Reducing methane emissions by just 3 per cent per decade would result in “no further warming” from the Irish national herd by 2050, the Oireachtas Agriculture Committee will hear tomorrow.
At a meeting to calculate methane emissions, leading climate scientist Professor Myles Allen of the University of Oxford is expected to claim that methane from Irish livestock will “fall precipitously” after 2030 if an updated method to measure the impact of the greenhouse gas is applied.
The professor is expected to call for a separate policy to be put in place for methane from livestock.
It comes as the government is due to confirm the target for emissions cuts in agriculture by the end of July, while runway discussions are underway on the overall proposed 22-30 percent reduction by 2030.
In a memo to the committee, Prof Allen says: “Ireland is one of the first countries with a significant agricultural sector to have developed ambitious climate policies that offer significant opportunities to be policy leaders.
“The standard way of characterizing the climate impact of emissions in terms of ‘carbon footprint’ or ‘CO2 equivalent emissions’ does not really reflect the impact of human activities on global temperature.
“It was introduced 30 years ago, well before the need for net zero was recognized, and it was never intended to push politicians to pursue such an ambitious temperature target. This has long been recognized as a problem for agriculture.”
However, he says “the error depends on whether these emissions are increasing, constant or decreasing”.
“A herd of 10 cows produces about a ton of methane per year,” says Prof. Allen.
“The standard carbon footprint calculation suggests that this methane equates to 28 tonnes of CO2 per year, whereas (like the Irish average) this herd has been built up over the last century, it only causes ongoing warming equivalent to around eight tonnes of CO2 per year year by a factor of three to four times less than 28.
“But if the herd is increased by just one cow, that increase alone will cause warming equivalent to an additional 13 tonnes of CO2 per year over the next 20 years and 0.8 tonnes of CO2 per year thereafter.
“Conversely, if emissions are reduced by as little as 3 percent per decade (either by gradually reducing headcount or, for example, by adding algae to the feed), then the methane emissions from these herds will not cause further warming because the effects of the decrease offset the warming effect of ongoing methane emissions.”
https://www.independent.ie/business/farming/news/climate-scientist-3pc-reduction-in-methane-will-halt-warming-by-2050-41849500.html Climate scientists: 3% less methane will stop warming by 2050