Achieving proposed methane targets under the Government's Zero Carbon Bill by 2050 will require changes to future farming practices, Rabobank's animal protein and sustainability analyst Blake Holgate says.
In Rabobank's latest Agribusiness Monthly report, Holgate said achieving the targets would be a challenge for the livestock sector.
The Bill set targets for reducing New Zealand's greenhouse gas emissions out to 2050.
It proposed reducing gross emissions of methane by 10 per cent from 2017 levels by 2030 and 24 per cent to 47 per cent by 2050.
Those were absolute reduction targets and would not be able to be offset through the planting of trees.
Carbon dioxide and nitrous oxide emissions would be required to reduce to net zero by 2050.
Emitters of those greenhouse gases who were unable to reduce their emissions to zero would be able to use activities such as tree-planting to offset any residue emissions, he said.
Various sector groups have criticised the proposed targets. Deer Industry New Zealand described the targets for methane reduction as "unrealistic''.
Holgate said there were no tools or practices available to farmers to significantly reduce their methane emissions, beyond reducing stock numbers.
The Prime Minister's chief science adviser had stated good farming practices, such as breeding and farm management, might reduce methane emissions by an estimated 5 per cent to 10 per cent.
Achieving deeper reduction would likely require productivity gains - while not increasing production - new technology, and land use change, he said.
Farmers and industry groups would be able to make submissions on the Bill as it passed through the select committee process.
Both Beef + Lamb New Zealand and DairyNZ would push for the range of reductions to be lowered to 10 per cent to 22 per cent to align with recommendations made by the Parliamentary Commissioner for the Environment, he said.
Read the full Rabobank Agribusiness Monthly June 2019 report below: