New Zealand and the climate crisis; pining - planting pine trees - for a low emissions future?

‍ New Zealand Climate Crisis: No 12

NEW ZEALANDERS AND THE CLIMATE CRISIS - WILL WE ACTUALLY REDUCE EMISSIONS OR WILL INSTEAD CONTINUE TO PLANT PINE TREES FOR A LOW EMISIONS FUTURE?

[Article 2850 words - an eleven minute read]

The impact of recent storms has ensured that it is the matter of adaptation - determining how we will live and work differently as a consequence of climate change in future - that is front of mind for many New Zealanders at the moment. The fact remains however that it is the rate at which we (and the other countries we share the world with) are able to reduce emissions and transition to low emissions economies that will determine the degree to which the world, that our descendants will inherit, is conducive or inhospitable to (if not life to), our society in its current form. To this end, some five years ago, we embarked on a 30 year journey to reduce our greenhouse gas emissions, (for so long an unconsidered by-product of modern human life) with, domestically, a dual, 2050 target; for all GHG other than methane to reach net zero and, for biogenic methane - from living organisms, including cows and sheep -  a 14 - 24% reduction below 2017 levels[1]. The target and the mechanisms to enable its achievement being enshrined  in legislation, in 2021 New Zealand moved into an emission reduction implementation phase. The cornerstone of the system is a series of Emission Budgets [EB’s] for (after EB 1:2022 - 2025) five yearly periods[2] out to 2050. These articulate our level of emission reduction ambition over the period and there are also companion Emission Reduction Plans [ERP’s] that set out the policies and strategies that enable the EB outcomes to be achieved.

It is at this point that New Zealand has strayed from the orthodox, and most effective, long-term strategy; that of reducing our emissions (the two largest areas being agriculture and transport[3]) at source and instead relegated this approach to a secondary role - in favour of primarily exotic (pinus radiata) plantation forestry[4] It is not in dispute that plantation forestry is a useful tool to help mitigate the current very high (and increasing) levels of atmospheric CO2 especially in the short-term. However, New Zealand has two major problems related to its emission reduction ambitions. Firstly, - and a topic outside the scope of this article - the current New Zealand government cancelled many of the source reduction-focused measures designed to facilitate the achievement of a low emissions economy. Secondly, it has also - and the subject of this article - chosen to rely, if not exclusively, then heavily, on planting exotic forests as the mechanism by which our climate emission reduction goals will be achieved. This deplorable situation has occurred for several reasons:

Firstly,because the New Zealand environment happens to offer very favourable conditions and space for growing treesthat sequester CO2 and especially for pine trees (pinus radiata).  New Zealand occupies a small corner of the South Pacific, has a low population density, and its geography and temperate climate are both well suited to growing a wide range of things including animals, grass and trees and it has a considerable amount of space available.[5] From a climate change perspective trees, (Indeed the vast majority of plants,) have a wonderful property, that of photosynthesis. This is a system of processes that enable them to convert (sun)light into chemical energy to fuel their metabolism. More importantly from a climate change perspective, the process, as well as releasing oxygen, converts carbon dioxide - the major GHG -  into carbohydrates (glucose). Some of this is used to meet the energy needs of the plant, some is converted into starch (a stored energy source), some is converted into cellulose (used to provide cell walls and structure) and some is converted into complex molecules like proteins and lipids (fats/oils) to produce new leaves, roots, and wood for plant growth. What this means is that all growing plants that utilise photosynthesis - from grasses, to exotic trees such as pinus radiate and the wonderful tree species that make up our native forests (rimu, totara etc) all act as  “carbon sinks” in that, while growing,  they actively remove CO2 (sequester) from the atmosphere and store it in a form that does not contribute to the global warming process that Is the signature of climate change[6]. A tool therefore exists - planting large areas of land in forests and utilising their carbon sink functionality - that governments can use to complement source emission reduction efforts to the benefit of our environment There is one major caveat that is important to the matters discussed here. All life forms, from grass to trees to people, are carbon based and all life forms have a beginning and an end. The term for the plant-based carbon life cycle is the biogenic carbon cycle. The stages in this process include the absorption of carbon dioxide from the atmosphere by through photosynthesis, its storage as biomass, and its subsequent release back into the atmosphere through respiration or decomposition. Because of this process - and with CO2 continuously being taken up from, and released into, the atmosphere by plants in a system that has existed for millions of years - it is vital to distinguish between (1) the “baseline” carbon sequestration by plants and especially trees, that was in place before the current, human generated, problem of climate change commenced and (2) the efforts made, recently, to address climate change (and its excess of CO2 in the atmosphere) by planting additional trees to enhance the carbon sinks provided by nature. To ensure transparency and a shared understanding and agreement on the latter (i.e. as to the additional actions taken), countries have developed frameworks  that define what forests are eligible to be formally included in such schemes. These rules ensure that the additional, purposeful, plantation forestry initiatives can be managed and measured in terms of their domestic and international impact in contributing to atmospheric CO2 reduction efforts[7],[8]  . While all growing trees sequester carbon, the rate at  which sequestration occurs varies hugely, both geographically (within New Zealand and elsewhere) and by tree species. Pine trees [pinus radiata] have a number of advantages; they can grow almost anywhere, are resistant to environmental pressures and are fast growing. Pine trees only grow for ~40 years (but will start to die off well before they are 100 years old) and, commercially, operate on a 28 year rotation cycle. One tree will sequester ~700 tonnes CO2 per ha though this figure will vary significantly around the country depending on factors such as soil fertility In contrast a 28 year old totara forest will store only ~240 tonnes CO2 per ha but may live for 1000 years. [Some totara trees in Northland have been found to store >1300 tonnes CO2 per ha and it has been estimated that New Zealand’s indigenous forests are storing am estimated 1.7 billion tonnes of carbon (or around 6.5 billion tonnes of CO2)][9] In terms of carbon farming, the major driver that favours pine rather than native plantations is financial. It offers superior immediate financial returns for investors over a 20–30 year cycle compared to native forests. While native forests are considered better for long-term "set and forget" investments, this requires both high carbon prices and an exceedingly long investment timeframe that does not suit most investors The effect of our purposefully growing large numbers of pine trees to remove CO2 from the atmosphere, is that our country’s performance, in terms of reducing atmospheric CO2 levels, must then be presented in a dual form.: §  Firstly, the sum of our point source emissions of all GHG (e.g. from agriculture and transport). These are “gross” emissions and are expressed in CO2 equivalents (i.e. tonnes or megatonnes of CO2e) . §  Secondly, the level of residual emissions that remain (once the amount eg tonnes of CO2 removed from the atmosphere by carbon sinks such as forestry is subtracted from the gross figure). These are “net” emissions and it is this figure that is important from the perspective of minimising environmental harm. The importance of this choice (to deliberately allow very large areas of plantation forest to be grown as an integral part of New Zealand’s emission reduction efforts)   to is evidenced by the fact that planting trees - primarily pinus radiata - are a critical part of the functioning of the New Zealand Emissions Trading Scheme (ETS), the main tool for meeting our domestic climate change emission reduction targets The ETS is an emissions pricing scheme intended to incentivise lower-emissions practices and products by gradually raising the pricing of climate pollution. This impact should get passed along the supply chain, and so slowly raise the cost of higher-emissions goods and services relative to low-emissions alternatives over time.[10] The importance of forestry to the functioning - or otherwise - of the ETS cannot be overemphasised. This is because forests, while they grow and sequester carbon,  are a key source of NZU (New Zealand Units; NZU, 1 NZU representing 1 tonne of CO2) that are the ETS currency.and may be freely traded between forest owners and owners of industries that are required to purchase NZU to cover their emissions[11] As a result, while land, including farmland, will be purchased for forestry purposes for reasons that include but are not restricted to possible participation in the ETS and any value that may accrue from that process, Beef+ Lamb NZ has estimated that at least 350,000 ha of sheep and beef farmland has been purchased for conversion into forestry since 2017 (or 19% of the 1.82 million ha of land in production forest in NZ)[12]. While I expect that more farmland will be converted in the future as the returns from farming forests are greater than  farming sheep/beef animals, the government has recently put in place the Climate Change Response (Emissions Trading Scheme—Forestry Conversion) Amendment Act to address concerns that high carbon prices were incentivising this process.

