Climate Change Future

A toy model for forecasting global temperatures – 2011 redux, part 1

A little over two years ago, I wrote the following post on BNC: How hot should it have really been over the last 5 years? In it, I did some simple statistical tinkering to examine the (correlative) relationship between global temperatures and a few key factors, namely greenhouse gases, solar irradiance, and ENSO. In the next couple of posts, I’ll update the model, add a few different predictors, and correct for temporal autocorrelation. I’ll also make a prediction on how global temperatures might pan out over the coming few years.

In the 2008 post, I concluded with the following:

To cap of this little venture into what-if land, I’ll have a bit of fun and predict what we might expect for 2009. My guess is that the SOI will be neutral (neither El Niño or La Niña), the solar cycle 24 will be at about 20% of its expected 2013 peak), and there will be no large volcanic eruptions. On this basis, 2009 should be about +0.75, or between the 3rd and 5th hottest on record. Should we get a moderate El Niño (not probable, based on current SOI) it could be as high as +0.85C and could then become the hottest on record. I think that’s less likely.

By 2013, however, we’ll be at the top of the solar cycle again, and have added about another +0.1C worth of greenhouse gas temperature forcing and +0.24 of solar forcing compared to 2008. So even if 2013 is a La Niña year, it might still be +0.85C, making it hotter than any year we’ve yet experienced. If it’s a strong El Niño in 2013, it could be +1.2C, putting it way out ahead of 1998 on any metric. Such is the difference between the short-term effect of non-trending forcings (SOI and TSI) and that inexorable warming push the climate system is getting from ongoing accumulation of heat-trapping greenhouse gases.

So, now that we have data for 2009 and 2010, how did I do? Not too bad actually. Let’s see:

1. After bottoming out for a long period, the 11-year sunspot cycle has restarted. So much for those predicting a new Maunder Minimum. By the end of 2010, we had indeed reached about 20% of the new forecast maximum for cycle-24 (which is anticipated to be about half the peak value of cycle-23).

2. We had a mild El Niño in 2009 and early 2010, before dipping back into a strong La Niña. See here.

3. There were no large equatorial volcanic eruptions. The best we got was Iceland’s Eyjafjallajökull (don’t ask me to pronounce it), which actually helped climate change a little bit by stopping flights over Europe for a week.

4. 2009 was ranked as the 5th warming on record. I had ‘forecast’, based on my toy model, that it would be somewhere between 3rd to 5th. I said that 2009 would be about +0.25C hotter than 2008; the real difference was ~ +0.15C (based on the WTI average index data). This was followed up by 2010 equalling with 2005 as the hottest year on record. Pretty much right in line with my guesstimate.

5. Anthropogenic GHGs continue to accumulate; atmospheric CO2 concentrations built up by 1.9 ppm in 2009 and 2.4 ppm in 2010. That forcing ain’t going away!

I still stand by my 2008 prediction of us witnessing record-smashing year in 2013… but I’ll have to wait another couple of years to confirm my prognostication. However, I’m not going to leave it at this. There are a couple of simple ways I can improve my toy model, I think — without a lot of extra effort. Doing so will also give me a chance to show off to BNC readers a few resampling methods that can be used in time-series analysis, and to probe some questions that I skipped over in the 2008 post.

In short, I think I can do better.

In Part 2, I’ll describe the new and old data streams, do some basic cross-correlation analysis and plotting, bootstrap the data to deal with autocorrelation, and look briefly at a method for assessing a model’s structural goodness-of-fit.

In Part 3 I’ll do some multi-term fitting to data going up to 2005, and use this model to project the 2006 — 2010 period as a way of validating against independent data (i.e., that not used in the statistical fitting), then re-fit the best predictive model(s) to all the data, and make a forecast for 2011 to 2013 inclusive. The big catch here will be getting the non-CO2 forcings right.

Stay tuned.

By Barry Brook

Barry Brook is an ARC Laureate Fellow and Chair of Environmental Sustainability at the University of Tasmania. He researches global change, ecology and energy.

39 replies on “A toy model for forecasting global temperatures – 2011 redux, part 1”

You sure like to beard the deniers,Barry,and good for you.

Now I can sit back and laugh at the noise of the swamp creatures.


