Nothing natural about heat wave

16:00, Jan 08 2014
WARMING UP: Annual temperatures continue to trend upward.

Expect more heat.

Last year was New Zealand's second hottest since records began 144 years ago. We had our warmest winter too in 2013. Australia also heads out of its hottest year.

New Zealand's mean temperature last year was 0.84 Celsius above the 1961-1990 long-term average of 12.17C, the second highest since records began in 1870. The only year it was hotter was 1998, which was 0.89C above average, climate scientist Dr Jim Salinger says. A former lead author for the Intergovernmental Panel on Climate Change, he has just released a book, Living in a Warmer World.

COOLING OFF: Popular beaches were packed on January 2. These youngsters having fun on a stand up paddleboard at Orewa beach can expect more days in the surf escaping the heat.

Above average temperatures are expected to continue this year, Dr Salinger says.

This follows on from Australia's Bureau of Meteorology Annual Climate Statement 2013 release last Friday confirming Australia had its hottest calendar year since records began in 1910.

The Australian averaged mean temperature for 2013 was 1.20C above the 1961-1990 long-term average.


It's significant the record high for Australia happened in a year when the El Nino Southern Oscillation, which alters ocean temperature and climate patterns in the Pacific, was in neutral, climate scientist Professor David Karoly from the University of Melbourne School of Earth Sciences says.

"This record could not occur due to natural variability alone and is only possible due to the combination of greenhouse climate change and natural variability on Australian average temperature," he says.

"It is not possible to reach such a temperature record due to natural climate variations alone. In simulations with no increases in greenhouse gases, none of the more than 13,000 model years analysed reach the record temperature observed in 2013. Conversely, in simulations for the period of 2006 to 2020 with natural variability and human influences, including increases in greenhouse gases, such records occur about once in every 10 years.

He says this variation is only possible due to the combination of greenhouse climate change and natural variability on Australian average temperature.

This follows a recent major Australian climate change study which points to an average global temperature rise of at least 4C by 2100 and possibly more than 8C by 2200.

Rodney Times