The Rate Debate Slowing



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DDI 12 Warming Core

The Rate Debate

Slowing


Earth is actually getting colder - disproves anthropogenic warming

Klimenko 11 (RAS Klimenko, Moscow Power Engineering Institute, 2011, "Why is Global Warming Slowing Down?," Doklady Earth Sciences, Vol. 440(2))

The first decade of the present century has ended with a remarkable climatic event: for the first time over the past 65 years, the fiveyear average global temper ature over 2006–2010 turned out to be lower than the value for the previous fiveyear interval (2001–2005). In addition, the absolute maximum temperature, which was attained as long ago as in 1998, has not been surpassed for thirteen years. Both these facts seem ingly support the arguments of the opponents of global warming theory, at least those who regard the anthro pogenic origin of warming questionable or even far fetched. Indeed, the anthropogenic emission of car bon dioxide, which is the major greenhouse atmo spheric component, has risen by 60% from 5.2 giga tons to 8.5 gigatons of carbon, and its concentration has increased from 339 to 390 ppmv (parts per million by volume). How then do we explain the apparent slowdown in the rate of global warming? Evidently, the observed global rise in temperature (Fig. 1) is a response of the climatic system to the combined action of both anthropogenic and natural impacts. Some of the latter are precisely the factors responsible for the current climatic paradox. Further, we will attempt to identify these factors and, based on their analysis, forecast the global climatic trends for the next decades. Figure 2 presents the wavelet spectra yielded by continuously analyzing the time series of global tem perature over 1850–2011 [1]. Here, we analyze only one of three existing global temperature datasets which are continuously updated, namely the HadCRUT3 temperature series provided by the Uni versity of East Anglia (accessible at http://www.cru. uea.ac.uk/cru/data/temperature/), because this is, as of now, the only dataset covering more than a 150year interval, which is crucial for our study. We note that it only recently became possible to analyze such long time series and, thus, identification of multidecade rhythms became a solvable task. The temperature data were preliminarily rid of the longterm anthropogenic trend associated with the accumulation of greenhouse gases and aerosols in the atmosphere; this trend was calculated from the energybalance climate model developed at the Moscow Power Engineering Institute (MPEI) [2]. The resulting temperature series, free of anthropogenic trends, will contain important infor mation on the influence of natural factors. Figure 2 shows that, throughout the entire interval of instrumental observations since the mid nineteenth century, the data contain rather stable 70year and 20year cyclic components. A less significant 9year cycle was present in most observations (during 1870– 1900 and 1940–2000), and a 6year cycle persisted over a considerable part of the entire time span. Closely consistent results were also obtained when analyzing the temperature series by the maximum entropy method (MEM) (Fig. 3). As the order of the auroregression (AR) method is known to significantly affect the result, in our case this parameter was chosen to be onethird the length of the studied data series: according to the long experience in application of MEM in climate research, this value is suitable for providing useful information. All the harmonic com ponents identified above are statistically significant with a confidence level of 90%. Supposedly, the source of the dominant 70year cycle is the North Atlantic, where this harmonic is reliably identified not only in the ocean [3–5] but also on the continental margins: in Greenland [6], England [7], Finland [8], at the Novaya Zemlya Archipelago, and on the Yamal Peninsula [9]. More over, this periodical component is not only recognized in the instrumental data but it is also revealed in the time series of paleotemperature and pressure which date back to over hundreds and even thousands of years ago. We believe that this rhythm is associated with the quasiperiodical changes in the atmospheric and oceanic circulation known as the North Atlantic Oscillation (NAO) and with the related pulsations in the advection of warm waters to the basins of the Nor wegian and Barents seas. Indeed, the time series of the NAO index contain an approximately 60to 70year component [10] and show a strong positive correlation with the time series of temperature in the Northern hemisphere [11].


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