Thursday, 26 January 2012: 8:45 AM
Warming Episodes in the World's Longest Instrumental Temperature Record As Revealed by the Ensemble Empirical Mode Decomposition
Room 354 (New Orleans Convention Center )
Central England Temperature (CET) is the world's longest instrumental temperature record (1659-2010). It began just after the onset of Maunder Minimum (MM) in the coldest part of the Little Ice Age. MM is the period 1645-1715 when the Sun became very quiet, as indicated by the almost absence of Sunspots on the surface of the Sun that could be observed by the naked eye and by telescope, which was invented in 1610. We show that the low frequency portion of the long record is in remarkable agreement with that of the global mean surface temperature available after 1850, thus adding 200 years to the instrumental record. It reveals a century (1750-1850) with little trend, separating two warming episodes with almost linear trends: a rapid warming at the end of MM which coincided with a respite from frequent volcanic eruptions after 1680, and the current 150-year global warming of likely anthropogenic origin, which started after the Second Industrial Revolution. It does not have its origin in the MM as implied by artificial linear trend drawn through the record. On top of the nonlinear trend there are five cycles of an oscillation (the Atlantic Multi-decadal Oscillation (AMO)). The extra cycles found in this study confirm that it is an internal mode of oscillation. It accentuated the severe cold in Late MM and the minor cooling in the 1970s. It also explains the Early Twentieth Century Warming (ETCW) and adds a natural dimension to theories for the recent "stalling" of the global warming.
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