True, cows emit methane — but so have ruminants throughout the animal kingdom throughout history. More importantly, methane from dairy cattle is not the issue we are led to believe it is.
Let me explain.
Agriculture contributes 13 to 16 per cent of total greenhouse gas emissions (in CO2 equivalents). Of this, about one-tenth is attributed to dairy farming, which is just 1.6 per cent of national GHG emissions, so our cows should barely rate a mention.
The issue is that methane is a disproportionate 25 per cent to 30 per cent of the total agricultural GHG output, and an extraordinary 60 to 70 per cent of dairy farm GHG emissions. It is the last figure that puts dairy in the sights of the activists.
However, there is a bit more to this story that rarely makes the news. Methane produced by ruminants is old carbon.
Unlike coal and gas where the methane is new to our environment’s carbon pool having been previously locked up in ancient subterranean storages, methane from cows was CO2 circulating yesterday.
Furthermore, in another 10 years, this methane will be CO2 again. In effect, if the global ruminant herd is stable, methane from animal production systems should not be counted — it is a zero-sum equation.
Unfortunately, the genuine methane polluters (coal and gas) are more important to GDP and thus have more political clout, so we remain the focus of climate alarmists.
As a rule, I like to see a problem as an opportunity, and in this case, I am reminded of some sage advice received early in my career — never waste a crisis.
And this crisis — notwithstanding, it is political rather than factual — is certainly an opportunity.
There is no doubt agriculture, and dairy, can be done better and can quickly transition to a business that consumes GHG rather than contributes them.
The secret is in the grass, forages and grain grown for our livestock, particularly grazed pasture.
Dairy saves the planet
There are compelling reasons all dairy farmers should seek to minimise GHG emissions and all other contributions to environmental degradation — chemical residues, nitrogen, and phosphorus excesses in particular.
Forget looming legislation, social licence, or any other enforced change — it’s just the right thing to do.
Better still, we now know beyond any reasonable doubt, that transitioning to a sustainable management system is more productive and more profitable than chemical-dependent farming.
We know for example:
- That of the N applied as fertiliser, only 26 per cent is used by the plant — the rest is lost to the environment.
- That one-third of the energy from plant photosynthesis is used to convert N fertiliser to an organic form before the plant can use it — what if we eliminated that step — yields would double.
- That plants have very low requirements for P — just enough to keep their energy-producing machinery ticking over. They need a little P — about one-tenth of what we apply — in the right form all of the time. Thus, about 90 per cent of P applied is wasted.
- Water is stored in the soil within the humus fraction. Humus is destroyed by cultivation and N fertiliser. More humus equals more soil water and increased water use efficiency.
There are many more, and over the next few months I will reveal a path by which assemble these into a process by which to transition your farm from chemical dependence to a sustainable, C and N sequestering machine without compromising productivity or profitability.
Using free natural resources as the principal inputs, dairy farms can be net consumers of GHG and lead an agricultural revolution that saves the planet.
Dr Les Sandles is a renowned thought leader and provocateur in the dairy industry. Best known for his role in revolutionising nutritional and pasture management practices, Les has turned his attention to the ‘last frontier’ — transmogrifying the forage production system into a C-munching machine.
