A New-and-Improved 457-Year History of ENSO Variability
Braganza, K., Gergis, J.L., Power, S.B., Risbey, J.S. and Fowler, A.M. 2009. A multiproxy index of the El Niño-Southern Oscillation, A.D. 1525-1982. Journal of Geophysical Research 114: 10.1029/2008JD010896.
Based on tree-ring, coral and ice-core data obtained from the western equatorial Pacific, New Zealand, the central Pacific, and subtropical North America -- which constitute, in their words, "a set of multiproxy indicators from locations that span a broader area of the Pacific basin than has been attempted previously" -- Braganza et al. developed a new annually-resolved Pacific-basin-wide ENSO index for the period AD 1525-1982.
The five researchers report that "the proxy ENSO index over the last 450 years shows considerable amplitude and frequency modulation in the 3-10 year band on multidecadal time scales." However, they say that "in the context of the entire record, we find no pronounced signal of twentieth century climate change in ENSO variability."
Contrary to the projections of many climate models that have been made over a period of many years, Braganza et al. were unable to discern any unusual behavior in ENSO activity during the transition from what was the coldest period of the current interglacial to just before what the world's climate alarmists claim was the warmest period of the past two millennia, which finding raises further questions about the validity of the model projections.