In a recent interview, Kevin Trenberth, Distinguished Senior Scientist, from NCAR said the upcoming 2014/15 El Niño might shift global surface temperatures upwards by 0.2 to 0.3 deg C to further the series of upward steps. Curiously, Trenberth is continuing to suggest that the warming we’ve experienced since the mid-1970s resulted from naturally occurring, sunlight-fueled El Niño events and that we might get to experience yet another of those El Niño-caused warming steps as a result of the 2014/15 El Niño. So let’s take a look at what he’s suggesting and what the future MAY POSSIBLY hold in store…if Trenberth’s dreams come true.

Peter Sinclair of ClimateCrocks recently produced two YouTube interviews with NCAR’s Kevin Trenberth about the upcoming 2014/15 El Niño. See Part 1 here. At about the 9-minute mark in Part 2 (here), Trenberth speculates, sounding gleeful, that the upcoming El Niño may lead to another in the series of upward steps in global surface temperature:

One of the real prospects to look out for is whether we go back into a different phase of this Pacific Decadal Oscillation. And one of the potential prospects we can watch out for is whether the next whole decade will be distinctly warmer…uh, uh…and so, in terms of the global mean temperature, instead of having a gradual trend going up, maybe the way to think of it is we have a series of steps, like a staircase. And, and, it’s possible, that we’re approaching one of those steps. And we will go up, you know, two- or three-tenths of a degree Celsius to a next level, and maybe we won’t come down again. I think that’s one of the things we could possibly look out for.

Some of you may believe that Kevin Trenberth is actually looking forward to another upward step…not just looking out for one. So let’s take another look at the upward steps in global surface temperatures he was happily discussing.

Kevin Trenberth introduced his “big jumps” in global surface temperatures in an article last year, without stating their cause. We discussed those big jumps and identified their causes in the post Open Letter to the Royal Meteorological Society Regarding Dr. Trenberth’s Article “Has Global Warming Stalled?”. Please refer to that post for the detailed discussion. Figure 1 is an update of Figure 10 from that post with data through 2013. NCDC global land+ocean surface temperature anomaly data were used for consistency with Trenberth’s original article (Data source here.)

Figure 1

SUPPOSE TRENBERTH’S DREAMS COME TRUE

Trenberth is now suggesting that global surface temperatures might shift upwards 0.2 to 0.3 deg C again in response to the 2014/15 El Niño. So for illustration purposes only, let’s take the data from the 16-year period of 1998 to 2013 and shift them up those 0.2 and 0.3 deg C and insert them in the time period of 2015 to 2030. See Figure 2. The period-average temperature anomaly of 0.57 deg C for the period of 1998-2013 would shift up to 0.77 deg C or 0.87 deg C for 2015-2030.

Figure 2

WOULD AN UPWARD STEP HELP THE CLIMATE MODELS?

An upward shift in global surface temperatures would definitely help the models for a few years, but, because the global surface temperatures warmed in a step, the hiatus period that followed would again cause a continued divergence between the models and the real world. See Figure 3 for a model-“data” comparison starting in 1979 and running through 2030.

Figure 3

The graph includes the multi-model ensemble-member mean for the climate models stored in the CMIP5 archive, with two scenarios: RCP6.0 and RCP8.5. And the two sets of future “data” are created once again by taking the NCDC global surface temperature anomalies for the 16-year period of 1998 to 2013, shifting them up 0.2 to 0.3 deg C and inserting them in the time period of 2015 to 2030. Figure 4 includes the same model-data comparison but with the commonly used start year of 1998.

Figure 4

TRENBERTH’S CONFLICT

Kevin Trenberth appears to have conflicting causes for the global warming we’ve experienced since the mid-1970s. On one hand, for decades, Trenberth has been a true-blue proponent of the hypothesis of human-induced global warming, with the warming caused by the emissions of manmade greenhouse gases. On the other, for about a year, he has been promoting the “big jumps” in global surface temperatures, with the steps in the staircase of global surface temperatures being caused by El Niño events.

