MadMonk

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  1. What data are you basing that on? Unless you are just referring to polar ice cap mentioned in the article, but what James Taylor is referring to is precisely sea ice.
  2. No the anomaly relative to the entire period, so by definition there are equal number of points above and below 0. Seriously? The entire argument is based on the two data point. Even if you stop the analysis at 2014 it would hardly support the notion of no retreat (data) It seems to be a recurring theme that your sources almost always fail to examine data critically.
  3. That is not temperature anomaly at all: the right set of plots are differences between the two networks. The trend in the data is basically zero, but it is not unexpected for a short record over regional climate.
  4. Are you referring to the top right chart?
  5. Yeah I usually write my response over the course of the day so I may miss edits. Sorry. Well, a lot of stations were built before long term climate monitoring is need, so unfortunately we have to work with what have to a certain degree. I certainly think that we can get away with far fewer stations in well covered counties like US, e.g. if one is worried about over weighting of potentially contaminated urban stations you can certainly drop them all, (though it doesn't really make a difference). In fact NOAA has already deployed a US Climate Reference Network with long term climate monitoring in mind: However comparing the two network they are virtually identical over the past decade (see temperature series since 2004 on left). Not exactly. Ultimately the weighing simply depends on the density of station in a region which doesn't really much subjectivity. I looked at the description for the algorithms for the NOAA and HADCRUT4 data sets and the weighing part is really simply to implement (Perhaps 5-6 lines of code?). As the goal for all global temperature data set is to provide average temperature for grid boxes, the simplest algorithm you can use is to take an average of all the stations in each grid boxes before you compute the global average. GISTemp is bit more sophisticated, BEST even more so with kriging, which is a commonly used spatial statistical interpolation in various field. The bottom line however is that the global temperature anomaly estimate from BEST is very similar to the others, which suggest that simple method is sufficient!
  6. i think you are mis-representing my position: what I think is that there is not clear reason to suspect US data is different from other country. The reason why that specific comparison is only done for US stations is that Heartland Institute/Anthony Watts only rated US stations. Satellite data are all produced by US based groups, and all satellites that carry the MSU/AMSU instrument are US based. Not sure what the exact figure is on urban vs rural station, but the average global temperature is not a simple average across stations: different weight is assigned to different stations depend on density. If there are say 50% of urban stations, they are give less weight so the don't have an undue influence on the global climate. Equidistant grid is not actually necessarily. You can certainly take an average from a non uniformly distributed measurements! In fact if you want to get better picture for regional change probably a non uniform grid will be far better, and if you are worry about urban effects you'll certainly want higher density there so you can detect non climatic effects! One factor that you may not have considered is that at present the land surface is possibly over sampled: you can go from BEST (39000 stations) to GIStemp (6300 stations) and they basically give you an identical answer. You can further thin out GIStemp by using only very rural sites, and that makes less than 1% difference in the global trend. UHI is not a myth, but "global warming is due to UHI" is a myth. I think you have to understand that there are significant differences between absolute temperature and temperature anomaly They sound similar but have very significant differences: absolute temperature is affected by UHI, temperature anomaly less so. Absolute temperature can change significantly over a short distance but temperature anomaly have strong correlated even between stations up to 1000km apart. As we are more concerned about changes over time, temperature anomaly is a much more accurate measure. There are lots of ver new interesting uses for Satellites, and they do give us a lot of new information about the state of the earth's climate system and have immense value; however what I don't support is uncritically assuming they are more accurate and beyond reproach just because satellites look shiny and new. Certainly this is not how modern science operates.
