Ruminant agriculture can help us deliver net zero emissions

New science, by a global team of IPCC researchers based at Oxford University, shows categorically that methane from Britain's ruminants is not causing global warming – instead ruminants provide a viable pathway to net zero emissions from UK agriculture by 2030. 

What? But cattle and sheep produce methane almost constantly…  Yes, but a focus on the emissions themselves is misleading – instead it's the warming impact of those emissions that actually matters. Currently global warming from UK agricultural methane is less than zero.

Why is this important?

Farmers own and manage three quarters of these islands – and in terms of land use and food production – this – changes – everything. 

The current focus on agricultural emissions, centred on biological methane, is likely to drive dangerously unsustainable land use and the further intensification of animal and arable agriculture.  Instead farmers can produce nutritious, affordable, quality food, while sequestering carbon, restoring nature, delivering mitigation against extreme weather, and establishing rural economic resilience. 

Far from being unsustainable, grass-based cattle and sheep systems can be climate neutral by 2030, and they can help to restore biodiversity and soil health.

With vets increasingly involved in the sustainability debate it’s essential to be aware of the role of agricultural methane, and to advise farmers to develop farm health plans that use the most accurate metrics. BVA have an interesting blog around advancing the status of animal welfare within this agenda.

Further explanation

Until now climate science has centred on carbon equivalence using a metric, GWP100, which characterises emissions instead of warming. An Oxford Martin research team has updated this measure of global warming potential, and for the first time, allowed us to accurately account for the warming impact of methane. 

While carbon dioxide (CO2) and nitrous oxide (N2O) are active in our atmosphere for many human generations, methane – a powerful, but short-lived, greenhouse gas – is broken down in about a decade. This means that the methane emissions of a herd of 100 cows today are simply replacing the emissions that were first produced when that herd was established by a previous generation of farmers. There was an initial pulse of warming when the herd was established, but there is no ongoing warming from that herd.

Under the new, updated metric, GWP*, the greenhouse gas emissions from UK agriculture fall from 46.5 MtCO2e in 2016, to just 9.5 MtCO2e*. Warming from CO2 and N2O across that period are the same as previously reported, but methane is recalculated as -10.6 MtCO2e*. That’s a negative emission value, because methane levels have fallen since the base year of 1996.

The transformation in the results is staggering.  By accurately measuring the impact of methane, agriculture’s emissions under GWP* are just 20% of their original value.

What does this mean for the UK Sustainability agenda?

This science is robust.  It was well received at COP 24 in Katowice.  Since then, Farmwel and FAI Farms have been working closely with Oxford University researchers to advise Defra, the Department for Business, Energy, and Industrial Strategy, and the Committee on Climate Change on this science and the resulting land use implications.

Cattle and sheep are not the enemy – instead it’s high-yield, high-fodder (maize, soy and cereal) production systems, which are driving humanity towards the precipice. Benefits under GWP* are gained through well-managed grass-based agriculture; by a diverse patchwork of rural businesses, and the restoration and maintenance of rural economies. We can still eat meat and dairy, as part of a new era diet that includes greater nutritional diversity, but also restore natural balance on all farm land. Within the BVA UK Sustainable Animal Agriculture position, sustainable consumption and the concept of ‘less and better’ is recommended. In this way we can re-establish the building blocks of biodiversity on all farms, not just in protected, spared islands of nature surrounded by ever more intensive agricultural land use.                                                 

For clarity, GWP* is not a prescription for business as usual.  As the population grows humanity must reduce its per capita meat and dairy consumption.  And for methane to continue having a neutral impact, emissions must still fall, but only by 0.3% each year.

Good policy, great farming, innovative businesses, and better diets could deliver net zero warming from agriculture by 2030.

Vets can help by sharing this information, using the BVA sustainability and the veterinary profession action plan and by helping farmers link excellent farm animal health and welfare with measures to mitigate climate change and boost biodiversity on their farms.