bradschrag

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bradschrag last won the day on March 16

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  1. Generally, climate is referred to as periods of 30years or greater. So any consistent trends longer than 30yrs could be considered climate change, but of course should be taken with a grain of salt. However, the longer the trend, the more definitive it becomes. Currently we are on a consistent warming trend for about the last 150 years, with a minor cooling trend in the 40's that is mostly attributable to a change in the AMO phase (Atlantic Multidecadal Ociscllation, basically a long term version of El Nino) and aerosols. Using models, we can estimate how much of the current warming is anthropogenic. It's all us. This has an easy to follow observation with the other components that influence the planets radiative balance. It steps through adding in these components individually so you can see the individual and cumulative effects: https://www.bloomberg.com/graphics/2015-whats-warming-the-world/ Sorry, I don't understand what you are asking here. Hmmm... I'll see if I can find a link, but the basic rule is that to determine that the climate is changing we need to have a large enough timeframe to exclude natural variability. The extreme example of this is of course every day when the sun rises and sets. Some people have conceded that because the temperature changes by many degrees during the day, climate change is irrelevant or not occurring. This is false of course, as day/night (diurnal cycle) exists regardless of AGW. So we need to zoom out far enough that those positiive and negative phases of those cycles are offsetting one another. There are a couple really large scale cycles (orbital for example) that we can't really zoom out far enough on in the context of human timeframe, but that cycle is in decline so it is most assuredly not a cause of climate change. Things like PDO, AMO are generally on the timescales of decade to multidecade (about 60yrs for AMO). However, the other key thing to be aware of is generally speaking, the longer the phase, the smaller it's influence is on the system. So in short again, a timeframe long enough to not be influenced by internal variability is what should be focused on. The other key thing is recognizing all the factors that go into radiative forcing. I mentioned earlier the cooling in the 40's-70's is partly attributed to a huge increase in aerosols from factories. It's also partly the reason for the old global cooling scares.
  2. Policy isn't my thing. Speaking generally, efforts to curb, reduce, and even draw down co2 are the direction we need to be heading. How to do that without stripping others of accessibility to stable living is the key of course. Again, speaking generally, I don't think there is a one size fits all solution.
  3. No. NOAA is perhaps the largest collection of temperature data. But the problem you are always going to arrive at, Jonathan, when you try to highlight one record over another is consilience: http://climatestate.com/2013/06/18/research-closes-gap-between-warming-and-co2-rise/ It becomes problematic for your logic because these records are: 1. Independently collected 2. Independently maintained 3. Have independent methodologies (all published except for UAH) to adjustments A few years back, the Koch brother started a project at Berkeley, headed by physicist Richard Muller. The objective was to come up with a completely independent, unique methodology for examining the temperature data. There was much talk among this group that the algorithms that other agencies used were inappropriate. After developing their own methods, collecting data (I believe they use NOAA raw data as well as some other agencies), they published their results. The results, more consilience: See, all this high level of agreement by multiple independent agencies becomes a problem for you because all it leaves you with are really two options: a) claim conspiracy and gloat b) develop your own methodology and see what you find Option B is wonderful! Word of caution when taking this route, be sure you have a proper understanding of weighting. You can't simply gather all the data and average it together. There's a disproportionate representation of the number of stations and where they are located, as well as how often and when readings are taken. Care must be exercised to properly weight the data spatially and temporally (in space and time). By the way, this word consilience comes back to bite when you step back and consider the breadth of scientific subjects and disciplines that have covered and support AGW. It's many fields of science that have looked at this topic from their relative perspective and that is why there is this idea of consensus. But I digress, I just said the ugly c-word. Sorry. Brant, at what point did I sat it wasn't corruptible? However, that something is corruptible doesn't mean it is corrupt. For you to make the assertion it is without evidence is a logical fallacy. In regards to CC or AGW, I don't really care if it's referred to as CC or AGW. I tend toward AGW in conversations personally. This is cute, Ellen. And by cute, I really mean pathetic. Maybe try addressing some of the evidence I've brought forward instead of attacking the individual. It's called ad hom and it's really sad excuse of a debate tactic. It's interesting here Brant that you think being presented data is a form of bullying. In regards to the kind of forum it is or isn't, you don't have to participate in this conversation. So stop subjecting yourself to bullying tactics of looking at charts. Fairly certain that isn't the objectivist way of living. As I said earlier Jonathan, it's much easier to address 1-2 specific topics at a time, rather than 5-6 large open ended questions. Here are a couple more resources about adjustments and temperature: https://judithcurry.com/2014/07/07/understanding-adjustments-to-temperature-data/ (this one even has a chart showing adjustments increasing the warming trend ☣️, and it's posted on a skeptics blog ☣️☣️) http://berkeleyearth.org/methodology/ (Berkeley Earth Surface Temperatures - methodology) https://www.metoffice.gov.uk/hadobs/hadcrut4/data/current/download.html(HADCRUT data center) https://data.giss.nasa.gov/gistemp/ (GISS data) On final parting plot just ran across, JMA (Japan) temperature analysis: https://skepticalscience.com/jma_temperature_record.html
  4. I find this to be a slippery slope. Hiroshima was a product of humans. Just because we evolved in nature and utilize parts of isn't a safe implication that what we are doing isn't destructive. Human history is quite frequently filled with humans acting as if there were no repercussions for their actions when in hindsight we realize how ignorantly we acting. I absolutely agree that adding to the shared knowledge base is key to human growth. Seems a bit pointless to do so, however, when given access to the information individuals simply disregard the warnings in favour of their own whims.
