Climate change?: New Zealand experiences warmest winter on record
The winters of 2020 and 2021 were influenced by La Nina, warm coastal waters, frequent high pressure and more northerly and north-easterly winds than normal.
New Zealand has just experienced its warmest winter on record, well exceeding the previous record which was set just last year, new data revealed on Friday.
Data from the National Institute of Water and Atmospheric Research's (NIWA) seven-station temperature series showed that this winter (June to August) was 1.32 degrees Celsius degrees above average last winter it was 1.14 degrees Celsius above average, reports Xinhua news agency.
The figures also show seven of the 10 warmest winters on record have occurred since 2000.
NIWA meteorologist Nava Fedaeff also said there were 76 locations across the country that experienced a record or near-record warm winter.
To put this winter's record warmth in perspective, Fedaeff delved into historic weather records and found that the last time New Zealand experienced a similar sequence of events was 50 years ago.
The winter of 1970 was at the time New Zealand's warmest winter on record only to be beaten by the winter of 1971.
"What was considered to be unusually warm at the time is no longer considered unusual. The winter of 1971 now stands in 13th place of the temperature rankings while the winter of 1970 is 18th."
Fedaeff also said what may have been considered record-breaking in 1970 is now considered near average.
"For instance, the once record-breaking winter 1971 is 0.75 degrees Celsius cooler than the winter we have just experienced."
A key difference can be found in carbon dioxide concentrations measured by NIWA at Baring Head, near Wellington.
In the early 1970s they were 320 parts per million, today they are 412 parts per million.
The years 1970 and 1971 were both La Nina years featuring warmer than usual coastal sea temperatures and higher than normal pressure over and to the east of the country which led to more northerly and north-easterly winds than normal.
The winters of 2020 and 2021 were also influenced by La Nina, warm coastal waters, frequent high pressure and more northerly and north-easterly winds than normal.
"These similar winters, decades apart, show us that there are key natural ingredients to getting a warm winter but adding climate change to the mix is like taking the same recipe and swapping plain flour for self-raising," Fedaeff added.