New Zealand has some of the sweetest, purest, clearest clean air anywhere in the world.
Most of the time.
In most places.
This is the continuing story of those other times and places.
New Zealand is harbouring four guilty secrets about its air – four situations where our current way of life is putting our health at risk unnecessarily. The good news is that they can all be dealt with using a little science and a little will.
I recently blogged about how concentrating people and buildings in dense urban centres is good, so long as you don’t pack polluting vehicles into the same streets.
But what about the air in our suburbs, especially in our smaller towns? Well, it turns out their air quality can be even worse than our busiest city streets.
The pictures above are from Arrowtown, a beautiful community of just over 2000 residents. It’s not on the way to anywhere and so, bar the occasional tour bus visiting from the nearby tourist magnet of Queenstown, has very little traffic. At 3pm it regularly has some of the cleanest air in the world. But by 5pm on a calm winter’s evening it can be one of the most polluted places in Australasia.
And the cause is plainly obvious to anyone there as the Arrow River valley rapidly fills up with thick woodsmoke. And it’s especially obvious to anyone with asthma or any respiratory condition who will find their chest tightening, or anyone with sensitive eyes who will feel the sting. The smoke builds up and is often still there next morning, when residents wake to the winter chill (in mid-winter the sun doesn’t rise over the adjacent hills until 10 or 11 am) and throw another few logs on the fire.
Wood was the natural choice for home heating fuel when colonists established New Zealand – a land largely of isolated settlements surrounded by forest. Twentieth century investments now make electricity the fuel of choice and heat pumps the most popular appliance for new builds. But we don’t change our heating methods regularly, largely because it’s a prohibitively large investment for many households, and old habits are deeply entrenched. Broadly speaking the colder or more remote or poorer the location, the more strongly residents cling to their wood-burners. Bad experiences with power cuts, power price hikes and under-performing heat pumps, even though they may be rare, tend to have an out-sized influence on people’s wariness of switching to electricity. And these perceptions compete with positive feelings of nostalgia, independence and comforting familiarity that come with wood (plus the fact that for some wood can be sourced for free). Even in warm and fast-changing Auckland it is estimated that around 20 % of homes relying on wood for heating (https://knowledgeauckland.org.nz/media/1091/tr2018-018-auckland-air-emissions-inventory-2016-home-heating.pdf).
But the impacts are real. The most recent assessment concluded that exposure to particles from home heating emissions contributed to 962 premature deaths, 3375 hospitalisations and over a million “restricted activity days” in 2016 (https://environment.govt.nz/publications/health-and-air-pollution-in-new-zealand-2016-findings-and-implications/). Evidence like this has led to national legislation and regional and local rules requiring home heating appliances to meet emission standards. This approach, in principle, allows wood and wood products to continue to be used, so long as the emission standards can be met. This has been enabled by, while in turn stimulating the development of “low” and “ultra-low” emission burners, as well as pellet burners. The result has been that, whereas in the warmer parts of north and coastal New Zealand where heat pumps are slowly replacing wood burners, in the cooler south and interior wood-burning culture lives on and is likely to do so for decades to come.
But after a couple of decades of regulation and low-emission appliances, air quality data, especially from the south, is revealing a painfully slow rate of progress. On our current trajectory towns like Arrowtown may expect to finally meet the proposed National Environmental Standard for Air Quality (PM2.5) until well into the 2030s or 2040s, and meeting the World Health Organisation Guidelines (for daily PM2.5) may not happen until the 2080s.
There are three main reasons for the slow progress. Firstly, “low” and “ultra low” are relative terms. Compared to older woodburners they may be low. But they are not low compared to the alternatives – gas and electric. In fact, the average “low” emission woodburner emits the same amount of particulate matter as six average diesel trucks.
Secondly, “low”/”ultra low” refers to what they can achieve, under ideal laboratory conditions, not what they actually achieve in the real world, where they may not be maintained, or wet wood or used, or users put other “non wood” items in the fire (like refuse).
Thirdly, there are probably an awful lot of unconsented, non-compliant or just unknown wood burning appliances out there. Including disused ones that could be brought back into action whenever electricity becomes unreliable or too expensive.
But it doesn’t have to be like this. All of this pollution is of our own making and it is fully within our power to make it go away. A proper transition to reliable and affordable electricity would deliver the cleanest air quality in the world to an area with significant health inequalities and a strong dependence on tourism, which is partly predicated on a green environment with clear skies and clean air. Given the right regulatory incentives, our heating industry has shown it can respond and innovate. Appliances that not just meet standards in the lab but that can guarantee it every day could play a major role in managing the energy transition and environmental transformation that would be the envy of the many parts of the world struggling with the same issues.
We’ve just got to want it.
