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Hank11198 at 09:27 AM on 12 January 2020Doubling down: Researchers investigate compound climate risks
Nigelj @ 34
I am educated in the science of structural design. I am no expert in determining what loading should be applied to a structure in order to balance risk to economy. As you said structures are designed on the basis of a 50 year life. Although some are used longer we have to put some limit on a design time. The study I link too stated a 1 to 10% increase in intensity for a 2C warming with the probability that the strongest storms will be less frequent. That will probably be 2100 if we don’t change our direction which is 80 years from now, long past the design life of a structure. Taking the largest estimate way past the life of a structure with a decreased probability of frequency for structures we know the failure limit is way past the design limit just seems to need further study, which I’m not qualified to do. You can say you are just tossing around ideas but I can promise you ideas like this tend to be spread around the internet by those saying engineers are derelict for not preparing for the future by their disregard for climate change. Just like the opposite side says climate scientists are irresponsible for being alarmists.
I wasn’t putting words in your mouth. I was using my words to say it ‘appears’ you are saying the professionals aren’t doing their job.
“It looks like our codes are weighted a long way towards lowest cost. However I doubt that has anything to do with the engineers on the committees that develop codes”. What? How can the codes be weighted towards lowest cost without the engineers who write the codes being responsible? As I have said before I can only speak for the US codes. But in the US the politicians and bureaucrats have zero input in the development and revisions to the structural design codes. In the US the government has legislated the material design codes to be the law which they didn’t have to do. Although I doubt any engineer would design any differently even if they weren’t the law. But there have been so many lawsuits regarding damages when a structure fails I would imagine the politicians are afraid not to legislate those laws. In addition no insurance company would insure a structure not certified by a Professional Engineer.
If I have taking things the wrong way then I apologize. But it still seems to me that it would be better if the experts are not second guessed in social media at least until there is evidence they are not doing their job. And saying our building codes are weighted towards lowest cost without evidence is doing exactly that. It’s certainly your right to do that, at least in America, but that’s what is being done to climate scientists and I’m opposed to that also.
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nigelj at 07:35 AM on 12 January 2020The never-ending RCP8.5 debate
Nick Palmer @53, yes we see at least some issues the same way, and I respect your views as well.
I looked at the video, and read Barlows comment and your comment, and your debate between yourselves.
Overall I find your views the most credible. Thats the short answer.
I don't see that you were being overly insulting. You called him a fanatic just to get his attention, perhaps borderline insulting. Having got his attention, you could have been clever and then said sorry didn't mean to be too abrasive :)
But Barlow made some good points as well. Like a lot of issues the truth looks like it maybe somewhere in the middle between you guys, on some of this at least.
The thing is Barlow is an ecologist and I've noticed these sorts of people catastrophise about climate change a lot, probably to be expected as they fall in love with nature a bit. I actually respect that, but the risk is they loose objectivity and Barlow has.
Barlow is confused about the state of the science way back then. The state of the science in the 1970's and 1980's was definitely too uncertain for us to conclude we were warming the climate and should do something. The AGW signal was only confirmed in the early 1990's and even then it was not clear what the hell we should do. We had to have some real world evidence of some actual warming like this, plus detection of AGW, to confirm the theories.
But by the mid 1990s it was very clear we had a problem, and that it was serious enough to justify robust mitigation, and that we had some good mitigation options.
It's absurd of Barlow to say models in the 1970s were accurate, so action should have been taken back then. We only know they were accurate with the passing of time since then.
Regarding Barlow claiming the risks were downplayed for decades and hes claiming virtually a cover up. This is a thorny issue. I dont really think they have been on the whole. We just didn't know enough back then. It's not like the link between smoking and cancer which was quite compelling at even an early stage, so using scare tactics did make some sense.
However I do think the IPCC reports "lowball" some things a bit in recent years as I've mentioned. Whether this is political pressure or scientists being conservative is an interesting question.
Maybe I sit a little bit between you and Barlow on the whole thing. But my bottom line is if scientists put scary scenarios in front of the public, and they should, these scenarios need some pretty good evidential basis. They cannot just be speculation full of endless "what ifs".
Regarding the Australian bushfires. I dont think Climate Adam was hyping things. They definitely look very concerning. Yes more area was burned in the past but this latest fire seaon has just started. Its not unreasonable to suspect we are heading towards an absolute record setter, and climate change is a factor in it (which you did mention).
Of course your area calcs look robust to me and it was useful to mention those.
This is a tough one for me. I've sometimes done the same sort of thing as you. The hyper alarmists have sometimes made wild, exaggerated hand waving claims on various things and I have criticised their views and been labelled a luke warmer as a result which is so frustrating.
However in these posts I always mention that I think climate change is deadly serious and why, to try and get across that I'm not minimising the problem, but that we just need accuracy. I also make a point of posting alarmist science where I think it does actually have a robust basis.
Sorry for a rather nuanced reply but I'm just being honest. Hope it helps a bit.
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BaerbelW at 06:43 AM on 12 January 2020Seal of approval - How marine mammals provide important climate data
A recent article published by Esprit Smith on NASA's website on December 4, 2019 provides another example where data collected by seals around Antarctica provides new insights:
Seal Takes Ocean Heat Transport Data to New Depths
The article includes a link to a related post written by Carol Rasmussen and published on May 2, 2019:
Data with Flippers? Studying the Ocean from a Seal's Point of View
H/t to David Kirtley, who made me aware of the article.
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nigelj at 06:14 AM on 12 January 20202019 in climate science: A continued warming trend and 'bleak' research
Cooper @13, yes I see it now at comment 10, and your 2x looks feasible. Its just you jumped around a bit comparing different things.
This looks like something that should be in the general media. Most people would assume that statements of warming made in the media apply to land. Its a seriously misleading thing. Must mention it to our local science writer in our main newspaper.
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michael sweet at 06:00 AM on 12 January 2020Doubling down: Researchers investigate compound climate risks
The discussions of how buildings are designed are interesting.
Flood damage is expected to be worse in the future because AGW causes harder rainfall. It has been recently reported that most nuclear power plants are not designed to withstand the most severe anticipated floods. While there are not many nuclear power plants it occured to me that much infrastructure like drinking water plants, sewage plants, airports, chemcal facilities and other heavy industry are located near rivers or the ocean (where sea level rise is also a problem). There were reports of many facilities being flooded by Harvey in Texas.
I am not an engineer but it occured to me that if nuclear plants are not designed to withstand expected flooding many other industrial facilities will also not be designed to withstand high floods.
Do the engineers here have any comments on how major infrastructure will be affected by increased flooding?
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nigelj at 05:56 AM on 12 January 2020Doubling down: Researchers investigate compound climate risks
Hank @33
"In effect you have decided that you know enough about the statistical analysis of wind speeds .....etc... and many other things that makes you an expert in how the structural codes should be changed. "
I never claimed that. I was simply tossing some ideas around sparking some discussion.
You are the expert, so roughly how much cost would upgrading the code to cope with an increase of 17% of wind pressure add to 1) a typical timber framed house and 2) typical highrise building?
