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El Niņos: Good, Bad or Indifferent?
Volume 9, Number 12: 22 March 2006

Climate alarmists typically contend that global warming increases the frequency of El Niņos, and that El Niņos exacerbate climate- and weather-related disasters. In an eye-opening analysis that repudiates the latter of these claims, Goddard and Dilley (2005) explore the subject in a paper that was published a few months back in the American Meteorological Society's Journal of Climate.

The two scientists from the International Research Institute for Climate Prediction at The Earth Institute of Columbia University in Palisades, New York, USA, introduce their study by noting that the huge "reported 'cost' of El Niņo events contributes greatly to misconceptions about the global climate effects and socioeconomic impacts of El Niņo and La Niņa." For one thing, they say that the monetary cost figures typically bandied about "represent a gross estimate of all hydrometeorological impacts worldwide in [specific El Niņo] years," noting that "how these losses compare with those during ENSO-neutral periods has not been established," and that "during El Niņo events, El Niņo is implicitly assumed to be associated with all climate-related losses." Hence, they proceed to rectify this less-than-perfect situation with a more rational approach to the problem.

At the end of their many analyses of different types of data, Goddard and Dilley arrive at three major conclusions. First, they find that "overall perturbation to precipitation over land areas is only weakly affected by ENSO extremes," as they report that "the risk of widespread extreme precipitation anomalies during ENSO extremes is comparable to that during neutral conditions," and that "the highest values of integrated rainfall perturbation are not greater during ENSO extremes than during neutral conditions." Second, they find that "the frequency of reported climate-related disasters does not increase during El Niņo/La Niņa years relative to neutral years." Third, they find that seasonal rainfall forecast skill "increases, in magnitude and coverage, during ENSO extremes," such that "the prudent use of climate forecasts could mitigate adverse impacts and lead instead to increased beneficial impacts, which could transform years of ENSO extremes into the least costly to life and property," in a radical reversal of the prevailing climate-alarmist view of the subject.

So what are some of the beneficial impacts of ENSO extremes that Goddard and Dilley say could yield a more complete appreciation of the socioeconomic impacts of El Niņo and La Niņa events? One example, in their words, is the well-established fact that "tropical Atlantic hurricanes that threaten the southeastern United States, the Caribbean, and eastern Central America occur less frequently during El Niņo years (Gray, 1984)," while another is that "warmer winter temperatures commonly are observed in the northern United States during El Niņo, leading to less energy use and, therefore, lower energy prices (Chagnon, 1999)."

Considering these several observations in their totality, Goddard and Dilley conclude that "between mitigating adverse climate effects and taking advantage of beneficial ones through the prudent use of climate forecasts, El Niņo and La Niņa years may eventually result in substantially lower socioeconomic losses, globally, than are realized in other years." Yet even in the absence of such rational actions, their work reveals that, averaged over the globe, the people of the earth currently have nothing more to fear during extreme ENSO years than they do in ENSO-neutral years.

Sherwood, Keith and Craig Idso

Chagnon, S.A. 1999. Impacts of 1997-98 El Niņo generated weather in the United States. Bulletin of the American Meteorological Society 80: 1819-1828.

Goddard, L. and Dilley, M. 2005. El Niņo: catastrophe or opportunity. Journal of Climate 18: 651-665.

Gray, W.M. 1984. Atlantic seasonal hurricane frequency. Part I: El Niņo and 30 mb quasi-biennial oscillation influences. Monthly Weather Review 112: 1649-1668.