dense wrote: » I have never seen the ends of so many barrels being scraped in order to try and fail to find any evidence of the catastrophic effects that man made climate change is supposedly wreaking.
Hurricane Harvey provides an excellent case study as it was isolated in space and time. We show that prior to the beginning of northern summer of 2017, ocean heat content was the highest on record both globally and in the Gulf of Mexico, but the latter sharply decreased with hurricane Harvey via ocean evaporative cooling. The lost ocean heat was realized in the atmosphere as moisture, and then as latent heat in record‐breaking heavy rainfalls. Accordingly, record high ocean heat values not only increased the fuel available to sustain and intensify Harvey but also increased its flooding rains on land. Harvey could not have produced so much rain without human‐induced climate change.https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018EF000825
Akrasia wrote: » Hurricane Harvey. A storm that dropped the most rain of any storm in recorded history onto Americas 4th biggest city causing 125 billion dollars in damage. But you can put your head back under the sand if you like.
part of the River Liffey was dried up, to the extent of two miles.
Deleted User wrote: » If the liffey ran dry it would be blamed on climate change would it not? It did in 1452 and was recorded in the annals of the four mastershttp://www.obrienclansociety.com/history/annals-4.htm It also froze several times. Of course that too would be blamed on climtae change
The continuous heat pump from the ocean by Harvey makes it a self‐contained storm. As observed by several Argo floats (Figure 3), near‐surface temperatures were >30°C before the storm passage; see also Figure 4. After the storm passage, the near‐surface ocean temperature (Figure 3) was reduced by 2°C but was still ~28.5°C and thus larger than the SST threshold for TCs. SST observations by satellites (Figure 4) also show a broad region in the Gulf of Mexico with SST >30°C before Harvey (1–20 August) and an average cooling of ~1 to 2°C after Harvey (compare 1–20 September with 1–20 August; Figures 3 and 4). This suggests that the “cold wake” was not cold enough to significantly suppress the TC intensity, enabling Harvey to continue while over land as the warm ocean conditions still facilitated storm development. The implication is that the warmer oceans increased risk of greater hurricane intensity and duration.https://agupubs.onlinelibrary.wiley....9/2018EF000825
Akrasia wrote: » Your data doesn't contradict what I said. First of all, the atlantic SST graph you posted covers the entire atlantic ocean, but this is misleading because the entire atlantic ocean isn't where hurricanes form and track. So we should be correllating SSTs in the parts of the atlantic that affect cyclone formation and wind shear The NAO index graph does correlate with the ACE graph, where the NAO is higher, the ace is generally higher. Secondly, hurricanes and SSTs vary year by year, so you would need to do a correlation year on year rather than using the 10 year smoothed curve which can show trends but multi year oscillations can balance each other out. A full analysis should be comparing individual years and seeing if the warmest ssts correlate with the strongest or highest frequency storm years. (and the data should only include SSTs during the hurricane season) Finally, the MJO needs to be thrown into the mix because it plays a big role in whether the cyclones can form as MJO dictates wind sheer We need a proper study, not just throwing graphs out there in isolation. Emanuel 2007 gave us this graph Here's another study that looked at data going back to the 1940s. The reason they didn;t go back further is because data is less reliable the further back we go One of the authors of this paper gave this presentation this year and it explains and updates the results of his study.
Akrasia wrote: » Perhaps it would, it is difficult to separate natural variability from the consequences of anthropogenic warming. But we do actually understand the physics that dictate rainfall events like Hurricane Harvey. Events like this are one of the more confident predictions of climate change and that paper I linked to did the maths and found that without the record high SSTs and atmospheric warming, the amount of rainfall would have been impossible, and these are direct consequences of the warming we have caused in a naturally cooling phase
Gaoth Laidir wrote: » There's a bit of goalpost-moving going on here. You were the one who first posted 10-year mean ACE data, yet you're now against it. But I do accept your point on the full Atlantic basin, so I've plotted just the tropical HADSST3 max SST for 5-35N and 100-0W, for only the 7 months from May to November. Sorry but I'm sticking with the 10-year mean. If warmer SST means higher ACE then the means should show that relationship. Here I'll "just throw out" the 10-year ACE and AMO (where did you get NAO?) charts again. ACE was still higher when the SST was lower pre-1900. Highest SST was around 1940, yet that coincided with relatively lower ACE. That's all I'm wondering about.
