Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search

 

New paper finds no significant 20th century warming for NZ

New paper finds no significant 20th century warming for New Zealand

A Reanalysis of Long-Term Surface Air Temperature Trends in New Zealand * by C.R. de Freitas, M.O. Dedekind and B.E. Brill.

A research paper on the homogenisation of the temperature record in New Zealand, reducing the current official rate of 0.9°C per century to 0.3°C, has just been published in the international scientific journal Environmental Modeling & Assessment.

The paper addresses the values of the data adjustments required during 100 years of the Seven-station Series, which is recognised as being representative of New Zealand as a whole. It also considers corrections to station data contaminated by vegetation growth, urbanisation and other factors.

The New Zealand historical temperature trend has not been addressed in the scientific literature since the first Seven Station Series was published by MJ Salinger in 1980. At about the same time, a paper by JWD Hessell called in question the quality of the New Zealand historical weather data used in the series.

The new paper builds on both viewpoints by applying modern techniques to correct sub-optimal raw data and to recalculate the 1980 adjustments. The method used for recalculations was that described in the leading New Zealand paper, Rhoades & Salinger (1993).

Lead author Chris de Freitas commented: “Regional and national temperature trends are widely used for a large number of societal design and planning purposes and it is important that they should be as reliable as modern methods allow”.

He added “New Zealand provides one of the longest continuous climate series in the Pacific Ocean as well as one of the longest in the Southern Hemisphere. This means our trends are of ongoing interest to a wide audience of scientists.”

The paper finds that New Zealand warmed over the 20th century at the rate of 0.3°C per century, which allowing for accepted margins of error means that there has been no significant warming.

The de Freitas et al paper has already attracted international attention. At the widely read website, http://www.co2science.org/articles/V17/oct/a34.php, Dr Craig Idso's review says, inter alia:
"The significance of de Freitas et al.'s work is two-fold. First, the authors report that the old, contaminated data with the inflated warming trend has been 'widely used as inputs for societal design and planning purposes' all across New Zealand. Second, de Freitas et al. note these data are 'extensively used in hindcast verifications for regional and local models.' However, as the saying goes, ‘garbage in equals garbage out.’ Therefore, at best, the corrected New Zealand temperature trend, which is three times smaller than the uncorrected version, calls into question all results, findings, conclusions, and policies built upon or derived from the old contaminated data record. And at worst, it invalidates them.”

Abstract

Detecting trends in climate is important in assessments of global change based on regional long-term data. Equally important is the reliability of the results that are widely used as a major input for a large number of societal design and planning purposes. New Zealand provides a rare long temperature time series in the Southern Hemisphere, and it is one of the longest continuous climate series available in the Southern Hemisphere Pacific. It is therefore important that this temperature dataset meets the highest quality control standards. New Zealand’s national record for the period 1909 to 2009 is analysed and the data homogenized. Current New Zealand century-long climatology based on 1981 methods produces a trend of 0.91 °C per century. Our analysis, which uses updated measurement techniques and corrects for shelter-contaminated data, produces a trend of 0.28 °C per century.

Ends

© Scoop Media

 
 
 
Business Headlines | Sci-Tech Headlines

 

Industry Report: Growing Interactive Sector Wants Screen Grants

Introducing a coordinated plan that invests in emerging talent and allows interactive media to access existing screen industry programmes would create hundreds of hi-tech and creative industry jobs. More>>

ALSO:

Ground Rules: Government Moves To Protect Best Growing Land

“Continuing to grow food in the volumes and quality we have come to expect depends on the availability of land and the quality of the soil. Once productive land is built on, we can’t use it for food production, which is why we need to act now.” More>>

ALSO:

Royal Society: Calls For Overhaul Of Gene-Technology Regulations

An expert panel considering the implications of new technologies that allow much more controlled and precise ‘editing’ of genes, has concluded it’s time for an overhaul of the regulations and that there’s an urgent need for wide discussion and debate about gene editing... More>>

ALSO:

Retail: Card Spending Dips In July

Seasonally-adjusted electronic card spending dipped in July by 0.1 percent after being flat in June, according to Stats NZ. Economists had expected a 0.5 percent lift, according to the median in a Bloomberg poll. More>>

ALSO:

Product Stewardship: Govt Takes More Action To Reduce Waste

The Government is proposing a new way to deal with environmentally harmful products before they become waste, including plastic packing and bottles, as part of a wider plan to reduce the amount of rubbish ending up in landfills. More>>

ALSO:

Earnings Update: Fonterra Sees Up To $675m Loss On Writedowns

“While the Co-op’s FY19 underlying earnings range is within the current guidance of 10-15 cents per share, when you take into consideration these likely write-downs, we expect to make a reported loss of $590-675 million this year, which is a 37 to 42 cent loss per share." More>>

ALSO: