Man killed in snow roofalanche.

[Hawkmoon]

Aw, c'mon, Hawkmoon.  Think about what I said and about what you're saying.

Ayup, built to code.  Yet roofs still collapse.

Yes, they do. Usually because they are older structures that would not meet current codes, but sometimes because somebody made a mistake (such as the collapse of the Hartford Civic Center back in the late 1970s or early 1980s).

You're talking about building stresses within the ASSUMED limits of the Code-makers.

Safety factor, let's say 50% or whatever you choose.  But I reckon they had a 51% snowfall. So yes, hell yes.

And since vertical snow load is dependent on the roof angle, there's no wonder flat roofs are more vulnerable and A-frames less so.

"The building codes do NOT allow any reduction in the required
snow load for the possibility that the snow might slide off."  I did not say they did.

The point is that all the engineering that goes into safe building codes are based on given stresses plus safety factors balanced against costs, etc.  But what if the snow load is over that safety factor?

Yes, hell yes, you get roof collapses. And I know you do a lot of architectural work.

So yes, hell yes, you get actual honest-to-Gawd roof collapses, no kiddin' around, no argument, building codes notwithstanding.

I never said there aren't collapses. I've even investigated a couple. What I said is that building codes don't allow any reduction in the roof snow load the engineer designs for because the architect didn't call for snow guards. And I don't know any architect or structural engineer who would include the possibility of snow sliding off a roof as a parameter in calculating the load they would design the roof structure to support.

[Ben]

Yes, they do. Usually because they are older structures that would not meet current codes, but sometimes because somebody made a mistake (such as the collapse of the Hartford Civic Center back in the late 1970s or early 1980s).

In the Idaho Snowmaggedon of 2017, quite a few roofs collapsed. Some because they were older, but others because the roof load and pitch requirements had been reduced in some counties due to some decades of less snow. I guess they figured that was the "new norm" and then Mother Nature gave them a slap.

[griz]

 Really, we've reached the point that coastal damage can only be limited.

I'm still not convinced, and frankly I think the powers that be at NOAA, NASA, EDF (and many more) are not convinced that the sea level has us doomed to drown.  The reason is simple:  DC and New York city, where their headquarters are, are pretty close to seas level already, and nobody is making plans to move.

[Brad Johnson]

Siding with 230 on this one.

Just because a roof is designed and constructed properly doesn't mean it's immune to problems, or that the load spec is necessarily accurate for the locale.

Design specs are invariably keyed to "most probable" event scenarios with some modicum of safety margin built in. The specs are usually developed based on the structure's expected service life and the likelihood of an event's occurrence during that time (like considering 50-, 100-, and 500-year flood levels when designing a bridge with an expected 30 year service life). All it takes is one instance of an improbability, or an unforseen combination of within-probability extremes, for that safety margin to be exceeded. That happens way more often than people like to admit, especially professionals who's reputation and income depend on consumer perception of design safety. Unfortunately, Mother Nature has a tendency to bitch slap statistical probabilities right where it hurts.

We had the issue of unexpected combinations here at the Museum back in Dec 2016. Two snowfalls and a period of low temps, all three events within statistical probability (albeit on the extreme ends) and given consideration in building design and construction. Unfortunately the design probabilities were considered on an independent basis, not as concurrent events. We ended up with an unmelted extreme snowfall topped by another extreme snowfall. Ultimately the snowpack weight exceeded roof load specs and we had a partial collapse.

Brad

[brimic]

Never look up a plumbing drain pipe, and never stand under a roof when they are clearing it off.

[Scout26]

Sorry, but I don't think that one guy getting squished by a bunch of snow is reason to completely destroy our economy and go back to living in mud huts.

From what I recall reading and seeing on charts, was that CO2 was a trailing indicator of climate change.

[Brad Johnson]

From what I recall reading and seeing on charts, was that CO2 was a trailing indicator of climate change.

It is. Depending on the study quote, the lag is between 200 and 500 years. It came from Vostok ice core data. From what I recall, they are looking at the way ice takes up atmospheric CO2 to try and eliminate (or at least greatly minimize) the discrepancy.

Brad

[Hawkmoon]

Just because a roof is designed and constructed properly doesn't mean it's immune to problems, or that the load spec is necessarily accurate for the locale.

