Plan to Halt Wind in the Woolies

Australia has some inventive solutions to greenhouse emissions, from burying carbon dioxide to building a half-mile-high tower to generate solar energy.

But government researchers yesterday announced the strangest proposal yet - plans to vaccinate livestock to prevent them letting off methane.

Methane is 23 more times more potent than carbon dioxide as a greenhouse gas and is produced by single-celled organisms which break down grass in the stomach and intestine before letting it out into the atmosphere.

Each year, a cow produces in methane the equivalent energy of four tanks of petrol. Australia's 140m sheep and cattle are responsible for 14% of the country's greenhouse gas emissions.

In New Zealand - where a revolt by farmers last year halted plans for a livestock emissions levy dubbed the "fart tax" by protesters - the 40m cattle and sheep produce 60% of greenhouse emissions, more than the transport and power industries.

The proposed vaccine will encourage natural antibodies to attack the organisms. Recent tests conducted for the government scientific institute Csiro in Queensland, to be reported in a forthcoming issue of the journal Vaccine, were able to cutemissions by 8%.

The vaccine would also make the cows' production of meat and milk more efficient since the protozoans take away up to 13% of the energy value of the grass eaten.

Margaret Puls, of Csiro's livestock industry project, said that the research was an important step forward, but that a functioning vaccine was some way off yet.