An agricultural greenhouse gas expert says total methane emmissions from livestock are rising despite increased efficiency in dairy production.
Andy Reisinger, deputy director of the Agricultural Greenhouse Gas Research Centre, was speaking at the New Zealand Climate Change Conference in Palmerston North.
Dr Reisinger said the amount of methane produced per litre of milk is reducing due to more efficient farming practice.
But he says total methane emissions are still rising because the increasing number of cows is outstripping efficiency improvements.
Dr Reisinger says technological solutions are not available as they are in other areas of climate change, where carbon free energy sources can be used.
We don't have methane free cows at this stage, and that's largely why New Zealand has invested, on a per capita basis, more than any other developed country in research to develop solutions that allow us to reduce agricultural emissions without constraining agricultural production."
Dr Reisinger says almost half of New Zealand's greenhouse gas emissions come from agriculture, unlike any other developed country.