Secondly because the government has, foolishly and short-sightedly, embarked upon what it calls a “least cost” approach to addressing climate change challenges. While it appropriate for the New Zealand government to keep the transition (to a zero emissions economy) costs in mind when determining the emission reduction measures it takes, the “least cost” path it has chosen is misnamed. As used in the climate change context, “least cost” from this government is code for , spending almost nothing, instead outsourcing much of our emission reduction work to the plantation forestry sector and foisting the cost and the consequences of our inaction on emission source reduction onto the next and subsequent generations. This strategy has also enabled successive New Zealand governments to avoid taking - despite the now well documented economic and other advantages - the politically unpopular decisions and actions that reducing major source emissions (including farming and transport) would require.

Thirdly, a reliance on exotic plantation forestry as the central mechanism to transition New Zealand to a low emissions economy has a number of major limitations that the government chooses to ignore. Problems with this approach have been identified by a number of stakeholders including, critically, the Commissioner for the Environment[13] and the Climate Change Commission He Pou a Rangi[14]‍ ‍The identified problems include: §  Plantation forests will become increasingly exposed to climate change exacerbated risks including droughts, forest fires, extreme weather events  and[15] exotic pests. Destruction of plantation forests, by whatever means, releases the sequestered CO2 back into the atmosphere §  Significant social impacts. The conversions of sheep/beef farming land to plantation is bad for our rural communities. The impacts of the reduced labour force associated with farm forestry impacts on rural populations including the viability of rural schools and communities and also reduces the area of high quality land used to grow food §  Environmental damage. Monocultural plantations such as pinus radiata can result in the loss of native habitats and biodiversity, soil erosion and sedimentation of waterways. If harvesting is carried out in high erosion risk areas the loss of root reinforcement, leads to increased landslides and slope failure, especially during heavy rain. This situation is compounded by the issue of ‘slash’ - forestry debris - from clear felling activities that, when washed into waterways and onto beaches has major environmental costs and is hugely expensive to clean up[16] §  Trees sequester - store- C02 for a lot less time than CO2 stays in the atmosphere; as noted above pine trees will start to die off  and release their sequestered CO2 well short of 100 years. In contrast, ~65 - 80% of emitted  CO2 is absorbed by the upper oceans and terrestrial vegetation over 20 to 200 years, the upper ocean saturates, the remaining 20% to 40% mixes into the deep ocean and reacts with ocean sediments, a process taking hundreds to thousands of years, and the very last fractions of CO2 are only removed through incredibly slow geological processes—like rock weathering and the formation of carbonate rocks taking up to several hundred thousand years.   To cover this difference, significant areas will need to be planted in pine in perpetuity. Worse, given the disconnect between (1) our national and international commitments to reduce emissions and (2) the lack of action on actually reducing source emissions we will need to plant increasingly large areas in plantation pine forestry to meet our goals.   Finally, it is fitting (albeit depressing) that the government, in keeping with its determination to avoid leading work to address climate change impacts on our communities, has also chosen to present, to the world, an unrealistically rosy picture of our international emission reduction efforts.. This is the Nationally Determined Contributions (NDC) - five yearly, increasingly ambitious emission reduction goals - that New Zealand has signed up to as part of the Paris Agreement. In contrast to almost all other countries (who use “net-net” targets that do not consider carbon sinks generated by plantation forestry in the articulation of their targets), New Zealand’s NDC reduction targets are framed as “gross-net” ones that are calculated against a historic emissions baseline figure that includes plantation forestry. Our NDC commitment for the current period (a net reduction of 50% from 2005 by 2035) is measured against gross 2005 emissions. Recalculating this as a “net-net”  target (that metaphorically compares ‘apples with apples’ rather than the ‘apples and oranges’ that New Zealand uses) sees the emission reduction figure that more accurately describes the environmental benefit shrink from 50% to 28% as the 2005 plantation forestry sink contribution is taken out of the equation[17]. A future New Zealand landscape dominated by pine trees (and which doesn’t deliver the emission reductions that our planet and our communities need) rather than promoting the range of benefits that our glorious native forests deliver is not one I want for my children, grand-children and their descendants.    

