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How should climate change be considered in design codes and specifications?

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IDS

Civil/Environmental
Jun 1, 2001
3,221
The climate affects many aspects of engineering design, including wind speeds, flood levels and temperature extremes. Design codes must set specific levels for these things, and the appropriate level varies depending on geographical location. The appropriate levels and geographic extents have been set in the past based on historical records, with little, if any, consideration of how the climate may change in the future.

Regardless of the reasons for climate change, it is clear that the climate is likely to change significantly in the future, and there will be at least some locations where climate conditions will become more severe (e.g. higher maximum wind speeds, higher sea levels and storm surges, higher maximum temperatures).

1) How should design codes be changed to deal with the risks associated with climate change?

2) What can we do as individuals or representatives of engineering organisations to ensure that these changes are put in place, and are considered in a logical manner, with due consideration of the risks and costs involved?

Doug Jenkins
Interactive Design Services
 
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Doug,
Great questions and i would agree with the thrust of you post. We should be proactively consider the necessary changes now because a lot of what we do now will impact structures, facilities , systems etc for a very long time into the future.

A couple of barriers.

1. As you have seen in some recent posts there is obviously several opinions out there about the causes, severity and impacts of climate change. These opinions are not only in the engineering community.
2. Governments are generally involved in the setting and mandating of standards. By mandating standards that allow or consider climate change, means that the government by default accepts that climate change is certain and it will have sufficent impact on society that standards need to change. Many governments, Australia included have not acceptted that yet. A government that accepts that climate change is a problem has a moral obligation to do something about it, which may not always be popular.
3. Many standards are set by experience, or in response to events(car crashes, medical accidents, building collapses etc) because society expects that such things to not happen. Climate change has been insidious and in many cases has not caused events that are absolutely linked to climate change. Therefore as a society we are not yet yelling loud enough that we demand change.

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"
 
I appreciated the comment "regardless of the reasons for CC", to focus on the effects and their remediation.

Codes are set by several different authorities, federal, state, municipal. This should allow things to happen (rather than barriers), or at least have a professional decision.

Should we change our definition of 1/100 year storm winds ? This is contentious, some claim that CC brings increased storms, others not So have an engineer/authority look at the data and make a conclusion. Maybe we don't have data for 1/100 years but we can see 1/10 years well enough.

Sea level change is another. Is it or isn't it changing ?

another day in paradise, or is paradise one day closer ?
 
Should we change our definition of 1/100 year storm winds ? This is contentious, some claim that CC brings increased storms, others not So have an engineer/authority look at the data and make a conclusion. Maybe we don't have data for 1/100 years but we can see 1/10 years well enough.

This is where the question of what to do should be seen as an engineering question, not a scientific question. Uncertainty in the data increases the risk, it doesn't reduce it.

If we want to design structures to have a very low risk of failure over their design life we certainly shouldn't be reducing the return period, we should make the best estimate we can of what level the maximum considered event will be, based on the best data and statistical methods we have available.

Doug Jenkins
Interactive Design Services
 
exactly. We make conservative predictions based on data. These predictions then drive changes in the codes. ... easy !?

another day in paradise, or is paradise one day closer ?
 
Given the level of dispute around the causes and effects of climate change it will be a brave regulator that mandates a higher standard than the current because of the "predicted" impacts of climate change. I am sure this is happening already and there are plenty of Codes around that are leaning this way.

However when a piece of land has its zoning changed because it is expected to be effected by sea level rise or new building codes significantly increase the cost of houses, some one will draw the climate change uncertainty card and get the new code overruled in court.

I am not saying we should not try however.

The other issue is that so much of our standards and codes are based on the past and then applied retroactively to prevent what happened in the past from occurring in the future. That makes good sense. But the future under climate change will be different to the past, so those hard won lessons may not be enough.

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"
 
we're seeing in another thread here that considerable work is being done already to address sealevel change.

i'd've thought that "someone", maybe the Corps of Engineers ?, maybe whoever makes the codes ??, could look that the very reasonable question "does the code 1/100yr event (and 1/10yr) protect structures as intended ?". Collect data ...
what data is the code based on ?
what does this data look like over the time since the code was made ?
is there a reasonable trend?
does this change the standards ?

I saw in another forum that Denver is getting concerned about temperatures (the number of 100+deg days per year). But this is more about resource (power) loading than design codes.

another day in paradise, or is paradise one day closer ?
 
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