  7. Yes it is only US, but as the same analysis technique is applied globally, so is there a reason to believe that the same technique will fail else where? Moreover, urban area is only 3% (source). If the increase in global temperature is largely due to biases by urban stations, they would have to be biased warm massively. Is there any evidence of this? The raw data is out there, and if the warming is so obviously biased by bad measurement as contrarians claim, why hasn't any shown this yet? Time and time again scientist have considered arguments advanced by people like "Friends" of Science and Heartland Institute, and have proved that Urban Heat Island is not an issue: rural stations are warming just as fast urban, good sites are warming up just as fast as bad sites. Even the assumption that urbanization results in a warm bias is patently false: there are plenty of situations where urbanization leads to cool biases that needs to be corrected for, and they largely balance each other out, so even raw data gives you a fairly good estimation of global temperature trend (again, compare raw and adjusted data). Yes, but all that means is that you get a number for each patch of the surface (~250km by 250km), but it is meaningless unless you can accurate stitch together records from different satellites to assess long term trend, and that is where the vulnerability of satellite temperature record really lies. Basically every criticism contrarians have levied against surface thermometers apply to satellites: satellite orbits slowly decays, the time of measurement gradually shifts. The difference is that unlike land base thermometer where you have 39,000 independent instruments that can be used to check against one another for non-climate related shifts, we only have 1-2 instruments at a time so any systematic bias is much harder to detect and correct for. To reiterate, I'm not saying that satellite data is inherently worse than land temperature record, but I don't think all the biases are accounted for. Given all the possible pitfalls, and how sensitive the trend is to specific adjustments, I have found little empirical data to support the notion that satellite data is more reliable than land data.
  8. I'm not sure what you are getting at. The point is that since 1979, the adjustment to raw land data is about 0.05 degrees, adjustment from one version to another in satellite data is 0.1-0.2 degrees, so the magnitude of change is up to 4 times. I think you would agree that the adjustments made to satellite is at least as large as land based records. An important consideration that all the land based records reports temperature anomaly (this is a subtle yet hugely important point) precisely to eliminate this particular issue, as we are interested in the change over time, so as long as the surrounding is not changing over time the siting issue is much less than what one would think. This is very different from a weather station that is used for weather forecast, which requires the precise absolute temperature. I also mentioned that are very good ways to remove this bias if there are sudden changes, and you can empirically show that it is actually doing a fairly good job at removing any biases (e.g. Wickham et al 2013, Hausfather et al 2013). Note that the first of these studies were done by a group put together by Richard Muller, who had been a very vocal critic of the land based record and wanted to show climate scientists how it's supposed to be done. This is what their conclusion is: Even if we take Watt's study at face value, then surely once you weed out these stations and only used the ones rates as good would prove that global warming is a hoax. Unfortunately, it doesn't make a difference: the good and best sited stations give pretty much the same answer as all stations. Note that the good or best sited stations are based on Watt's own classifications). So yes, the global surface temperature record is indeed robust with respect to siting issues. So you agree that's not a sign of reliableness? I think you read the graph incorrectly: the adjustments are made to retroactively warm the past (<1940).
  9. Heavily massaged? This is a bit Ironic given the history of his own UAH satellite data set. Given that all data sets (climate related or not) requires adjustments to correct for biases and errors, changes to land temperature is no less legitimate to the adjustment needed for satellite data, which as I mentioned could be just as large. Comparing overlapping era (1979-present): UAH adjustment from one version to the next (5.6 to 6.0) can be up to 4 times larger than the adjustments in surface record made to raw data The trend in surface record is basically unchanged between raw data and final product. In contrast the trend in UAH data changed by 200+% back in 1998 to correct for orbital decay (source), 40% change in 2005 to correct for diurnal drift (source). (as a side note, both of these error was caught by the RSS team. Good thing for quality control ) More recently it is suggested that UAH used an incorrect calibrating factor (source), which if proven to be correct would lead to a 100% change in trend (this is for upper troposphere). Basically, you can use fluffy descriptions to make satellite sound advanced and fancy, but if at the end of day you sit down and objectively look at quality measures (robustness), there are very significant questions regarding satellite data set, and I have yet to come across some objective criteria that suggests satellite data is more reliable. Put it this way, if I tell you that the trend in land temperature record would double by adjusting the data for one station, what would you say? Yes they recalibrate every 8 seconds, yes they are stable to a thousand of a degree, but what good does that do when you need to make 50% changes every five year? You can have the most advanced instrument in the world, but the weakest link in satellite temperature retrieval is the physics of the atmosphere, nature of satellite orbits, and the longevity of the satellite itself. Some additional information: For all the complains about "massaging data", here is a comparison between raw and corrected thermometer data. All the major adjustment are made before 1940, note that the adjustments were upwards, thus making the overall trend lower, as I mentioned before). The adjustment after 1979, the satellite era, is basically negligible, about 0.05 degrees, and because it is mostly uniform the adjustment to trend would be very small compared to the actual trend of 0.145 degrees per decade. This is what adjustments and fixes to trends in UAH looked like from 5.6 to their latest 6.0 version. I don't have time to rescale the axis, but the adjustment towards the wend is about -0.2 degrees.
