Denier Comment of the Day February 25, 2013

Today’s comment comes courtesy of Sir Lew in the comments from my YouTube video on range shifts. For those who haven’t seen it, here it is.

So, under my video about range shifts we get the following comments about models and El Nino? Relevance?

Ok, that was a cheap shot. Sir Lew may have been responding to an earlier comment I made to someone else. The smart thing to do of course is to hit reply when replying to someone on YouTube so that everyone knows who and what it is you’re replying to. I’ll assume it was this comment.

So, here is the short exchange between Sir Lew and I.

So, here we are. Where to begin? I think the first step is to talk about El Nino and where it fits into the scheme of things. This from the Australian Bureau of Meteorology…

The South American El Niño current is caused by large-scale interactions between the ocean and atmosphere. Nowadays, the term El Niño refers to a sequence of changes in circulations across the Pacific Ocean and Indonesian archipelago when warming is particularly strong (on average every three to eight years). Characteristic changes in the atmosphere accompany those in the ocean, resulting in altered weather patterns across the globe.

NOAA says…

El Niño is a disruption of the ocean-atmosphere system in the Tropical Pacific having important consequences for weather and climate around the globe.

So, El Nino and it’s opposite La Nina are definitely part of the climate system in that they affect weather on the shorter time scales. But one has to wonder what Sir Lew is getting at here? I suspect this is in reference to the popular denier meme that “there’s been no warming since 1998″ which relies on deniers using the high El Nino temperature and drawing a line to the La Nina years around 2010 and how all the IPCC  1990 models are wrong because they didn’t account for fluctuations in ElNino/LaNina/SOI. But is that actually true? How wrong are the models?

Observed annual global temperature, unadjusted (pink) and adjusted for short-term variations due to solar variability, volcanoes and ENSO (red) as in Foster and Rahmstorf (2011). 12-month running averages are shown as well as linear trend lines, and compared to the scenarios of the IPCC (blue range and lines from the 2001 report, green from the 2007 report). Projections are aligned in the graph so that they start (in 1990 and 2000, respectively) on the linear trend line of the (adjusted) observational data.

Sea level measured by satellite altimeter (red with linear trend line; AVISO data from (Centre National d’Etudes Spatiales) and reconstructed from tide gauges (orange, monthly data from Church and White (2011)). Tide gauge data were aligned to give the same mean during 1993–2010 as the altimeter data. The scenarios of the IPCC are again shown in blue (third assessment) and green (fourth assessment); the former have been published starting in the year 1990 and the latter from 2000.

So far so good. It would seem that the models are pretty good. The experts though did get one model and subsequent predictions horribly wrong. That would be this…

Observed (red line) and modelled September Arctic sea ice extent in millions of square kilometres. Solid black line gives the average of 13 IPCC AR4 models while dashed black lines represent their range. The 2009 minimum has recently been calculated at 5.10 million km2, the third lowest year on record and still well below the IPCC worst case scenario (Copenhagen Diagnosis 2009).

These three graphs were pulled from SkepticalScience and so to answer Sir Lew’s question as to whether the models are accurate, I would say yes and no. Unfortunately, the models that are wrong are underestimating the problem. As for the assumption that El Nino wasn’t known about in 1990, well a little less laziness and a quick search of the literature reveals plenty of papers from well before 1990. For example here, here and here. The following video explains how El Nino and La Nina along with other natural phenomena create noise only in the temperature record. If you don’t get it after this Sir Lew, you never will. I suspect though that you don’t want to.

One final note, to Sir Lew, referring to scientists with quotation marks i.e ‘scientists’, is rather childish particularly when you are in no position to accurately assess the level of expertise of said scientists. I will be looking forward to you defending your comments with some science.

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