Global Warming meets Peak Oil Design
Continuing with the discussion of weather effects from a couple posts ago, there are a lot of other requirements we can define.
Jeff pointed out that we need to more carefully examine how much rain falls during the growing season, rather than just the whole year’s average. I’m looking for the data on that for our selected Iowa location and I’ll get back to you.
In the following draft requirements, the term “withstand” may need some further definition. The understanding of what withstanding something may vary from person to person – some might consider it to mean every part of the structure and farm stays intact, and some might imagine it means only the core structure must survive. Any thoughts on a better way to define this term?
The Homestead shall withstand temperatures of 115 ° F or greater.
The highest recorded temperature in the area is 102 ° F. Although the global warming models predict only modest increases in summer temperatures, I added a buffer to capture any error. If it gets hotter than this, we’ll be in trouble anyway. (See this -- courtesy of BigGav.)
The Homestead shall withstand temperatures of -30 ° F or less.
The lowest temperature recorded in the area is -28 ° F. In my estimation, it’s safe to assume we will not see temperatures lower than that over the course of the Homestead’s lifetime. In fact, we should consider whether -30 ° is too restrictive and could needlessly increase the cost of the design.
The Homestead shall withstand no less than XX lbs. of accumulated snow load.
I need to find the seasonal snow depth maximum.
The Homestead shall withstand sustained winds of no less than XX miles/hour.
This exact number is up for debate. Typical maximum winds top out at about 60 mph over any sustained period of time, but I haven’t found any models of increasing storm intensity due to global warming.
The Homestead shall provide shelter for no less than 4 people from tornadic winds (300 miles/hour).
This does not mean that the house has to be designed to resist tornadoes – that would be near impossible to achieve. Rather, the requirement implies some sort of storm shelter – a room in the basement, a storm cellar, or a standalone reinforced building.
The Homestead shall withstand no less than 50” precipitation per year.
This requirement is designed to capture the maximum expected yearly precipitation in a year at our location.
One thing that occurred to me in developing these weather requirements is that we haven’t specified how long we want the homestead to last. Climate models typically don’t publish results past 2100 – and some research predicts further dramatic warming after than, depending on how the anthropogenic (human-caused) forcings change. Do we want this homestead to survive for our grandchildren? Our great-grandchildren? 200 years? More?
The further out we place our target end-life for the homestead, the more uncertainty we encounter.