Maybe its too high to be feasible. Like I said I believe in tough codes, but its always a balancing act between toughness and what the public can reasonably afford. I dont see where we differ - you tell me.
"And it appears you assume that the professionals that produce these codes are either not aware of environmental changes and how they affect the design of structures or they are deliberately ignoring those changes because of political pressure or greed. Pretty much exactly what climate change deniers are saying and using against climate scientists. "
Please stop putting words in my mouth. I have already said the exact opposite above "It looks like our codes are weighted a long way towards lowest cost. However I doubt that has anything to do with the engineers on the committees that develop codes....( I explained my reasons)"
The codes in NZ do appear to set lower standards than some other countries. This is not my opinion, the issues has been raised by various experts after the Canterbury earthquake. The question is why. I think its probably political in origin but I doubt it reflects badly on engineers.
Politicians or bureaucrats sometimes have the last say on approving building codes. This is not the venue to pontificate in detail on all this, other than to say this is a very different thing to denialists claiming politicians write or approve climate science (which they dont). You are comparing apples and oranges.
However bureaucrats do sign off the IPCC report summary for policy makers, so that is something to bear in mind. Evidence suggests the language in this report got watered down a bit in one of the reports. Very likely became likely etcetera.
You are taking things personally as an attack on structural engineers. Nothing could be further from the truth. I have lots of respect for engineers. You have taken things completely the wrong way.
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Hank11198 at 00:56 AM on 12 January 2020Doubling down: Researchers investigate compound climate risks
I will admit that I may be defensive about my profession after practicing and experiencing it for 50 years but I hope I can still be objective. I think we are all on the same team of trying to prevent climate change deniers from spreading their false and damaging message. However....
One of the things I have consistently found is that climate change deniers use bits and pieces of scientific research and twist it into the opposite of what the research found. If they can convince the public that they know as much about climate change as the scientists because the data is just simple to understand, then they have accomplished their mission. One of the things I have learned in my limited research into climate change is that what can appear simple on the surface is very complicated when digging down into the details, something that deniers take advantage of every day. In my experience the same is true of all technical professions so in the end I ask and defer to the opinions of peer reviewed published material as explained by the authors. So I think that ironically the same thing is happening in this debate.
Nigelj has stated this:
“However let's take an increase in wind pressure of 17% as you mentioned. This doesn't sound too horrendously severe. I agree much of the global warming threat comes more from flooding etc. Anyway upgrading the code for a 17% increase in pressure sounds like a bit of extra wall and roof bracing and more fixings, so not a huge increase in cost.”
In effect you have decided that you know enough about the statistical analysis of wind speeds, the application of that analysis to structures, the development of risk factors the economics of risk and the risk to the public among many other things that makes you an expert in how the structural codes should be changed. Yet you have pretty much admitted you have no expertise in any of these areas. And it appears you assume that the professionals that produce these codes are either not aware of environmental changes and how they affect the design of structures or they are deliberately ignoring those changes because of political pressure or greed. Pretty much exactly what climate change deniers are saying and using against climate scientists.
From what all of you have said it seems you have some if not a fair amount of structural training. If so you should know that the design of structures are limited by the yield strength of the material for wind design in most cases. This is far from the “failure” of a structure unless you consider the “failure” of a structure to be some limited permanent deflections of the structure. This is evidenced by the success of seismic designed structures to prevent the total collapse of structures which exceed the wind forces by a large amount. In other words there is almost always a large amount of redundancy in structures due to many factors that are not considered in design. So rarely is this a matter of risk to public safety, but to economic risk.
I am by all means in favor of requiring structures to consider human safety first and economy risk second. However there is no way codes can be written to cover all possible risks. My company and some of the companies I have worked for have multiple standard products they sale. The costs of upgrading all those products by a 17% increase in wind pressure would include a massive amount of redesign (I’m not sure everyone realizes the amount of time and work that goes into designing a large structure), the replacement and/or modification of millions of dollars of tooling required for the existing structures and the amount of published marketing material that would need to be replaced. This is not just adding some bracing. Existing structures would be grandfathered in with a new code but sales of new structures have to meet the new codes. If the experts decide an increase is necessary I will be leading the cause to get it implemented. But I’m not in favor of unnecessary feel good changes that can have unintended consequences.
I am all in favor of public pressure to create changes in public policy when it is obvious the government is ignoring public safety. I think that is pretty evident with climate change when you look at heat waves, drought, floods, rising seas, the consensus of climate scientists, etc. Of course structures do fail for many reasons. But I have not seen, nor has anyone here presented any evidence of an increase in structural failures due to increased wind pressures.
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Cooper13 at 00:51 AM on 12 January 20202019 in climate science: A continued warming trend and 'bleak' research
@nigelj
Subsequent posts linked to data for the past 5-6 decades indicate the Land:Global ratio for warming is indeed approximately 2.
1.6 is the lower end of the estimate - if you look at longer time-scales back to the beginning of the 20th century. But where most of the warming has occurred (past 5+ decades), it is a ~2x ratio; that is based upon the linear trendlines, not 'ballparking' off graphs.
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Nick Palmer at 21:57 PM on 11 January 2020The never-ending RCP8.5 debate
nigelj@51
I think I've expressed before that I respect your views. Although we differ slightly I think both of our points are view are reasonable enough, as are we, that I think both of us could change or modify each other's position with suitable new credible evidence - at least I hope so.
Having said that, may I ask a favour? I would appreciate you (or any other SKS'er) doing a 'reality check' on this short 7 comment thread on one of 'Climate Adam's' Youtube videos. I would like your opinion on whether I or Steven Barlow (or both of us) went too far, and whether our assessments about each other, and our views, were reasonable.. Thanks in advance.
https://www.youtube.com/watch?v=2kJvKgOqWrc&lc=UgywrnJct_lMB_vKWXx4AaABAg -
nigelj at 15:41 PM on 11 January 2020The never-ending RCP8.5 debate
Nick Palmer @51, definitely commenters. The website articles remain a beacon of sanity.
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Nick Palmer at 09:52 AM on 11 January 2020The never-ending RCP8.5 debate
nigelj@50
"Alarmists who exaggerate the science are very frustrating, and do more harm than good, like the mirror image of the hard core denialists. There are a couple over at realclimate.org"
At realclimate?! That's disappointing. I hope you mean commenters rather than contributors! -
One Planet Only Forever at 07:39 AM on 11 January 2020Doubling down: Researchers investigate compound climate risks
A better way to make the point of my comment @20 may be to state that the objective of the current day population should be for the accumulated result of everyone's actions to be an improvement that lasts into the future, making the future better for humanity. And the supposedly more advanced or more fortunate a person is the more helpful they should be required to be in order to maintain their status.
While debating how much worse the future is being made, the important thing to remember is that the discussion is all about things being Worse. Fossil fuels cannot be burned forever, so any perceived benefit from fossil fuel use has no future. The only exception is the temporary transitional use of fossil fuels to kick-start sustainable development in the few remaining regions that are still in extreme poverty.