If 2013 is a record breaking year it still may not convince some doubters. If the average comes from longer runs of warm days and less frosty winter nights then some will say the climate has improved. Alas we need floods, fires, cyclones and food shortages to convince enough people that action is needed.


It is going to take a hell of a lot more than climate related natural disasters to convince the retards in our national leadership to take effective action.

The current expulsion of hot air re a carbon tax is a good example.The retards want to keep toying with financial incentives (just like the CPRS) which only plays into the hands of the moneyed 1%.

Taking effective, positive action to reduce emissions from the biggest polluter,coal fired electricity generation,is just too hard.In fact,I don’t think they have even got their tiny brains around this issue.

A carbon tax will simply drive up the cost of just about everything while doing absolutely SFA to reduce carbon pollution. As usual,the citizens pay.


If people here are actually objective, and appropriately sceptical (as opposed to simply being climate catastrophe zealots), why hasn’t anyone here asked the obvious questions, such as:

Can you predict how much difference a carbon price in Australia would make to the climate?

Can you say how high the carbon price would have to be to stop global warming?

Can you say, – have you even seriously considered – what would be the consequences for humanity of such a carbon price?


Peter you should also ask what is the cost of not taking carbon mitigation steps. There are numerous scholarly studies that try to to discount future costs and benefits. Almost all conclude there is a net benefit to major short term emission cuts. However it is easier to quantify gradual change (eg crop yields) rather than abrupt changes or extreme events. How do you value people dying by fire or flood or losing their livelihoods?

In relative terms Australia should do more since we are such high per capita emitters and we are especially sensitive to climate change. FWIW I believe climate change is not the most pressing problem but a looming shortage of liquid fuels. I think that will drag coal down with it while throwing food production and transport into disarray. Therefore we must rapidly decarbonise to maintain some semblance of business-as-usual. Carbon constraints may appear costly in the short run but long term we’ll be better off.

If that sounds too vague throw up some numbers about costs and most likely it will be possible to come up with some other numbers about omitted benefits.


Barry you are going to have to bring electrical energy from space weather into this model somehow. These sources of electrical energy are being all but ignored.

If you take the example of the sort of energy you get causing that last big cyclone. This level of kinetic energy is almost impossible to imagine without electrical-to-kinetic energy conversion.

Here is what I’m driving at:

The other thing is you have to bring the role of the moon into it. Piers Corbin gets his very good results by bringing the moons influence into matters.


graemebird, thanks for the suggestion. This toy model is a statistical (correlative) approach, rather than a mechanistic one, so it would need an appropriate data stream to incorporate the effects you mention and evaluate the deviance explained by them. I currently have a solar input via TSI. What do you suggest for space weather (as a forcing rather than simply a driver of white noise) and the role of the moon?

gallopingcamel, it very much depends on your adapative temperature constraints. Tropical species, for instance, are already at, or close to, their thermal tolerance limits, whilst for others, it’s a matter of competitive advantage/disadvantage relative to other species in the system (or invades that arrive to exploit the new opportunities). Biotic homogenization is a common feature of extinction events — some do very well, at the expense of the majority.


“Can you predict how much difference a carbon price in Australia would make to the climate?”

I can. No difference at all.

“Can you say how high the carbon price would have to be to stop global warming?”

The climate is cooling so the question is incoherent. Were the climate to be warming no amount of taxes on CO2 would stop it.

“Can you say, – have you even seriously considered – what would be the consequences for humanity of such a carbon price?”

If we were all like France already it might not make much difference. But substitution of main energy sources is the slowest undertaking in the world of economics. So any too-fast attempt at this direction means the immediate collapse into Third World status.


Peter Lang,you ask 3 rhetorical questions which are unanswerable.

I prefer to cut to the chase.Financial incentives or disincentives will not do the job that is required in any sort of realistic time frame.In a nation like Australia which is sovereign in its own fiat currency a properly designed and implemented program to replace coal fired generators with nuclear will not place undue stress on our economy.

The current crop of deficit hawks who hold power,both in and out of government,regard “surplus” as one of those magic words just as “racist” is one of those magic words of abuse which is supposed to wither its targets.

Nuclear power is one of the answers to our energy problems.But it is only one problem among many.
The fundamental problem is an inability or a refusal to think outside of the conventional wisdom.This is the killer.


Podargus. I wouldn’t sleep at nights if I were you. Your dog is plotting against you. The same people paying me are conspiring with your family members against you.