Design specs are invariably keyed to "most probable" event scenarios with some modicum of safety margin built in. The specs are usually developed based on the structure's expected service life and the likelihood of an event's occurrence during that time (like considering 50-, 100-, and 500-year flood levels when designing a bridge with an expected 30 year service life). All it takes is one instance of an improbability, or an unforseen combination of within-probability extremes, for that safety margin to be exceeded. That happens way more often than people like to admit, especially professionals who's reputation and income depend on consumer perception of design safety. Unfortunately, Mother Nature has a tendency to bitch slap statistical probabilities right where it hurts.

I don't deny that the possibility of an overload exists, nor have I said that collapses don't or can't happen. Building codes are based on a consensus process. They aren't perfect, but their intention is to protect life and property. What I said is that the omission of snow guards on a sloped, metal roof is an irresponsible act. It's a bug, not a feature. I will guarantee with about a 99.375 percent certainty that the snow guards were not intentionally omitted in order to facilitate snow sliding off in roofalanches. They were omitted either to save money, or because the designers didn't think about having them installed.

The "specs" for roof loadings aren't made up by the architects or engineers -- they are established by the building code. These days, all states use the International Building Code, so there is a level playing field. Engineers can design more conservatively, but they can't design for less than the snow load established by the building code. Sadly, in the real world virtually no engineer ever designs for more load than what the code establishes for the simple reason that it would cost more, and clients won't pay for more than the minimum loads established by the code.

The roof in the video that prompted my comment didn't even have snow guards over the front entrance. IMHO that's professionally negligent. Watch the video at 1:28 if you want to know why.

[MechAg94]

It is. Depending on the study quote, the lag is between 200 and 500 years. It came from Vostok ice core data. From what I recall, they are looking at the way ice takes up atmospheric CO2 to try and eliminate (or at least greatly minimize) the discrepancy.

Brad

That sort of sounds like they have an answer and trying to revise the question.  Either way, it is another reason I don't favor any drastic actions.  We just don't know enough yet. 

[charby]

That sort of sounds like they have an answer and trying to revise the question.  Either way, it is another reason I don't favor any drastic actions.  We just don't know enough yet. 

I work in agriculture and I go to a lot of agronomy meetings, most directed at the individual farmer, so the science is scaled down to make understandable for the masses. There is always a PhD or 2 that gives a talk at these meetings, yes global warming/climate change has been mentioned by them for a least 10 years or slightly longer when talking climate or long term growing conditions. Most the talk has been about wetter springs and falls, perhaps having the change to a longer day corn or different maturity group soybeans to maximize yield potential. Nothing about stop using tractors and going back to horses. More about thinking about how to adapt to change.

Now the discussion has changed from high temps are rising, but that the high temps haven't changed much, but the low temps are rising. Even the chemical companies are talking about this, especially in season long weed control with pioneer weed/pest species. They aren't selling that chemicals are going to take care of your entire weed problem alone, but selecting chemicals and application timing along with farming practices to combat weeds/pests in the changing climate. That conversation has really changed, from 100% chemical control to mixing chemical/biological/cultural practices to control pests/weeds. I think they are experiencing part of what scientists have been saying and that change of the climate is affecting US agriculture. 

[makattak]

I work in agriculture and I go to a lot of agronomy meetings, most directed at the individual farmer, so the science is scaled down to make understandable for the masses. There is always a PhD or 2 that gives a talk at these meetings, yes global warming/climate change has been mentioned by them for a least 10 years or slightly longer when talking climate or long term growing conditions. Most the talk has been about wetter springs and falls, perhaps having the change to a longer day corn or different maturity group soybeans to maximize yield potential. Nothing about stop using tractors and going back to horses. More about thinking about how to adapt to change.

Now the discussion has changed from high temps are rising, but that the high temps haven't changed much, but the low temps are rising. Even the chemical companies are talking about this, especially in season long weed control with pioneer weed/pest species. They aren't selling that chemicals are going to take care of your entire weed problem alone, but selecting chemicals and application timing along with farming practices to combat weeds/pests in the changing climate. That conversation has really changed, from 100% chemical control to mixing chemical/biological/cultural practices to control pests/weeds. I think they are experiencing part of what scientists have been saying and that change of the climate is affecting US agriculture. 

Ok, can we, then nail down that the prediction is that the temperatures will RISE, ON AVERAGE, over the next decade?

Because the weasel words in the press have all been trying NOT to say that.

I want a firm prediction (like science is supposed to provide) about the rise in temperatures and an amount that will be correct within +/- 10%. So we can test the hypothesis.