Looking reasonably holistically at any future that is the result of GHG emissions continuing to accumulate beyond today's levels exposes that the future, on the whole, is being made Worse. How much worse the future becomes is a direct function of how high the accumulated total impacts become. And less corrections of the harm creation today makes things worse. And a continuation of the attitude that there is some way to justify making the future worse will undeniably create a much worse future, potentially worse than the worst that has been conceived so far (and that is not an extremist claim).
A serious correction is required to end the cycle of making-up excuses for continuing to act harmfully. One of the worst excuses is believing that history proves that industrial materialistic consumerism always makes things better. An even worse excuse is believing that any challenges created can be overcome by the brilliance of innovative developments.
Things could become much worse than the conditions potentially created by RCP8.5 by 2100. The future of humanity should continue well beyond 2100. And hopefully those future people will not have to deal with an even worse future after 2100.
As shocking as some of the potential futures for humanity may appear to be, they are still potential futures, especially if less correction happens today, or the next day, or the next day ....
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nigelj at 06:03 AM on 11 January 2020Doubling down: Researchers investigate compound climate risks
Ignorant Guy @30, oops I didn't read your link for some reason. Sorry. No it doesn't mention 10X but "if" Hansen said 10X that article may be what he had in mind. I recall mention of these super storms pushing quite huge boulders up beaches, which suggests high wind speeds affecting the oceans.
I find it a bit hard to see how 'slightly' higher wind speeds and 'slightly' more precipitation being ten times worse. Granted the two effects combine, but 10X seems intuitively seems like its stretching things.
The problem seems to me more that that the IPCC reports might be underestimating how bad storms will get. Thats a whole other subject and space doesn't allow, but theres numerous discussions on the IPCC low balling some things. But without a correct estimate its hard to develop codes.
And for the record I believe its wise to have quite high building code standards, so not done on the cheap. But there are limits to this, because eliminating all damage would make building costs astronomical. Its a balancing act.
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nigelj at 05:45 AM on 11 January 20202019 in climate science: A continued warming trend and 'bleak' research
Cooper13
You said at the start @ 6 that "It is well established from observations, and from projections/models, that land temperatures (where most of us live, and where we grow our crops and livestock) increase at roughly 2x the rate that global temperatures rise."
I think this is wrong but it is maybe a sort of "typo" on your part. Global temperatures are the average of the land and ocean temperatures arent they? The data suggests land temperatures are increasing maybe 1.5% faster than the average global temperatures (eyeballing your graphs)
Dont get me wrong. Your basic point is really important namely that land temperatures are increasing significantly faster than both ocean temperatures as you mention elsewhere, and the "average temperatures" we typically use in discussion that combine land and ocean. By using this average of land and oceans we miss the fact that land is heating significantly faster.
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Ignorant Guy at 01:03 AM on 11 January 2020Doubling down: Researchers investigate compound climate risks
nigelj @29
You link to the exact same paper as I did.
I never said that Hansen specifically mentioned "10X worse wind speeds". Did you find "10X worse wind speeds" in that text?
"Worse storms" are not necessarily storms with higher wind speeds. Storms with more precipitation are also "worse".
If we anticipate a certain worst case level for a bad storm and build our infrastructure to withstand such storms with only small damages then a storm with only slightly higher wind speeds and only slightly more precipitation could cause significantly more damage. And so it could be "10X worse".
I repeat again: My point was _not_ that Hansen ever said we would see storms with 10X wind speeds. My point was that if anyone says that we may encounter storms that are "10X worse" that claim is too vague to be immediately rejected as unreasonable.
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Cooper13 at 01:01 AM on 11 January 20202019 in climate science: A continued warming trend and 'bleak' research
@anticorncob6
Here's the whole article, with sourcing and a snippet:
In the past six decades, land temperatures have risen about 2.3°F, a warming rate of nearly 0.4°F a decade, as the top chart shows. That’s nearly double the temperature rise of the ocean, which is 1.25°F per decade. Moreover, in the past 30 years, the rate of warming appears to have sped up even more, with land temperatures rising more than 0.6°F a decade. That’s now a bit more than double the ocean warming.
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nigelj at 15:50 PM on 10 January 2020Doubling down: Researchers investigate compound climate risks
Ignorant Guy @28, J Hansen talking about 10X worse wind speeds may have been referring to 'superstorms' in earths past. Theres some paleo evidence for these huge storms. Research paper here.
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Cooper13 at 15:27 PM on 10 January 20202019 in climate science: A continued warming trend and 'bleak' research
@MA Rodger and @anticorncob6:
Rodger- you are correct; looking at 1975 to 2018, where the increases have become fairly linear (likely because of the continually increasing forcing with higher GhG concentrations), the trend is absolutely 2x.
We do need to be careful with cherry-picking a particular starting point, as that does alter the slopes somewhat. Choosing more like 50 years, 1968-2018 we get slopes of:
+0.17°C/decade (+0.31°F/decade) for Land AND Ocean (global)
+0.29°C/decade (+0.52°F/decade) for Land ONLY
So, 2x isn't all that bad a guess, really. Certainly the land-amplification (which is just an average - it's not the same everywhere) is somewhere between 1.5x and 2x of the global number. If you're a conservative farmer, concerned about your livelihood, I'd be going with the 2x assumption and acting accordingly (e.g. making your legislative representatives aware that you CARE about this and want action taken to minimize it)
Here are direct links to the page with those calculations, 1968-2019, as the pages will load with those selections saved:
So, my 'back of the napkin' guess in the first post may not be all that 'alarmist', the numbers indeed support it. Pass that along to people you encounter on this topic - perhaps SS will run a short post on this, as it's more about communicating the understanding than some magical revelation here. They will likely be able to cite sources which better clarify the background science, as well.
-Cheers
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nigelj at 15:22 PM on 10 January 2020The never-ending RCP8.5 debate
Nick Palmer @49
I strongly agree its important to bring the denialists politics and ideologies out in the open, and I use every trick in the book to try to do that, including being quite blunt with them at times. I'm very polite here because this website is strictly moderated, but I'm blunter elsewhere.
However I mostly try to stop short of ad hominems where possible, because I feel we loose the moral high ground and sympathy of fence sitters in the middle of the debate. Plus I'm not really the name calling type.However whats appropriate does depend on the context, and I'm not saying you are wrong especially if it works for you. Just mentioning my approach.
Its frustrating, as a lot of these politically motivated denialists work for lobby groups, and rule number one with lobby groups is to not discuss personal information and political leanings. I find sometimes you have to prod them quite hard! But their politics usually comes out in the end with a stream of slogans and buzzwords.
While I struggle with certain political ideologies, I tend to avoid attacking them head on and vilifying them, because it alienates people, and just doesnt work. But I'm very critical of specific political policy and data claims and I'm happy to tell people they are spreading ignorance!