Now how about you rephrase things without the d-word name-calling.


So,we have a new denier on the board,graemebird.

Bird is an old hand at this stuff and often plies his trade over on the ABC’s The Drum.

On The Drum the Bird, modest chap that he is, is frequently heard to be squawking, proclaiming himself to be the embattled custodian of the One True Scientific Method (TM). Pfff … what would all those National Academies know anyway.


Barry are you referencing to temperature or heat content? Conceptually when you reference to heat content, water vapor production becomes a negative feedback in most places, because of the refrigerant effect of evaporation. But then again if we aren’t getting the dust or the cosmic rays for cloud formation that wouldn’t hold true and it would be a positive feedback in a slightly longer time horizon perhaps.

The way I see it you have a number of different climate zones. And the only real difference when the planet warms up is the tropical zone expands and pushes the other zones North, South and up the mountains. Because it would seem that the tropical zone is the only zone where evaporation isn’t a strictly negative feedback when it comes to heat content.

So supposing we went through a really bad heating like 55 million years ago. Well its been suggested that we could shield the atmosphere with SO2 rockets, sent out of commercial airliners when we crossed near the equator and over the water. But another way would be simple ionisation of the air to bring on rainfall. With the hope of getting the tropical zones to contract. and pull all the other zones back.


graemebird is returning after an extended break following earlier BNC ban. In general, I’m okay with him expressing his opinion here, provided he stays civil and on topic. That goes for everyone — always has. I let Lalor, Machiavelli and many others hang around, after all, and I agree with almost nothing they say. Everyone should focus on playing the ball, not the man, or else just choosing to ignore comments that you can’t be bothered responding to.


Quokka. Nimrod. Stop threadwrecking and take your vile insults and sundry mental problems over to my blog if you are going to be such sissies about open debate.

It used to be about the science. I don’t remember taking a shot at you so back off.

This project of Barry’s interests me greatly since I’ve always daydreamed about doing the same thing. I think its possible to trump the atrocious work of those over-funded propagandists at Goddard.

Now my suggestion is this: don’t just develop one small model. Develop three in parallel. That might seem to be three times the work but it won’t wind up like that.

Developing three small models in parallel will put you miles ahead of the competition. Plus if one model weights very lowly, the effect of CO2 you can put it down to simply being part of the process.

Let the record show that Nimrod and Quacker took a shot at me and not the other way around.


“It is going to take a hell of a lot more than climate related natural disasters to convince the retards in our national leadership to take effective action.”

See that Nimrod? Is it only our side that has to show self-restraint. The insults come so thick and fast from your crowd that you have ceased to notice them . I did not see you telling Podargus to pull his head in.

Podargus . Natural disasters appear to be driven by space weather.


quakka,please excuse my ignorance.I don’t frequent the commentariat scene.
Barry,I was going to take your advice about ignoring the likes of ‘bird.I generally do that anyway but ‘bird puts the likes of Drongo and Camel into the hall of fame.

‘bird,when you make statements like “the climate is cooling” then that makes you a denier,paid or volunteer.

When you say that “Natural disasters appear to be driven by space weather” then that puts you well and truly in the fruit loop box.

My recommendation is that you seek some therapy as your condition could lead to serious health problems if that has not already occured.

I’ve had my laugh or 3 for the morning now I’ll go and do something more sensible.


If you are interested in climate disasters why not read about the storms such as those that created the Zuidersee and reduced the size of Helgoland by 97%?

History has much to tell us about climate especially when it comes to “extreme weather”. Take a look at:

Scroll down the main page and then click on the link titled “the lessons of history” you can read about some truly extreme events.


Graeme Bird first came to my attention by posting a series of abusive comments replete with foul language on the comment thread of the following post from my blog. I deleted most of his comments ( he was posting one after another as rapidly as he could type them for an hour or more) to prevent him from making the thread unreadable, but left enough of them remain for people to understand where he was coming from, and why I had deleted the majority of them.

I will not be posting anything on Graeme Bird’s blog. I believe that to do so would undermine my credibility and undeservingly enhance his. Graeme Bird is not permitted to post on my blog, and if any comments are posted there which appear in my judgement to be by a Bird sockpuppet, they will be deleted.


spangled drongo, on 4 March 2011 at 12:04 PM — I use GISTemp (surface temperatures as that is where we live). Yes, I’m up-to-date.


