalGeologist at 09:38 AM on 9 April 2010Skeptical Science Housekeeping: Preview, translations and icons
There is a nice write-up on SkepticalScience.com appearing in the most recent (8-April-10) issue of the Yale Forum on Climate Change & The Media The article asks, "Are you listening, Washington, D.C.? – try this trick." (referring to the nifty SkepticalScience iPhone app, not to "hiding the decline"!) -
Doug Bostrom at 09:00 AM on 9 April 2010A database of peer-reviewed papers on climate change
There's an article on journal impact here at Wikipedia for those interested in accepted or at least less controversial ways of assessing such things. -
Riccardo at 08:28 AM on 9 April 2010CO2 lags temperature
nhthinker, actually you should be satisfied by the interest of climatologists on "the impact of their scientific inquiry", at least for what concern next century. Some of them also addressed the not-so-pressing problem of next ice age tens of thousands years ahead. And, finally, the impact of ongoing climate change has been addressed regionally, some winners and some loosers in the short term, only loosers in the BAU scenario in the long term. All of these things has been put on the table for the wider audience to be able to decide what to do. I really don't get about what you're complaining. -
VoxRat at 08:00 AM on 9 April 2010Ocean acidification: Global warming's evil twin
Berényi Péter #44: "BTW, I wonder how they figured out how much average ocean pH was 250 years ago with such accuracy. " I was wondering that, too. It's not easy to figure out from the link (Wikipedia). -
nhthinker at 07:51 AM on 9 April 2010CO2 lags temperature
Most scientists care about what the impact of their scientific inquiry is. So we get pleadings about saving the planet for a scientist's 10-year old daughter and let the future generations fend for themselves. But I guess you don't consider that a value judgment as long as its coming from a scientist "on your side". If you want to leave the impression that you think there is no amount of human caused CO2 that would be good, then you have successfully left that impression without actually saying it. But it certainly does not seem that it is coming from scientific curiosity when you make a choice not to consider the question of whether there is any amount of human induced CO2 that could be considered valuable to the environment as a scientifically valid question. One would expect that you as a scientist studying CO2 should be at least be glancingly interested in the answer to such a question. -
Berényi Péter at 07:22 AM on 9 April 2010Visual depictions of Sea Level Rise
#83 doug_bostrom at 02:20 AM on 9 April, 2010 you should take a look at David Roper's site Done. Same silly curve fitting I was trying to make fun of. -
Berényi Péter at 06:42 AM on 9 April 2010A residential lifetime
#84 Philippe Chantreau at 16:01 PM on 7 April, 2010 How much vegetation is necessary to store 1 year's worth of emissions? How much land does that require? The carbon stored in plant biomass is about 8 kg/m2 both in grasslands and forests. The carbon released to the atmosphere is some 8 × 1012 kg annually. Therefore you would need 1012 m2 which translates to 387000 sq miles (larger than Texas). -
Jim Powell at 06:37 AM on 9 April 2010Skeptical Science Housekeeping: Preview, translations and icons
John, Thanks for helping me; next time I may not need it thanks to the Preview button. Jimbo. -
Riccardo at 06:27 AM on 9 April 2010Ocean acidification: Global warming's evil twin
Berényi Péter, diurnal and annual temperatures may vary a couple of tens of degree Celcius. Does it mean that the biosphere is already adapted to similar changes in average temperature? The same question can be asked for almost any physical/chemical variable. You reasoning is a huge oversimplification. -
Berényi Péter at 06:13 AM on 9 April 2010Ocean acidification: Global warming's evil twin
#35 Ned at 00:52 AM on 9 April, 2010 Your flat assertion that the existence of natural variability around the mean somehow immunizes the ecology to variability in the mean seems to be unjustified. It would be unjustified indeed had I claimed such a thing unconditionally. However, it was not the case. I said it should not have observable effect provided shift is negligible compared to natural variability. If diurnal pH changes up to 1 pH do occur in coral reefs with no devastating consequences, a less than 0.1 pH change since 18th century is insignificant. BTW, I wonder how they figured out how much average ocean pH was 250 years ago with such accuracy. -
