Tuesday, October 28, 2014

New paper finds El Ninos were more common during Little Ice Age, opposite of climate alarmist claims

A paper published today in Geophysical Research Letters finds that El Ninos were more common during the frigid Little Ice Age, and conversely, La Ninas were more common during the Medieval and Roman Warm Periods. This finding is the opposite to claims by the IPCC and climate alarmists such as Kevin Trenberth that global warming, if it resumes, will make El Ninos more frequent.

The paper joins others debunking the claim that El Ninos have become more common during the 20th century, or that global warming increases the frequency or strength of El Ninos. 

Upwelling variability off southern Indonesia over the past two millennia

Stephan Steinke et al

Modern variability in upwelling off southern Indonesia is strongly controlled by the Australian-Indonesian monsoon and the El Niño-Southern Oscillation, but multi-decadal to centennial-scale variations are less clear. We present high-resolution records of upper water column temperature, thermal gradient and relative abundances of mixed layer- and thermocline-dwelling planktonic foraminiferal species off southern Indonesia for the past two millennia that we use as proxies for upwelling variability. We find that upwelling was generally strong during the Little Ice Age (LIA) and weak during the Medieval Warm Period (MWP) and the Roman Warm Period (RWP). Upwelling is significantly anti-correlated to East Asian summer monsoonal rainfall and the zonal equatorial Pacific temperature gradient. We suggest that changes in the background state of the tropical Pacific may have substantially contributed to the centennial-scale upwelling trends observed in our records. Our results implicate the prevalence of an El Niño-like mean state during the LIA [Little Ice Age] and a La Niña–like mean state during the MWP [Medieval Warm Period] and the RWP [Roman Warm Period].

Related: New paper debunks claim that greenhouse gases make climate "more El Niño-like"


  1. Sounds unlikely.

    El Nino pushes more energy into the air and so warms the atmosphere especially around the equator.

    How could that not push the climate zones and jets poleward ?

    How could that pull the climate zones and jets equatorward as proposed n this paper ?

    1. I'm just the messenger. And this is by no means the only paper showing El Ninos were more frequent during the LIA and cold periods.

  2. I suspect that those papers are relying too much on the drought cycle in the south west USA rather than the average global effects of El Ninos and La Ninas.

    It is quite possible that an El Nino induced growth in the size of the Hadley cell over the Pacific would push the climate zones poleward but yet give more cool dry north westerly winds in south west USA which would then be on the eastern side of the expanded cell.

    In the northern hemisphere winds on the east side of high pressure are from the north.

    The cooling in the US south west would then simply be a result of the change in predominant wind direction in that region and not an indication of an equatorward shift globally.

    I think that by not taking into account the differing regional effects of the expanded Hadley cell they are getting the wrong answer.

  3. See here:


    The map in Fig. 2 indicates drier conditions
    over Northern Africa and part of the Mediterranean (a direct result of the cyclone track shifting northward during El Nino; Bronnimann, 2007), wetter conditions over most of
    Europe and drier conditions in Scandinavia."

    I suspect the same process occurred in south west USA so that this new paper and any others reaching similar conclusions have interpreted regional climate changes incorrectly.