A couple of days ago one of the leading figures in the New Zealand climate crank pantheon, the Climate “Science” Coalition’s very own Bryan Leyland, popped in to Hot Topic and left a comment drawing attention to his new favourite game — “predicting” global temperatures by projecting the southern oscillation index forward seven months. He bases this on the “work” of John McLean, last mentioned here a couple of months ago when I looked at his prediction (happily promoted by the NZ C”S”C) that 2011 will be the ’coolest year globally since 1956 or even earlier’. Suffice to say, it won’t be.
Leyland first notes the infamous McLean, De Freitas and Carter paper of 2009, then his own “prediction” that this year’s La NiÃ±a would bring a cooling in global temperatures, and then says:
What is remarkable about this is that a retired engineer with access to the Internet has been able to make accurate predictions of future climate. Yet, to my knowledge, no computer-based climate model nor any mainstream ’climate scientist’ predicted this cooling. To me, this is truly remarkable.
What’s really remarkable is that Leyland is actually only showing his ignorance of some pretty basic climate relationships.
As I commented when McLean et al was published (back in 2009), we’ve understood that the state of the El NiÃ±o Southern Oscillation (ENSO) has an impact on global temperatures for a very long time indeed. The Climatic Research Unit’s Phil Jones showed this in a paper in 1989, and the Swedish meteorologist Hildebrandsson may have written about the idea in the 1890s. Even more obvious perhaps, for a retired engineer with an internet connection, you can trawl back through the Goddard Institute for Space Studies GISTEMP web site, and find comments about ENSO’s effect on global temperatures. This is what they said a decade ago:
The global warmth in 2001 is particularly meaningful, because it occurs at a phase of the Southern Oscillation in which the tropical Pacific Ocean is cool. The record warmth of 1998, in contrast, was bolstered by a strong El NiÃ±o that raised global temperature 0.2°C above the trend line.
Not only that, but GISS has been producing and updating this figure (source) since it was first published in 1999:
The influence of ENSO on global temperatures amounts to common knowledge amongst those who study climate. When a La NiÃ±a follows an El NiÃ±o, you get a cooling. That’s not news. And when the current La NiÃ±a ends temperatures will pick up again, and we’ll be heading back into record territory. That’s because the underlying planetary energy imbalance isn’t going away, and the main driver of that imbalance — the amount of CO2 in the atmosphere — is increasing every year. Take a look at another GISTEMP graph (source):
This shows the global average temperature smoothed over 60 months (to minimise ENSO impact) and over 132 months (to reduce the effect of the 11 year solar cycle). There’s only one way that line is heading (barring a volcano or two) and that’s up.
Leyland finishes his soothsaying with a chilling warning:
Records from all over the world show that a long sunspot cycle is followed by cooling in the next cycle and a short sunspot cycle indicates warming. The last sunspot cycle was 12.5 years and the previous one was 9.5 years. The evidence tells us that a 3 year increase in cycle length will result in cooling of at least 1°C. As the total amount of warming that has occurred since the early 1900s is 0.7°C, this is potentially very serious. We could be returning to the conditions in the little ice age.
The only reference Leyland gave me for this assertion was a pdf of one his talks, which contains a few unreferenced slides (it’s turtles all the way down). However, the solar cycle length effect is one of the oldest and most effectively debunked theories offered by sceptics, as this page at Skeptical Science points out. On that flimsy basis, Leyland goes one better than his pal McLean, who you will recall predicted that this year could be as cool as 1956 (not looking good, that one) and warns that over the next decade we might see a return to global temperatures last seen a century ago. Let’s see what that might look like:
McLean’s 1956 prediction was stupidly implausible. Leyland at least ensures that his year to year fall (at about -0.1ºC per year) is within the range of physical possibility, but requires every year for a decade to be cooler than the last if he’s to reach his goal — wiping out 150 years of global warming. Unfortunately, that’s just as implausible because it completely ignores the growing energy imbalance I noted above. That’s not going to change any time soon.
So, in the real world, where might temperatures be heading? Arthur Smith at Not Spaghetti took a look at this a couple of months ago, using statistical models (based on a post by tamino at Open Mind) that account for all the major climate drivers. His “model 1″, with ENSO set to neutral, is plotted in red above. As you can see, after a pause this year caused by the current La NiÃ±a, we get back into record territory in 2012. With the current solar cycle ramping up (which increases the amount of energy reaching the earth from the sun), and La NiÃ±a ending, temperatures move on up. Barring volcanoes, this where I expect global temperatures to go in the near term.
The lesson here is pretty simple. Leyland is pleased to trumpet his ability to make a trivial prediction because he appears to lack the sort of straightforward understanding of the climate system that would be available to anyone willing to read an introductory textbook. That lack of understanding leaves him prey to any old tosh — which is abundantly available around the crank web. When you rely on the Climate Cluelessâ„¢ for your science education, you end up looking foolish.
PS: Leyland also reminded me that I had offered to bet against his proposition that world would soon enter a cooling phase. If Leyland is willing to stick with his prediction as graphed above, then I will happily bet $1,000 that the world will not cool by 1ºC over the next 10 years. We might also be able to frame a shorter term bet. Over to you, Bryan.