Doug Bostrom at 05:57 AM on 9 April 2010CO2 has a short residence time
N/A, read Spencer Weart's book for a thorough background on this topic. To get directly to the point you raise, you might start with chapter two, The Carbon Dioxide Greenhouse Effect Long story short, we've got a robust set of reliable physics tools found amply predictive in a plethora of applications including this particular case coupled with extensive laboratory experiments and a record of field observations as well as models of climate behavior, all mutually consistent and all leading inexorably to the notion of additional C02 in the atmosphere causing an increased temperature of the part of the Earth we're concerned with. At this point, the onus is on folks choosing to disagree with all of the above to state a persuasive case of why and how all those things should fail in a way that does not upend much of what we think we understand of radiative physics, the ideal gas law and much else. That's a steep hill to climb, nobody's yet made it to the top. -
Ned at 05:55 AM on 9 April 2010CO2 lags temperature
Science doesn't tell us what is "good" or "bad." Those are value judgments. Science tells us "If you increase the radiative forcing from greenhouse gases, the planet will warm." Whether that's good or bad, or more likely some mixture of both, depends on your viewpoint. Your repeated insistence that you want people to focus more on value judgments while simultaneously insisting that you want the discussion to be more scientific seems irreconcilable to me. -
Ned at 05:49 AM on 9 April 2010CO2 has a short residence time
N/A, we've "convicted" CO2 of causing warming for physical reasons, not just because of statistical correlations. In fact, Arrhenius predicted that CO2 would cause warming long before we had any of the data showing these correlations. Some of the reasons for believing that CO2 is responsible for the warming are discussed on the page How do we know CO2 is causing warming?. -
nhthinker at 05:31 AM on 9 April 2010CO2 lags temperature
Actually, the purpose of this site seems to be to cite scientific literature that CO2 from humans causes warming and warming in the short term is necessarily bad. That there seems to be an aversion to discuss why some level of human caused CO2 may be necessarily good and an aversion to interest in understanding what that level would be seems like it has some non-scientific motivations to me. If you are interested in CO2 but not interested it what the optimum level that the humans should keep in the atmosphere to balance all the potential disasters, seems kind of limited scope of inquiry to me. If you want to take the position that the "right" level of CO2 would be the level that would occur without humans, then say so. Such a position does not have a scientific basis unless you consider humans unnatural. -
CO2 has a short residence time
With climate science as in astronomy when we are looking into past events, it is hard to distinguish between circumstantial evidence, theoretical conjectures, and thought experiments which supports a given hypothesis which may not be falsifiable (i.e., it cannot be refuted or replicated by experiments. Thus it is easy to mistake a correlation with cause and effect. Can you give some advice on how one can untangle this confusion? What repeatable experiments have been done or can be done in a high school lab to show that global warming is "caused" not "correlated" with a rise in CO2 and is due only to the onset of the industrial age and is not caused by something else? What does it take to transform a correlation into a cause? It only takes one valid counter example to demolish a hypothesis. Are all the proposed counter examples for the predominant cause of global warming proven to be invalid or cannot be proven by experiment. Is it possible to have two contradictory hypotheses about global warming which are not falsifiable. That is, they cannot be proven by experiment. -
Berényi Péter at 04:46 AM on 9 April 2010Skeptical Science Housekeeping: Preview, translations and icons
Thanks for the preview. I'll certainly use it (I know who I am :) -
Ned at 04:44 AM on 9 April 2010CO2 lags temperature
