NOAA Says ‘50% Chance’ El Niño Will Develop In Second Half Of 2012, Which NASA Says Would Lead To ‘Rapid Warming’

NOAA’s Climate Prediction Center issued an “El Niño Watch” today. This chart from NOAA makes clear why that is a big deal:

Global average surface temperatures during El Niño and La Niña years.

An El Niño in the second half of 2012 would make it quite likely that 2013 would be the hottest year on record. NASA had a long discussion of this very point in a January analysis, “Global Temperature in 2011, Trends, and Prospects.”

NASA explains that the apparent recent slowdown in global surface temperature rise is likely to prove “illusory”:

The cool La Niña phase of the cyclically variable Southern Oscillation of tropical temperatures has been dominant in the past three years, and the deepest solar minimum in the period of satellite data occurred over the past half dozen years. We conclude that the slowdown of warming is likely to prove illusory, with more rapid warming appearing over the next few years.

Of course, the warming never slowed down in the place where climate science predicted 90% of the heat would go in the first place — the oceans (as discussed here).

The El Niño Southern Oscillation (ENSO) doesn’t change the overall warming trend, but it is a short-term modulation, what NASA labels the largest contributor to the “natural dynamical variability” of the climate system. El Niño and La Niña are typically defined as sustained sea surface temperature anomalies (positive and negative respectively) greater than 0.5°C across the central tropical Pacific Ocean. You can read the basics about ENSO here.

NASA has some great charts to explain the impact of the solar minimum and ENSO on the recent warming trend:

Figure 9 reveals that solar irradiance is beginning to emerge from a protracted minimum, at least two years longer than prior minima of the satellite era, making the sun a significant source for cooling during the past several years. The magnitude of the solar forcing, which varies about 0.25 W/m2 from solar minimum to solar maximum, is much smaller than the forcing by human-made greenhouse gases. However, the most relevant comparison of the solar forcing is with Earth’s energy imbalance, 0.58±0.15 W/m2 (Hansen et al., 2011), because the combined effect of all forcings is less than that of greenhouse gases alone, and much of the greenhouse gas forcing has been “used up” in causing the warming of the past century. It is apparent that the solar forcing is not negligible in comparison with the net climate forcing.

Line plot of solar irradiance during past three solar phases

Figure 9. Solar irradiance from composite satellite-based time series

Because of the ocean’s thermal inertia, global temperature change caused by solar variability lags solar irradiance by about 18 months. Thus the influence of the sun in 2011 continued to be a cooling effect. However, the sun’s influence will change rapidly to a warming effect over the next 3-5 years.

What would an El Niño do in combination with this return to (almost) normalcy in total solar irradiance? NASA explained back in January:

Figure 7 helps us examine the issue of whether global warming has “stopped” in the past decade or at least slowed down from the rate of the prior two decades. Global temperature in 2011 was lower than in 1998. However, global temperature has a strong interannual variability tied to the Southern Oscillation (El Niño-La Niña cycle), as is apparent in Fig. 7.

Line plots of surface temperature anomaly and of Niño phase

Figure 7. Global monthly and 12-month running mean surface temperature anomalies relative to 1951-1980 base period, and 12-month running mean of the Niño 3.4 index.

Hansen et al. (2010) showed that the correlation of 12-month running-mean global temperature and Niño 3.4 index is maximum with global temperature lagging the Niño index by 4 months. Thus the 1997-1998 “El Niño of the century” had a timing that maximized 1998 global temperature. In contrast, the 2011 global temperature was dragged down by a strong La Niña. Indeed, the strength of the current double-bottomed La Niña, being based on ocean surface temperature relative to base period 1951-1980, is under-emphasized by the long-term trend toward higher temperature.

… there is a good chance of moving into El Niño conditions in the latter half of 2012, and in any case within the next 2-3 years. Because of the 6-month lag between tropical ocean heat content and global temperature, and the relatively cool state of global climate at the beginning of 2012, the next maximum global temperature is more likely to be in 2013 or 2014, rather than 2012.