  10. The article is not really about land based vs satellite measurements, but rather an article on a new research on reducing bias in satellite data, so I'm not sure why the fact that it doesn't advocate one over another is of any significance since they don't make a comparison between the two regarding accuracy and robustness. Moreover, my point is that "Satellite data was the way to go until the results didn't fit with the agenda." was never a correct description of the sentiment of the scientific community, for the reasons I have outlined previously, so I'm interested to see if there are indeed studies/ journal articles that support this. One of the reason why land record is consider to be more reliable is because different methods with the same data yields very similar results, where as satellite data sets differ from one another very significantly. Furthermore, the research mentioned in the article you linked actually highlights my point that there is still uncertainty with satellite data: the research suggests that the trend is biased 20-30% too low. This is not the only recent study that looks into uncorrected for biases, and confirmed biases have changed the trend ~50% (this is just from earlier this year) I'm not saying that we should ignore satellite data: it clearly has significant advantages and complements land based record, and issues will continue to be straightened out. However given how much activate research is still being done to resolve discrepancies, to claim that at present Satellite data is superior is clearly a stretch.
  11. I did double check the IPCC 3rd and 4th assessment reports 2001 and 2007, and the issues regarding satellite record has been outlined have been outlined in both reports, so it certainly didn't reverse course on reliability of satellite as you claimed, so I would be interested if you find anything. The only people I've heard insisting on Satellite being better and infallible would be contrarians and politicians like Ted Cruz and Lamar Smith. Not sure what you mean by "supportive of GW infrastructure"... Well that was just to show that "sea level is not rising" is clearly wrong. Naked eye is actually not great at pick up whether things are increasing at a constant rate. If you actually compute the trend it has sped up considerably: the trend for the past 25 years is double of what it was prior, so it is anything but constant. The current rate is actually closer to 3mm/year. Although it sounds low now, it is expected to continue to accelerate, part of it is due to the fact that ocean is a large heat inertia: it expands as it heats up, but it takes a while for the heat to get down to the deeper part of the ocean. The really issue is that even when the temperature is stabilized, it would take another couple of centuries before ice sheet melt and ocean expansion stop. Models have indicated that even if temperature stabilizes in 2050, the ocean would continue to raise at the same rate through 2100 without slowing down.
  12. Land surface record has always been and will likely be the standard, simply because we have a far longer record (if you include proxies): satellite data has only started since 1979, where as instrument land goes as far back as 1850. Moreover as I pointed out, Satellite don't actually give surface temperature measurement, which is most relevant to us! I'm not sure where you get this impression, but certainly as far as I know there has never been any such sentiment in the scientific community, and I would be interested if you can point me to a source that indicates the contrary.
