Managed properly, livestock on pasture can enhance and improve the environment by increasing organic matter, microbial activity and biodiversity while sequestering carbon in the soil.
Rowntree said common sense has been missing in debates about the role of livestock and climate change.
Even if all United States ruminant livestock were eliminated and every American followed a vegan diet, total US greenhouse gas emissions would be cut by just 2.6% or 0.36% globally.
“It’s a drop in the bucket.”
Perversely, a plant only diet will lead to increased use of synthetic fertiliser, greater soil erosion and nutrient-deficient diets.
The US emits 6000 to 7000 million tonnes of carbon dioxide equivalent a year but only 9% comes from agriculture and less than 3% from cattle.
NZ’s entire greenhouse gas footprint is less than the US’s beef emissions, he says.
Rowntree is critical some of the debate about contributions to climate change lacks scientific rigour and does not address whole systems, which reflects poorly on farming.
He says the livestock and climate change debate is pitting the public against food producers with finger pointing, accusations and lashing out.
He urges farmers to focus on what they can control and that is managing their land.
Methane has been produced for as long as there have been ruminant animals and Rowntree says it follows a natural biogenic cycle, breaking down after 10 years into carbon dioxide and water, which is then recycled to earth.
So long as cattle numbers are falling, as they have in the US for several decades, methane emissions are also declining, reducing the effect of the greenhouse gas.
Rowntree says farmers have an even better story to tell from managing regenerative pasture systems.
Such systems include multiple plant species, avoid cultivation and fertiliser and cannot be overstocked.
He defines regenerative agriculture as an alternative form of food and fibre production enhancing and restoring resilient systems that support and are supported by functional ecosystem processes and healthy soils capable of producing a full suite of ecosystem services.
“Among those are soil carbon sequestration and improved soil water retention.”
Managed correctly, NZ soil can sequester more than two tonnes of carbon dioxide equivalent a hectare a year, making farms carbon neutral.
Ruminants have a role in those systems providing fertility and creating a seed bed for seed propagation and establishment.
Massey University’s Al Rae Centre chief scientist Dorian Garrick said farmers need to do a better job telling their story but must also find solutions to issues that will offend consumers, such as how to stop killing two million bobby calves each year.
“People are buying the process not just the products.”
He also challenged bull breeders to broaden the traits they measure as part of estimated breeding values to not only improve their livestock but to satisfy public concerns and needs.
Massey is experimenting with urination sensors, which can identify nitrogen content of cattle urine.
Three new EBVs he recommends farmers add are reproduction, animal health response to identify animals that might have developed resistance to drugs and nutritional values of meat, such as iron.
Garrick says anaemia is a huge problem in women but studies show there is a variation of iron levels in pieces of meat, even from the same animal.