Kiwis have been shocked in recent weeks to discover their pristine glaciers turning pink, with apocalyptic orange skies covering New Zealand’s biggest city, Auckland. So much so that police have been deluged with emergency calls asking what is going on, as the land of the long white cloud is turning pink (kikorangi māwhero).

The catastrophic bushfires in Australia have also affected New Zealand. Because of the impact of trans-boundary air pollution (and its effects on other countries), there are legal implications to be considered.

The story starts three decades ago, when CSIRO scientist Dr Barrie Pittock and I foreshadowed future climate projections for Australasia because of global warming, with Australia becoming the burning drying continent. We have now arrived at that point. These bushfires lift dust and ash high up into the atmosphere, where they are caught in the strong prevailing westerly winds at those altitudes. The smoke particles are blown 2000km across the Tasman to reach New Zealand and further east.

There have been various factors, which have exacerbated the conditions over Australia and had impact downstream on New Zealand’s late spring and early summer climate. The first is the Indian Ocean Dipole, which is like an El Niño/Southern Oscillation pattern, but in the Indian Ocean. This has been very much positive, producing colder than normal water off western Australia and warmer than normal water off East Africa. Then the Southern Annular Mode has been very negative, spinning up the Roaring Forties and Furious Fifties in the southern oceans and pushing them north.

The consequences of these two patterns, intensified by global warming, have caused the driest and hottest year on record for the Australian continent, as noted in the Bureau of Meteorology’s 2019 annual climate summary.

In November, New Zealand had warm air transported from the interior of Australia by north-westerlies to produce the hottest November on record, being 1.6C above the 1981-2010 average. The Chatham Islands – an archipelago 800km east of New Zealand – were 2.3C above average, priming waters there for the marine heatwave. At the same time, anticyclones in the second half of November and much of December parked themselves over or east of the Chathams, calming the seas down, producing the marine heatwave to the east of the New Zealand region, covering 1m sq km.



Mean temperatures on the Chatham Islands for December 2019 were 3.8C above average, the largest for any month of observations since records commenced in 1878. A marine heatwave of this magnitude is very likely to impact the Chathams’ fisheries area, with an invasion of warm-temperate fish species and the possible dying out of coastal seaweed species.

The immediate bushfire impacts on New Zealand produced an orange smoke haze in skies across the entire country and turned its iconic glaciers a caramelised pink. The acrid-smelling smoke made the sun appear as either a red or golden ball, depending on the smoke thickness. Already five such events have polluted the New Zealand atmosphere, which is unprecedented. The darker glacier surfaces from December to March will promote more ice melt, compounding the loss already of a third of glacier ice between 1977 and 2018. However, any such impacts last only one season.

At the beginning of January, New Zealand air quality levels from the bushfires had declined to “code orange” in several locations. This is classified as “unhealthy for sensitive groups” such as those with asthma and chronic obstructive pulmonary disease. Bushfires increase dangerous air pollution in the atmosphere, with Australian studies showing an increase in respiratory diseases, though no such studies are available for New Zealand.

The impact of the air pollutants from bushfires on health and tourism – the latter because of cancelled tourist operations due to smoke haze – also raises the issue of trans-boundary air pollution, legislation for which has been developed in international law in the Canadian province of Ontario.

With trans-boundary air pollution, impediments that may have existed in the past in recovery of damages and clean-up costs are being removed gradually by many jurisdictions in what may be characterised as a more focused attempt to prevent or curtail polluting activities and to ensure that those responsible bear the costs (in real terms).

An example of this occurred two years ago in Costa Rica: the Inter-American court of human rights released an advisory opinion on environment and human rights. This has the potential to unlock real cross-border remedies for the victims of environmental degradation and recognises the right to a healthy environment as basic to the continuation of humankind. Given the Australian government’s denial on the existence of human-caused climate change, this could be a legal remedy that might be used, considering that communities in New Zealand have nothing to do with Australia’s greenhouse gas emissions.

The apocalyptic Australian bushfires, then, have produced dramatic effects downstream on New Zealand, which has become the land of the long pink cloud, with unprecedented smoke haze and air pollution events.