We learned of an important new report for the farm sector and its scientists not in press statements from the Ministry for the Environment (which published the report) or its minister, but from Beef+Lamb NZ.
The report, posted on the ministry’s website without fanfare today, is titled Net emissions and removals from vegetation and soils on sheep and beef farmland.
The report estimates the net emissions and removals from vegetation and soils on New Zealand sheep and beef farmland, using methods consistent with New Zealand’s Greenhouse Gas Inventory (MfE, 2020) and the 2006 Intergovernmental Panel on Climate Change (IPCC) guidelines for reporting (IPCC, 2006b).
Woody vegetation and drained organic soils on sheep and beef farms are estimated to be a net sink, removing 5487 kt CO2-e from the atmosphere in 2018.
Carbon dioxide (CO2) removals were driven by large areas of natural (indigenous) forest and planted (exotic) forests. Emissions from vegetation were driven by deforestation and harvesting of planted forests.
The overall net removals from existing vegetation on sheep and beef farms are projected to decrease over the next decade as the harvesting of planted forests increases.
The ministry report references a recent report prepared by Auckland University of Technology, funded by Beef + Lamb New Zealand, which estimated woody vegetation on sheep and beef farms may be removing between 10,394 kt CO2-e and 19,655 kt CO2-e per year, suggested to be offsetting 63 to 118 per cent of the gross agricultural emissions from this sector (Case and Ryan, 2020).
In contrast, the findings of the new ministry report indicate net carbon dioxide removals are 63 per cent lower than the midpoint estimate of Case and Ryan (2020), equivalent to 33 per cent of the on-farm agricultural emissions.
These lower net carbon dioxide removals are mainly due to the inclusion of emissions from forest harvest, scrub clearance and deforestation, and the application of more appropriate sequestration rates for natural forest and scrub/shrub classes which better reflect vegetation age and management practices.
The authors say the report provides a robust and up-to-date estimate of net carbon dioxide removals occurring on sheep and beef farmland. Future research could focus on improving the methods to estimate carbon stock change in vegetation and soils on farmland, and identify where sequestration could be increased.
Beef + Lamb New Zealand says the ministry’s reportis valuable because it recognises there is significant sequestration happening on sheep and beef farmland in New Zealand and is part of an ongoing process to build understanding of this important issue.
Chief executive Sam McIvor says B+LNZ stands by the AUT research it commissioned that arrived at different figures, but the numbers are not the focus.
“We absolutely stand by Dr Case’s independently reviewed robust and credible research. While there are differences in some of the methodologies MfE used in their report – particularly their netting-off of all harvested forest that doesn’t take into account the replanting and additional new planting we know is happening – it reinforces the importance of on-farm sequestration.
“What is encouraging is that MfE’s report recognises there is significant sequestration happening on sheep and beef farmland. Even using a highly conservative approach, they’ve arrived at a figure of a 33 percent offset of on-farm emissions by vegetation, which shows farmers are well on the journey no matter who is crunching the numbers. This sequestration is on top of the 30 percent reduction in absolute emissions that sheep and beef farmers have made since 1990.
“MfE’s figure of 33 percent is also sequestration primarily derived from the 1.4 million hectares of native forest on sheep and beef land, which is hugely significant as farmers are currently unable to get most of this recognised in the Emissions Trading Scheme. Our aim all along has been for sheep and beef farmers to be recognised for the sequestration happening on their land. If farmers are to face a price for their agricultural emissions, it’s only fair they get credit for their action already taken to date on greenhouse gas emissions, such as reductions and sequestration.
“We’re committed to working with Government, iwi and sector groups on the He Waka Eke Noa process, particularly, to formalise this recognition.”
Mr McIvor says the recent Climate Change Commission draft advice to Government highlighted the important role native forest should play in New Zealand’s response to climate change.
“The Climate Change Commission is recommending moving away from large scale exotic forestry, to encouraging the integration of native forest within farms, which B+LNZ supports. MfE’s report also highlights the need for farmers to get recognition of what is already there.
“This is a relatively new area of research. Dr Case’s report was the first time anyone had attempted to measure the sequestration happening on farm. We’ll keep advocating for a farm-scale view of emissions and sequestration, as well as encouraging our farmers to keep up their great work protecting and enhancing their landscapes. This isn’t just about carbon offsetting – native vegetation, in particular, provides other important ecosystem services such as enhanced biodiversity, soil conservation, and improved water health outcomes.”
As another contribution to the discussion, Mr McIvor says B+LNZ will soon release new independent research into the amount of planting/replanting that has occurred across New Zealand over the past few years.
About the different methodologies
B+LNZ notes there were different approaches used between MfE’s and AUT’s reports and that the reports had very different purposes from the outset. It says these are key points about the different methodologies:
- MfE’s report included emissions from harvesting and land clearance without factoring in replanting, where the AUT report focused only sequestration from existing vegetation and biological emissions. This could be an area of further analysis, including the scale and effect of replanting of harvested forests.
- MfE used different mapping approaches to estimate what forest was present on sheep and beef farms. B+LNZ will continue to advocate for more granular information about the scale of planting on sheep and beef farmland and ultimately farm-scale analysis, to be employed.
- MfE’s report discounted small blocks of planting throughout sheep and beef farmland, including shelter belts and riparian planting. B+LNZ disagrees with this approach as our understanding is smaller blocks of vegetation within a farm are, across the sector, significant.
Source: Ministry for the Environment; Beef+Lamb New Zealand