The greenhouse gases that cause global warming have increased to new record levels in New Zealand’s atmosphere, new data shows.<\/p>\n
At the same time, the country’s climate is changing, with warmer annual temperatures and a greater proportion of rain falling during extreme events.<\/p>\n
A tranche of data published by Stats NZ today showed carbon dioxide concentrations in 2025 rose to the highest levels yet recorded.<\/p>\n
The long-lived gas hit 423.1 parts per million (ppm), a 30 percent increase since monitoring began in New Zealand in 1972.<\/p>\n
The greenhouse gas data, collected at Earth Sciences New Zealand’s monitoring station at Baring Head<\/a> in Wellington, contributes to an international network of stations used to understand overall global warming.<\/p>\n Global concentrations of CO2 also hit a new record of 426ppm last year – a more-than 50 percent increase on pre-industrial levels (280ppm).<\/p>\n Carbon dioxide persists in the atmosphere for thousands of years, meaning concentrations of the gas – and therefore global temperatures – would continue to increase until the world stopped producing emissions.<\/p>\n Earth Sciences principal atmosphere technician Gordon Brailsford said instead, carbon dioxide concentrations were going up at a faster rate than ever.<\/p>\n “Each decade has a greater growth rate than the previous decade… That’s reaffirmed in the data released today.”<\/p>\n The first sign that things were changing for the better would be to see a slower rate of growth one year than the previous year.<\/p>\n “If we can build on that, then we can get away from this compounding growth that we’re having,” he said.<\/p>\n “What we’re looking at, at the moment, is trends that just continue to go up.”<\/p>\n New Zealand’s climate was changing at the same time, Stats NZ said.<\/p>\n Annual average temperatures had increased by 1.36\u00b0C since 1908, when reliable records began, with winter averages rising particularly quickly.<\/p>\n Rainfall patterns painted a more complex picture.<\/p>\n Some places in the North Island now received more annual rainfall, while other locations – such as Tauranga and Whang\u0101rei – were significantly drier.<\/p>\n The South Island was generally getting wetter, Stats NZ said.<\/p>\n What was also clear was that more of the country’s rain was arriving all at once, during storms and other severe weather events.<\/p>\n At 11 of the 30 weather stations included in the analysis, the proportion of annual rain falling on ‘very wet days’ had slowly increased between 1960 and 2025, at a rate of 0.6 to 1.8 percent a decade.<\/p>\n The vast majority of New Zealand’s extreme rainfall is driven by ‘atmospheric rivers’<\/a> arriving from the tropics.<\/p>\n As the global atmosphere warms, it can hold more water vapour – meaning more rain when those atmospheric rivers do arrive.<\/p>\n Extreme rainfall can overwhelm stormwater and river management systems, causing flooding; and destabilise land – leading to landslips.<\/p>\n Levels of methane also rise<\/p>\n Levels of methane in New Zealand’s atmosphere also slightly increased in 2025, from 1880ppm in December 2024 to 1890ppm in December 2025.<\/p>\n Overall, methane concentrations have increased 13.6 percent since December 1989, the first year the station began monitoring the gas.<\/p>\n Methane is much shorter-lived in the atmosphere than carbon dioxide – which makes its inclusion in emissions targets controversial –but has a greater immediate warming effect<\/a>.<\/p>\n New Zealand has pledged to reduce its emissions of both gases, although the government weakened the methane target last year<\/a>.<\/p>\n The 2016 Paris Agreement – which New Zealand is a signatory to, along with almost every other country in the world – pledges to keep global warming to well below 2\u00b0C and pursue efforts to limit the increase to 1.5\u00b0C<\/a>.<\/p>\n In 2024, the annual global temperature increase surpassed 1.5\u00b0C for the first time.<\/p>\n Researchers have said there is a strong likelihood<\/a> that this year and next could break that record again, following northern hemisphere heatwaves and a burgeoning ‘super El Ni\u00f1o’<\/a> that has caused ocean temperatures to dramatically spike.<\/p>\n