  5. Actually they don't. When one looks at the adjustments, they are equally weighted up and down. Some one could then say that their is a temporal shift in the adjustements, ie early ones shifting down, late shifting up, as a means to exaggerate the trend. The issue there is this is completely opposite of what is seen. The net sum of all adjustments reduces the total trend: https://www.skepticalscience.com/news.php?n=3280 As for the rest of everything you have to say, it's all conspiracy. Not going to waste my time disproving your teapot in orbit that you can't validate by your own will.
  6. Yes, I agree there is uncertainty. The most recent work is looking like the total feedback is positive. That's why I specifically quoted their work (saying 'likely positive') as well as provided a link to their paper (albeit paywalled) and provided the key diagram that supports their assertion.
  7. I'll do my best. In regards to who and when, Joseph Fourier first hypothesized about the greenhouse effect. He noted that the atmosphere must in some way be absorbing, or inhibiiting, invisible light (IR) from leaving the planet (approx 1820's): https://en.wikipedia.org/wiki/Joseph_Fourier Arrhennius in 1896 would be the first to hypothesize that changing co2, including by burning fossil fuels, could enhance the GHE. He also estimated that doubling co2 might lead to approx 5C change in temps! This is seeming a bit high with current research, but I find how close his number is to out estimates to be truly remarkable. https://www.lenntech.com/greenhouse-effect/global-warming-history.htm In regards to your comments about changes in the experiment (changes in equipment and observational biases), Zeke has a great writeup here in regards to they why, where, when, who of adjustments. The end result: adjustments don't impact the overall global trend in any significant way. https://www.carbonbrief.org/explainer-how-data-adjustments-affect-global-temperature-records I can't say for certain that all algorithms are publicly available for download, but some are for sure. For example, here is NOAA PHA algorithm. https://www.ncdc.noaa.gov/ushcn/pairwise-homogeneity-adjustment-software Whether the algorithm is publicly available or not, I can say with a greater degree of certainty the they provide literature explaining their methodlogy: http://static.berkeleyearth.org/pdf/berkeley-earth-summary.pdf Raw and adjusted data are also available through NOAA and other collection agencies. Some people have gone so far as to create their own individual algorithms from scratch: @caerbannog666 has tons of plots on his page and his algorithm is available for anyone to download, go through, and compile on their own. Or if using other's work isn't your thing, come up with your own methodology. As another example of individual analysis, @BubbasRanch has done his own work, and is most definitely on the skeptic side of the debate. However, his results, albeit he doesn't communicate it well in my opinion, agree rather well with NASA results. He also never explicitly compares his results in a side-by-side fashion as @caerbanogg666 does, but I would still personally vouch for his work, just not the implications of what he says it means 😉 That's all I have time for at the moment. Let me know if you have questions about any of this content, or where which questions I can focus my next responses on. 1-2 direct questions at a time is much easier to field and respond to than 5-6 huge open ended questions. Thanks.
