Climate sensitivity uncertainty and the necessity to transform global energy supply (2005)

By Bob van der Zwaana,b,
, Reyer Gerlaghc

자료: http://personalpages.manchester.ac.uk/staff/Reyer.Gerlagh/papers/Energy_31_2235.pdf

※ 메모: 

1. Introduction

The sensitivity of the global mean temperature to increasing levels of atmospheric carbon dioxide (CO2) is currently known only to about a factor of three. To be more precise, the climate sensitivity, DT2X—defined as the global mean climatological temperature change DT resulting from a doubling of atmospheric CO2 content X—is thought, today, to lie in a range of about 1.5–4.5 1C.1 These numbers have been derived primarily from computer-models, have been reported by the International Panel on Climate Change (IPCC), and have subsequently been used by both scientific and policy-making communities the world over for almost a decade now [1,2]. 

In a recent article, Caldeira et al. [3] reported their finding that, in analyses in which scientists attempt to determine the levels of allowable CO2 emissions, the uncertainty with which we currently know the value of the climate sensitivity, DT2X , has a larger effect (that is, is more determinant for the calculation of these levels) than the uncertainty in our understanding today of the carbon cycle. Also, previous studies emphasized the significance of climate sensitivity uncertainties in optimal control models designed to rationalise short- and long-term climate change policy (see, e.g., the work by Lempert et al. [4] and Ambrosi et al. [5]). While the sensitivity parameter represents undoubtedly one of the largest sources of uncertainty in 

studies of global warming, other parameters (including those concerning climate thresholds, the carbon cycle, as well as the damages of climate change and the costs of reducing greenhouse gases) are also important in this matter and should as such be considered (as demonstrated, for example, by Nordhaus and Popp [6] and Keller et al. [7]). Because of the sizeable uncertainties that dominate so many of the scientific results in the field of climatic change studies, and the relevance of these uncertainties for effective and efficient global warming policy-making, the subject of uncertainty analysis has recently been receiving increased attention (as can e.g.

be seen from the number of conferences today dedicated to this topic; see, for example, [8]). 

This article explores the relation between climate sensitivity uncertainties and the necessity to transform world energy supply. In particular, we put our modelling results into perspective with the findings presented by Caldeira et al. [3] and focus on the desired transition of the global energy system during the 21st century. ....