Alarmists who exaggerate the science are very frustrating, and do more harm than good, like the mirror image of the hard core denialists. There are a couple over at realclimate.org and I've battled with them, politely. They get real nasty and call me names and label me a denialist or luke warmer. Some of these guys look like they have personality issues, dunning kruger, etcetera. They mean well, but that's about the best I can say.
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Ignorant Guy at 15:00 PM on 10 January 2020Doubling down: Researchers investigate compound climate risks
Hank @ 23
The 10-20% increase in wind speeds was mentioned in the paper by Hansen et al that I referenced. (And I see now that I got the year wrong. 2016, not 2015.) Hansen et al themselves referenced this to Emanuel, 1987, 2005, which I haven't read. I got the link to the Hansen piece from a net search. This:
https://www.atmos-chem-phys.net/16/3761/2016/acp-16-3761-2016.pdf
The "10X worse" was first mentioned here by dkeierleber @ #9, and dkeierleber attributed that to Hansen.
What Hansen really meant I don't know. I didn't find the right reference.
My real point was that "10X worse" is so vague that we can't really say anything about how reasonable it is without more details. 10X worse what? Wind speed? Wind pressure? Wind power? Number of buildings damaged? Cost of damages? Number of people injured?
I can imagine this (speculation - I don't build houses): If a collection of buildings are designed to stand for a certain wind pressure and they are exposed to a storm with a lower wind pressure then none are damaged. If they are exposed to a storm with a higher wind pressure lots are damaged. So there will be a threshold effect. As soon as a building has been damaged the amount of damage will depend on the total energy dissipated into the damaged building. That will be about proportional to the wind power X the duration of the wind. Thinking about it like that "10X worse" is not too far-fetched.
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nigelj at 14:55 PM on 10 January 2020Doubling down: Researchers investigate compound climate risks
Hank @24, buildings in New Zealand also have to withstand something like 1000 year storms from memory. We don't get hurricanes, the worst tends to be tropical cyclones occasionally with very severe gales, so category 2 wind speeds typically. Data on regional zones and maximum limit state wind speeds here.
www.level.org.nz/site-analysis/wind/
Making housing resistant to every conceivable threat with near zero damage would probably lead to houses being built like concrete bunkers. The public would never put up with that, and neither would I.
However let's take an increase in wind pressure of 17% as you mentioned. This doesn't sound too horrendously severe. I agree much of the global warming threat comes more from flooding etc. Anyway upgrading the code for a 17% increase in pressure sounds like a bit of extra wall and roof bracing and more fixings, so not a huge increase in cost. Our public look like they would be ok with that from discussion I have seen on this sort of thing especially if it was phased in. They are quite safety conscious types in the main, except for the libertarian fringe. But they wouldn't wear big changes to the code and huge cost burdens.
Yes its reasonable to treat agricultural structures differently from fire stations. It's just commonsense. I'm 99% sure we do that. To be honest as an Architect I leave most structural stuff to the engineers, although I do know how to do basic beam calcs etcetera. The only structural stuff I do is light timber frame prescriptive code stuff, so I'm a bit hazy on some of the wind design load criteria details.
You get an insight on what the public will bear from the earthquake issue. The Christchurch earthquake was a wake up call, especially as a lot of old brick masonry buildings failed (no surprise there). As a result there were proposals to change the code so that older buildings have to be upgraded to improved earthquake resistance, although not as much as new buildings. People have generally gone along with this as a whole quite well, but there were complaints about costs so the original scheme was downgraded a bit, and owners have been given more generous time frames to upgrade. Some information below on the final proposals. Makes sense to me.
www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=11446301
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One Planet Only Forever at 13:54 PM on 10 January 2020Doubling down: Researchers investigate compound climate risks
Hank @22,
In my comment @25 I should have included that when Canada had a Conservative Party as Leaders it also acted "...in a protectionist manner with actions resisting the corrections required to limit the future climate change consequences". And Canada's Provincial leadership, like USA State leadership, also is heavily skewed to Right-Wing Conservative leadership acting in protectionist ways to resist the corrections required to limit climate change impacts on future generations (and resisting other corrections required to achieve the Sustainable Development Goals).
And a similar observation can be made of what is happening in Australia.
The correlation of New Right-wing Conservatives (not the same as the environment protecting and helpful to Others Conservatives of years ago), and resistance to expanded awareness and improved understanding and the application of that learning to develop sustainable improvements for the future of humanity is a tragic global phenomenon.
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One Planet Only Forever at 12:43 PM on 10 January 2020Doubling down: Researchers investigate compound climate risks
Hank @22,
We substantially agree. And one of my links was to a structural problem in Canada. And there are indeed many other cases of structure failures in Canada.
The root cause of many of the structural problems around the world (poorer quality of design, materials, construction, or maintenance) is economic systems developing desires to get things that are cheaper and quicker (more profitable). Professional Engineers have to stand firm against those pressures, not allowing the 'protection of the public and the environment from harm' to be compromised by any 'economic considerations', or they are unprofessional (an engineer cannot responsibly evaluate 'potential for profit' against a reduction of level of safety against harmful consequences - just as it is inappropriate for economists to compare the lost opportunity of people today with the harm their pursuit of opportunity will do to future generations, especially inappropriate when they discount those future costs).
A side consequence of pursuit of profit is 'protectionist actions' attempting to protect a pursuit of profit from challenges or corrections. And the current USA leadership, and other national leadership like it, is acting in a protectionist manner with actions resisting the corrections required to limit the future climate change consequences.
An early example of USA protectionism is the designation of a unique rail spacing that kept British rail equipment from being imported. The resistance to the use of metric units is a more recent example. And it is likely that protectionism was a major factor in the USA still using A36 steel specifications long after most of the rest of the world had updated to better 44 ksi material specification for general structural steel.
And the change of steel production to 'recycling of steel', with the potential for different material compositions than steel made from pig-iron, happened long before the tragedy that exposed that the A36 standard written for pig-iron production of steel was dangerously out-dated compared to other long-established structural steel production specifications.
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MA Rodger at 11:13 AM on 10 January 20202019 in climate science: A continued warming trend and 'bleak' research
Coopee13 @6,
You say 2x may be an exaggeration, but NOAA data for Global Land 1975-2018 yields a linear trend of +0.30ºC/decade while Global Ocean yields +0.13ºC/decade.
anticorncob6 @5,
You ask why the differential between land & ocean. This is because the ocean depths are still warming up and so cooling the ocean surface temperatures.
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Nick Palmer at 11:07 AM on 10 January 2020The never-ending RCP8.5 debate
nigelj@48 wrote "and violently attacking their world view won't do that. Discussion needs to be subtle and more upbeat"
I said I found my methods very effective because what I aim to do is draw out and lay bare in front of any watching audience 'what lies beneath' the apparently sincere 'sceptical' views. Most of the audience/readers don't know that these denialist memes have been debunked a thousand times, so all they see is one 'sciency sounding' argument versus another nand most are not sophiscated or knowledgable enough to make a value judgement as to whose views are more credible. That is why, IMHO, the SKS method of countering pseudoscience with science is not the bese way of getting through to the great mass of the ordinary public.
By all means 'innoculate' the public with 'stickier' facts but if one can publicly rip off the mask of a right or left wing propagandist (or evangelical) and show that they are spreading misleading partial truths and constructed deceit to sway the minds of the public towards their chosen ideology, I believe it has a more fundamental positive effect. People don't like it when they are being lied to by fanatics. So yes, I use what some might call ad hominems to achieve this. I particulary use them when arguing on Tony Heller's videos!
BTW, I hate to say it, but I've found in my mission to 'tell it straight' that because I sometimes take on alarmists who exaggerate the science or dangers as well as denialists, that those who argue using the 'worst that could happen' (on steroids) possibilities are actually more resistant to rational argument and correction than out and out climate science deniers. -
Cooper13 at 10:46 AM on 10 January 20202019 in climate science: A continued warming trend and 'bleak' research
Forgot that link:
https://www.ncdc.noaa.gov/cag/global/time-series/globe/land/ann/7/1880-2019?trend=true&trend_base=10&begtrendyear=1880&endtrendyear=2019
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Cooper13 at 10:45 AM on 10 January 20202019 in climate science: A continued warming trend and 'bleak' research
Mods - can you eliminate that oversized graph, or shrink it in my post above?
Also, @anticorncob6: here is a link to the NASA climate data, and you can look at trends for global land+ocean vs. just global over land.
Add in the trendline function, and the trend per decade for global is +0.7C/decade; for global land only it is 0.11C/decade, or a factor of 1.6
That is close to my guesses in the above post; yes, it isn't exactly 2. So if that's too much of an exaggeration, then use 'greater than 1.5x', which are still concerning numbers.
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Cooper13 at 10:33 AM on 10 January 20202019 in climate science: A continued warming trend and 'bleak' research
@anticorncob6:
https://thinkprogress.org/global-warming-now-twice-as-fast-over-land-than-the-ocean-nasa-chart-shows-52b4afe01345/Also, WoodForTrees has a site you can plot data from GISTEMP and CRUTEM yourself (GIS is global temps, CRUTEM is land-only). Plotting those from 1880 on, you can see the land temperature increase is larger (not exactly 2x, but perhaps 1.7x, as overal rise is 1 to 1.1C, land only is closer to 1.7-1.8C). So, 2x may exaggerate the issue somewhat, but the effect is larger than 1.5x.
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anticorncob6 at 09:32 AM on 10 January 20202019 in climate science: A continued warming trend and 'bleak' research
@Cooper13 Where is the evidence that land warms twice as much as the global average? And why would land temperatures increase twice as fast as ocean temperatures?
I've heard that the Arctic is warming unusually fast, but not all land.
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Hank11198 at 09:16 AM on 10 January 2020Doubling down: Researchers investigate compound climate risks
Nigelu @ 21
Right now in the US the design wind for risk category II buildings along the coast is based on a 1200 year storm and for the interior a 700 year storm. The design wind for risk category III and IV buildings along the coast is based on a 3000 year storm and for the interior a 1500 year storm. If you were in charge of the design codes, what wind rating would you have engineers design structures?
Also do you think it is reasonable to have agricultural structures such as diary barns designed to different standards than say fire stations?
I’m not trying to be argumentative I’m just trying to get a feel for how much decreased risk the general public might be willing to pay for.
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Hank11198 at 09:06 AM on 10 January 2020Doubling down: Researchers investigate compound climate risks
Ignorant Guy @ 19
I don’t know where you found a 10-20% increase in wind speeds but I would be interested to see a link. Here is a link to a study on global warming and hurricanes. (I may not have inserted the link so it can be one-clicked so I included the text)
https://www.gfdl.noaa.gov/global-warming-and-hurricanes/
That study showed a 4% increase in wind speed per degree Celsius increase. For a 2C increase that would be an increase in wind speed of 108%. Wind power dissipation may well be as you say proportional to the cube of wind speed but structures are based on wind pressures which are a function of the wind speed squared. That would be an increase in pressure of 17%. The 10x comment was made by dkeierleber during a discussion of designing safe buildings. I don’t think I was being unreasonable in assuming he was referring to wind pressures in that discussion since wind pressures are how buildings are loaded. Right now the design code requires in southern Flordia a building to be designed for 180 MPH for risk category II and 200 MPH for risk categories III and IV. A 10x increase in pressure would change that to 570 MPH for risk category II and 630 MPH for risk categories III and IV. I do think that is harmful to the cause of those that think there is a climate crisis. Right now the Glacial National Park is taking down signs that state the Glacial will be gone in 2020. I don’t know what was behind them putting those signs up to begin with but as you can imagine the deniers are having a field day with it.
As for 10x the cost of damages you may be right although that still seems to me a very high bar. For everything I’ve read the damages are usually due mostly to flooding, not so much wind. My understanding is that rising sea levels, flooding, and heat & drought will be more costly than increased winds.
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Hank11198 at 08:15 AM on 10 January 2020Doubling down: Researchers investigate compound climate risks
OPOF @ 18
As I’ve said I can’t speak for codes in other countries. In the US the IBC has been legislated in all 50 states and anyone demanding those laws be broken are subject to prosecution. Clients I have dealt with did not even know the code enough to know what the design requirements were.
My argument has mainly been with dkeierleber’s comments that building built previously were structurally better than today and that today’s codes are written by people with high school education. That is simply not true.
As for structural failures because of a lack of proper maintenance you are absolutely correct. In the US, ASCE has been warning for years that our infrastructure is being poorly maintained. They give a grade every year and for the last several years it has been a D-.
It certainly appears the pedestrian bridge you referenced had design problems. That doesn’t mean the design codes are responsible for engineers that don’t follow the code. And quicker and cheaper does not mean the structure is not safe. We have been lowering the cost and time to build structures for years with better materials and manufacturing technology. It is an engineer’s job to design the most efficient structure that meets all safety requirements.
Maybe you don’t have an answer to why the US failed to investigate the potential risk of the A36 specification is because it’s very difficult to predict potential risk. As they say 20/20 hindsight is always correct. But being able to predict the future is difficult. I just did a search for structural failures and they happen all over the world including Canada.
Resistance to change is not limited to the US. All countries and most individuals struggle with change. I have no idea why railway rail spacing has anything to do with this. Railway rail spacings are different in multiple countries around the world. And profit-motivated resistance to correction is present in all countries, not just the US.
I completely agree with you about the dangers of 1.5C increase. We are on the same side about the need to rapidly end fossil fuel use. I don’t know what you have done but I’ve put in solar panels and changed out my A/C units to more efficient units which dropped my average electrical bill from $350/month to $136/month. But that’s a different subject from saying the structural codes are written by high school graduates.
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nigelj at 05:34 AM on 10 January 2020Doubling down: Researchers investigate compound climate risks
Some scientists and commentators are talking about a need for category 6 hurricanes here and here.
