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Comments 151 to 200 out of 246:

151. Albatross at 14:38 PM on 22 June, 2011
     Tom @149, Indeed. Up.
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152. JMurphy at 18:46 PM on 22 June, 2011
     Norman wrote : "Disasters are increasing but not enough data is available to determine if hazards are increasing." It seems, Norman, as Tom Curtis has shown, that you do not read what evidence you are presented with and cannot find out simple information for yourself. However, even when you are presented with it all (and even if you might have read some of it), it seems that you do not want to accept that which goes against your world-view. If you had read the post of mine which you were apparently replying to, you would have spotted the very same quote that you repeated. You would also have found out that it was produced by Oxfam, although it does reference the Munich Re report, and that it gives good definitions of all the relevant terms. It would help if you could compare what you believe to be the case, and what is actually the case, especially with regard to 'disasters', 'hazards', etc.
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153. Camburn at 02:10 AM on 23 June, 2011
     Tom@150: The river study provides enough information to realize that river flow has not increased in the past 50 years. That tells us that even tho we have warmed in the past 50 years, climate has not responded as thought it should. One has to think global in regards to extreme events. A flood here and there is not out of the ordinary, as it is a common occurance globally. What should have showed in the study, to support AGW, is an increase in flow. It didn't. To people expeiencing flooding, it seems extreme. On a global scale, it is normal. As the study indicates, what we think should be happening and what is actually happening have diverged. To a thinking man, this indicates a deeper study of the models projecting an extreme event. Something within the parameters is not quit correct.
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154. Norman at 12:24 PM on 23 June, 2011
     JMurphy @ 152 I will try to demonstrate what is actually the case with disasters. I will use data on tornadoes to demonstrate. I will link to two web sites that I am using for this demonstration. Graph of Strong to Violent Tornadoes. Source for tornado graph. Tornadoes that became disasters. Also need this information: Number of Strong to Violent tornadoes in 2011...it is 80 so far. If you look at the first NOAA graph you will see that in 1974 there were >120 F3 or Above tornadoes. Now look at the link "tornadoes that became disasters". In 1974 there were 3 tornado disasters. In 2011 with 80 F3 or above tornadoes you have 6 tornadoes of this magnitude that caused disaters and a total of 9 tornadoes that struck cities. This is an example of where the number of hazards does not relfect the actual number of disasters. Look at 1964. This would be a close year to 2011 for F3 or above tornado activity. There were no disasters from tornadoes that year. Not sure it this little exercise is what you requested but I hope it clears up what I am getting at.
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155. Norman at 12:30 PM on 23 June, 2011
     Tom Curtis @ 149 I did look at the one day precipitation but did you look at the extremes in maximum temperature. It is up then down and up but not as extreme today as in the past.
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156. Norman at 12:36 PM on 23 June, 2011
     Tom Curtis and Albatross, I posted this graph of F3 and above tornadoes from NOAA on a post to JMurphy. Severe Tornadoes historical graph. You can see this unusual large peak in 1974. What this tells me is with extreme weather events you may get these spikes from time to time but does it mean anything? So why is the Russian heat wave any more unusual than the tornado spike, or the Pakistan flood. I still cannot see what evidence has been presented that would make you feel extreme weather events are increasing in number and intensity because of global warming.
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157. Norman at 12:49 PM on 23 June, 2011
     Camburn, Thanks for the links.
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158. Norman at 13:15 PM on 23 June, 2011
     Tom Curtis @141 I was investigating and working to understand the concepts presented about catastrophe and Great Natural Catastrophe. My graph was of Great Natural Catastrophe. I am wondering how do you determine conclusively that the increase in catasptrophe is not the product of increased reporting? Like with tornadoes. F0 tornado number skyrocketed after the 1990's but the larger tornado number stayed relatively the same. Maybe a lot of catastrophe's in third world countries were not reported in a few decades ago but now more awareness is taking place leading to more reports generated but not meaning more actual events are taking place.
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159. scaddenp at 13:44 PM on 23 June, 2011
     re: Tornado data. Since this thread is about severe weather AND global warming, wouldnt it be more relevant to look at severe events that are actually predicted increase with global warming? Anyone got a paper saying tornadoes will increase as the planet warms?
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160. JMurphy at 19:35 PM on 23 June, 2011
     With regard to tornadoes, a post by Andrew Freedman in the Washington Post gives a good overview, with links to papers : Are La Nina and global warming behind the extreme tornado activity? There was also an interesting piece in Science Daily a few years back : Global Warming Will Bring Violent Storms And Tornadoes, NASA Predicts But, as scaddenp notes, why are we suddenly focussing on tornadoes ? Not a diversion, for some strange so-called skeptical reason, is it ?
