Predicting the predictable

Avid readers of news will notice that only rarely does anything genuinely new happen.

Instead, broadly similar news tends to hit the headlines about the same time each year, that occurrence being even more predictable during the quiet weeks early in the new year.

There is the New Year honours list. Then there are the inevitable stories about the mounting holiday road toll, tragic drownings, climbing accidents, camping mishaps and stormy weather.

The latest hardy annual to join the regulars during the past decade or so has been the climate summary for the previous year, with its statements of how much warmer the weather was compared with the long-term averages.

Given the consistent warming trend being experienced, it would be easy to shrug the shoulders and switch off from this news. But we must take notice.

Niwa's annual climate report for 2017 shows what most Otago residents will already have suspected - that it seemed a lot warmer right through the year than it often is.

There were, of course, the usual extremes of heat and cold around the region, but a general mildness notably took the edge off the winter, even if last summer was nothing to write home about.

For the record, the nationwide mean temperature calculated from the Crown Research Institute's seven-station network across New Zealand was 13.15degC.

That was 0.54degC higher than the 1981 to 2010 annual average, making last year the fifth-warmest year since the seven-station series began in 1909. The warmest year in that series was 2016, with 2013, 1999 and 1998 also in the top five.

The network comprises Musselburgh in Dunedin and three other South Island stations, at Lincoln, Appleby (Nelson) and Hokitika airport, as well as Kelburn in Wellington, Masterton, and Mangere in Auckland.

The locations were chosen for their geographic coverage and their long temperature records, and the network has been peer-reviewed for robustness by the Australian Bureau of Meteorology.

This slow but consistent turning up of the temperature dial should be hugely concerning to us all. Our climate is changing - of that there is no doubt.

There remains a small but dedicated group of climate-change deniers who question the science, and the motives of the climate scientists, at every turn - United States President Donald Trump among them. But the fact our climate is indeed changing - the evidence being the inexorable rise in average temperatures in many parts of the world - is beyond question.

It would be foolish and simplistic in the extreme to blame any single storm that comes along on climate change. After all, there has always been bad weather in this country and New Zealanders know all about the miseries of dealing with severe wind, rain or snow.

Where the influence of climate change can be seen is in the longer-term picture, such as repeated storms of a severity that maybe used to occur once every decade or so, or in these persistently rising average temperatures.

At the same time last week there were at least three significant storms affecting many millions of people across the globe. Although geographically unconnected, there were immense snowstorms and bitter cold in the northeastern United States, Storm Eleanor was battering Britain, and a subtropical low was bringing strong wind and heavy rain to northern and central New Zealand.

Coincidence? Probably. It is more likely we will know about such contemporaneous events sooner these days, given the proliferation of social media and online news sites. The down side of such immediacy, however, is how easily coverage can get out of proportion, fuelled by emotive hyperbole.

The wind and rain that hit the North Island last week was the kind of system we see most summers. Yet Niwa branded it a ''monster storm'', probably in an effort to attract the attention of the public and media.

Such exaggeration plays right into the hands of the deniers and the President Trumps of this world, and those who might consider such embellished warnings as crying wolf.

It does not help those genuinely working towards mitigating the effects of climate change using robust data to develop the best future policies.



Volcanic ash that is light enough to remain in the upper atmosphere can greatly add to the effects of global warming. There has been the Icelandic eruption across the Northern Hemisphere, the Mexican eruption across the equatorial zone and the Phillipine eruption across the Southern Hemisphere.