Scientists are trying to reduce the amount of methane coming off New Zealand dairy farms.
The vast majority of methane from dairy farms is emitted from cows as the burp and belch while digesting grass and despite their best efforts scientists haven't been able to figure out how to reduce it.
But about 10% of methane from dairy farms comes off their effluent ponds.
At the New Zealand Climate Change Conference this week, Dr Kevin Tate, a research associate at Landcare Research, presented his latest work. He has been placing bacteria with an insatiable appetite for methane above the ponds.
"We've managed to develop a very active population that consume masses of methane ... They're also self-regulating in the sense that as they consume methane they produce water, so they never dry out.
"Some of them can also fix nitrogen and they also seem to be able to catch ammonia from the ponds, which is very useful additional property and also they help with odour control. So they seem to do a lot of things very, very well."
Dr Tate says they are testing a floating bio-filter and trying to develop a cheap technology that will be attractive for farmers to use.
He says the technology could be on dairy farms within a few years.
"We could do it fairly soon, but we do need to demonstrate that the floating bio-filter technology works as well as the original prototype that we tested on the Massey University farm. We're doing that at the moment.
"I would say in another three years we should be in a position to say, 'This is how much it would cost you', we can show how they can be managed well on a farm by a farmer to make it as simple as possible. So far, experience shows us they're virtually maintenance-free, they look after themselves essentially."
Dr Tate says the floating bio-filter technology is attracting attention from overseas agricultural businesses too.