There would be no conflict if Trenberth was able to show that manmade greenhouse gases somehow contributed to the warm water that fuels El Niño events. But Trenberth has always noted that it is sunlight that provides the warm water for El Niños. In a recent post (see here), we presented two examples of this from his peer-reviewed papers, and for those of you new to this discussion, they’re worth repeating. The first is Trenberth et al. (2002). They write (my boldface):

The negative feedback between SST and surface fluxes can be interpreted as showing the importance of the discharge of heat during El Niño events and of the recharge of heat during La Niña events. Relatively clear skies in the central and eastern tropical Pacific allow solar radiation to enter the ocean, apparently offsetting the below normal SSTs, but the heat is carried away by Ekman drift, ocean currents, and adjustments through ocean Rossby and Kelvin waves, and the heat is stored in the western Pacific tropics. This is not simply a rearrangement of the ocean heat, but also a restoration of heat in the ocean.

The second paper is Trenberth and Fasullo (2011). They write (my boldface):

Typically prior to an El Niño, in La Niña conditions, the cold sea waters in the central and eastern tropical Pacific create high atmospheric pressure and clear skies, with plentiful sunshine heating the ocean waters. The ocean currents redistribute the ocean heat which builds up in the tropical western Pacific Warm Pool until an El Niño provides relief (Trenberth et al. 2002).

And we confirmed in the post Open Letter to the Royal Meteorological Society Regarding Dr. Trenberth’s Article “Has Global Warming Stalled?” that it is sunlight that provides the warm water that serves as fuel for El Niños.

“….MAYBE WE WON’T COME DOWN AGAIN…”

Trenberth’s statement in the YouTube interview, “And we will go up two- or three-tenths of a degree Celsius to a next level, and maybe we won’t come down again,” is similar to one made in his August 2013 interview on NPR . There he is reported to have said:

…what happens at the end of these hiatus periods, is suddenly there’s a big jump [in temperature] up to a whole new level and you never go back to that previous level again…

Those are curious statements. Trenberth has never taken the time to explain that we would NOT expect the surface temperatures to go back down again. So his “never go back to that previous level again” seems to be a clear case of misdirection.

An El Niño…

releases a tremendous amount of heat from the tropical Pacific to the atmosphere, and… it redistributes a tremendous amount of warm water within the oceans from the tropical Pacific to adjacent ocean basins, and… according to Trenberth and Fasullo (2011), an El Niño causes changes in atmospheric circulation that reduces the evaporation from the Atlantic and Indian Oceans and allows more sunlight to penetrate and warm those ocean basins to depth, both of which contribute to the warming of the Atlantic and Indian Oceans in response to an El Niño without the direct exchange of heat from the tropical Pacific.

Regarding 3, Trenberth and Fasulo (2011) includes:

Meanwhile, maximum warming of the Indian and Atlantic Oceans occurs about 5 months after the El Niño owing to sunny skies and lighter winds (less evaporative cooling), while the convective action is in the Pacific.

The upward steps are precisely what we would expect of ENSO if it is viewed, not as noise in the surface temperature record, but as a chaotic, sunlight-fueled, recharge-discharge oscillator.

It appears that El Niño events, combined with the heat uptake in the tropical Pacific during La Niña events, are major contributors to any radiative imbalance that may (or may not) exist.

CLOSING

The climate science community hasn’t bothered to properly account for the contribution of ENSO. And there’s no reason that we would expect them to do so. Any attempt by the climate science community to account for ENSO’s contribution to the warming of surface temperatures and the oceans to depth would detract from the hypothetical influence of manmade greenhouse gases.

EARLIER POSTS IN THIS SERIES

And for additional introductory discussions of El Niño processes see:

FURTHER READING

My ebook Who Turned on the Heat? goes into a tremendous amount of detail to explain El Niño and La Niña processes and the long-term aftereffects of strong El Niño events. Who Turned on the Heat? weighs in at a whopping 550+ pages, about 110,000+ words. It contains somewhere in the neighborhood of 380 color illustrations. In pdf form, it’s about 23MB. It includes links to more than a dozen animations, which allow the reader to view ENSO processes and the interactions between variables.

I’ve lowered the price of Who Turned on the Heat? from U.S.$8.00 to U.S.$5.00. A free preview in pdf format is here. The preview includes the Table of Contents, the Introduction, the first half of section 1 (which was provided complete in the post here), a discussion of the cover, and the Closing. Take a run through the Table of Contents. It is a very-detailed and well-illustrated book—using data from the real world, not models of a virtual world. Who Turned on the Heat? is only available in pdf format…and will only be available in that format. Click here to purchase a copy. Thanks. Book sales and tips will hopefully allow me to return to blogging full-time once again.

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