Marlborough Express - Robust scientific data needed in discussion on climate change

Columns
Wednesday, August 24, 2016

I'm sure it will come as no surprise to most people that weather statistics indicate we I have had an exceptionally warm winter this year.

There have been noticeably fewer hard frosts and aside from the polar blast a few weeks ago that brought snow to many areas, there has been little in the way of sustained cold temperatures. Ask people from the older generations and they will probably tell you that in their day, winters were much harsher and that the snow line on the ranges was much lower.

There is also the very real issue of the severe, ongoing drought in parts of Marlborough and in particular in North Canterbury.

There has been no significant rainfall in these areas for many months and in June, Government extended the medium-scale drought classification for North Canterbury until the end of this year. While I accept that weather events do not in themselves point to climate change, there is no doubt that climate change is occurring and that we are now clearly seeing the effects.

Climate change is a controversial subject, with strong opposing views. What does not help is when data is used selectively to try and make the situation look like something that it is not - and this includes overstating the facts.

I recently read an interesting article in The Press about Christchurch's weather temperature records.

Weather readings taken from the Botanical Gardens date back to 1863, making this data set one of the longest in New Zealand.

NIWA, so the article states, claims Christchurch is heating up more quickly than other parts of the country; apparently the city's temperatures are a quite significant 0.7 degrees Celsius warmer than at the end of 2004.

However, this claim is based largely on an urban weather station in Riccarton which was installed in 2002. It would be sensible to assume that this particular station, surrounded by concrete and industry, would return higher temperature readings than that in the Botanical Gardens, which is in a more natural setting just 2 kilometres away. The Riccarton station also does not provide us with long-term temperature readings to compare its current statistics to.

The article calls this mixing of data "selective science" and I am inclined to agree. It's a case of beginning with a hypothesis and then searching for data to support it, rather than using the most appropriate data.

Trying to overstate the case, for whatever reasons, may be well-intentioned, but it can only backfire; you cannot go into a crowded theatre shouting 'fire' when there isn't one.

Marlborough, too, has seen its Blenheim weather station moved from Pollard Park to its current site in Grovetown in, I believe, the 1980s. Again, this is bound to return different temperature readings and does not leave us with a true and accurate long-term picture of what is happening with our temperatures.

Of course, weather stations and data aside, there is other overwhelming evidence that climate change is happening, and much of that evidence is centred in the Pacific. There is little argument to be made against the stark reality of villages that are being swamped by increasing high tides.

In June, Climate Change Minister Paula Bennett travelled to the Pacific where she saw firsthand how communities are working to mitigate the effects of climate change and adapt to big weather events and king tides.

New Zealand is providing in excess of $200 million over the next four years for climate-related support, most of which will benefit the Pacific.

So we know climate change is a reality: what we need now to support this knowledge is robust scientific data, true and correct facts that cannot be left open to interpretation.