>The Texas A&M press release in the WattsUpWithThat post “Possible Linkage between the 1918 El Niño and the 1918 flu pandemic ?” stated that “some researchers” continued to believe that global warming was causing stronger El Nino events. Link to press release:
Quote from it: “Giese adds, ‘The most commonly used indicator of El Niño is the ocean temperature anomaly in the central Pacific Ocean. By that standard, the 1918-19 El Niño is as strong as the events in 1982-83 and 1997-98, considered to be two of the strongest events on record, causing some researchers to conclude that El Niño has been getting stronger because of global warming. Since the 1918-19 El Niño occurred before significant warming from greenhouse gasses, it makes it difficult to argue that El Niños have been getting stronger.”
Not to discount the work by Giese et al: a quick look at a graph of NINO3.4 SST anomalies that includes the 30 years before 1900, Figure 1, reveals that there were two comparably sized “Super” El Nino events in 1877/78 and 1888/89.
Link to the preprint version of Giese et al (2009) “The 1918/1919 El Niño”:
HADISST Anomaly data is available through the KNMI Climate Explorer: