From Taxes to the Toilet, Solutions to Reduce Bovine Methane Emissions
Taxes, chemical compounds, toilets, masks: in recent years, everything has been attempted to try to stem some of the most impactful climate-altering emissions on the planet, those of ruminants . With their digestive processes, but also with their excrement, cattle - and in quantity especially those in farms - are huge emitters of methane , a greenhouse gas that is decidedly impactful given that it is almost 87 times more powerful - over the course of 20 years - than for example CO2. A third of the methane emitted on Earth is linked to cattle through fermentation and digestive processes. For this reason, scientists and breeders have long been looking for systems to try to reduce the footprint of the livestock sector: so far there have been dozens of experiments that include for example the use of algae in the diet to reduce methane, but also the idea of taxing cattle emissions launched by Denmark , or actual masks to be worn by cows .
So far, however, on a large scale, a single system to truly curb emissions has not yet been found. But recently there have been new studies and encouraging attempts. One of the latest comes from a study in New Zealand , which is the world's largest exporter of dairy products. Here, as elsewhere, the sheds that house the cows are washed with jets of water to remove the excrement that is then poured into large tanks, ponds. Two scientists from Lincoln University, Keith Cameron and Hong Di , were trying to recycle that water through a process: adding ferric sulphate and other elements to purify it, chemical substances that allow the liquid parts to be separated from the solid ones. During this process, however, by carrying out tests, the researchers discovered something else: the methane emissions from the waste water , with their mechanism, had decreased by 90% .
Considering that manure is responsible for 10% of methane emissions from livestock , reducing its impact would therefore be very important: today, attempts are mainly made by working with large tanks - anaerobic digesters - that capture methane. However, these are expensive systems that not all companies can afford. Researchers therefore hope that, thanks to the new discovery, using sulphate directly in ponds containing liquids with excrement can significantly reduce the level of methane emissions without having to go through huge expenses. This innovation has been called EcoPond and is currently being tested on 250 companies in New Zealand. It promises, the experts write on their website, "a simple and effective treatment service that reduces methane emissions by over 90%" and is capable of "reducing emissions equivalent to 22 petrol cars" on a typical farm with 400 cows.
The process to reduce emissions must be repeated every six weeks. However, it is still unclear whether the elements used to inhibit methanogens in manure can have a long-term impact on soil and water quality and compromise microbial ecosystems, for example.
Another recent method described in a study by the University of California instead involves the idea of covering the ponds of excrement with a giant sheet connected to the digesters. With the right precautions and always working with high-efficiency digester systems, the cover can lead - explains the co-author of the study Francesca Hopkins - to an 80% reduction in methane emissions from a dairy farm. "When the system is well built and carefully managed, emissions can really decrease. This is what we have seen from the first experiments" says the expert.
These methods are also being developed, as is work on reducing ammonia emissions, which are always linked to excrement and decomposition. Recently in Switzerland , on a farm in Hellbühl, something decidedly curious was tested: a sort of toilet designed specifically for cows, capable of reducing these emissions by 15%. The toilet for cattle prevents the mixing of urine and feces, thus ensuring a lower emission impact. The new "toilet", in the experimental phase, had only one problem: training the cows to use it. They succeeded with an incentive: a kilo of feed in exchange for a lower impact on the planet.
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