  13. Not sure what you mean by the right and righteous cause, and I'm certainly not striving for popularity! Climate just happens to be an area of science that I am very interested in, and I do strongly believe in is that decisions should be based on sound evidence. Contrarians (such as "Friends" of Science) are good at obfuscating matters, and they frequently rely on half truths or neglecting important information. The irony is that they frequently claim that climate science is flawed, but if you examine their arguments they are full of holes and self-contradictory! Satellite data and land based data have different strength and weaknesses, and they in fact complement each other and should not be viewed as a substitution. The claim that Satellite data is more reliable is actually a very common misconception (I once thought so too until a course in satellite data retrival), but in reality: Satellites don't actually measure temperature directly, but rather radiation coming from the earth. Things get complicated as radiation gets absorbed and re emitted in varying amounts as it travels through the atmosphere. Inferring temperature actually requires a model, whereas thermometers give you direct temperature. Moreover satellites doesn't give you surface temperature! There are 10,000's of land based thermometers, and thus it is relatively easy to detect for non climatic changes. However as there are only a few satellites up at a time and they generally have to be replaced every 10 years it is actually a challenge to adjust the data to ensure you have a consistent temperature record as each satellite with have biases. Because a satellite can't maintain its orbit forever, you have to adjust the data as the orbit changes. Back in 1998 one of the data sets initially showed 0.05 degrees per decade cooling for a layer of atmosphere, but after an error in orbit decay has been spotted it became 0.07 degrees per decade. There are still recent papers pointing out fairly significant adjustments that may have been missed. I should note that Carl Mears, who heads one of the teams that construct satellite temperature, believes that surface records are still more reliable at present.
  14. I'll circle back to Volcanos and "climategate", but just want to focus your comment on urbanization, because it demonstrates some of the issues with the sources you are probably relying on, e.g. Friends of Science. The data I've shown is the global land and ocean surface temperature from weather stations, not satellites. From what you've said I think you are implying that the warming trend is due to urbanization. It is one of these arguments frequently made by contrarians that sounds reasonable on surface, but there are serious flaws. Even if we accept without question the claim that urban effect has contaminated station record, remember that we are talking about global temperature record, given that urbanization doesn't affect ocean (71%), areas that are never developed or always developed, the effect is likely going to be small. Moreover, these sources frequently claim that urbanization effect exaggerates warming, but the opposite happens just as frequently: urbanization forces weather station to move to an airport/rural area, which is an artificial cooling. what they also don't mention also is that scientist recognize these effects, and do employ methods to remove these urban effects, and they are largely very good. Sites such as Friend of Science never actually post details about the issue, because once you look into it actually renders the argument pointless: rural sites are warming just as fast as the rest:
  15. Without knowing the specific clip you saw it is hard to know what it depicted, but it doesn't seem like the timeline of the ice sheet has been revised recently. I found a map made in 1959 (source) that shows that BC, Alberta and Southern Ontario to be ice free by 10,000. Given that there are multiple lines of evidence to sort out ice sheet retreat (e.g. global temp, sea level, sediment, human migration), it is quite possible that the clip that you saw is simply wrong! it is true that the natural flux of CO2 is indeed very large (except for volcanoes, it is a common misunderstanding but human emission is at least 100 times larger than volcanos), but this ignores is that nature also sucks up a lot of GHG, so the type of argument only holds if nature is also a net emitter, but it turns out on the whole natural processes are actually sucking up anthropogenic CO2: only half of the anthropogenic CO2 remain in the atmosphere, so it is virtually certain that the rise in atmospheric CO2 is due to human activity. that would be true if indeed temperature has stopped rising. Not sure who you are referring to specifically, but despite years of accusations about scientists hiding/manipulating data, not once did anyone actually demonstrated any impropriety. Since raw data is actually freely available, why hasn't any one done a reconstruction to prove that global warming is a fraud? Wait, actually some one by the name of Richard Muller was all ready to show the world that the temperature increase was all an illusion due to improper data handling/manipulation, but all he managed to prove is that climate scientist were right all along. One more thing: ironically what is frequently lost amiss these accusations of impropriety is the adjustment to raw data actually makes the global trend lower when all is said and done.