Eructations from farm animals account for a fifth of all global emissions of methane, a greenhouse gas that is less plentiful but far more potent than the most notorious culprit, carbon dioxide (CO2).

Chewing over the problem, scientists at Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO) believe a new vaccine can help protect Earth from the ruminant menace, New Scientist reports.

A vaccine against three species of microbe which produce methane in sheeps' stomachs reduced methane belches by eight percent in a 13-hour test.

The formula is only a prototype, for the scientists believe they can wack more of the remaining species of microbe, which together account for 80 percent of sheep methane, the British weekly reports next Saturday.

Methane is 23 times more potent volume-for volume than CO2 in its ability to trap heat from the Sun. It is responsible for a fifth of the enhanced greenhouse effect over the past 200 years.

The gas is released into the atmosphere from agriculture, landfill and mining as well as from natural wetlands. CO2 is mainly disgorged into the atmosphere from burning oil, gas and coal.

Greenhouse gases are so called for their ability to hang in the atmosphere like an invisible shroud, trapping solar heat instead of letting it radiate out into space.

All rights reserved. copyright 2018 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.