” I use GISTemp (surface temperatures as that is where we live). Yes, I’m up-to-date.”

Even Phil Jones isn’t impressed with GISS:


“quakka,please excuse my ignorance.I don’t frequent the commentariat scene.
Barry,I was going to take your advice about ignoring the likes of ‘bird.I generally do that anyway but ‘bird puts the likes of Drongo and Camel into the hall of fame.”

This is why intellectual cowards maintain a level of ignorance. And its not JUST because low-IQ cry-babies like yourself expect to be able to insult strangers, and then weep to the moderator if they return fire.

Good Lord Quakka. Just imagine if we were to meet in person ……

“Its alright Mr Quakka. You can come out from underneath the table now.”

Would you people grow up? This sort of gutlessness might tarnish Barry’s reputation. And we need him to teach the public about nuclear energy and show people the right way of going about evolving climate models.


“Everybody knows that all four major global surface temperature products give essentially the same results.”

Thats right. So since we know for a fact that Hadley and Goddard are rig-ups we need not concern ourselves with the specifics of the fraud attendant upon the other two.

Nobody needs to be such a stooge all their days as to fall for the idea that the Northern hemisphere is way hotter when its covered in snow, then when the dustbowl wiped out farming in all these US States.

Its unassailable that Hadley and Goddard are rigged so we are left with no global temperature record butt for now the raw data from Goddard is probably good enough.


“Graeme Bird first came to my attention by posting a series of abusive ”

Why link to a thread when you couldn’t come good with the evidence? Isn’t that an embarrassment for you? Not in your circles hey?

And are you claiming you didn’t take a shot at me on this forum before I went to yours?

A big girls blouse and a hypocrite to boot.


graemebird, on 5 March 2011 at 12:16 PM — You are terribly confused.

For example, its still winter in the Northern Hemisphere [as I can attest by going outside].


Shall we get back to the subject of the thread and stop insulting one another – which gets no-one anywhere and puts off any visitors to Barry’s worthwhile blog


“David B. Benson, on 5 March 2011 at 1:22 PM said:
graemebird, on 5 March 2011 at 12:16 PM — You are terribly confused.
For example, its still winter in the Northern Hemisphere [as I can attest by going outside].”

I’m not the least bit confused Benson. You are Benson.

Warming and cooling have a cumulative nature to them, The oceans can quickly lose more joules than the atmosphere ever had. In fact everything we do here amounts to wagging the dog with his tail. Any model ought to be focused on heat content and only extrapolate to temperature after the fact.

So much time can be wasted when the focus is on the wrong metric. So much bad ideas are generated by not choosing the best one. Bad economists look at interest rates whereas better economists think about money supply.

Now being as the dustbowl crisis implied cumulative oceanic joules to allow that to happen, (short of some massive burst of energy from the sun that we would in any case know about) it follows that the climate was hotter in the 30’s then now. .

The evidence in terms of numbers shows us that the 30’s was the hottest decade. You don’t just go from dustbowl conditions to be covered in snow everywhere but Florida. This is not credible.

Benson, your confused position, were you capable of thinking about it, would force you to an understanding that winters in the 30’s were COLDER AGAIN then this winter in the Northern Hemisphere…..

…. So year after year of astonishingly cold winters, in your fantasy, would have to follow after year after year of punishingly hot summers.

Have you got a new theory about super-cold winters and mega-hot summers???????

It didn’t happen Benson, Once again you are confused Benson. You are mistaken Benson. The numbers don’t lie. Nor do the pictures.

Hitler did not see that Soviet Winter coming. Why would he? European, as well as American weather had been hot during the 30’s.

And we are talking not just a little bit hotter than now. A great deal hotter. Since the raw data needs to be corrected for the urban heat effect.

It was a lot lot hotter in the 30’s. Its not a line-ball thing.


“Ms Perps, on 5 March 2011 at 8:35 PM said:
Shall we get back to the subject of the thread and stop insulting one another – which gets no-one anywhere and puts off any visitors to Barry’s worthwhile blog”

I agree totally perps. What do you think of my view that the core of the model ought to be developed as a heat content model. And only convert to and from temperature at the periphery of assumptions.


Leave a Reply (Markdown is enabled)

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s