nhthinker writes: The inability of scientists here to discuss what the "right amount" of extra CO2 is the appropriate amount to balance the short term needs versus the long term needs of humanity seems like a very unscientific approach to me. The fact that people don't choose to discuss things in the way you want doesn't imply any "inability" or "unscientific approach" on their part. -
Ned at 04:38 AM on 9 April 2010CO2 lags temperature
nhthinker writes: What problem do you have with use of the term "apocalyptic" to describe the hostility to life of the next ice age? Well, it's awfully slow for an "apocalypse" since it develops slowly over a period of tens of thousands of years. Also, of course, humans have already lived through multiple glacial/interglacial cycles and in fact dramatically expanded our geographic range, our population, and our behavioral development (language, tool usage, etc.) right smack in the middle of the last glacial cycle. Do you know of an adjective that would be more accurate to describe a planet that has lost 80% of its biomass to premature death and starvation? Source, please. Where does that 80% come from? "Premature death and starvation" seems a bit overdramatic for something that only transpires slowly over a period of millennia. You carefully avoided the answer as to whether humans should do what is scientifically necessary to prevent the next ice age. (A response like "we're doing it anyway" is not an answer). Again, I'd recommend a little more politeness and a little less confrontational style. I haven't avoided any question in this thread. We are, of course, actually in an ice age. As I understand it we're near the start of an interglacial that would probably last for another 50,000 years even if we didn't burn another kg of coal or oil. To answer your question directly, I don't think we should lift a finger to "prevent" the next glacial advance. I think our descendants 2000 generations in the future should be able to decide how they want to handle it. In fact, if burning fossil fuels and raising the CO2 concentration of the atmosphere were the best way to prevent a future glacial advance, that would be all the more reason to reduce our consumption of fossil fuels now and save some for the future generations who will really need them, right? Following your logic, we're currently wasting precious resources that will be desperately needed by our 2000x-great-grandchildren in AD 50,000. More to the point, worrying about the next glacial advance (which almost certainly won't happen for 50,000 years, and if we burn enough carbon may not occur for 500,000 years or more) is rather foolish when the next century or two will experience serious environmental problems caused by too much warming and the resulting alterations of the hydrologic cycle. What you're suggesting is analogous to worrying about flooding in the middle of a drought. We should focus on more immediate concerns. -
nhthinker at 04:19 AM on 9 April 2010CO2 lags temperature
The entire purpose of this forum is to link to scientific literature that human introduced CO2 is causing global warming and the clear implication here is that extra CO2 is a bad thing. The inability of scientists here to discuss what the "right amount" of extra CO2 is the appropriate amount to balance the short term needs versus the long term needs of humanity seems like a very unscientific approach to me. You are welcome to call it "policy" question. To me, it clearly has its roots in scientific exploration of causes and effects and near term disasters versus long term disasters. But it's your site and you are welcome to limit it to discuss the limited inquiry you want. Cheers. -
citizenschallenge at 04:07 AM on 9 April 2010Skeptical Science Housekeeping: Preview, translations and icons
Fantastic and thank you John. . . . . . and thanks to all the other folks helping you keep this site going and improving. For myself, you have leap-frogged all the previously top rung AGW information websites. They are still valuable and needed, but for the interested lay-person I believe Skeptical Science is the number one spot going!!! Peterm And the Preview button is genius ;-) -
Tom Dayton at 03:54 AM on 9 April 2010CO2 lags temperature
nhthinker, what you're now focusing on is a policy question that is off topic for this thread on CO2 lagging temperature:I assert that humans should intentionally do what ever necessary to prevent the next ice age. It should be done with a significant safety margin of error to account for unusual but expected events like massive volcanoes and asteroid hits. Do you disagree? If so, why?