Because the models have all been wrong, every time, for my entire life. Yet, somehow we're supposed to ignore that and accept that they've been right all along.

[griz]

Ok, can we, then nail down that the prediction is that the temperatures will RISE, ON AVERAGE, over the next decade?

Because the weasel words in the press have all been trying NOT to say that.

I want a firm prediction (like science is supposed to provide) about the rise in temperatures and an amount that will be correct within +/- 10%. So we can test the hypothesis.

Because the models have all been wrong, every time, for my entire life. Yet, somehow we're supposed to ignore that and accept that they've been right all along.

That's been my problem.  If "they" could come up with a model, agreed upon by the same majority, that accurately reflects what has happened in the past 100 years, I would change my mind.  As it is now they only agree that industry, internal combustion engines, and cows, are bad.

[charby]

That's been my problem.  If "they" could come up with a model, agreed upon by the same majority, that accurately reflects what has happened in the past 100 years, I would change my mind.  As it is now they only agree that industry, internal combustion engines, and cows, are bad.

I've seen the charts/graphs of the past, just about every agronomy meeting I go to. Google will present you with more peer reviewed charts than you can read and interpret in a rational amount of time.

Science deniers still refuse to look at them, make up every excuse not to believe the data, or at least rationally (without emotion) discuss it. Then you hear the arguments against with Greenland and Vikings farming it, then the medieval warm up before the little ice age, etc. Usually by people who's only science background is a rocks for jocks class at the local community college.

Need to read the X and Y access value before opening your mouth, yes the lines look dramatic, but the Y axis has pretty small number temperature change vs the wide spread of the X axis of time.

The climate people I tend to side with are the ones who say yes, we do show that annual global temps have been on the rise, not sure if it will continue and still uncertain if it really influenced by mankind, creating or saving. If it continues to rise, we are going to be forced to change many practices such as growing food and where we live.

[makattak]

I've seen the charts/graphs of the past, just about every agronomy meeting I go to. Google will present you with more peer reviewed charts than you can read and interpret in a rational amount of time.

Science deniers still refuse to look at them, make up every excuse not to believe the data, or at least rationally (without emotion) discuss it. Then you hear the arguments against with Greenland and Vikings farming it, then the medieval warm up before the little ice age, etc. Usually by people who's only science background is a rocks for jocks class at the local community college.

Need to read the X and Y access value before opening your mouth, yes the lines look dramatic, but the Y axis has pretty small number temperature change vs the wide spread of the X axis of time.

The climate people I tend to side with are the ones who say yes, we do show that annual global temps have been on the rise, not sure if it will continue and still uncertain if it really influenced by mankind, creating or saving. If it continues to rise, we are going to be forced to change many practices such as growing food and where we live.

I'm an economist by training, so I'm intimately familiar with models and with people who place absolute certainty in models that end up being spectacularly wrong.

I assume you are in agronomy. Now, I'm not a trained agronomist, but I am very interested in my garden and have a lifelong familiarity with growing things.

I have to ask you a question about changing what food you grow in Iowa: Do you know the size of the plant hardiness zones? How many things does Iowa grow that can only survive in 5a and will wither from the heat of 6a? (Incidentally, I'm fairly certain that much a change in temperature is actually outside of even the median of the mostly wrong models.)

[Jamisjockey]

Not to mention people were smart enough, for the most part, back then to not built right on the beach and/or on barrier islands

LOL
https://en.wikipedia.org/wiki/1900_Galveston_hurricane

[MechAg94]

I've seen the charts/graphs of the past, just about every agronomy meeting I go to. Google will present you with more peer reviewed charts than you can read and interpret in a rational amount of time.

Science deniers still refuse to look at them, make up every excuse not to believe the data, or at least rationally (without emotion) discuss it. Then you hear the arguments against with Greenland and Vikings farming it, then the medieval warm up before the little ice age, etc. Usually by people who's only science background is a rocks for jocks class at the local community college.

Need to read the X and Y access value before opening your mouth, yes the lines look dramatic, but the Y axis has pretty small number temperature change vs the wide spread of the X axis of time.

The climate people I tend to side with are the ones who say yes, we do show that annual global temps have been on the rise, not sure if it will continue and still uncertain if it really influenced by mankind, creating or saving. If it continues to rise, we are going to be forced to change many practices such as growing food and where we live.

