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Sunday, March 5, 2023

Peter 'Winsley: Can we turn forest slash from waste and risk into a valuable resource?


Therefore the winds, piping to us in vain, as in revenge, have sucked up from the sea contagious fogs; which falling in the land have every pelting river made so proud that they have overborne their continents…
Shakespeare, A Midsummer-Night’s Dream

Cyclone Gabrielle has caused death and destruction, and amplified awareness of the need to manage forestry slash. Slash is the branches, small logs and other woody material left after plantation forests are harvested, typically from low value hill country. At best slash is waste. At worst it can do enormous damage when washed downstream, clogging up rivers, harming pastoral farming and horticulture, damaging transport and other infrastructure, cluttering beaches, and impacting on kai moana.

Key events that have triggered downstream problems with slash include cyclones Bola (1988), Gita (2018), Hale (January 2023) and Gabrielle (February 2023). Climate change is likely to make such storms more frequent and more damaging.

Pyrolysis biochar can convert the slash problem into environmental and economic opportunity. The focus should be on biochar’s contribution to our climate change policy as well as productivity and wider environmental benefits.

There is more carbon dioxide in the soil than there is in plants and the atmosphere combined. Vegetation soaks up carbon dioxide and sequesters it in plant biomass. However, this “fast cycle” carbon is stored only for a few months or years until the plant material decays and the carbon returns to the atmosphere as carbon dioxide.

Pyrolysis biochar is “slow cycle” carbon made when biomass is burned in a low oxygen environment and turned into charcoal. When sequestered in soil this charcoal is known as biochar – a form of carbon that remains in the soil for centuries or millennia.

Biochar is not soil or fertiliser. It is carbon with high porosity and Cation Exchange Capacity (CEC). Biochar’s porosity and CEC helps water and nutrient retention and recycling and are associated with enhanced microbial activity and with healthier and more diverse soil microbiome. Biochar also reduces soil acidity.

Phil Stevens makes a superb case for biochar to become a core part of New Zealand’s climate change response , explaining how biochar can deliver environmental and productivity benefits as well as permanently removing carbon dioxide from the atmosphere. Given the value proposition, what is standing in the way?

The language in New Zealand’s climate change response policies and legislation focuses largely on emissions reductions. However, the Intergovernmental Panel on Climate Change (IPCC) has signalled that negative emission technologies that take carbon dioxide from the atmosphere as well as reducing emissions are both needed to avoid catastrophic climate change. Biochar is a negative emissions technology as well as having wider productivity and environmental benefits.

Climate change is so complex that it can only be addressed from multi-disciplinary perspectives. Lack of progress so far reflects a monumental failure of humanity to think universally and act intergenerationally. It also shows the limitations of economic theory and practice. The Coase Theorem implies that the market will solve externalities by itself so long as property rights are complete and transaction costs are minimal. These conditions are not met in the case of forestry slash.

Some extreme outlier events such as cyclones have impacts vastly disproportional to their statistical probability. In such cases insurance markets fail.

Garrett Hardin’s “tragedy of the commons” describes the overuse by individuals of a common resource. Alternatively, a “tragedy of the anti-commons” occurs when too many people have a stake in a resource and often value it so differently that coordination is impossible.

Elinor Ostrom won her Nobel Prize for demonstrating how small, local communities manage shared natural resources, such as pastures, irrigation water and fisheries. Faced with Ostrom’s evidence that local communities can self-govern commons in sustainable and efficient ways, Hardin revised his model and described it as the “tragedy of the unmanaged commons.”

Regulation as well as our economic models has failed us. Since at least 1992 forestry has had a Code of Practice for Forestry Operations which has been updated and includes guidelines to manage slash. Local authorities have been lax in regulatory enforcement. Regulation tells people what they are allowed or not allowed to do. However, central or even regional government edict sits uncomfortably with the subsidiarity principle, that is that decision making should be devolved to where the local issues are best understood and where the effects of any actions will lie.

Regulators may see only a problem that needs to be contained or eliminated. However, what is needed is a mindset change so people see opportunities in forest slash resources.

The targets for emission reductions differ between countries. Their scope and amplitude vary among countries in accord with stages of economic development and industry structures. In New Zealand the Emissions Trading Scheme (ETS) design, and the rules governing “carbon farming” are complex and ever-changing. Some international trade in carbon credits has been fraudulent.

