The climate – how predictable is it?

Abundant summer rain in SA has taken the weather forecasters and climatologists by surprise. They did not expect La Nina to persist for a third successive year- which was thought highly unlikely. La Nina describes an upswelling of cooler water in the Pacific Ocean that brings more precipitation with it – in Southern Africa – and less in other parts of South America.  Its opposite is the little boy- La Nino – associated with warmer seas – and a drier South Africa. The quality of the weather forecasts has apparently been improving but the predictions of the climate models more than 10 days ahead are surely not to be described as confidently made with little margin for error.

Therefore, what confidence should we attach to forecasts of climate over the next fifty or more years? Yet society is being called upon very vociferously to believe in the climate models and their predictions of very harmful global warming. We are therefore being called upon – perhaps better described as being forcefully instructed so by our betters – to eliminate emissions of carbon dioxide – at enormous expense – to limit global warming. Costs of the astronomical order of 200 trillion dollars are bandied about. Which incidentally makes it extremely unlikely that resources of that order of magnitude will be willingly supplied by still highly constrained economies – and their dependents. Many billions of whom still lack clean and affordable energy to heat their shelters and cook their food.

The climate models will not only have to accurately estimate the volume of Co2 and other gas emissions to come and estimate within narrow limits their impact on average temperatures, and also predict how different parts of the planet will respond differently. They will also have to estimate the influence of the other powerful natural forces that will simultaneously and powerfully act on climate. Forces prominent in any climate model will have to include estimates of the variable influence of our lucky old Sun on climate.  I am told by an expert that there is significant disagreement on whether we are about to enter a relatively quiet sunspot cycle, which normally leads to a period of cooling.

Another persistently powerful forces on climate will be ocean flux of which the Ninas and Ninos are an example. To quote the same authority “- the Atlantic Multi-decadal Oscillation (AMO) is a cyclic phenomenon of sea surface temperature anomalies in the North Atlantic Ocean. They switch between positive and negative temperature phases over ~80-year periods. The consensus view is that the AMO is about to shift to a cool phase”.

Climate models are necessarily highly complex and hence prone to error. The climatologists carry grave responsibility for the accuracy of their models. And the politicians will be held responsible for the expected trade-offs of present costs (higher taxes and energy prices) for future- always less than certain – benefits. I am no climate expert. However, I am well-aware of the fallibility of long-term forecasts of the state of any economy. And of the weakness of scenario building that inevitably attaches too much weight to recently observed phenomena. I am conscious that the planning horizon of any firm that commits to capital expenditure is seldom beyond 20 years for very good reasons. Relying on benefits beyond twenty years are too uncertain to influence current outcomes- it is also true of governments and its plans.

It makes good sense to wait and see what dangers and the opportunities that climate change may bring over the long run. A stronger better endowed economy will have the capacity to better manage adversity. The potential danger of global warming adds to the case for faster not slower growth- for more, rather than less resilience. Humans are well practiced in adapting to natural challenges. We can rely on them to cope with continuous climate change.

Relying on ambitious plans imposed top down has not yet proved a useful strategy for humanity.   The plan to control climate through intervening severely in the global market for energy is highly ambitious and top down in a manner not ever embraced before. Yet the search for cheaper, less noxious, less dangerous, and more reliable energy is one of the positive steps for mankind that are still worth taking. What South Africa could be doing with great urgency would be to bring the oil and gas recently discovered off our shores onshore