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161. Tom Curtis at 20:20 PM on 23 June, 2011
     Norman @155, yes I did, and the difference in extreme maximum temperatures is due to the well known fact that the hottest years in the Continental US were in the 1930/40s. Of course, the 30s and 40s where not as hot as the 90s and 00s globally, as is also well known. Consequently we would expect a similar chart for global extreme maximum temperatures to peak in the 00s, if one existed. @157, that's it? Just thanks for the links? If any links showing AGW to be real and dangerous are posted, you are quick respond with a comment, any comment no matter how ill founded, so long as it plays down the evidence. But if links apparently supporting a denier point of view are posted, you just accept them uncritically even when at least one of them has been shown to be of very poor quality. You really ought to stop saying that you are just trying to learn here, because you are not keeping up the pretence very well. @158 in fact the greatest increases in reporting have been in North America, and in Asia, particularly China and India. The trend in South America has been flat, while that in Africa has matched the global trend, but reporting rates are very low. As the areas of greatest increase in reporting have also been high population areas with modern communications over the entire period, the suggestion that the increase is due to increased reporting in third world nations is ill founded.
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162. Norman at 21:01 PM on 23 June, 2011
     JMurphy @160 My use of tornadoes in Post 154 was a response to your challenge "It would help if you could compare what you believe to be the case, and what is actually the case, especially with regard to 'disasters', 'hazards', etc." I used the tornadoes because I was able to find data about them for the purpose of showing how a hazard becomes a disaster and pointing out that the number of actual hazards does not translate into number of disasters. I was not using tornado number to disprove the link between Global warming and extreme weather events.
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163. Norman at 21:06 PM on 23 June, 2011
     Tom Curtis, My problem with the 2010 Munch Re report you posted on 141 was that they were showing that the catastrophic storm number in America was increaing. There are 10,000 severe thunderstorms in the US a year and out of that number Munch Re calls a few hundred catastropic and shows an increasing number. I just do not understand how they are generating their strom catastrophes. I am not sure what they are using and it becomes difficult to determine the reason for the increase when the actual number of severe storms far exceeds their counting. I will try to work on this as time permits to better understand it and see if there is a real link. I do like all the links you send me. I do like to learn. Because I question things does not mean I do not appreciate the material presented.
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164. Tom Curtis at 21:38 PM on 23 June, 2011
     Norman @various: 1) As the following chart shows, there has been a significant increase over time of the types of conditions that spawn tornados. Therefore while the conjecture that increased reporting of EF0 to EF2 tornadoes is simply an artifact of increased reporting, in fact it is at least partly a consequence of increased tornado frequencies. It is worthwhile comparing that chart to reported tornadoes: The significant correlation between days with tornado favourable conditions and reported tornadoes suggests that observational artifacts are not the sole cause of the increased in reported tornadoes. 2) Although 1974 was exceptional, as has been 2011, your analysis in 154 is unjustified. In particular while there have been 80 EF3 plus tornadoes to date in 2011, compared to approximately 124 F3 plus Tornadoes in 1974, there have been 6 EF6 tornadoes to date in 2011 compared to 6 (Wikipedia; 7 Tornado History Project). There also have been 17 EF 4 tornadoes to date in 2011, compared to 24 F4 (Wikipedia; 23 Tornado History Project) in 1974. Furthermore, all of the F4 and F5 tornadoes, and 64 of the F3 plus tornadoes occurred in just one outbreak, on April 3rd and 4th. That outbreak is the second largest on record, falling just behind the outbreak of outbreak of April 25-28, 2011, which had 330 tornadoes compared to the 1974 super outbreak with 148. The April 2011 Super outbreak only rates third in F/EF 4 and 5 Tornadoes (with 1974 ranking first), but there were two other major outbreaks in April 2011, and some minor ones. Given the near equality of F/EF 5 tornadoes between 1974 and 2011, and the small difference between in number of F/EF 4 tornadoes your assumption that the difference in numbers of damaging events is a function of anything other than an increase in hazards is unwarranted. In fact, it is not even based on a correct use of the definition. For a hazard to be classified as a disaster, it need harm only a single human being or their property. An EF0 tornado that blows ripe apples to the ground in a orchard thereby becomes a "disaster" and, if reported, will be recorded as such in the Munich Re chart. Finally, as an aside, the chart of high CAPE_SHEAR days shows a very low value for 1974. That is not an error. Except for the one super outbreak in April, and a small outbreak in September, 1974 was a quiet year for tornadoes.
