California’s dairy farmers have reduced the sector’s methane levels by 30pc in just four years while simultaneously receiving an extra $2,000 per cow for annual manures — on top of yearly milk sales.
Professor Frank Mitloehner, specialist in atmospheric impacts of livestock at University of California, Davis, outlined the achievements, delivered via anaerobic digestion (AD), at the European Dairy Farmers (EDF) Congress in Cork.
It comes as Department of Agriculture officials warn the potential for AD in Ireland is “limited” because just 10pc of methane is sourced from manure here, compared to 50pc in California.
It also comes ahead of next month’s newly organised Oireachtas Agriculture Committee meeting on methane from Irish livestock which will hear from top climate scientist Professor Myles Allen of Oxford University with Prof Mitloehner now also expected to contribute among other experts.
Addressing the EDF event, Prof Mitloehner said: “Four years ago the State of California mandated a 40pc reduction of methane to be achieved by 2030, below 2013 thresholds.
“Our farmers at first went ‘wow, how in the world can we possibly achieve that?’ Little did they know the legislator would not leave them alone, they wanted to financially incentivise them to aggressively reduce methane by helping them to pay for it.
“They took public money and partnered with the dairy industry to reduce methane. A typical California dairy has about 1,500 milking cows, they used to have open lagoons, now we cover them, and they trap the biogas, a form of anaerobic digestion.
“They convert it into transportation fuels for trucks and buses. This pathway of dairy biogas to transportation fuels is considered the most carbon negative fuel type.
“As a result, farmers who do that receive carbon credits. These incentives amount to almost half of the milk price per cow. If a cow makes $4,000 per year for the milk sale, you’ll get close to $2,000 for the cow’s poop per year.
“Farmers are rushing to this, it’s a goldrush. It’s happening in a major way, and it has led to a 30pc reduction of methane for the California dairy industry without even looking into enteric emissions and the significant potential of feed additives.
“If in 2027 the dairy industry no longer has any negative impact on climate, we are getting credit that we can sell to other industries – and that is happening today, we have companies like Shell, BP, BMW buying carbon credits from our dairies.
“In California, 2pc of all public dollars used to reduce methane goes to the dairy industry which produces 30pc of all methane in the state – now that is a great return on investment. I hope Europe will follow that example, because it’s an example that works.”
Dale Crammond, DAFM inspector on livestock emissions, told last week’s Oireachtas Environment Committee that “just 10pc of methane in Ireland is in manure form, unlike California where half the methane would be in the manure”. during a debate on AD potential. “The potential is much greater [in California], it’s limited here in terms of what we can abate from the manure.
“Where it may have a role would be if it was to potentially displace livestock – that’s if farmers were no longer producing beef, for example, and they were to grow grass for a feed stock; then a big emissions abatement would occur from the displacement of those livestock from that land.”