Part of my problem is 1) I really dislike all the "sky is falling" nonsense pushed by the media and the political people, 2) there is a lot of erroneous or filtered data put out in the past by "believers" trying to justify their belief, and 3) the political solutions people present are just pure communism and won't help one bit.  I don't know what data to trust.  I just know this idea that civilization will end is complete BS.  Discussing how we might see minor shifts in the coming years/decades that will affect how we do certain things is a whole lot more reasonable and something that would be more interesting to talk about.  

https://www.youtube.com/watch?v=N-yALPEpV4w
Listened to this last night.  Sounds like he is a environmentalist who has become more realistic and solution oriented.  He talks a lot about how nuclear power is actually a good thing.  

[Scout26]

Part of my problem is 1)  Discussing how we might see minor shifts in the coming years/decades that will affect how we do certain things is a whole lot more reasonable and something that would be more interesting to talk about.  
 

But then you can't herd the masses into mud huts to sit in the dark and eat gruel while their "betters" jet set around the country/planet using all their electronic devices, and eating steak...

[Ben]

The climate people I tend to side with are the ones who say yes, we do show that annual global temps have been on the rise, not sure if it will continue and still uncertain if it really influenced by mankind, creating or saving. If it continues to rise, we are going to be forced to change many practices such as growing food and where we live.

Now, now... thinking like that might lead to productive conversation. Just stop it.

I will give fed.gov credit for trying to create that conversation through the term "climate resiliency", which we were using through the Bush and Obama admins. You simply accept that climate is variable, nevermind the cause, thus you look at planning human infrastructure  to be resilient to it. The problem was that the "administrator scientists" (different from actual, operational scientists) wanted to play politics and thus tied it into the AGW and then later "climate change" politics, because that's where the budget money was. So now climate (and we should include "weather") resiliency is lumped in with the AGW "we have 12 years to live!" stuff and we can't have constructive conversations.

[makattak]

Now, now... thinking like that might lead to productive conversation. Just stop it.

I will give fed.gov credit for trying to create that conversation through the term "climate resiliency", which we were using through the Bush and Obama admins. You simply accept that climate is variable, nevermind the cause, thus you look at planning human infrastructure  to be resilient to it. The problem was that the "administrator scientists" (different from actual, operational scientists) wanted to play politics and thus tied it into the AGW and then later "climate change" politics, because that's where the budget money was. So now climate (and we should include "weather") resiliency is lumped in with the AGW "we have 12 years to live!" stuff and we can't have constructive conversations.

Another data point is that the people who most zealously buy into these crap models do things like, to pick a random example, fail to maintain or build new reservoirs for a growing population because "rain and snow are a thing of the past."

But spend billions on a train to nowhere.

[Ben]

Another data point is that the people who most zealously buy into these crap models do things like, to pick a random example, fail to maintain or build new reservoirs for a growing population because "rain and snow are a thing of the past."

But spend billions on a train to nowhere.

Yup. And in that state, ironically, this last drought would have been a nothingburger had Jerry Brown of all people, in the 70's, been allowed to finish his father's legacy with just one more strategically placed reservoir.

The objection to that at the time was by the parents of the people who now will not say the word "nuclear" when talking about atmospheric carbon reduction.

[charby]

I'm an economist by training, so I'm intimately familiar with models and with people who place absolute certainty in models that end up being spectacularly wrong.

I assume you are in agronomy. Now, I'm not a trained agronomist, but I am very interested in my garden and have a lifelong familiarity with growing things.

I have to ask you a question about changing what food you grow in Iowa: Do you know the size of the plant hardiness zones? How many things does Iowa grow that can only survive in 5a and will wither from the heat of 6a? (Incidentally, I'm fairly certain that much a change in temperature is actually outside of even the median of the mostly wrong models.)

Sorry, I was referring to the a chart that shows global temps from the past 100 years or longer. Something as big as the global climate and how varied it is, really hard to get an exact model to predict the future. You can build models that product many trend lines, but picking what trend is actually going to happen is near impossible until you move closer to an event, kind of like hurricane models.

Growing zones is not so much of a food plant withering in heat, but can it survive the winter temps, think more on perennial plants here. there are a few plants that will not do well in warmer temps, like rhubarb and some blueberries, so you're not wrong. Apples need so many days of cold weather dormancy too, why you don't find much fruit bearing apples south of Memphis, TN.