We have millions of buildings designed to resist certain wind strengths. With more frequent winds above what the buildings are designed to withstand, you get more damage overall, and this is where we are heading. Given the lifespan of buildings is typically 50 years minimum and often considerably more, a lot of buildings will be at risk, particularly housing. Strengthening these structures will be an expensive pain in the proverbial.
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One Planet Only Forever at 03:45 AM on 10 January 2020Doubling down: Researchers investigate compound climate risks
Ignorant Guy @19, Good Point.
Defining how bad climate change consequences will potentially be should not be expected to be restricted to "Specific Units of Measure". Like attempts to perform economic evaluations, many things cannot, and should not, be expected to be fully Quantifiable. What can be quantified can be when it is reasonable to do so, along with all of the unquantifiable considerations.
Things being 10x worse is indeed a murky point.
The fundamental related understanding is that it is unacceptable for any individual to act in a way that potentially creates negative consequences for another individual. That understanding involves many unquantifiable considerations. And it does not allow a trade-off where one person decides it is OK to have negative impacts on another because they 'mathed it out and overall it is Good (they figure that their benefit exceeds the harm they think they do to others)'.
What is actually important is to stay focused on: Any negative consequence inflicted on future generations, or Other current day people, due to a lack of correction of harmful unsustainable ways of living is simply Unacceptable.
In spite of the fact that it is a distraction to discussion of how much worse things will be due to human caused climate change there is some merit in those things being discussed, even extreme potential consequences. Structural engineers have to consider possible effects that are not covered by Code Minimum Requirements (at least responsible ones do that - including considerations of safety of construction of their structures).
I am aware of the cube relationship for wind. A 10x increase of maximum wind force requires more than doubling the wind speed. So I suggest that is a 'long way off'.
However, I did not mention that how far into the future that worse condition is is actually not a relevant factor. The future of humanity on this planet is potentially more than a billion years. It does not matter how much later that worse condition is caused by harmful unsustainable activity (some economists incorrectly believe that such future costs can be Discounted, when they incorrectly also believe that they can quantify all aspects of this issue for Their analysis).
However, on the point of Hansen's concerns, the following 2017 Washington Post article, "Ancient storms could have hurled huge boulders, scientists say – raising new fears of rising seas" refers to a study that suggests that the dramatically worse impacts that were part of what Hansen was expressing concern about (boulders being moved by waves) could happen with lower wind speeds.
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John Hartz at 00:52 AM on 10 January 2020Fossil fuel political giving outdistances renewables 13 to one
Adding fuel to the fire...
Thanks to the coal industry’s rapid decline, U.S. greenhouse gas emissions likely dropped slightly last year. But don’t get too used to that trend, because the oil and gas industry is poised to more than offset that reduction. By 2025, oil and gas companies have plans to expand enough to release as much new greenhouse gas pollution as 50 new coal-fired power plants.
According to state and federal records, oil, gas, and petrochemical industries are on track to build or expand 157 projects—such as refineries, oil and gas drilling sites, and plastics plants—in the next five years. New research from the Environmental Integrity Project shows that the projects could emit 227 million tons of additional greenhouse gas pollution by the end of 2025. That means the U.S. could produce 30 percent more greenhouse gas pollution by 2025 than it did in 2018.
“This analysis shows that we’re heading in the wrong direction and really need to slow emissions growth from the oil, gas, and petrochemical industries,” Courtney Bernhardt, Research Director at the Environmental Integrity Project, said in a statement.
The US Oil and Gas Industry's 5-Year Plan Is a Climate and Health Nightmare by Dharma Noor, Earther, Gizmodo, Jan 8, 2020
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Doug Bostrom at 18:36 PM on 9 January 2020Fossil fuel political giving outdistances renewables 13 to one
Putting that $359 million spent on influence by fossil fuel interests during the 2017-2018 election into perspective: 2017-2018 revenue for US oil and gas was ~$317 billion. These companies are buying their own customized reality for barely over 1/10th of 1% of their revenue.
Really, corruption should be handled like taxation: a minimum percentage should be charged.Politicians selling us out for chump change add insult to injury.
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Ignorant Guy at 17:35 PM on 9 January 2020Doubling down: Researchers investigate compound climate risks
There was some controversy about future storms going to be "10X worse" (mentioned first dkeierleber, #9) and Hank at #10 said that claims of storms 10X worse is unrealistic and unhelpful and then OPOF, #11, said "I [...] agree that wind forces 10X worse are a long way off". But "worse" is not a SI-unit or in any way rigorously formally defined. I don't think what was meant from the beginning was 10X windspeeds. I tried to find the paper by Hansen 2015 to look for mentioning of 10X worse storms but didn't really find it. I did find this:
"increment [...] as much as 10-20%. Such a percentage increase of wind speed in a storm translates into an increase of storm power dissipation by a factor ~1.4-2, because wind power dissipation is proportional to the cube of wind speed " (mentioned in "Ice Melt, Sea Level Rise and Superstorms: Evidence from Paleoclimate Data, Climate Modeling, and Modern Observations that 2°C Global Warming is Highly Dangerous", Hansen et al, 2015).
So wind power increases much faster than linear with wind speed. I can imagine then that damages also increases faster than linear with wind power. So it is not completely unreasonable to to foresee future storms to be 10X as destructive, "destruction" measured as cost of damages. -
nigelj at 06:09 AM on 9 January 2020The never-ending RCP8.5 debate
Nick Palmer @46, my experience of online denialists is similar, and they do indeed fall into those three groups. You could add another very small group of apolitical scientific cranks with massive dunning kruger (Victor over at RC). As my Dad used to say "it takes all sorts to make a world".
Dealing with politically motivated denialists frustrates me. Hard to know whether to delve into the politics, or just stick with the science, and let their politics be on show for people to see their motives and reach their own conclusions. However one thing is for sure, we have to try to win over as many people on the right of politics as possible, and violently attacking their world view won't do that. Discussion needs to be subtle and more upbeat. But you know that.
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william5331 at 04:52 AM on 9 January 20202019 in climate science: A continued warming trend and 'bleak' research
Agriculture, the 'bad boy' of many ecologists, could be a major part of the solution of putting carbon back into the soil which bad agricultural practices stetching back a few millenia has vented into the atmosphere. Read the three books by David R Montgomery, Dirt, Growing a Revolution and The Hidden Half of Nature for chapter and verse. What is great about the approach he reports on is that it improves the bottom line of farmers from the small-holding life-style-blocks right up to giant agri-businesses.
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One Planet Only Forever at 04:07 AM on 9 January 2020Doubling down: Researchers investigate compound climate risks
Hank @14,
I have seen foreign clients demand that their buildings in Canada be designed for less loading than the Canadian code (some claiming the USA code is Universal). The basis for their demand was that they did not believe that the code load was justified and as the client they thought they could dictate the design requirements (like they apparently could in other nations that did not require Registered Professional Engineer's to be gate-keepers against desires for things to be cheaper or done quicker).
And there have been cases of structure failures because of a lack of proper maintenance. In some cases the owner sought out an inspector who would deem everything OK like the Elliot Lake shopping plaza collapse (some people love being able to find someone who will say what they want to hear). Many bridges, including in the USA, are becoming disasters waiting to happen.