  8. Any changes in the system are driven by changes. This seems obvious but there is an often overlooked implication of that statement. Even though an aspect of the system might have a large factor in the energy balance (albedo) it isn't relevant to changes unless it is changing as well. Albedo is made up of 3 main components scattering by the land and surface, clouds, and reflection from ice and snow. Of these 3 factors, the first and last are changing the most. Land use changes (clearing of forests) creates an increase in albedo while melting of snow and sea ice creates a decrease in albedo. Clouds overall aren't changing from much to none. I've seen some reports putting them at a slight decline, but currently can't find that. So as to whether or not they are impactful to albedo, I'd have to say no. What is referred to as the wild card, or uncertainty with clouds is what kind of feedback clouds will be. Everyone recognizes without issue that clouds reflect sunlight, but they also trap heat. How a cloud impacts the system not only depends on the cloud type that forms but also the timing of them. Obviously nighttime clouds are rather lousy at reflecting incoming light but do a wonderful job of trapping heat. Overall, the feedback effect of clouds is currently considered 'likely positive' (https://www.nature.com/articles/nclimate3402). Clouds are what will bring the system back into equilibrium eventually. As I see it, the simplistic explanation is: Warming causes a decrease in relative humidity -> causes a decrease in cloud production -> less cloud production means a gradual buildup of specific humidity -> this eventually restores the hydrologic (cloud) cycle The hydrologic cycle can't really be fully restored though until the system has stopped warming. Current observations are specific humidity is increasing but relative is still in decline. https://www.climate.gov/news-features/understanding-climate/2013-state-climate-humidity Good general link about clouds https://www.sciencedirect.com/topics/earth-and-planetary-sciences/cloud-cover
  9. I can't say precisely when all of these hypothesis were made, but these are the staple hypothesis of AGW: (https://scied.ucar.edu/longcontent/predictions-future-global-climate) 1. First and foremost - burning fossil fuels increases atmospheric concentrations of co2. Seems like a no-brainer but I've crossed paths with individuals who dispute that the current rise in atm co2 is not due to human burning of fossil fuels. 2. As a consequence of #1, Increasing non-condensing greenhouse gas concentrations will cause the system to warm 3. As a consequence of #1, pH of the ocean will shift to a more acidic pH as they absorb more co2 4. Along with #2, increasing ghg will simultaneously cause the stratosphere and on up to cool 5. As a consequence of #2, there will be some positive feedbacks triggered, ie reduced albedo due to loss of sea ice, increased water vapor in the atm 6. As a consequence of #2, there will be sea level rise (SLR). There are 2 reasons for this. 1 - warmer water takes up more volume and 2 - melting glaciers To me, those are the key hypothses of AGW, each of which has now been observed. See below for simple responses to each point, starting with #2. If I need to cover my bases on #1, let me know: 2. https://www.bloomberg.com/graphics/2015-whats-warming-the-world/ 3. http://www.whoi.edu/OCB-OA/page.do?pid=112157 4. https://www.wunderground.com/resources/climate/strato_cooling.asp (contains links to supporting papers) 5. https://www.nature.com/articles/nature06207 6. https://www.pnas.org/content/115/9/2022 For those wanting to read papers that might be behind a paywall, there is a chrome (maybe firefox as well) extension called unpaywallme. It will give you a lock icon that changes to color when you reach a paywalled paper that has a free version available. It's not 100%, but it will get you most papers for free.
  10. Apologies for not interpreting your question as simply what did the GHE refer too. Apparently I've spent too much time arguing with deniers about basic founded principals that I saw your question as an attack on the existence of the greenhouse effect. In regards to your question about repeatable science, I'm going to go back once again to radiative transfer models(RTM or LBL for line-by-line). This is how we approx the GHE for the system. The RTM's demonstrate that we have a very solid understanding of how much energy the system emits when it's fed the proper inputs (as is the case for all models). This is demonstrated when we run models for a particular region and then use a satellite to take a snapshot of the upwelling infrared (IR) of that region. That is what the original image I linked you was demonstrating. Here's another prime example of how well MODTRAN matches satellite observations. For reference, the x-axis simply represents wavelengths (or wavenumbers) and the y-axis represents intensity.
