Thursday, March 3, 2011

A. D. Husler & D. Sornette: Evidence for super-exponentially accelerating atmospheric carbon dioxide growth




Evidence for super-exponentially accelerating atmospheric carbon dioxide growth


A. D. Husler and D. Sornette 


Department of Management, Technology and Economics, ETH Zurich, Kreuzplatz 5, CH-8032 Zurich, Switzerland



Abstract



We analyze the growth rates of atmospheric carbon dioxide and human population, by comparing the relative merits of two benchmark models, the exponential law and the fi nite-time-singular (FTS) power law. The later results from positive feedbacks, either direct or mediated by other dynamical variables, as shown in our presentation of a simple endogenous macroeconomic dynamical growth model. Our empirical calibrations confi rm that human population has decelerated from its previous super-exponential growth until 1960 to "just" an exponential growth, but with no sign of more deceleration. As for atmospheric CO2 content, we find that it is at least exponentially increasing and most likely characterized by an accelerating growth rate as of 2009, consistent with an unsustainable FTS power law regime announcing a drastic change of regime. The coexistence of a quasi-exponential growth of human population with a super-exponential growth of carbon dioxide content in the atmosphere is a diagnostic that, until now, improvements in carbon effi ciency per unit of production worldwide has been dramatically insuffi cient.


http://arxiv.org/PS_cache/arxiv/pdf/1101/1101.2832v2.pdf

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