As at March 2023 New Zealand’s policy has been to encourage tree planting on land ill-suited to food or high value fibre production, with this earning carbon credits. Climate change policy has effectively favoured short rotation radiata pine over other species such as redwoods, or native species, or different land-use options such as extensive pastoral farming using regenerative agricultural practices.

Forestry is extolled as an industry that delivers environmental “goods” such as sustainable materials, biodiversity and (temporary) carbon sequestration. However, slash that is washed downstream and causes harm is an environmental bad. The expectation is that slash should be disposed of through burning or be left on the ground to rot with its only value being to stabilise sediment in erosion-prone areas. These options are carbon-neutral; only pyrolysis that delivers biochar from slash has a positive impact in removing carbon dioxide permanently from the atmosphere.

A mindset change is needed to value slash as a biomass feedstock for biochar production, value-creating uses, and then its permanent sequestration as a carbon store.

Without international agreement on measuring and pricing soil carbon (including biochar) it is difficult to place a price on biochar from slash. A shadow price could be assigned. Shadow prices are assigned to goods not normally traded in markets, such as intangible assets or production costs. Pricing could include “an insurance premium”, avoided cost, and a value placed on the productive impact of the biochar.

Forest slash is a diffuse rather than concentrated resource. It is uneconomic to gather it up and transport it to centralised processing facilities, whether these be to make wood chips or biochar.

For slash the best solution may be to treat it in place, especially if it can be converted to biochar and applied to forest soils to promote forest health and productivity.

Often slash is left in place, partly because no value is seen in it and because it may help prevent sediment erosion. The slash may also be piled up and burnt. However, slash piles that burn and smoulder for long periods of time and at high temperatures can create hydrophobic soils that do not retain water well. With woody materials on the forest floor being entirely burnt, important soil nutrients are lost.

Some gains may come from constructing slash piles differently. For example, base logs can elevate the rest of a pile above the soil and result in around 10-15% of the biomass being turned into biochar. There are many types of mobile pyrolysis plants available internationally. These range from industrial-scale kilns to heat-resistant laminate “blankets” that can be wrapped around a burning slash pile. These blankets are impermeable to air; however, they have adjustable vents controlling air flow and allowing process calibration.

The East Coast pine forests are owned by many different investors, including foreign, iwi and individual investors. They have been incentivised by government policies. Industry in effect captures the benefits and socialises the cost of plantation forestry in steep, erosion-prone country.

The forestry contracting workforce is beset with problems such as poor safety, low pay, and lack of job security. It may be possible to smooth out workflows with contracted staff moving from harvesting trees to creating value through biochar production and remedial work, for example to stabilise sediments.

A Ministerial Inquiry is now underway into the mobilisation of woody debris (including slash) and sediment in Tairāwhiti/Gisborne and Wairoa districts. It will submit its report to the Minister for the Environment and the Minister of Forestry by 30 April 2023.

Ministers should note that where emissions reductions fall below what is needed to meet New Zealand’s targets carbon credits may be bought offshore. As at March 2023 the forecast is this may see New Zealand by the end of this decade spending about $12.8B buying carbon credits from other countries. Any government that approves such payments overseas for “intangible” and difficult to verify assets may be challenged given the alternatives that could be funded within New Zealand.

The Inquiry is obliged to accept written submissions. Hopefully these submissions can help catalyse mindset changes in relation to biochar and forestry and lead to at least a shadow price for biochar. This would help turn waste and risk into opportunities for a more sustainable and rewarding forestry sector in what is one of New Zealand’s most socio-economically deprived regions.

Dr Peter Winsley has worked in policy and economics-related fields in New Zealand for many years. With qualifications and publications in economics, management and literature. This article was first published HERE


2 comments:

David Lillis said...

Excellent article, Peter. For many years you too have been pushing biochar as part of New Zealand's climate change response. Keep up the good work!
David Lillis

Armand said...

By far the best way to proceed, would be to forget about the insignificant amount of greenhouse gas NEW ZEALAND produces, and spend the money saved into protecting areas and residential areas which are at risk from the elements. Also ensure that those who pollute rivers and environment as a result of their commercial activities, pay the cost of any subsequent damage and reinstatement. This has been done in the past as a result of a major climatic event. In February 1958, a major storm caused the Waikato River to flood and closed State Highway 1 between Auckland and Hamilton. In the 60's stopbanks were improved and other work undertaken to ensure that this did not repeat. Farmers and businesses along the river were taxed by having rates imposed which reflected the benefit they received from this work.

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