  11. Thanks for the question. First, a link. Yes the number they are using is 6m, rather than .5m, but there are other assumptions being made by your question that are inaccurate. So I'll focus on those inaccuracies. https://www.scientificamerican.com/article/sea-level-could-rise-at-least-6-meters/ Yes, for 2C warming the middle of the road number is around .5m of SLR (sea level rise). This is not the amount of SLR you can expect once you've reached 2C warmer, it's the amount you can expect once the system has fully equilibriated and is back to being in dynamic balance. I say all that because we aren't there. We've warmed over 1C already, and there's currently another 1-1.5C of warming in the pipeline if we stopped burning fossil fuels tomorrow. As we continue to increase co2 concentrations we are only adding more warming into that pipeline. I guess my main point here is it's an ok assumption that we might only rise .5m in 80 yrs, it's not ok to think that that is all the SLR that will occur. I also agree that 80yrs seems like a while for humans to migrate and adapt. However, many of the towns, cities, and villages that do lie within this danger zone of SLR aren't going to be salvageable. One can't simply relocate the city of Miami for example (although their issue is partly subsidence, I hope it's illustrative of the issue nonetheless). The other things that is glossed over by these statements and questions revolves around the inherent chaos of storm systems in these areas. Many coastal towns have been built to account for these storm surges safely. Be it through barriers or simply proximity to the coastline in more remote parts of the world, these natural and man-made barriers or going to prove to be less effective. This raises the long term costs and damages associated with SLR. Now, will we rise 6m? I hope not. That's very drastic change given the timespan. That's the key issue and concern behind AGW after all. It's not whether or not the ice caps have disappeared in the past, they have. It's not whether or not we've been warmer in the past, we have. It's not about whether or not co2 has been higher in the past, it has. The issues surrounding the current changes to the system is how quickly they are changing. The most recent mass extinction (PETM - Paleocene-Eocene Thermal Maximum https://en.wikipedia.org/wiki/Paleocene–Eocene_Thermal_Maximum) event seems to most likely have been driven by a very large outgassing of methane. Methane is a more potent ghg than co2, however it has a relatively short lifecycle in the atmosphere. That's because methane (ch4) breaks down into co2 and water, and the co2 has a very long adjustment time in the atmosphere. So this co2 can have a very long and persistent effect. My reason for mentioning the PETM is the current rate of change far exceeds the rate's seen in the PETM. The 1C warming we've witnessed over the last 100yrs would have taken 2500yrs during the PETM, and it wiped out approx 50-60% of the biosphere. These mass extinction events don't happen literally overnight, only figuratively. Too much of the dismissal by individuals on the basis of lack of evidence, I think , is due to not witnessing a catastrophe due to AGW during their individual lifetime. My personal thoughts on it is that the human lifespan and experience isn't long enough for any individual to realize the full impacts of what is happening. Each subsequent generation going forward will see a slightly less productive, slightly more shallow biosphere. There won't be a morning that comes where all of humanity to wake up and realize something terrible has happened, like a bomb going off. It will be a much slower and more gradual slide and to me, that's more dangerous because it simply leaves the doors open to individuals to dismiss as some other cause.
  12. Also, one other note. In science, a theory is a hypothesis that has been repeatedly tested or criticized without falsification. That AGW is a scientific theory speaks enormously to the amount of validation that goes into it. For anyone to dismiss it as simply a theory that might be wrong rewrites them to bring the evidence to the table to overturn it.
  13. Ok, but I hardly see how that applies to climate. I started at the line-by-line radiative transfer models because it's highly applicable to the topic. Is strawmanning all you are going to be good for here?
  14. > Biggest criticism - While the climate models do a fair job at prediciting the surface temperatures, they don't do as well replicating the mid troposphere temps. This could hint at TCS (transient climate sensitivty) being a bit overstated, in my opinion. > What holes - I'm not sure what constitutes a "hole" to you. From comments and criticisms I've seen of the original Mann hockey stick, it would seem there may have been some... hmmm... methodology that isn't entirely sound. That said, Mann's work has been replicated by over 50 other independent, peer reviewed studies using entirely different proxies and methodologies from his own. So what could be considered a hole (Mann's work, and again I'm not one that can speak for or against his work) in isolation has been repeatedly shown to be a non-issue. Jim Java (@priscian on twitter and github) has compiled a list of these independent studies, but in the meantime here's this: > biggest weakness - Again, I'm not sure how to respond to that. Spectroscopy is very well understood and validated. Line-by-line radiative transfer models do an excellent job modeling outgoing infrared radiation. Because of this, we can tweak the inputs (ghg concentrations) and see what happens to the resulting output. Of course there are some intricacies that pop up here that, again see above, I believe result in issues with TCS. However, TCS aside, we still have a good handle on equilibrium climate sensitivity due to an enormous wealth of knowledge in paleoclimatology. From paleo data, ECS can be well approximated to be ~3C for a doubling of co2 (approx 3.7Wm-2😞 http://science.sciencemag.org/content/337/6097/917.full > show us your critical scientific side - You first.
  15. No, a question was asked for repeatable science. That's what is being offered. I asked up front before my explanation if we were all in acceptance of the GHE, or if we needed to start before that. So we don't need to bicker about the GHE?