‍ FOOTNOTES:

[1]Along with many other countries, we are also party to a number of agreements that commit New Zealand to reduce greenhouse gas emissions and other actions related to addressing climate change and its impacts including the Paris Agreement. [See Section 4.1 above]

[2] “Quinquennial” for those that prefer longer words

[3] Agriculture generates ~50% of our gross emissions mainly as methane and transport ~18% as CO2.

[4] Over the 14 year period covered by the first three Emission Budgets (2021 - 2035) ~ 90% of emission reductions projected to be achieved will come from increased forestry sinks rather than emission source reductions See Ministry for the Environment, “Appendix 3 - 2025 Projections by sector and emissions budget" in the proactively released document "BRF6754 Final Greenhouse Gas Emissions Projections for 2025".December 2025

[5] MfE “Our Land 2021”, ~1% of NZ land is urban, ~42% used for farming and horticulture and ~8% for forestry and ~49% native land cover https://environment.govt.nz/news/new-report-shows-impact-of-demands-on-land-in-new-zealand/

[6] The largest natural sinks are forests, ocean, and soil.

[7] In New Zealand it is only post-1989 forests. See eg Interim Climate Change Committee “Action on Agricultural Emisions.2019”.  ICCC Technical Appendices https://www.climatecommission.govt.nz/our-work/advice-to-government-topic/interim-climate-change-committee-reports

[8] Ministry for Primary Industries “Getting Started in Forestry,” https://www.mpi.govt.nz/forestry/getting-started-forestry

[9] Mitchell C, Stuff. “Root & Branch: What trees can and can’t do to address the climate change crisis.” 2019. https://interactives.stuff.co.nz/2019/09/root-branch-trees-climate-change-crisis/

[10] Eg Climate Change Commission, “What is the NZ Emissions Trading Scheme (NZ ETS)?”https://www.climatecommission.govt.nz/get-involved/exploring-the-issues/what-is-the-nz-ets#:~:text=Its%20purpose%20is%20to%20incentivise,low%2Demissions%20alternatives%20over%20time.

[11] The other sources of NZU are as industrial allocations (provided free to firms whose activities are deemed to be emissions intensive and trade exposed) offered at the quarterly auctions held by the government (the volumes and reserve prices being set appropriately to achieve emission reduction targets) and any surplus NZU held but not required by ETS participants.

[12] Wallace N and Rennie R, “ETS brakes forestry, but pressure on farmland remains:” April 16, 2026. https://www.farmersweekly.co.nz/special-report/the-rural-cost-of-forestry-conversion/ets-brakes-forestry-but-pressure-on-farmland-remains/

[13]PCE Submission 2nd Emissions Reduction Plan consultation August 2024

[14] Climate Change Commission  October 2025 https://www.climatecommission.govt.nz/assets/Advice-to-govt-docs/other-documents/2025-10-06-submission-on-PCE-Alt-F-report-issues-for-Environment-Select-Committee.pdf

[15] Ministry for Primary Industries, The threat to New Zealand’s plantation forests from four pests under a changing climate MAF Technical Paper No. 2011/4, March 2022. https://www.mpi.govt.nz/dmsdocument/6229-The-threat-to-New-Zealands-plantation-forests-from-four-pests-under-a-changing-climate

[16] Urlich S and Williamson A, “Cyclone Gabrielle exposed the risks of forestry slash. New research suggests little has changed” https://www.rnz.co.nz/news/environment/594665/cyclone-gabrielle-exposed-the-risks-of-forestry-slash-new-research-suggests-little-has-changed

[17] New Zealand’s gross and net emissions in 2005 were 82 and 57 Mt CO2e, respectively. The NDC net target is 50% of gross emissions  [0.5 x 82 = 41 Mt]. Measured against the actual 2005 net emissions however, this represents only a [(57-41 = 16)/57] x 100=  28% reduction on net 2005 emissions - not a 50% reduction