Tuesday, February 27, 2024

Biochar touted as a climate change solution

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Soil amendment technology stores carbon for thousands of years, says lobby group.
Biochar Network New Zealand chair Warrick Isaachsen says biochar stores carbon, increases yield from plants and some animals, improves soil and water quality, and reduces fertiliser and irrigation dependency.
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Biochar Network New Zealand is campaigning to increase the profile of biochar.

A product made by heating tree or plant waste or other organic matter, biochar – often used as a soil amendment technology – removes carbon from the earth’s atmosphere, the organisation said.

Biochar is one of few negative emissions technologies recognised by the Intergovernmental Panel on Climate Change, safely storing up to half the carbon in its source material for hundreds – and even thousands – of years.

“With large volumes of green residues from forestry, urban and agriculture resource streams, New Zealand is an ideal place to produce biochar,” said Warrick Isaachsen, chair of Biochar Network New Zealand. 

“Not only does biochar store carbon, it increases yield from plants and some animals, improves soil and water quality, and reduces fertiliser and irrigation dependency. This means that people who use biochar also save money while improving ecosystem viability.” 

Internationally, Biochar is well regarded for its versatility and benefits not just in agriculture and horticulture, but also its many applications in construction and tech, the organisation said.

New Zealand’s tree dependence to meet international greenhouse gas commitments is vulnerable to climate change and associated extreme weather events such as drought, wildfire, storm, and pest and disease risks, it said. Biochar can eliminate these carbon offset risks, and can sequester carbon over a much longer period than the life of a pine tree while providing benefits from its use. 

One tonne of carbon sequestered in biochar is equivalent to removing 3.67t of CO2 from the atmosphere for hundreds to thousands of years. International voluntary carbon markets and “climate active” businesses are leveraging this chemistry to financially support biochar project development around the world. 

Momentum around biochar is building in NZ, with a number of biochar-related projects in development, the organisation said. Biochar Network New Zealand has been invited to be part of the inaugural Ministry for Primary Industries Fieldays Forestry Hub next month, and internationally renowned biochar expert Professor Stephen Joseph will be in the country to engage with the Marlborough Grape Growers Cooperative, give the keynote address to the New Zealand Society of Soil Science, and attend Fieldays.

There are plenty of important reasons for NZ to grow more trees, said Biochar Network, and one of these is the supply of biomass and forest residues for the production of biochar and pyrolysis co-products, including energy.