Saturday, April 7, 2007

Efficiency Revisions

For various reasons, I had set the maximum year measured by my consumption model at 3814, some 1807 years in the future. I decided to reset that maximum year to 4007, or 2000 years in the future, and re-run my efficiency numbers. Based on this change, while the current conditions would still result in a species population crash in 2014 and a human population crash in 2047, the minimum efficiency factors needed to avoid human casualties and loss of other species increased somewhat. Specifically, to keep from losing human population within 2000 years, we will need to increase our efficiency of consumption (or reduce consumption altogether) by a factor of 124 (if done in five years) to 258 (if done in 50 years). To keep from losing other species, the range is 281 to 1662 for the same time spans.

If we don’t meet the efficiency target for no human population loss, the model can project what our casualties will be for various efficiency factors achieved exponentially over a given time span. For example, if we exponentially increase our efficiency for the next 30 years, we will lose everyone if we multiply our efficiency by less than 30 over that period, and we will have no casualties if we multiply our efficiency by at least 182. Between those two values, the casualties decrease exponentially as efficiency increases. An efficiency factor of 50 results in 1.9 billion casualties (27 percent of peak). An efficiency factor of 100 results in 168 million casualties (two percent of peak).

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