I'm not sure whether there is an appropriate thread on this Skeptical Science site, since this site focuses on science rather than policy. But you might try The Upcoming Ice Age Has Been Postponed Indefinitely, or maybe Are We Heading Into A New Ice Age? Please don't be upset if off-topic posts get deleted from any of the threads, though. -
Doug Bostrom at 03:48 AM on 9 April 2010CO2 lags temperature
Nhthinker, you've been provided with excellent information indicating that perhaps 40,000 years from now we should consider another ice age to be reasonably imminent. Right now we have a more urgent problem erupting under our feet, multiple lines of evidence indicating we're in some degree of difficulty due to C02 pollution. Why not check back here in, say, 35,000 years? Meanwhile the rest of us will get on with solving the present issue. -
CBDunkerson at 03:48 AM on 9 April 2010Skeptical Science Housekeeping: Preview, translations and icons
Even as someone who has been using HTML for years I'm glad to see the preview button as there have been several times that I have wondered things like, 'does this site support font tags?' and either taken them out or just went ahead and hoped for the best. That said, please note Ned's comment above about 's and, as you can see in my text above, the fact that if you hit preview a few times these 's are actually accumulating in the comment box and will come out in the final note if not removed.Response: Fixed the accumulating slashes glitch, thanks for pointing this out. -
nhthinker at 03:14 AM on 9 April 2010CO2 lags temperature
What problem do you have with use of the term "apocalyptic" to describe the hostility to life of the next ice age? Do you know of an adjective that would be more accurate to describe a planet that has lost 80% of its biomass to premature death and starvation? You carefully avoided the answer as to whether humans should do what is scientifically necessary to prevent the next ice age. (A response like "we're doing it anyway" is not an answer). I assert that humans should intentionally do what ever necessary to prevent the next ice age. It should be done with a significant safety margin of error to account for unusual but expected events like massive volcanoes and asteroid hits. Do you disagree? If so, why? If there is full agreement from scientists that humans should, for the good of future generations assure that an "unnatural" amount of CO2 should be kept in the atmosphere to prevent an ice age, then who decides what the right added level should be? Those that are only concerned and emotionally connected with their immediate offspring? Or those that have a more balanced concern with the long term? Were the dramatic changes to climate/environment caused beavers considered "natural" because the they were not self-aware of their impacts? Are the changes to the environment changed by self-aware beings any less natural? To see a difference between the beavers and the humans is to agree with the druids. -
Chris G at 02:52 AM on 9 April 2010Ocean acidification: Global warming's evil twin
Ah, I think I detect a pattern related to the preview pane. Look's like apostrophes are escaped as part of coping with XML(?) in the preview, but not returned to original when submitted. It's a minor defect. -
Doug Bostrom at 02:50 AM on 9 April 2010Humans are too insignificant to affect global climate
Because it's a hobby horse for me, let me amplify Ned's remark about our crude habit of burning our petroleum. Not only is petroleum pyromania pathetically primitive, but burning this resource will seriously balloon our future energy requirements while simultaneously throwing sand into the gears of our economy. Using petroleum for liberation of heat via combustion is a wretched waste that is going to come back and haunt us in a bad way. We're heavily dependent on polymers made from oil. Nearly all of our daily activities are dependent on products made using petroleum feedstock. That's because the simple molecule of methane and all of its more evolved and advanced cousins are absolutely fabulous structures for rearranging into different configurations, tweaking with the addition of other components and then creating useful things. All of that hydrogen and carbon we lean on was jammed together for free, eons ago, over plenty of time when nobody was tapping their foot waiting for their next roll of polyethylene, collection of O-rings, damping bushing, etc. As we burn what could be made into relatively durable and incontrovertibly essential artifacts, we're going to see the prices of nearly every product we use steadily creep upward quite independent of direct impacts of rising motive power costs. If we continue to burn petroleum willy-nilly as we do now, our requirement for hydrocarbon feedstock to produce things we need will collide with insufficient supply. At that point, we're going to have to -manufacture- methane and all its more useful cousins, and that's going to require a staggeringly large amount of of energy. Marrying hydrogen and carbon is only possible with a large energy dowry, which of course is why the stuff burns so nicely. That energy demand is going to be stacked on top of what will already be a horrendous challenge, that of substituting for and eliminating hydrocarbons for thermal applications such as heating and motive power. We really do need to change our approach to how we use petroleum. We can start by recognizing what rotten stewards of this resource are our petroleum producers, refiners and marketers, how defective is their drive to encourage waste. However, they're not really the primary problem. These entities have commercial considerations compelling them to encourage us to be thoughtless, feckless consumers. At the end of the day, it's up to us to cease our fascination with igniting petroleum and instead consider it irreplaceable, something to be husbanded jealously. -
Chris G at 02:49 AM on 9 April 2010Ocean acidification: Global warming's evil twin
