Good News for Emissions in NZ

The news that New Zealand might be a net absorber of CO2 is exciting and challenges our approach to emissions management. The Emissions Trading Scheme (ETS) requires an emission certificate for each tonne of CO2 equivalent emitted, encouraging consumption choices towards lower emissions. The benefits can be wide-ranging, for example while fuel-efficient vehicles not only emit less CO2 they also improve urban air quality.

However, while the ETS covers the entire economy, it fails to fully account for CO2 sequestered by critical sectors, particularly forests. Foresters and qualifying entities can earn emissions certificates for CO2 sequestration, but stringent qualification rules imposed on forests create gaps in the ETS’s approach.

It may surprise you to know that all of our emissions reductions are calculated from January 1^st 1990 under the Kyoto Protocol, which extended the United Nations Framework Convention on Climate Change. In effect, our ETS incentivises forests established from 1990, which means that all forests established prior to that date are not included.

In addition to this inequity, post-1990 shelter belts and riparian plantings are also not included because they do not meet the minimum area and or height requirements. Food-producing trees are also not included. Why this is the case is a mystery.

On the other hand, emissions measurement practically captures almost every molecule of CO2 emitted.

A balanced approach to addressing greenhouse gas emissions is crucial to ensure it is fair and effective. A comprehensive understanding of all CO2 sequestered would give a clearer view of our emissions profile.

Fortunately, researchers, such as Steinkamp et al (2017)¹, have done just that by utilizing the atmospheric inversion method to explore New Zealand’s carbon dynamics. Their discoveries reveal New Zealand’s terrestrial biosphere as a net CO2 sink, removing approximately 98 (±37) Tg (teragram) of CO2 per year from the atmosphere during 2011–2013.

Before your eyes glaze over those figures, one Tg equals one million tonnes, therefore we remove somewhere between 61 and 135 million tons of CO2 more than we emit each year. Or to put it another way, we have well and truly surpassed net zero.

Encouragingly, another recent research by Bukosa et al (2021)² not only confirms this trend, but found an even more robust CO2 sink in recent years, particularly in Fiordland’s indigenous temperate rainforests.

The shifting political landscape surrounding climate change signals a growing recognition of scientific evidence. That New Zealand appears to be a net CO2 sink is encouraging but there is more work to do. As with all science, others will attempt to replicate the results and if this is able to be done then policymakers will be forced to account for all sequestered CO2 to portray an accurate emissions profile.

It is nothing short of bureaucratic nonsense that we count for all emissions but do not count all the CO2 that is absorbed in New Zealand. Embracing scientific evidence has driven our development and underpins the comfortable lifestyles we lead today.

We should debate why we are not accounting for all the CO2 absorbed in New Zealand. After all, it is the net emissions of CO2 in the atmosphere that has the warming effect – shouldn’t we assess that accurately?

¹Steinkamp et al (2017) https://acp.copernicus.org/articles/17/47/2017/

²Bukosa et al (2021)https://ui.adsabs.harvard.edu/abs/2021EGUGA..2314323B/abstract

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