And a recent pedestrian bridge collapse while under construction in Florida is a dire warning about New Design. The video of the NTSB meeting is enlightening. That bridge was designed and built as an example of a quicker cheaper way to build bridges.
Regarding the delay in the USA updating their structural steel from the A36 standard: The delay I am referring to was not a delayed response to the identified tragedy of Northridge. I am referring to the fact that the old lower-strength A36 specification was very slow to be upgraded to the higher-strength more stringent specifications that were implemented for basic Structural Steel around the planet long before the problem of continuing to use that old lower quality specification was exposed by Northridge.
The change of structural steel production from raw-iron to recycled steel was the cause of the problem. A36 was written in those old days of raw production when contaminants in recycled steel did not need to be restricted by the A36 specification. Exactly why the USA failed to investigate the potential risks of continuing to use the A36 specification when recycled steel production began is a mystery I do not have an answer to. What I am aware of is the history of USA protectionist actions like the continued use of Imperial Units which delayed and limited the competition from foreign producers (but also limiting the ability of USA made products to be exported if their production did not go metric - the USA coming up with its own Railway Rail Spacing is an earlier example). That resistance to stop using Imperial can also be argued to be 'simple resistance to change'. But it is almost certain that there is more to it than just a resistance to change. I presume, in a similar way, the delay of updating the A36 was also more than just 'resistance to change' (which relates to dkeierleber's correct observations of the potentially serious negative consequences of pursuits of popularity and profit).
And that protectionist profit-motivated resistance to correction (that can also easily be popular) can be seen in the actions of certain factions in the USA and other nations as they fight against the corrections of unsustainable creation of negative consequences that are identified by the improved understanding of climate science.
The science is clear that total global impacts exceeding a 1.5C increase of global average surface temperature is unsafe (harmful) for future generations. There is fairly well understood significant negative consequences due to that amount of warming, And beyond 1.5C warming there are significant uncertainties regarding how much more negative things will be.
There is virtually no chance that there will be Positive Future Impacts of warming beyond 1.5C. And since perceptions of wealth today are so heavily based on unsustainable activity there is serious doubt about today's wealth continuing to exist in the future.
A correction to Sustainable Development, not just the rapid ending of fossil fuel use, is urgently required. Resistance to that required correction is seriously detrimental to the future of humanity. And the reality that change/correction resistance can be so powerfully fuelled by desires to Protect Developed Perceptions that are popular and profitable is a serious threat that humanity needs to figure out how to Govern and Limit.
The uncertainty regarding the severity of negative consequences of combined climate change impacts is more reason to more rapidly pursue Sustainable Development and all the changes and corrections of current incorrect over-development that are required.
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tag at 03:18 AM on 9 January 2020It's not bad
It seems that one negative of the Artic melt is missing.
The amount of fresh water released by the Artic melt is diluting the Gulf Stream and has started to impede its normal circulation
This will bring intense cold to Europe as warm water will not reach the continent in winter
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MA Rodger at 03:01 AM on 9 January 2020The never-ending RCP8.5 debate
While the 'robust' discussion on the damage that would be wrought by a BAU future appears to have abated, I'm not surprised such discussion can become 'robust'. I think you need to keep firmly on mind what BAU is, on what it will cause climate-wise and also how quickly, if the consequences of BAU are to be discussed. And I would stick to temperature as a gauge of 'what it will cause.' SLR is too much of a long-term thing. According to IPCC AR5, even at +1.5ºC we are due 4 metres of SLR, evenyually.
As for what increased global temperatutre will bring, I note an article in the UK's Daily Mail that presents an interesting extreme, although there was already one critique of XR's Roger Hallam that made a similar claim. The Mail quotes a report from pension company Aviva saying:=
Aviva warns that the world is on track to warm by more than 3C by 2100 – double the 1.5C limit that was set in the 2016 Paris Agreement.
The fund manager estimates that warming on this scale would wipe £10trillion off the value of global stock markets.
The cost would rise to around £33trillion if temperatures rise by 6C. 'While the likelihood of that much warming is low, the results would be catastrophic,' the report said.
This mixing of the £33trillion cost (that is 30% of global share values) with it being 'catastrophic' does raise the question of 'catastrophic to whom?' It is perhaps pension-fund managers and presumably not the global population as a whole.
I note a similar conclusion on financial terms was given by Ken Caldeira when criticising Hallam:-
Climate damage has been discussed extensively in various IPCC reports and in the peer-reviewed academic literature. Estimates of climate change damage for this century, in business-as-usual scenarios, are typically in the range of a few percent of global GDP to tens-of-percent of GDP for the most extreme damage functions in the most extreme scenarios. There is no analysis of likely climate damage that has been published in the quality peer-reviewed literature that would indicate that there is any substantial likelihood that climate change could cause the starvation of 6 billion people by the end of this century.
So for those who are saying that +3.0ºC would leave 90% of the global economy functioning happily and that even +6.0ºC would still leaving two-thirds in tact; for such folk, the idea of +4.0ºC causing six billion deaths will take some explaining.
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Nick Palmer at 00:24 AM on 9 January 20202019 in climate science: A continued warming trend and 'bleak' research
I think the paper referenced above in the article is of enormous use to those who come up against the 'Mediaeval Warm Period was global' argument.
"No evidence for globally coherent warm and cold periods over the preindustrial Common EraRaphael Neukom, Nathan Steiger, Juan José Gómez-Navarro, Jianghao Wang & Johannes P. Werner"
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nigelj at 12:54 PM on 8 January 2020Doubling down: Researchers investigate compound climate risks
Hank @16, thank's for the comment and I do understand there has to be a sensible compromise between code requirements on property protection versus cost. However it appears the buildings in the Canterbury earthquake suffered more damage than buildings in Japan and other places subject to the same forces. I recall discussion in our media on this but I can't find anything using google. I can tell you earthquake codes were reviewed.
It looks like our codes are weighted a long way towards lowest cost. However I doubt that has anything to do with the engineers on the committees that develop codes. In my experience structural engineers in NZ are very commited to tough building codes, I've worked with plenty of these guys. Several times they have recommended going above code.
However heres another couple of examples where ideology combined with cost cutting appears to have intruded. Our building code was revised in 1995 and the fire code was changed from something that included both safety and a mild level of property protection to just safety. And the construction code was changed removing the requirement for treated timber framing and metal flasings around windows etc, and this lead directly to an expensive leaky homes crisis.
Insulation requirements were downgraded to a bare minimum. During all this the government of the day was promoting deregulation, austerity, freedom of choice, lower costs, etc the whole neoliberal paradigm. These definitely look to be factors in the changes Ive mentioned.
While you dont want to over regulate and cause massive expense, these three examples of downgrading the code were stupidity and a disaster. As a result, the code was revised yet again, and insulation requirement was increased and we went back to treated timber etc around 2005.
