Nasa climate figures have all but confirmed that 2016 is well on the way to becoming Earth's hottest year on record.

While the final confirmation will only come when the measurements are tallied early next year, the US space agency confirmed that the past month was the warmest September on record by a narrow margin in a year where numerous climate and temperature records have already been smashed.

This global trend was confirmed to the NZHerald Focus team's Tristram Clayton today by Philip Duncan of WeatherWatch, who said that every single month in New Zealand between January and July had seen temperatures well above the average.

Our August and September though, while still quite warm, had been tempered by a few cold southerlies, which meant those months have not been record-breaking locally.

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"But at the moment we have this heat wave temporarily moving up the country, mid to late twenties around Canterbury yesterday, and today we are seeing that going into Hawke's Bay in the North Island. But whether that is related to a big global event or part of a localised weather pattern ... maybe a bit of both going on."

In the NZHerald Focus video Duncan talks about the weather trends Kiwis can look forward to as spring moves into summer.

Earlier today scientists at Nasa's Goddard Institute for Space Studies (GISS) in New York announced that September 2016 was the warmest September in 136 years of modern record-keeping.

It was a razor-thin 0.004 degrees Celsius warmer than the previous warmest September in 2014, and was also 0.91C warmer than the mean September temperature from 1951-1980.

Monthly temperature anomalies with base 1980-2015, superimposed on a 1980-2015 mean seasonal cycle. Image / Nasa,GISS,Schmidt
Monthly temperature anomalies with base 1980-2015, superimposed on a 1980-2015 mean seasonal cycle. Image / Nasa,GISS,Schmidt

However, GISS director Gavin Schmidt warned that "while monthly rankings are newsworthy, they are not nearly as important as long-term trends".

He said monthly analyses are updated when additional data become available, and the results are subject to change.

The monthly analysis by the GISS team is assembled from publicly available data acquired by about 6,300 meteorological stations around the world, ship- and buoy-based instruments, and Antarctic research stations. The modern global temperature record begins around 1880 because previous observations didn't cover enough of the planet.

The record-warm September means 11 of the past 12 consecutive months dating back to October 2015 have set new monthly high-temperature records. Updates to the input data have meant that June 2016, previously reported to have been the warmest June on record, is, in GISS's updated analysis, the third warmest June behind 2015 and 1998 after receiving additional temperature readings from Antarctica.

 A map of the September 2016 LOTI (land-ocean temperature index) anomaly, showing that much of the warmer temperatures occurred in the northern hemisphere. Image / Nasa, GISS
A map of the September 2016 LOTI (land-ocean temperature index) anomaly, showing that much of the warmer temperatures occurred in the northern hemisphere. Image / Nasa, GISS

In June Nasa had already warned that 2016's climate records were continuing to break global records, while the United Nation's World Meteorological Organisation also said that 2016 is on track to be the world's hottest year on record, with June 2016 marking the 14th consecutive month of record heat for land and oceans, also the 378th consecutive month with temperatures above the 20th century average.

Nasa said then that two key climate change indicators - global surface temperatures and Arctic sea ice extent - had broken numerous records in the first half of 2016.

Each of the first six months of 2016 set a record as the warmest respective month since 1880, with the six-month period from January to June also the planet's warmest half-year on record, with an average temperature 1.3C warmer than the late nineteenth century.

Nasa said that five of the first six months of 2016 also set records for the smallest respective monthly Arctic sea ice extent since consistent satellite records began in 1979, according to scientists at its Goddard Space Flight Center, in Greenbelt, Maryland. The one exception was March, which saw the second smallest extent for that month.

The scientists said that while these two key climate indicators broke records this year, it is more significant that global temperature and Arctic sea ice are continuing their decades-long trends of change.

They said both trends are ultimately driven by rising concentrations of heat-trapping carbon dioxide and other greenhouse gases in the atmosphere.

The extent of Arctic sea ice at the peak of the summer melt season now typically covers 40 per cent less area than it did in the late 1970s and early 1980s. Arctic sea ice extent in September, the seasonal low point in the annual cycle, has been declining at a rate of 13.4 per cent per decade.