By: bappit , 8:04 PM GMT on June 25, 2013
Next: Hot Towers
Previously: That Reminds Me ... or The Limitations of Language
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In a previous blog, I refer to the "elephant effect" as the inverse of the "butterfly effect". Instead of a small scale process producing an effect at a large scale, an elephant effect is a large scale process producing a small scale effect.
Climate change is full of elephant effects. A prime example is an increase in global CO2 concentrations over the span of a human lifetime leading to the melting of a large portion of arctic sea ice in a much shorter time. (Of course, melting arctic sea ice is not exactly small potatoes.) Other smaller scale effects of the planetary change in CO2 are droughts, heavy rain events or even bouts of cold weather. Each of these effects occurs through a chain of cause and effect leading from the large scale--a global, long duration increase in CO2--to events on smaller scales.
The transition from large scale to small scale creates problems for understanding these phenomena. We usually do not have all the data, equations or experiments that are required to confidently assert that some particular smaller-scale consequence follows from a larger scale cause. We can model large scale events on a coarse grid or small scale events on a fine grid. Constructing models that combine differing scales is more work--especially when one is planetary and climatic. Hurricane models do use a finer mesh of modeled data points to represent the core of a storm inside a coarser synoptic scale grid, for instance the HWRF, but that is an exception.
Though it can be difficult to prove an elephant effect, at the same time it can be equally difficult to prove that there is no connection. For example, is a single localized heavy rain event lasting a few days a result of increasing global CO2 concentration observed over the last few decades? It is not difficult to reasonably argue that in the aggregate there should be more heavy rain events: a) more heavy rain events occur because b) water content in the air is increasing because c) the air and oceans are warmer because d) CO2 concentrations are dramatically increasing thereby e) trapping more energy in the air-ocean system. Given these obvious links, proving that there is no cause and effect relationship between any single heavy rain event and higher CO2 concentrations would seem as difficult as proving that there is. Both hypotheses face the same difficulties.
Since disproving a linkage can be as difficult as proving a linkage for a single event, why might it still be easy to glibly deny the existence of particular elephant effects? One reason could be a kind of flat earth mentality, more or less. For example, if the phenomenon causing the effect is too large to fit on my flat earth representation of the world (i.e., my map) then that phenomenon automatically does not exist. If we say the cause does not exist, then we can say the linkage cannot exist either. (Maybe we are just in the habit of using maps that are too small.) Similarly, if one stops investigating along the chain of cause and effect just because the next step leads to an unfamiliar question, then one has again reached a metaphorical edge of the earth. At that point the honest thing to say is "I don't know."
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