Sir, – The article "Producing more milk with fewer emissions" (Science, January 22nd) is a very welcome antidote to the general negativity towards agri-food when it comes to climate action. Similar to the Smart Farming programme, it's important to see the best of science informing climate action.
The latest EPA climate figures indicate that overall methane emissions have increased by single digits since 2015, and not the 50 per cent referred to in the article.
I would like to draw your attention to new research from Oxford University (Allen, Cain & others) which more accurately accounts for the warming effects of greenhouse gases that have different atmospheric lifetimes. This research highlights how short-lived climate gases which are in the atmosphere for approximately 10 years, such as methane, are misrepresented against carbon dioxide, which lasts in the atmosphere for thousands of years. This was the topic of a recent IFA climate seminar, at which Prof Frank Mitloehner from the University of California (Davis), highlighted that livestock emissions are different from emissions from fossil fuels.
One of the key insights came from Prof Mitloehner. He said that while methane is a potent gas, it breaks down in the atmosphere after approximately 10 years. This means that if cattle numbers remain relatively static, then methane emissions from cattle are not contributing to global warming.
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At the event, Prof John Fitzgerald, chairman of the Climate Change Advisory Council, acknowledged that the way methane is accounted for is probably not appropriate.
We must have the most up-to-date and accurate science informing policy decisions.
The IFA will be making this issue a priority in 2020. We cannot continue to base policy on science that has moved on.
When the science changes, policy must change. – Yours, etc,
PAUL O’BRIEN,
National Environment
Chairman,
IFA,
Irish Farm Centre,
Drimnagh,
Dublin 12.