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165. Tom Curtis at 21:59 PM on 23 June, 2011
     Norman @163, in answer to your question about thunderstorms, the map on page 10 of this document gives a clue. Amongst the 960 events they list are floods in South East Queensland for December. On the ground that was a series of distinct flood events striking different towns at different times, but it was the same weather event. Likewise they list two major storm events in Australia, and three in the United States lasting from one to four days. Although each would have contained tens, and possibly hundreds of individual thunder storm cells, they where all part of the same weather event, and hence counted as just one event. One of the US storm events was a tornado outbreak,/a> which contained 60 tornadoes as well as, without doubt, innumerable thunderstorms, but for Munich Re's statistics is is just one event.
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166. Eric (skeptic) at 23:43 PM on 23 June, 2011
     No trend in violent tornadoes, see fig 5 and section 5: http://www.flame.org/~cdoswell/publications/Sigtor_climatology.pdf Two main ingredients for a strong tornado are rising air and fallng air. The first ingredient is obviously going to become more abundant, and with it, the risk of more tornadoes in general. The second ingredient requires mid-level dry air pushed by a strong jet. The rain hits the dry air creating a strong downdraft. If there is no downdraft, then there will be no strong tornado. The strong jet will likely be further north, see http://www.cgd.ucar.edu/cas/jyin/IPCC_paper_GRL_Jeff_Yin_final.pdf Also for a better argument about the "extreme ENSO" that Tom brought up earlier, the models project more "El Nino-like" conditions, see http://journals.ametsoc.org/doi/pdf/10.1175/JCLI3746.1 Whether extreme or not, the lack of La Nina will be less conducive to low latitude storm tracks. Likewise in the same paper they point out the projected upward trend in AO which will also be less conducice to low latitude dry air and low latitude jets.
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167. Eric (skeptic) at 23:48 PM on 23 June, 2011
     I should have also added that the trend in violent tornadoes has little to do with an apparent increase in tornadoes in general which I would expect to increase and widen in coverage. One more caveat is that we could see violent tornadoes shift into Canada. Hasn't happened yet, but it seems plausible to me.
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168. Rob Painting at 23:56 PM on 23 June, 2011
     Eric (skeptic) - "the models project more "El Nino-like" conditions" Actually Eric that's a common misconception, it simply means that the central and eastern tropical Pacific warms more than the western Pacific. See figure 5a in the Meehl paper you link to. ENSO events are still expected to happen, but the background state changes.
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169. Eric (skeptic) at 00:13 AM on 24 June, 2011
     Rob, thanks for that correction. I presume that figures 5a, 6a and 7a depict that background state or some sort of average? Then I can't use 5a or 6a for any projection about tornadoes. 7a, however, suggests a lot fewer storms in lower latitudes that are right now causing tornadoes.
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170. Albatross at 00:27 AM on 24 June, 2011
     Eric @169, "One more caveat is that we could see violent tornadoes shift into Canada. Hasn't happened yet, but it seems plausible to me." Interesting that you should say that. Canada recorded its first F5 tornado in 2007 (Google 'Eli Tornado').
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171. Eric (skeptic) at 00:31 AM on 24 June, 2011
     Albatross, I just did, thanks. We will be plagued with a small sample size for a while trying to find trends with this type of event.
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172. Eric the Red at 01:52 AM on 24 June, 2011
     The Elie tornado was the first confirmed F5. A couple others may have reached f5 status, but were unconfirmed. If we started seeing one a decade, that would be a significant increase. Since there has not been an increase in violent tornadoes in the US, I suspect that we will not start seeing one in Canada either.
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173. Albatross at 02:05 AM on 24 June, 2011
     EricR, I think that you misunderstood the purpose of my post. I was simply pointing out that there had been the first documented F5 in Canada, nothing more, nothing more. I was hoping that we could use the NEXRAD data to quantify any trends in mesocyclones, but even those radar data are not without issues, not to mention the huge computing resources required to process the data. The UofOklahoma started something but it seems to have gone nowhere.