More with a rising low temps, places like Iowa are going to have a longer growing season. Need to think in terms of growing degree days and not hardiness zones for annual crops. https://en.wikipedia.org/wiki/Growing_degree-day

Growing degree days is not a new thing, it is how many grass type crops, like corn and wheat varieties are picked for a certain area.

No, I don't think all of Iowa will ever become hardiness zone 6, but the southern bottom counties may in time. I grew up in SE IA, we can grow apricots there and harvest a crop about 9 out ten years. Late frost at blossom set is what happens for the 2 out of ten years. Where I live now near the Minnesota border, maybe 1 out of 10 years I would get a apricot harvest. Tree would survive just fine, except for those 1 out of 25 years like this winter where the actual temp drops below -25F for a few days and kills the apricot tree (cold snaps the vascular tissue in the stem). Going to be a lot of zone 4 peach trees dead this year in north Iowa/southern Minnesota.

But adjustments that are being made is something like picking a corn variety with a few more growing degree days to maturity to protect existing yield. More CO2 means more CO2 for early weeds that emerge as soon as the soil warms in the spring, higher low temps mean more growing degree days for weeds to grow. More CO2, more carbon for the crop, grow taller faster, needs more nutrient inputs. Slightly warmer winter temps means more insects over winter, etc. Just a slight increase changes lots of variables.

Growing a home garden is easy to control, try basing your living on a few thousand acres of corn and soybeans where it is currently hard to break even, let alone make a profit. Having to spend an extra $10-30 an acre for fertilizer or herbicide might take any profit away or make you go into the hole.

[charby]

Now, now... thinking like that might lead to productive conversation. Just stop it.

I will give fed.gov credit for trying to create that conversation through the term "climate resiliency", which we were using through the Bush and Obama admins. You simply accept that climate is variable, nevermind the cause, thus you look at planning human infrastructure  to be resilient to it. The problem was that the "administrator scientists" (different from actual, operational scientists) wanted to play politics and thus tied it into the AGW and then later "climate change" politics, because that's where the budget money was. So now climate (and we should include "weather") resiliency is lumped in with the AGW "we have 12 years to live!" stuff and we can't have constructive conversations.

I don't disagree

[230RN]

Sorry, but I don't think that one guy getting squished by a bunch of snow is reason to completely destroy our economy and go back to living in mud huts.

From what I recall reading and seeing on charts, was that CO2 was a trailing indicator of climate change.

I frankly did not think my OP would go off on climate variability, so don't blame me.

I had no idea the thread would take off in that direction.  I just meant the OP as precautionary in the same way as "look out for avalanches" but in this particular situation of hanging around  under a snow-laden roof.

As I said, most of the roofalanche videos are funny in a Three Stooges sense, but Bad Things Can Happen Anyhow.

BTCHA

I just guess some folks were cocked and locked to interpret the OP that way, though.

But since Pandora got out of the box, my longstanding position on climate change is (per attachment), "It's your sample size, stupid!  You can't tell a damned thing from only 200 years of measurements !"

So call me in 1000 years and tell me how it's going.

Terry, 230RN

Temp, CO₂, over 400,000 years by proxy.  The validity, despite the noisiness, is proven by the eyeball-obvious regularity of the major cycles.

[Scout26]

I frankly did not think my OP would go off on climate variability, so don't blame me.

I had no idea the thread would take off in that direction.  I just meant the OP as precautionary in the same way as "look out for avalanches" but in this particular situation of hanging around  under a snow-laden roof.

As I said, most of the roofalanche videos are funny in a Three Stooges sense, but Bad Things Can Happen Anyhow.

BTCHA

Terry

Thread drift is a feature, not a bug on APS.


Getting back to the point CHarby made.  Yes, farmers need to be prepared for climate change.  However, they need to be prepared both ways, for longer/warmer ad shorter/colder.   Given the changes in the Erf's magnetic field, along with the Giant Ball of Fusing Hydrogen going into it's "less active" cycle.  I forsee and predict that Erf will get colder and not warmer... But that doesn't reduce our reliance on fossil fuels.   

If the Climate Changers (and yes, the Erf's climate frequently changes), were honest that it really is about going green, then they would demanding and marching for Nuclear Power plants.

[230RN]

"Thread drift is a feature, not a bug on APS."

Oh, I know.  That's why I never said anything about it in "my" thread until now.  I confined myself to stuff related to snow on roofs.

The thread kind of oscillated between that and the fyoocher of the Erf.

(I did not mean Pandora got out of the box, I meant that all the stuff got out of Pandora's box.)