New Zealand's farmers have criticised a proposed tax on the flatulence emitted by their sheep and cattle.
The move is part of the Wellington government's action to meet its commitments under the Kyoto Protocol on global warming.
Scientists estimate that methane emitted by farm animals is responsible for more than half of the country's greenhouse gases.
Flatulence from cows, sheep and other ruminants is a serious environmental problem, accounting for about 15% of worldwide emissions of methane - one of the most potent of greenhouse gases.
Last year New Zealand signed up to the Kyoto Protocol, and agreed to reduce production of such gases.
The proposed flatulence tax is expected to raise NZ$8.4m a year ($4.9m) from next year.
The money is be used to fund research on agricultural emissions.
However New Zealand farmers argue that taxpayers should pay for the research, because reducing the emissions benefits everyone.
"This decision is yet another example of the government's desire to act in the wider public interest but expecting rural New Zealand to pay for its largesse," Federated Farmers President Tom Lambie said.
Sheep, cattle, goats and deer produce large quantities of gas through belching and flatulence, as their multiple stomachs digest grass.
Ruminants are responsible for about 25% of the methane produced in Britain.
In countries with a large agricultural sector, the proportion is much higher. In New Zealand, farm animals produce 90% of methane emissions.