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Hank11198 at 11:52 AM on 8 January 2020Doubling down: Researchers investigate compound climate risks
@13 nigelj
Nigelj I can only speak for the US but I have researched the European codes since we sell around the world and their codes are very similar. There is a very logical reason buildings are designed to just prevent the building from collapsing during a high seismic event and it has nothing to do with neoliberal ideology.The forces on a building during a seismic event are a function of the building mass. The mass of a building results in loadings that are up to 8-10 times the forces due to extreme wind pressures. Therefore a building that is designed for extreme wind at $200/sq ft would be $1000/sq ft if designed to the same requirements. Just a foundation to support the additional weight would be massive. For the billionaires this might be acceptable, however a developer that was investing in a building for rent would never be able to find any clients. Therefore the tradeoff is a building that is safe for humans but at risk of having to be rebuilt or even destroyed if a high seismic event happened. This type of risk happens every day in the stock market.
With the committee that was writing the design code I served on there was never a discussion of trying to minimize the code requirements. There was lots of discussions about how to assure the code produced structures that were safe and operational. Structural engineers are the most sued engineering profession in the US. That’s not because they are incompetent or because they try to cut corners. It’s because structural failures are usually much more expensive, not to mention lethal, than designs in the other engineering professions. We lose a lot of sleep hoping we didn’t divide by 2 instead of multiplying by 2.
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Hank11198 at 11:22 AM on 8 January 2020Doubling down: Researchers investigate compound climate risks
@12, dkeierleber
You have stated before that buildings built to standards of 1890 are structurally better than buildings built to current standards. Yet you have not provided any evidence of that. Nor have you stated what standards you are talking about in 1890.
If you are talking about residential buildings you are correct that SOME developers build the cheapest and fastest they can. If you are talking about commercial and industrial buildings that is something different. Commercial and industrial buildings as well as other structures in the US require they be designed and certified by a professional engineer. Only a very small number of structural engineers would risk their license by designing a building that does not meet code requirements. That is evidenced by the small number of structural failures in the US.
The three US building codes were combined into the International Building Code in 1994 so other countries that do not have the resources for research could adopt it as their own code. Structural design has never moved out of the code book. The three original codes also referred to AISC for steel design and the other codes for concrete, aluminum and wood. They also used the wind speed maps that were based on ASCE 7. The IBC is primarily a fire code that specifies ASCE 7 and the material codes for the structural loading and design sections. I don’t know where you get the idea that those codes are written by individuals that only have a high school education. They are written mostly by engineers with advanced engineering degrees.
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Hank11198 at 11:00 AM on 8 January 2020Doubling down: Researchers investigate compound climate risks
@11 OPLF
Nice to see engineers are represented here and concerned about climate change.I am only familiar with the US codes. I do know that in the 1980’s steel mills started suing more modern production processes that resulted in steels specified as A36 had a higher yield strength of around 50 ksi are more. As a result the beam to flange weld metal at the joints became under-matched which may have contributed to excessive strains at the joint. The Northridge earthquake in 1994 resulted in several studies that were initiated by AISC and the AWS over the next few years which revealed the problem. Soon after the codes were changed to address this and numerous other issues. I did not realize there was ever a delay in updating any codes due to protectionist actions. However I’m always eager to learn so would appreciate any documentation you know of regarding this.
I graduated in 1971 and have worked in 5 different industries, transmission lines, railroad bridges, large satellite antennas, consulting engineering, and high voltage sub-stations. Maybe I’ve just been lucky but I have never been asked to compromise any design based on costs or any other factor. I have of course been asked if a less expensive product could be substituted for some part but only if it checked out to meet code requirements. The only thing close to this was a somewhat humorous experience when I was going over a part with some people in the shop. One of the welders stated he had built many of these and the plate was too thicker than needed. I handed him my pin and stated “Ok just write that on the drawing and sign and date it”. He didn’t make any more comments.
I certainly realize the need to stay on top of changing weather and agree with you that areas can experience changing environmental requirements. I believe the engineers on the committees that write and revise the codes in the US do track extreme weather events and take this into account. Living in the South ice and snow are not usually controlling conditions so I’m not as familiar with those types of loading. With the exception that even in the South, ice on wires combined with wind can control the design of supporting structures.
Concerning your final note. The US code does not consider hurricane categories. Instead it has wind maps that specify the wind speed at locations throughout the US. At this time the highest wind speeds are 180 MPH along the Gulf Coast. I don’t think any hurricane has hit the US with those wind speeds. I would also point out that the highest wind speeds in a hurricane are limited to near the eye of the storm. In addition for most structures the maximum wind speed must attack the structure from one specific direction for the structure to be fully loaded to the design load. That reduces the likelihood that a structure will be fully loaded in a hurricane. But as I said, structural loading is statistical in nature. So there is always the risk that any storm could exceed the design loading on a structure. We just want to lower that risk to an acceptable number.
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Nick Palmer at 10:00 AM on 8 January 2020The never-ending RCP8.5 debate
Sorry if I went outside the forum rules. While I was writing #41 I was simultaneously taking on a very tricky, very agressive denialist/sceptic and I probably slipped into the mindset I use when taking on such types, which I have found extremely effective - not at convincing them (which is very hard) but it is one of the best techniques I have discovered for drawing out into the open, where the audience can see them, 'what lies beneath' - the underlying motivations that make such types so incorrigible. Call into question their rationality or intelligence and 9 times out of ten they will come back with stuff attacking one's own position which reveals that they are mostly hard line right wingers scared of left wing solutions, a smattering of evangelicals who believe God so loves us that he has designed Earth with hidden negative feedbacks which will prevent us doing anything much, or (rare these days) hard line left wingers who believe climate science was faked up so the West can deny energy and development to the Third World.
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nigelj at 08:36 AM on 8 January 2020The never-ending RCP8.5 debate
Evan @44, in a word, yes. A guy called Mike over at Reaclimate.org posts a lot of weekly, monthly and yearly data on MLO CO2 levels. I've thought much of this is a bit to short term to mean much, but I'm beginning to think he's the only guy with his eye firmly fixed on the ball, for want to a better description.
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nigelj at 07:38 AM on 8 January 2020Doubling down: Researchers investigate compound climate risks
Hank, I also share many of your views, but the truth on this thing is possibly more nuanced. I'm a semi retired Architect, involved in the design of both housing and highrise construction in New Zealand.
Our building codes are quite detailed on everything including structure. There was a massive earthquake in Christchurch recently and modern buildings survived better than older brick masonry buildings and concrete framed buildings, as you would expect.
However there are huge caveats around all this. dkeierleber has a point to some degree. Our codes are minimal codes, so for example earthquake and fire codes target only life safety, not property damage. This is because of neoliberal thinking that constantly aims to minimise building codes.
As a result although modern highrise buildings and timber farmed houses survived the earthquake and not many people were killed, these structures suffered considerable damage and many had to be demolished and rebuilt. The bottom line is the codes are pretty minimal, and neoliberal ideology is definitely involved. I dont have time to go into all the details, but I know this for a fact.
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