So if there is an El Niño in the second half of the year, then a very warm 2013 seems the likely outcome. What are the chances of that?

The monthly ENSO diagnostic discussion from NOAA’s Climate Prediction Center (CPC) and the International Research Institute for Climate and Society (IRI), which included the “El Niño Watch,” explains:

The extensive volume of above-average sub-surface water temperatures indicates that the tropical Pacific SST anomalies will likely warm further in the coming months. A majority of models predict ENSO-neutral to continue through the June-August (JJA) season (Fig. 6). Thereafter, most of the dynamical models predict El Niño to develop during JAS, while the statistical models tend to favor the continuation of ENSO-neutral. Thus, there remains uncertainty as to whether ENSO-neutral or El Niño will prevail during the second half of the year. The evolving conditions, combined with model forecasts (Fig. 6), suggest that ENSO-neutral and El Niño are roughly equally likely during the late northern summer and fall.

Finally, the ENSO discussion concludes:

The CPC/IRI forecast calls for ENSO-neutral conditions through JAS, followed by an approximately 50% likelihood for El Niño during the remainder of the year (see CPC/IRI consensus forecast).

Stay tuned. The heat is on.

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10 Responses to NOAA Says ‘50% Chance’ El Niño Will Develop In Second Half Of 2012, Which NASA Says Would Lead To ‘Rapid Warming’

  1. NOAA is also out with their state of the climate report for May and the spring season.

    The U.S. has seen the warmest 12-month period (Jun 2011-May 2012), the warmest year-to-date, warmest spring, and the 2nd warmest May on record.

    This map shows that a whopping 31 states had their warmest spring on record.

  2. Here is the correct link that I meant to post for the map showing that 31 states had their warmest spring.

  3. Doug Bostrom says:

    Well, if this is not already rapid warming it’ll be interesting to see the speedy version.

  4. Peter M says:

    It should prove rather interesting to see a year without the restraints of La Nina- and less solar ‘sleep’. It will make 1998, 2005 & 2010 seem cool.

  5. Jim Eberle says:

    I disagree with the view that El Nino’s become more prevalent with global warming. La Nina’s should become more prevalent as climate warms because the Hadley Cells shift poleward and intensify with warming. This increases the strength of the easterly Trade Winds on the south side of these semi-permanent high pressure areas, driving warm surface waters westward in the equatorial Pacific allowing cool water upwelling along the Pacific coast of South America creating what should evenually become a nearly permanent La Nina. Does anyone have a different view?

  6. Bird Thompson says:


  7. peter says:

    To Jim Eberle,

    I think if you read the article above you already got the other view from I imagine the best informed people to begin with.


  8. Mulga Mumblebrain says:

    Interesting speculation, but I doubt that La Nina will become ‘permanent’. Long-lasting, repeating rapidly perhaps, but the acceleration of climate destabilisation will plainly, I would guess, drive us to climate regimes dominated by entirely novel conditions and cycles, and La Nina, El Nino, decadal oscillations and the like will become distant memories.

  9. prokaryotes says:

    Mass die off on the horizon.

  10. Michael Pope says:

    Development of El Niño combined with recovery of solar radiation should see the return of drier, hotter conditions in the southern hemisphere. For Australia this could mean a greater number of cyclones, some of which may be above average strength. It could also mean re-emergence of drought conditions in the southern half of the continent, adversely affecting food production in that area. The 2013 bush fire season may therefore be worse than average and quite severe in 2014.

    The Australian States are likely to continue to squabble over water rights. Farmers are likely to persist in wasteful use of available water, demand a right to use it in unsustainable levels while producing less food. Lessons which should have been learned from the Queensland floods will be forgotten and the warnings of climate scientists will be ignored with the result that we again build in areas increasingly prone to future flooding as climate events become increasingly severe.

    Shall we ever learn? I doubt it- at least not before it is too late to take effective, timely action to limit socio-economic losses.