I\'ve been thinking for some time that ocean acidification is potentially a bigger problem than sea-level rise, maybe even bigger than climate zone shifts. But, I haven\'t been able to bridge the gap between impacts to specific species of foraminifera and impacts to people. I\'ve read speculations that we might want to develop a taste for jellyfish, but I suspect there exists information on the food chain dependencies on the threatened foraminifera and the subset of those chains on which a lot of people are dependent for food. Any pointers? RobHon #16, my sister and I happen to have graduate degrees in psych, though I went the cognitive route (and ended up in a not in a research career) and she went social and teaches at university, your thoughts are within the realm of how I remember things in that area. I don\'t know the answer; attempts to ease the dissonance are often seen as attempts at manipulation. Defense mechanisms kick in (It\'s really hard to admit even to yourself that your actions cause harm to others.) and further attempts are most often met with hostility. Kind of like trying to force water on a dehydrated person, they don\'t feel thirsty, but you have to keep making water available. -
Doug Bostrom at 02:20 AM on 9 April 2010Visual depictions of Sea Level Rise
BP, you should take a look at David Roper's site: Sea Level Versus Temperature He's not in sync w/you regarding his conclusions but I'm pretty sure you'll enjoy looking at his methods. -
Chris G at 02:01 AM on 9 April 2010Ocean acidification: Global warming's evil twin
Bern, I don't have time to back you up with real papers at the moment, but I was thinking the same thing. For a 1st-order assessment, I imagine an overlay graph of the lifetimes of sulfates, particulates, CO2, whatever, and the different rates, and opposing effects, determine that a climate roller-coaster was likely. As well, systems tend to 'wobble' for a while after a disturbance, as inertial effects often cause an overshoot of equilibrium. -
Ned at 01:53 AM on 9 April 2010CO2 lags temperature
nhthinker writes: Using your daughter is clearly an emotional argument- any scientist can recognize that. Is this a forum for emotional arguments? I don't see any problem with John mentioning his daughter. Many of us who are scientists do in fact have young daughters, and being normal human beings we may be a bit more motivated in our work by the desire to make the world a better place for them to grow up in. In any case, it seems less problematic than your own use of "apocalyptic ice age" and "druids" above. Maybe when you're just starting out participating here you might want to be a little less confrontational? Just a suggestion. -
Chris G at 01:49 AM on 9 April 2010Ocean acidification: Global warming's evil twin
Ned, No worries. Actually, when I first read it, I assumed you were having a poke at the anti-AGW argument regarding the correlation of CO2 and global temps, or anything where the causation can be determined by physics, and not by simply looking at the stats. Cheers -
billkerr at 01:48 AM on 9 April 2010Are we too stupid?
wrt the nuclear issue fast breeder reactors (Gen IV) use existing wastes as fuel and only 1% remains as waste, compared with 99% of Gen II reactors. Nuclear is safer than coal. The only real problem is that nuclear is still more expensive. Barry Brook's Brave New Climate is a well informed pro nuclear site based on the premise that AGW is a real problem. Also Tom Blee's book Prescription for the Planet is an interesting read mainly for his knowledge of the Integral Fast Reactor but he has other interesting ideas too, such as the boron fueled car. -
Ned at 01:45 AM on 9 April 2010Skeptical Science Housekeeping: Preview, translations and icons
Tom writes: \"Thanks for the Preview button, John! Unfortunately it seems to be absent from the Arguments pages. \" Also, I notice that when I click the Preview button it adds back-slashes (\) before any quote-marks in my comment [see above]. That said, thanks for doing this. I apologize for all the times I've messed up my HTML (or just written the wrong thing) and I'll endeavor to make good use of the Preview button in the future. -
Ned at 01:42 AM on 9 April 2010Ocean acidification: Global warming's evil twin
Chris G writes: Ned (#2 & #3), I don\'t know, there\'s a correlation there, but you can\'t prove causality. :-P My motto is "Post in haste, repent at leisure." I think my frequent mishaps and typos probably helped provoke John into adding the "Preview" button. -
Ned at 01:37 AM on 9 April 2010CO2 lags temperature
Whoops, Tom has the name right and I have it wrong. It's Berger and Loutre, not Loulette. And when I write "If our understanding of that threshold is correct, it's possible ..." that should be incorrect not correct. Sorry for the confusion. -
Chris G at 01:34 AM on 9 April 2010Ocean acidification: Global warming's evil twin
Ned (#2 & #3), I don't know, there's a correlation there, but you can't prove causality. :-P -
Ned at 01:33 AM on 9 April 2010CO2 lags temperature
nhthinker writes: Please reference the peer reviewed article that claims to know that the next ice age will definitely not occur for the next 50,000 years. "Definitely" is not a word that's used much in the geosciences. The last couple of interglacials were relatively short, but in recent years people have realized that neither of them is a particularly good analog for the Earth's current orbital geometry, and that comparison to the MIS-11 interglacial is more apt (Berger and Loulette 2002). Even without any anthropogenic CO2, this yields a long interglacial followed by a descent into glacial conditions around 50k years from now:
Long-term variations of eccentricity (top), June insolation at 65°N (middle), and simulated Northern Hemisphere ice volume (increasing downward) (bottom) for 200,000 years before the present to 130,000 from now. Time is negative in the past and positive in the future. For the future, three CO2 scenarios were used: last glacial-interglacial values (solid line), a human-induced concentration of 750 ppmv (dashed line), and a constant concentration of 210 ppmv (dotted line). Simulation results from (13, 15); eccentricity and insolation from (19). (Berger and Loulette 2002).
