There is no evidence exotic tree monocultures will continue to sequester CO2 at high rates beyond the first few decades of their life
Opinion: Yet another heavy downpour leading to a state-of-emergency in Tairāwhiti this week highlights the existential threat we face from human-induced climate change.
Papatūānuku continues to suffer through our lacklustre response, which is focused more on planting fast-growing exotic trees (estimated at 60,000 ha in the past year alone) than actually reducing our greenhouse gas emissions.
The problems with this approach have been clearly highlighted in the Climate Change Commission's draft advice for the Government's 2026-2030 emissions reduction plan, which warns against this over-reliance on exotic trees in the Emissions Trading Scheme (ETS).
READ MORE:
* Vested interests have knee-capped the Emissions Trading Scheme
* Govt consults on removing forestry from ETS
* Māori foresters fail in urgent legal bid on ETS
* Climate Commission warns of fossil-fuelled NZ in 2050
The recently announced ETS review aims to address these concerns, and an additional report on the permanent forest category is also open for review.
Exotic tree monocultures established for carbon credits that are used to offset emissions are morally corrupt for three reasons: it does nothing for emissions reductions; it’s not permanent; and, it imposes substantial liabilities on future generations once the flow of carbon credits has dried up.
‘Plant and leave’ carbon farming (or carbon mining) is nothing more than a get-rich-quick scheme for a few investors capitalising on the climate emergency. Carbon farming has been facilitated by a fundamentally flawed ETS which allowed 100 percent emissions offsetting. I fully support option 4 in the Government’s consultation document, which aims to clearly separate emissions reductions from carbon sequestration.
There is no independent, objective scientific evidence in the New Zealand context to show exotic tree crops will continue to sequester carbon dioxide at high rates beyond the first few decades of their life or that they can maintain themselves as long-term carbon stores.
There is also no consideration of the threats they pose to a wide range of other values in Aotearoa. These concerns have been widely highlighted, and the only response of carbon farmers to these, which strike at the heart of their business model, is the unsubstantiated and ecologically fraudulent claim that they will somehow transition to native forests.
The concept of transition is at the core of the Government's proposals for what might be considered as permanent forest. Transitions can only occur in a limited set of circumstances, mainly in areas with reliable rainfall and good native seed sources.
However, even here substantial management will be required to ensure the transition actually happens, and needs to include opening up of the exotic tree canopy to let light in, the direct introduction of mature forest native tree species, and exotic plant and animal pest control (especially deer, goats and pigs). This management will be required for many decades, well after the income from carbon-credits has stopped.
Unlike exotic tree monocultures, native trees form genuinely permanent, diverse forests that can regenerate and maintain themselves in perpetuity while building below and above-ground carbon reserves and providing multiple other benefits to all of us
There has, however, been no consideration of how to guarantee such transitions. Even where they are possible, there is no financial or legal mechanism available to guarantee the management will take place. There has also been no objective consideration of the multiple risks posed by exotic tree monocultures and failed transitions or of the liabilities associated with these. Such liabilities will fall well after these tree crops have earned their carbon income, and ownership may have passed to others. For example:
* Who will bear the carbon liability if the exotic tree crop collapses through lack of management or because of fire and windstorm, change of ownership or bankruptcy?
* How will impacts from these tree crops on adjacent land uses be managed (such as wilding spread, as sources of diseases that affect timber plantations, and as sources of plant and animal pests more generally)?
* How will exotic tree species such as redwoods and blackwoods that persist through resprouting be removed from transitional forests?
One pragmatic solution to all of these concerns is for a percentage of the carbon credits earned by transitional exotic tree crops (Pure Advantage suggests at least half) to go into an independent fund that can then be used to guarantee the transition management will happen during and long after the income from carbon credits has finished.
Some carbon farmers are suggesting a self-administrated code-of-practice is sufficient, but this is like the tobacco industry being asked to self-regulate their activities. Audited management plans have also been suggested in the Government's review of the permanent forest category, but again, it would seem easy for an investor to default on this once they have received the majority of their carbon income. Both would be a disaster for Aotearoa.
Government needs to implement separate emissions reductions from sequestration. Government also needs to ensure the permanent category is primarily restricted to native forests, and where transitional exotic tree crops are included, at least a half of the carbon income needs to be retained to guarantee the transition. But, more importantly, it needs to alter policy settings to make it financially viable to establish native forests for carbon sequestration and all their other benefits.
Unlike exotic tree monocultures, native trees form genuinely permanent, diverse forests that can regenerate and maintain themselves in perpetuity while building below and above-ground carbon reserves and providing multiple other benefits to all of us.
Because they evolved in Aotearoa, permanent native forests also provide habitat for a wide range of native biodiversity, essential habitat that exotic tree crops can never provide. The Government needs to urgently promote the planting and regeneration of native forests widely across Aotearoa for landscape resilience, climate change mitigation and addressing the biodiversity crisis.
David Norton is a strategic science advisor to Pure Advantage
