Much is being made of a record-strength El Niño event that could well spell a drier, windier summer for the north and east of New Zealand. But, as a major new stocktake shows, it is forming against a backdrop of warming that’s pushed the country’s climate into “uncharted territory”.

The Our Atmosphere and Climate 2026 report shows New Zealand has warmed by 1.36°C since record keeping began in 1909, with seven of the ten warmest years within the decade since 2016.

Carbon dioxide (CO₂) levels, as measured at a monitoring station at Baring Head, are up by 30% since 1972 and the annual rate of increase has tripled since the 1960s. Globally, CO₂ levels are now higher than they have been for millions of years.

Ocean surface temperatures around New Zealand have warmed 34% faster than the global average and the Tasman Sea region has become a hotspot for marine heatwaves, with profound effects on marine ecosystems.

The warming will continue to accelerate an already dramatic loss of glacial ice in New Zealand, with glaciers expected to lose 50% to 85% of their remaining mass this century and some possibly disappearing completely unless emissions are brought down fast enough.

With the El Niño on top of the ongoing warming, some parts of the country can expect stronger........

© The Conversation