Gaoth Laidir wrote: » The video you posted yesterday showed that it's not that simple.
Akrasia wrote: » I don't see how you don't see the correlation. It is not a 1 to 1 correlation, but its definitely there. There is a dip in the ACE index during the time when WW2 was affecting shipping observations, but the rest of the data shows higher SSTs fuel more powerful storms. The reason this is important is because we are only now starting to pull above the realms of natural variability in local basins. From now on, warm events are mostly record events, and we have seen what can happen when we have record warm SSTs in the Atlantic hurricane basin.
Harvey was a disaster not just because it stalled, but because the SSTs remained hot enough to keep fuelling it despite the hurricane cooling the water in its wake.
Gaoth Laidir wrote: » Right, forget it. You don't get my point so move on. [\quote] do you accept that WW2 would have affected ACE scores for that period? Also do you accept that the data for the 1880s isn't as reliable as it is for more recent observations. If we can see a good correlation within the satellite era when our data is most reliable. I think it is a reasonable assumption to accept that small deviations from this corrrelation in the past might be down to errors in our about records on historical events Here too you're not getting my point. Cold upwelling in the wake happens most near the strongest winds near the eye, not 150 miles way up the coast, where only moderate southerly winds fed in rainband after rainband. It was the larger synoptic setup that caused the problems in Houston. All of those can be linked to the record high SSTs. We'll see what happens the next time we have such high SSTs in the gulf of Mexico. Unfortunately I don't think we'll have to wait too long
Here too you're not getting my point. Cold upwelling in the wake happens most near the strongest winds near the eye, not 150 miles way up the coast, where only moderate southerly winds fed in rainband after rainband. It was the larger synoptic setup that caused the problems in Houston.
Akrasia wrote: » Gaoth Laidir wrote: » Right, forget it. You don't get my point so move on. do you accept that WW2 would have affected ACE scores for that period? Also do you accept that the data for the 1880s isn't as reliable as it is for more recent observations. If we can see a good correlation within the satellite era when our data is most reliable. I think it is a reasonable assumption to accept that small deviations from this corrrelation in the past might be down to errors in our about records on historical events
Gaoth Laidir wrote: » Right, forget it. You don't get my point so move on.
All of those can be linked to the record high SSTs. We'll see what happens the next time we have such high SSTs in the gulf of Mexico. Unfortunately I don't think we'll have to wait too long
Akrasia wrote: » Also do you accept that the data for the 1880s isn't as reliable as it is for more recent observations.
Oneiric 3 wrote: » Essential reading:https://www.liebertpub.com/doi/10.1089/ast.2017.1671 Abstract:"In Frank and Sullivan (2016), the results of exoplanet studies were used to set an empirical limit on the probability that Earth was the only world in cosmic history where such an energy-harvesting species evolved. Their result showed that, unless the probability per habitable zone planet for such “exo-civilization” evolution (Pc) was Pc < 10−22, Earth is not unique. Even if, for example, Pc were as low as 10−19, the number of technological civilizations like our own across the history of the visible Universe would still be large enough (Nc ∼ 1000) for statistically meaningful average properties of exo-civilizations to exist. These average properties include , the average lifetime of a technological civilization. We note that represents the final factor in the Drake equation and, therefore, has a long history within the debate concerning exo-civilizations. Its importance for issues of sustainability are straightforward. Low values of (a few times 102 or 103 years) imply most of the choices we might make in our effort to build a sustainable version of our civilization will fail. Larger values of imply more paths to success". A real page turner...
DickSwiveller wrote: » I wish I could understand that. Oneiric, can you simplify what it is saying?
dense wrote: » Ah here!! I've been trying to get you to accept that for ages Akrasia!! That we must question the motivation of those who would have us believe that the quality and extremely limited coverage of the so-called global temperature data from the 19th century is in any way comparable to modern observations. So, following on from this, would you also now accept that proxy records, upon which the whole global warming thing was whipped into a real frenzy, are even less reliable than the unreliable data you've highlighted? #climatejustice
Gaoth Laidir wrote: » I'm sure WW2 had some effect, but to what extent we don't know. The fact still remains that the SST was warmer 80 years ago than today. Older data will have more uncertainty, which would also apply to all types of observations. Your much-referenced global warming relative to "pre-industrial" times would therefore suffer from the same problem, but you seem fairly certain of your numbers on that (sometimes). All of what? How much of the 50+ inches is attributable to the excess SST? 0.5 inch? 10 inches? 30? Any low pressure system sat in the same area for the same duration would have led to a sizeable total for Houston, even with more normal SST in the high 20s.
Oneiric 3 wrote: » Simple, it is soulless, 'academic' astro-bollox written by people with way WAY too much time on their hands. You should feel proud and honoured that you can't understand it. I certainly do! :cool:
Akrasia wrote: » Regarding ACE and hurricane records, you had absolutely no problem in thanking posts referencing studies that say hurricanes were under reported in the past. Gaoth Ladir himself spent pages arguing that hurricanes haven't gotten stronger because of a Landsea paper that says the data from before the 1970s is unreliable, and then he shifted seamlessly to a position demanding that I explain a spike in ACE in the 1880s You have absolutely no problem in accepting poor quality data as long as it says what you want it to say.
Akrasia wrote: » The few percent at the top are the most important. Houston is protected by a number of flood defenses. They were breached by the 10-15% of rainfall beyond what they were designed for. I am not certain of any figures. I simply repeat the statements made by the most eminent scientific bodies and studies that I can find. Climate scientists use real world data and also computer modelling to verify and experiment on the data. This is not perfect, but it's a hell of a lot better than the anti science 'it's all gobbeldygook so it can be dismissed' gut feeling brigade. Paleoclimate data is an active research field. We should base our opinions on the best available data, and not just cross our arms and say 'it's uncertain therefore we know nothing' Here's an example of one of the most widely cited reconstructions of temperatures going back more than 11k yearshttps://www.researchgate.net/publication/235885717_A_Reconstruction_of_Regional_and_Global_Temperature_for_the_Past_11300_Years Nowhere do they say they are certain of the data, but they do know where the uncertainties are, and they allow for them by crosschecking the data against other sources, and allowing for errors in their confidence interval. And if you don't believe it's accurate, there are almost 600 other papers that reference this paper, many of them are questioning their assumptions and checking their data and cross-referencing them with other papers in the field. This is the scientific method in action.
Akrasia wrote: » The few percent at the top are the most important. Houston is protected by a number of flood defenses. They were breached by the 10-15% of rainfall beyond what they were designed for.
Akrasia wrote: » The data has error bars, confidence intervals for this reason. Older data usually have higher error bars The way to be more confident of data is to have multiple independent sources. If global paleoclimate data was just from a single source then nobody would put much confidence in them. But there are dozens of independent proxy records which allow us to have more confidence in the data (but still with large error bars) Regarding ACE and hurricane records, you had absolutely no problem in thanking posts referencing studies that say hurricanes were under reported in the past. Gaoth Ladir himself spent pages arguing that hurricanes haven't gotten stronger because of a Landsea paper that says the data from before the 1970s is unreliable, and then he shifted seamlessly to a position demanding that I explain a spike in ACE in the 1880s You have absolutely no problem in accepting poor quality data as long as it says what you want it to say.
Akrasia wrote: » And what does that have to do with anything? Here's a tip Oneric. If you want to understand something, look for the best available evidence. What you're doing here is pointing at something that you think is stupid, and then using that as evidence that all science is stupid. You can find nonsense in every single field of human endeavour. But that doesn't mean that NASA can't launch a robot to mars and have it land safely using a feckin rocket powered sky crane
Oneiric 3 wrote: Come to think of it, why should we care what 'the science' has to say about climate change? since it is science that created this mess in the first place, and basically destroyed and exploited every possible natural resource on the planet? Maybe science should stick to what it knows best, like creating even more 'sophisticated' weaponry so murderous western states can sell them for huge profits to already war crippled countries.
Wanderer78 wrote: » You will actually find the majority of our environmental damage is due to our economic activities, and over reliance on fundamentally flawed political and economic ideologies such as neoliberalism and particularly neoclassical theory, whereby ideas such as continual 'growth' must be persued at all costs, even though it is having detrimental negative effects on our planet, and if allowed to continue, will more than likely, accelerate the end of our plants ability to harbor life, including human life.
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