The Pause may pause

Christopher Monckton is claiming there's been no global warming for 17 years and 9 months based on the latest RSS satellite data. (Link)

Graphic: Wood For Trees.

The claim is rubbish, of course, for the simple reason that this period begins with a super El Nino and ends with a couple of strong La Ninas. If there were no warming, the trend over this period should have been cooling; that it is flat should tell you that there is warming going on.

Monckton seems to understand that the trend will turn positive with the next El Nino event (probably later this year), as the El Nino adds warmth to the atmosphere (hence the title of this post, his words, "the Pause may pause".

But he adds "it may well resume late in 2015."

It's wishful thinking.

As the years pass, El Nino years become warmer and La Nina years less cold, as the full RSS data set shows.

The further we move away from 1996, the more El Nino years will produce a stronger warming trend, and the less La Ninas will bring it down. Not unless the next El Nino is a lot weaker than expected, and the next La Nina exceptionally strong will the trend return to a flat line: it's going to creep up over time, even though it may take 15 years more before a moderate el Nino year is going to equal the temperature of the 1998 super El Nino.

We are at the end of the "Pause".

Monckton makes another point that warming is less than expected by the models, which is true.

A comment to his post has a useful link to an RSS analysis, (from which the above graph comes).

The reasons for the discrepancy between the predicted and observed warming rate are currently under investigation by a number of research groups. Possible reasons include increased oceanic circulation leading to increased subduction of heat into the ocean, higher than normal levels of stratospheric aerosols due to volcanoes during the past decade, incorrect ozone levels used as input to the models, lower than expected solar output during the last few years, or poorly modeled cloud feedback effects. It is possible (or even likely) that a combination of these candidate causes is responsible.

 But that's a different kettle of fish.