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This started yesterday as a short comment on the changing forecasts by Hathaway on solar activity in Solar Cycle 24 but has now become something else.
As clarification, I distinguish here between prophecies and forecasts where:
- I take prophecies to be a promise about the future based primarily on faith and made by prophets , witchdoctors, soothsayers and politicians such as “You will be doomed to eternal damnation if you don’t do as I say”,
- I take “forecasts” to be an estimate of future conditions based on known data with the use of calculations, logic, judgement, some intuition and even some faith. They are extrapolations of historical conditions to anticipate – and thereby plan for -future conditions.
I do not consider here predictions or inferences about the future where there is an infinitesimal probability of error such as “The sun will rise tomorrow”. Forecasts, unlike prophecies, involve an element of bravery. Prophecies usually involve catastrophic and cataclysmic events and, if they don’t materialise can be rationalised on some change of behaviour that has transpired.
Over the last 30 years I have spent of a lot of time conducting and participating in reviews. Reviews of research projects, of construction projects, of organisations and processes, of designs, of strategies and action plans, of businesses and of companies.
The common features in all these different reviews, that I have found the most penetrating, have been the comparisons not only between forecast values and actual values, (which may be any values indicating performance and capable of being extrapolated), but also between past forecasts and current forecasts.
Whether considering construction progress or costs or sales figures or cash flow or profit or number of patents applied for, it is the differences between forecast and actual values, or values forecast before and values forecast later which have led to learning. In all these fields we are in the area of the behaviour of complex systems; and where people and their behaviour is involved any system is inevitably a complex system.
When there is no difference there is no learning.
When a forecast is fulfilled there is usually an air of congratulation, satisfaction and self-adulation and this leads to a deadly complacency that everything is “settled science” and well understood. In any enterprise of any kind, that kind of complacency is the kiss of death. It is the differences which lead to questioning, to proper scientific scepticism, to further investigation and ultimately to an increase of understanding and – perhaps – a better forecast. (Of course, ignoring all such differences and to merely “continue as before” can be equally fatal).
Which brings me to climate (which is not a science by any stretch of the imagination) and solar cycles. They are both in the realm not only of where “what we know is a great deal less than what we don’t know” but they are also both in the region where “we don’t even know what we don’t know”. We do not even know all the questions to be asked. They are both complex systems where – by definition – the complexity lies in the multitude of the processes involved and their interactions.
When climate – which is contained in the 100 m of ocean and 20 or so km thick, turbulent and chaotic atmospheric layer (and which is dimensionally miniscule in relation to the 140 million km of the earth-to-sun system) – is so complacently considered to be “settled science” then we have shifted into the area of faith and soothsaying and prophecies. When climate modellers are smug enough to believe they have understood the climate system and believe that their models are complete, then the models produce outputs which are not forecasts but prophecies. (No doubt soothsayers and shamans have sometimes made accurate prophecies but I still would not buy a used car from one of them)! Weather is in the realm of forecast (though you could argue that the most accurate forecast is still that “the weather tomorrow will be like today”) but climate is not yet there.
This kind of “arrogance” which pervades some of the climate “scientists” is not so prevalent when it comes to the study of Solar Cycles. There is a clear understanding that “we don’t know what we don’t know”. In addition to the 11 year and 22 year cycles, other cycles are hypothesised for 87 years, 210 years, 2300 years (or maybe 2241 or 2500 years) and 6000 years. We have no idea what causes these cycles. Even the 11 year cycle which has been most studied produces surprises every day but is properly in the area of “forecast” (and hopefully never again will be in the area of prophecy).
And this brings me back to the Hathaway forecasts for Solar Cycle 24. The forecasts have steadily decreased over the last 3 years.
Predicting the behavior of a sunspot cycle is fairly reliable once the cycle is well underway (about 3 years after the minimum in sunspot number occurs [see Hathaway, Wilson, and Reichmann Solar Physics; 151, 177 (1994)]). Prior to that time the predictions are less reliable.
Cycle 24 Forecast
We seem to be in a solar minimum. We may be seeing a 210 year cycle – or maybe not. There are changes to the forecasts not only regarding the maximum level of sunspot activity but also about when it will occur and what the length of cycle 24 might be. There is speculation as to what effect the length of the solar cycle may have on climate – but we haven’t a clue as to what mechanisms may be involved. This is not to say that there isn’t much speculation and hypothesising. There is a great deal of comment about the effect these changing forecasts may have on global warming or cooling or climate disruption. In some quarters there is much glee that the forecasts have been “wrong”. Some comments question the intelligence of the forecasters.
But of course the forecasts themselves say nothing about how the behaviour of the sun may impact our climate. They do not pretend to be prophecies or to be statements of inevitable outcomes. All they do say is that we don’t know very much – yet – about the sun. But we do know enough to make some tentative forecasts.
But I am very glad that people continue to be brave enough to make forecasts and I am quite relieved that the forecasts are not spot on. That at least ensures we will continue learning.
Tags: climate, Forecasting, Learning, Management, Philosophy, solar cycle
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