"However, climate scientist Kevin Trenberth questions the scientific basis for stringent methane reduction goals and has challenged the widely held belief that these emissions significantly contribute to global warming. He says, in a comment posted to the Newsroom story, that the moral panic surrounding New Zealand’s emissions, particularly related to methane, is scientifically unfounded.
NZ agriculture has already reached “net zero”: leading climate scientist contends in climate bombshell - CentristNo. These fellas aren’t destroying the Earth.

In Trenberth’s response to Daalder’s analysis, he contends that New Zealand’s agricultural methane emissions have already reached a state of net-zero impact on climate change.

Trenberth’s argument centres on the notion that methane emissions from livestock are part of a natural cycle. He explains that the methane emitted by cattle and land use basically represents a re-release of carbon dioxide that was temporarily stored in short-term grasses.

This cyclical process, according to Trenberth, does not result in a net harm to New Zealand’s carbon dioxide targets.

“The issue is that methane is so short lived that, in fact, NZ is already at “net zero” (with regards to) methane. The numbers of livestock have been stable enough since 2010 so the amounts emitted are completely compensated by the amounts oxidised to carbon dioxide.

“Since the methane started out as carbon dioxide in the atmosphere before being taken up in grass, and then eaten by livestock, the process is circular. The main issues with methane are fossil methane from mining operations,” he says.

Trenberth describes the Newsroom analysis as “hokey” and that New Zealand’s stable livestock numbers since 2010 have led to a balance where the methane emitted is offset by the amount oxidised to carbon dioxide.  Trenberth correctly points out that there are  fewer livestock today than there was back then, further strengthening the argument that New Zealand methane emissions are already at net zero."

https://centrist.co.nz/nz-agriculture-has-already-reached-net-zero-leading-clima...

Methane in the laboratory (dry air) is different to methane in the atmosphere. It is swamped in the atmosphere.

Grasses sequester CO2, livestock eat grasses, that is the literally eat the CO2. Then then emit methane which rapidly breaks down to CO2. Of couse no process is 100% efficient. So arguably less CO2 and methane is emitted than initially sequestered.