A case for changes to methane approach

I want to reassure him that B+LNZ is committed to doing all we can to help him, and other farmers, by arguing for a fair and appropriate framework for tackling climate change.

The latest International Panel on Climate Change (IPCC) report adds weight to our argument that the current targets of a 10% reduction by 2030 and 24.47% reduction by 2050 in New Zealand's Zero Carbon Bill are too high.

The IPCC report makes it clear that the current accounting metric for climate emissions, known as GWP100, overstates the effect of constant methane emissions on global surface temperature by a factor of 3-4 over a 20-year horizon. GWP100 also understates the effect of new (or increasing) methane emissions by a factor of 4-5 over a 20-year horizon.

The IPCC states that if methane is stable or reducing, (as it has been in New Zealand since 2001), then using GWP100 to report methane's contribution at a national level each year to climate change is inaccurate.

It notes that an alternative accounting method, known as GWP* scales emissions over time and better accounts for the different warming behaviours of short-lived gases.

We've been advocating for GWP* for some time, with other primary sector organisations here and overseas, and with the Government.

Following the IPCC report, we will be renewing our efforts to have the Government use GWP* and report on both emissions and warming each year, so that the true contribution of each sector's emissions to warming can be seen and understood.

We will also be redoubling our efforts for a review of the methane reduction targets in New Zealand's Zero Carbon Bill using GWP* in collaboration with other agricultural organisations.

We will also continue our work with counterpart organisations internationally to promote the global adoption of GWP* as the appropriate metric for measuring the climate impact of agricultural GHGs.

The IPCC report makes it clear that New Zealand's current methane targets do not "let farmers off the hook".

It states that a 0.3% reduction per year in methane is equivalent to net zero for carbon dioxide - that is, there would be no additional warming from methane at this level of reduction.

Using the science in the IPCC report, a similar target to "net zero" for carbon by 2050 would be a 10% reduction in methane by 2050.

The report therefore makes clear that the Government's current 24-47% methane reduction targets by 2050 are asking agriculture to "cool" (i.e., reverse previous warming), while fossil fuel emitters only have to get to no additional warming by 2050.

While the report supports our view New Zealand's methane reduction targets are too high, the fact remains every New Zealander in every sector needs to make a fair contribution to limiting global temperature increases by limiting emissions.

That's why in parallel we'll keep working towards a system for measuring and managing emissions and recognising sequestration through He Waka Eke Noa, the Primary Sector Climate Action Partnership signed by 11 primary sector organisations and the Government.

If every farmer knows their emissions numbers and has a plan for managing emissions numbers and has a plan for managing emissions, then we will be in a better position to demonstrate that we are making a fair contribution to the challenges the whole country, and the whole world, faces. That's important to our consumers and to the public. 

Through He Waka Eke Noa, we're also focused on ensuring farmers get better recognition for the sequestration happening on their farms from their native vegetation. 

We are taking this issue seriously, we have been strongly making the case, and following the recent IPCC report, we will be looking to redouble our efforts.

Andrew Morrison is the chairman of Beef+Lamb New Zealand.