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174. Albatross at 02:36 AM on 24 June, 2011
     Tom @164, Thanks for that interesting post. I followed the link to your top graphic and the links therein. Here is the link to the Munch Re report for others who are interested. And that led me to this interesting paper by Kaltenböck et al. (2008). They conlcude: "2) Low level moisture can be used as a predictor to distinguish between significant tornadoes or non-severe convection." And "While deep-layer shear discriminates well between severe and non-severe events, the storm-relative helicity in the 0–1 km and especially in the 0–3 km layer adjacent to the ground has more skill in distinguishing between environments favouring significant tornadoes and wind gusts versus other severe events." These findings corroborate other research for the United States on tornadic environments, and the increase in low-level moisture is particularly pertinent to AGW, as we know that (globally) low level atmospheric moisture is increasing and will continue to increase, and that lower cloud base heights are typically associated with tornadoes. Some are of the opinion that the predicted weakening of the jet stream will weaken storm potential, and in some regions it may. But as I have argued elsewhere, tornado alley is unique because of the presence of the great plains low level jet which is oftentimes critical in producing the high low level critical wind shear (0-3 km and 0-1 km AGL) which are typically observed in environments that produce tornadic supercells. So the predicted weakening of the tropospheric jet stream may not be as significant over this region as some might think. Brooks and Dotzek (2008) noted a marked increase in the incidence of hail reports since the early eighties for hail having a diameter of 7 cm or more.
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175. Eric the Red at 03:24 AM on 24 June, 2011
     Albatross, The Great Plains are definitely ripe for tornadoes, as they bring together the warm, humid Gulf air and cool, dry Rocky Mountain air. A weakened of the jet stream or a shift northward would lessened the impact of these two air masses. While an increase in moisture would serve to enhance development, any decrease in the cold, dry air would counter that effect, and simply produce heavier rains. Not that I am claiming that we know enough aobut tornadoes, but temperature and moisture gradients are very important to tornadic updraft development. My opinion (note word choice) is that the timing of othe tornado season may shift based on changing temperatures, but that the tornado locations are unlikely to move much. (FWIW)
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176. Eric (skeptic) at 03:40 AM on 24 June, 2011
     Eric (the other): seasonality of strong tornadoes would also be a key CC indicator for me. That's the first thing I looked at this year and there was nothing particularly early. My first link in 166 shows no seasonality change either. Unlike other CC impacts I think we are very early in the game. When we see heat and humidity like the deep south up in Canada, then we could see a new tornado alley up north.
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177. Albatross at 04:00 AM on 24 June, 2011
     EricR @175, Your opinion regarding the shift may be correct. You are, however, overstating the importance of cold fronts in triggering severe storms, and understating the importance of the great plains low-level jet (a barrier-type jet attributable in part to the sloping terrain and differential heating of the terrain, not a baroclinic jet). Severe storms can be triggered by outflow boundaries, drylines, trofs, sea breezes, lake breezes etc., just read the SPC mesoscale discussions. Wilson and Schreiber (1986) found that 80% of that of all thunderstorms in their study area were triggered close to mesoscale boundary layer convergence zones. Other researchers have made similar findings on the importance of mesoscale surface features in triggering severe storms. It is worth noting though that the great plains low-level jet is modulated to some extent by synoptic-scale features. "While an increase in moisture would serve to enhance development, any decrease in the cold, dry air would counter that effect, and simply produce heavier rains." Again you are placing undue focus on cold fronts. Care to back it up with something from the reputable scientific literature? To some it up, while I admire your efforts to speak to this stuff (and you do appear to be making a sincere effort), your unsubstantiated musings do not carry much weight I'm afraid.
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178. Eric the Red at 04:55 AM on 24 June, 2011
     Yes, the severe storms occur at the boundary layers. The greater the energy gradient at that layer, the greater potential for tornadic activity.
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179. Albatross at 05:07 AM on 24 June, 2011
     EricR @178, "The greater the energy gradient at that layer, the greater potential for tornadic activity." Sorry, but no. Eric, you seem to be trying to make it sound that you know what you are talking about but the more "information" you volunteer the more apparent it becomes that you do in fact not. And you have still not backed up your assertions with anything from the reputable scientific literature. If you like I could direct you to some literature on this subject.
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180. Eric (skeptic) at 05:33 AM on 24 June, 2011
     Albatross the seasonality of violent tornadoes is ample evidence that they require the springtime jet (which is both strong and late this year) and dry air availability from Canada or east of the Rockies. The outflow boundaries, lake breezes, etc are a dime a dozen and do not provide the pool of dry air nor the long range winds to advect dry air into a moving supercell to cause strong tornadoes. That isn't to say it can't happen. Aligned winds in the atmosphere can push a solitary MCS 1/2 way across the country with embedded supercells (no front or low needed). Otherwise something has to advect the dry air eastward, and I think the Great Plains LLJ is mostly south to north.
