Climate and Prediction

Climate and Prediction

As a newspaper of record, Wellington’s Dominion Post does a good job in keeping us abreast of climate predictions.  Anyone noting these over a period of time will have an endless source of entertainment, given that one by one they fail to deliver their doomsday scenarios.

The DomPost of 3 April 2014 tells us that over the next 100 years “the Environmental Ministry advice said a rise of between 0.5 and 0.8m should be prepared for, but the new report, from US geophysicist Paul Komar, said it was more likely to be at least a metre.”

Well, we don’t have Dr Komar’s justification for this extraordinary figure, but we can provide input from others.  For example, Columbia University gives a relatively linear global sea level increase of 3.2mm per annum over the last two decades.  This makes for a one metre rise in 312 years, or less than a foot in the next 100 years.  Dr Komar needs 10mm per annum if his prediction starts now, and a whole lot more if there’s a delay.  Given the glacial pace of sea level rise, this strains credibility, but the nature of prediction is such that it’s hard to challenge.  It requires belief, which is hard for the sceptic to accept.

Tectonic effects are so difficult to predict that no-one really tries except in the most generalised manner.  Yet the effects on localised sea levels are far more significant than sea-level rise.  The Solomon Islands' Ranongga is just one example, Japan’s 2011 earthquake another. 

The panic that seems to accompany sea-level rise can hardly be justified on the grounds of cost, and again, Japan’s 2011 earthquake is a good example.  Despite Japan’s best efforts at protecting itself, the World Bank’s estimated economic cost was US$235 billion, making it the costliest natural disaster in world history.  In contrast, the gradual pace of sea-level change, 150mm in the last century, has resulted solely in coastal storm damage and its costs, since amelioration has, if anything, declined over that period.  Furthermore, the inclination to build on areas vulnerable to storm damage has increased.

There is a false sense of perspective in this sea-level rise prediction.  100 years is the equivalent of a lifetime, a figure that makes sense to people in a way that kiloyears and megayears that climatologists deal with does not.  Yet we move house every six to eight years, meaning our investment in a specific property is very unlikely to be lifelong.  The average life expectancy of a house is 90 years, with properties in attractive or suburban coastal areas likely to be on the short end of the scale as the intrinsic value is realised in new building.  Properties in less attractive, more remote, coastal areas won’t lose value suddenly, rather, investment in them will decline over decades until the buildings fail to meet council standards.

Predictions cover such a range of possibilities that they tend to be highly forgettable until the one correct guess in a thousand gets trumpeted abroad and the predictor gets their moment of fame.  But the myriad that fail remain archived for those who delve into the records.  The British Meteorological Office forecast a rise of 0.3°C between 2004 and 2014.  To date, 12-month average temperatures have risen just 0.03°C.  They also forecast half of all years between 2010 and 2020 are likely to exceed 1998, the hottest year so far.  Not looking good – calendar year averages since then have been well below.  Indeed, global temperatures have remained almost completely flat since 1998 in spite of predictions of increases through steadily rising CO₂ levels.  Extrapolating the linear trendline between 1998 and 2013, for an increase of 0.038°C over the 17 year period, gives a 100 year increase of just 0.22°C.  Accurate?  No, but I'll happily pit my estimate against The British Met Office's. 

Apocalyptic predictions are part and parcel of Judaic religious belief and its offshoots. Their routine failure to materialise ironically reinforces belief through sophistry.  Even in a post-Christian era, they form an ineradicable part of the Western world-view.  As British historian Norman Cohn notes, “The old religious idiom has been replaced by a secular one, and this tends to obscure what otherwise would be obvious. For it is the simple truth that, stripped of their original supernatural sanction, revolutionary millenarianism and mystical anarchism are with us still.”    The apocalyptic vision of new-age prophets’ climatic catastrophe offers unwitting new-age believers the catharsis of personal redemption through new-age canonical law.  Reduce your carbon footprint, eschew consumption, support sustainability, share your country with those less fortunate, leave animals alone, repudiate genetic modification, ban fossil and nuclear power.

They should beware of what they wish for.