See also the subsequent work by David Archer, described in his book The Long Thaw and in various papers, such as Archer et al. 2005. Archer notes that the projected insolation will come close to the apparent threshold for glaciation in a few thousand years, then move away from that threshold and not cross it until 50k years from now.
If our understanding of that threshold is correct, it's possible that a mild return to glacial conditions could start in a few thousand years from now. But the most likely scenario is that it won't happen for another 50k years. That's without additional CO2. Here's what Archer et al. 2005 say about adding CO2:
"Release of 1000 Gton C (blue lines, Figure 3c) is enough to decisively prevent glaciation in the next few thousand years, and given the long atmospheric lifetime of CO2, to prevent glaciation until 130 kyr from now. If the anthropogenic carbon release is 5000 Gton or more (red lines), the critical trigger insolation value exceeds 2 s of the long-term mean for the next 100 kyr. This is a time of low insolation variability because of the Earth’s nearly circular orbit. The anthrogenic CO2 forcing begins to decay toward natural conditions just as eccentricity (and hence insolation variability) reaches its next minimum
400 kyr from now. The model predicts the end of the glacial cycles, with stability of the interglacial
for at least the next half million years (Figure 3c)."
nhthinker writes: Why won't you answer the question about the beavers?
I'm not sure I understand your point. If your comment above is imagining a hypothetical situation where beavers become intelligent, industrialize, and start to double to CO2 concentration in the atmosphere, then yes, once their scientists understood the probable climate impacts of their activities they would probably be well advised to modify their ways and develop better technologies.
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Tom Dayton at 01:23 AM on 9 April 2010Skeptical Science Housekeeping: Preview, translations and icons
Thanks for the Preview button, John! Unfortunately it seems to be absent from the Arguments pages.Response: I wondered who would bring that up :-) I've now added the Preview button to the argument pages. -
Tom Dayton at 01:11 AM on 9 April 2010CO2 lags temperature
njthinker: An article by Berger and Loutre (2002) explained why this interglacial could last 50,000 years past today. The exact number of thousands of years is estimated differently by different researchers; 50,000 is the current best estimate, but nearly all researchers agree that the number is in the tens of thousands of years from now, and all researchers agree that the number is many thousands of years from now. You can learn more about the triggers of ice ages by entering "Milankovitch" in the Skeptical Science "Search" field at the top left of every page. -
Steve L at 01:11 AM on 9 April 2010Ocean acidification: Global warming's evil twin
Again, the analogy between anthropogenic acidification denial and debunked AGW-denier arguments is remarkable. "We experience daily temperature fluctuations greater than the projected average temperature increase by 2100; therefore AGW is no big deal." Average surface water in the North Pacific will be unsaturated for Aragonite in the North Pacific by 2100? Don't worry! Small volumes are ephemerally unsaturated for Aragonite even now, and there are still pteropods. -
Jim Powell at 01:03 AM on 9 April 2010Ocean acidification: Global warming's evil twin
Wikipedia has an interesting chart on Ocean Acidification:
ocean pH between the 1700s and the 1990s.
According to Wikipedia
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