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181. Albatross at 05:48 AM on 24 June, 2011
     EricS @180, "The outflow boundaries, lake breezes, etc are a dime a dozen and do not provide the pool of dry air nor the long range winds to advect dry air into a moving supercell to cause strong tornadoes." Nonsense, as someone who works in this field I am confident in saying that you are really talking though your hat. Read this, one of the et cetera above should have been HCRs. Now you are just doing what EricS is doing. If a supercell ingests dry into its updraft it is done. I have seen this happen first hand. And you need to read up more about the "dryline".
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182. Eric (skeptic) at 06:00 AM on 24 June, 2011
     Thanks for the link and please provide others when you can. I think we are talking about two different things (long lived supercells that can spawn strong tornadoes in my case)
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183. scaddenp at 06:21 AM on 24 June, 2011
     Norman - "or the purpose of showing how a hazard becomes a disaster and pointing out that the number of actual hazards does not translate into number of disasters". Okay, I understand. However, while the a bad storm doesnt turn into disaster, an increase in bad storms surely increases the probability of a disaster.
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184. michael sweet at 07:40 AM on 24 June, 2011
     North Dakota is having historic record floods as we speak. But I suppose it could all be chance. They were due for a 100 year flood, it has been over 100 years since the last one-- which was 5 feet lower than the projected peak of this flood.
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185. Norman at 11:53 AM on 24 June, 2011
     scaddenp @ 183, I totally agree with your comment that an increase in bad storms will increase the probability of a disaster.
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186. Norman at 12:09 PM on 24 June, 2011
     Tom Curtis @ 165 Mr. Curtis, I forgot to ask you why you are using Munich Re as a source of acceptable information. They are not an unbiased group of scientists striving to reach the truth on this issue. Munich Re?. They are a huge multibillion dollar insurance company. They have a product they want to sell. Higher threat of disaster is a selling point. I hope you can find better sources to prove a connection between global warming and increased weather related disasters.
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187. Norman at 12:32 PM on 24 June, 2011
     Albatross @ 147 "Stanley Chagnon is your man and Google is your friend. " I did look up the study performed by Stanley Chagnon. He found that warmer winters had a better chance for more snowfall events (but they did find no effect on the biggest snow events). I also followed your advice on using Google to come up with this information. Not an extensive study and not as complete as Stanley Chagnon's. Two links. Omaha Nebraska Winter snowfall accumulations. (I use Omaha since I live near this city) Explanation for Heavy snowfall in winter of 2010. You can see Omaha had 20" more snow than normal in the 2009-2010 winter. In the second link you can see that the temperatures of the United States were really cold during this snowfall period (18th coldest winter since records were taken). This would be a strong exception to the warmer temps lead to more snowfall concept. Also the second link gives a nice explanation for what produced the cold and excess snow of that winter and it can all be explained quite well without global warming being introduced. The pattern was predicted based upon previous events of similar nature.
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188. Norman at 12:35 PM on 24 June, 2011
     michael sweet @ 184 Do you have an explanation that ties this flooding in with a warming planet? If you choose see my link above "Explanation for Heavy snowfall in winter of 2010" Can you find data similar to this that would show why a warmer globe triggered the heavy rains in that area that are responsible for this flooding in Minot?
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189. Norman at 12:55 PM on 24 June, 2011
     Tom Curtis @ 164 Material from an ealier post of yours 141 "A disaster is defined as a serious disruption of the functioning of society, causing widespread human, material or environmental losses, which exceed the ability of an affected society to cope using only its own resources (EEA 2006). The extent of the disaster depends on both the intensity of the hazard event and the degree of vulnerability of the society. For example a powerful earthquake in an unpopulated area is not a disaster, while a weak earthquake which hits an urban area with buildings not constructed to withstand earthquakes, can cause great misery (GTZ 2001, p. 14)." Now in 164 you state "In fact, it is not even based on a correct use of the definition. For a hazard to be classified as a disaster, it need harm only a single human being or their property. An EF0 tornado that blows ripe apples to the ground in a orchard thereby becomes a "disaster" and, if reported, will be recorded as such in the Munich Re chart." I don't think the two post are in coherent agreement with each other. Also why do you neglect the damage done by an F3 in your critique of my analysis. There were many more potential disaterous tornadoes in 1974 than in 2011 yet 2011 had a larger number of disasters. F3 tornado does cause a disaster when it hits a populated area. 0 0